Avaliamos o perfil dos portadores de Mucoceles bucais e estudamos microscopicamente suas características para correlacioná-las com as possíveis etiopatogenias, especialmente as obstruções ductais promovidas por proliferações epiteliais hiperplásicas e neoplásicas como o papiloma intraductal, Papiloma Ductal Invertido e Sialadenoma Papilífero. Realizamos o levantamento das informações registradas de 987 casos clínicos e suas respectivas peças cirúrgicas foram re-analisadas microscopicamente em cortes teciduais corados em HE. Os dados foram registrados e tabulados para comparações e correlações. A faixa etária mais comprometida foi a segunda e terceira décadas (399 e 345 casos) e o local mais afetado foi o lábio inferior (707 casos). A distribuição entre os gêneros foi praticamente igual. Em 262 casos os pacientes relacionaram a lesão com o traumatismo prévio. Dos 987 casos, 77 (7,8%) foram diagnosticados como Cisto de Retenção Mucosa e (910) como cisto por extrasamento mucoso. Os Cistos de Retenção Mucosa aconteceram predominantemente pacientes acima da quinta década de vida. Algumas situações simultâneas foram identificadas com frequência nas glândulas salivares associadas às Mucoceles, como a Sialadenite Crônica Inespecífica, Sialadenite Crônica Esclerosente ou Tumor de Kuttner, Oncocitose e Sialolitíase. Foram diagnosticados ainda, 21 Papilomas Intraductais, 6 Papilomas Ductais Invertidos e 3 Sialadenomas Papilíferos, além de 27 Proliferações Epiteliais Intraductais de diagnóstico não determinado. Concluímos que: a) além dos traumatismos, na etiopatogenia das Mucoceles bucais deve-se considerar a presença dos Papilomas Ductais como uma importante possibilidade a ser analisada especificamente nas observações microscópicas das peças cirúrgicas enviadas para análise histopatológica, considerando-se a sua natureza neoplásica. b) a Sialolitíase e a Oncocitose devem ser consideradas como causas obstrutivas ductais de Mucoceles bucais em suas análises clínicas e microscópicas. c) as causas obstrutivas parciais e totais podem estar associadas à etiopatogenia das Mucoceles bucais do tipo Cisto por Extravasamento Mucoso, especialmente quando ocorrem próximo ou no interior do corpo glandular. A retenção de muco pode promover a ruptura dos delicados ductos proximais e dos ácinos, promovendo o derramamento de muco no tecido conjuntivo do estroma glandular, iniciando-se o processo no interior da mesma. Quando mais próximas da mucosa bucal, as causas obstrutivas podem não romper o ducto pela sua estrutura epitelial e conjuntiva ser mais espessa e resistente, gerando Cistos de Retenção Mucosa com revestimento epitelial. / This study evaluated the profile of individuals with oral Mucoceles and investigated their microscopic characteristics with a view to correlate them to the possible etiopathogenesis, especially ductal obstructions caused by hyperplastic and neoplastic epithelial proliferations such as Intraductal Papilloma, Inverted Ductal Papilloma and Sialoadenoma Papilliferum. The study surveyed the records of 987 clinical cases and respective specimens, which were microscopically reanalyzed on tissue sections stained with hematoxylin and eosin. Data were recorded and tabulated for comparisons and correlations. The most affected age range was the second and third decades of life (399 and 345 cases), and the lower lip was the most affected site (707 cases). The distribution between genders was nearly equal. In 262 cases the patients related the lesion to a previous trauma. Among the 987 cases, 77 (7.8%) were diagnosed as mucus retention cyst and (910) as mucus extravasation cyst. The Mucus Retention Cysts affected mainly patients above the fifth decade of life. Simultaneous disorders were often identified in salivary glands associated to the Mucoceles, such as Nonspecific Chronic Sialadenitis, Chronic Sclerosing Sialadenitis or Kuttner Tumor, Oncocytosis and Sialolithiasis. There were also diagnoses of 21 Intraductal Papillomas, 6 Inverted Ductal Papillomas and 3 cases of Sialoadenoma papilliferum, besides 27 Intraductal Epithelial Proliferations of undetermined diagnosis. It was concluded that: a) in addition to trauma, the etiopathogenesis of oral Mucoceles should consider the presence of Ductal Papillomas as an important possibility to be specifically analyzed on the microscopic analysis of specimens submitted to histopathological analysis, considering its neoplastic nature. b) Sialolithiasis and Oncocytosis should be considered as causes of ductal obstruction of oral Mucoceles in the clinical and microscopic analyses. c) the partial and total causes of obstruction may be associated to the etiopathogenesis of oral Mucoceles involving Mucus Extravasation Cysts, especially when they occur close to or inside the gland body. The mucus retention may cause the rupture of fragile proximal ducts and acini, causing the outflow of mucus in the connective tissue of the gland stroma, giving rise to the process inside it. When closer to the oral mucosa, the obstructive causes may not disrupt the duct because its epithelial and connective structure is thicker and more resistant, giving rise to Mucus Retention Cysts with epithelial lining.

Resumo: A carcinogênese química em glândulas salivares animais não se apresenta como um modelo novo de pesquisa. O uso de DMBA em glândulas submandibulares de ratos produz carcinomas e sarcomas, associados ou não. Apesar de bem estudada a histopatologia deste tipo de carcinogênese, pouco se sabe em relação a imunoistoquímica das neoplasias. Este estudo se propõe a revisar pesquisa pregressa realizada por Mainenti (2006), na tentativa de melhor entender a formação de tumores induzidos por DMBA. O estudo original diagnosticou lesões não neoplásicas, principalmente sialadenites, e tumores como carcinomas, carcinossarcomas e um caso de sarcoma. O presente trabalho fez uso de lâminas e material de estoque em formol. Foram comparadas as lâminas originais com novas lâminas coradas em hematoxilina e eosina. Para a pesquisa de fibras colágenas utilizou-se a coloração pelo método do tricrômico de Gomori. A imunoistoquímica foi realizada utilizando os seguintes anticorpos: AE1/AE3, vimentina, α-SMA, calponina, desmina, miogenina, S-100, CerbB-2 e EMA. Certas lesões, previamente diagnosticadas como sialadenites, foram reclassificadas como carcinomas. A imunoistoquímica foi positiva para os seguintes anticorpos: AE1/AE3 para neoplasia epitelial, vimentina para tecido conjuntivo e tumores mesenquimais, α-SMA e calponina para poucas células fusiformes pleomórficas no estroma dos carcinomas e nas neoplasias mesenquimais. Concluiu-se que a imunoistoquímica revelou diferenciação muito sugestiva de miofibroblastos no estroma dos carcinomas e miofibroblastos compondo o fibrossarcoma e os carcinosarcomas. Estas células produziram colágeno revelado pelo tricrômico de Gomori. O componente epitelial neoplásico foi sugerido como derivado de células luminais. / Abstract: The chemical carcinogenesis, addressed to animal salivary gland, is not a novel research. The use of DMBA in rat's submandibular salivary gland is known to produce neoplasms like sarcomas and carcinomas either intermingled or not. Despite of the good amount of information regarding DMBA carcinogenesis histopathology in rat's submandibular parenchyma, little is known about the immunohistochemistry in such tumors. We proposed a revision of a previous research conduced by Mainenti (2006), in attempt to better understand the neoplasm formation after DMBA. The original experiment disclosed non neoplastic lesions, mainly sialadenitis, and tumors like carcinomas, carcinosarcomas and one case of sarcoma. The present work used all the material from the first research like surgical specimens in formol and slides. We compared the previous hematoxylin and eosin slides with new ones. We also used Gomori's trichrome in order to disclose collagen fibers. The immunohistochemistry was performed using the following antibodies: AE1/AE3, vimentin, α-SMA, calponin, desmin, myogenin, S-100, CerbB-2 and EMA. Some previous lesions, presented as benign ones, were diagnosed as carcinomas. The immunohistochemistry was positive as shown: AE1/AE3 for epithelial neoplasm, vimentin for connective tissue in mesenchymal tumors, α-SMA and calponin for scarce pleomorphic fusiform cells in the stroma of the carcinomas and in the mesenchymal neoplasms. We concluded that the immunohistochemistry strongly suggested myofibroblast differentiation in the stroma of the carcinomas and myofibroblast cells related to the fibrosarcoma and carcinosarcomas. These cells produced collagen shown after Gomori's trichrome. The epithelial neoplasm component was suggested as derived from luminal cells. / Orientador: Luiz Eduardo Blumer Rosa / Coorientador: Yasmin Rodarte Carvalho / Banca: Luiz Eduardo Blumer Rosa / Banca: Rosilene Fernandes da Rocha / Banca: Fábio Daumas Nunes / Banca: Maria das Graças Afonso Miranda Chaves / Banca: Adriana Aigotti Haberbeck Brandão / Doutor

Displasia ectodérmica hipoidrótica é uma doença genética rara, clinicamente caracterizada por alterações envolvendo os dentes, pele e suas estruturas anexas. Manifestações orais comuns incluem anadontia ou oligodontia, dentes conóides e xerostomia. Poucos relatos associam displasia ectodérmica e redução do fluxo salivar. O objetivo desse estudo é analisar possíveis alterações nas glândulas salivares de dez portadores de displasia ectodérmica que fazem acompanhamento no Departamento de Dermatologia Pediátrica da Universidade de São Paulo. Ultrassonografia foi realizada em dez casos em infantes portadores de displasia ectodérmica hipoidrótica nas suas glândulas salivares parótida e submandibular. Três apresentaram alterações na glândula parótida e/ou submandibular. Aplasia ou hipoplasia das glândulas salivares maiores é associada a casos de displasia ectodérmica e sugere-se acompanhamento rotineiro das glândulas salivares maiores usando ultrassonografia para prevenção de alterações decorrentes da hiposalivação na cavidade oral. / Background- Hypohidrotic ectodermal dysplasia is a rare genetic disease, clinically characterized by defects involving skin and their adnexal structures, as well as oral structures such as teeth, and occasionally salivary glands. These latter manifestations include anodontia or hypodontia, conical teeth and xerostomia. Objective- To analyze possible alterations in major salivary glands of ten patients with ectodermal dysplasia, using image exam. Methods- Ultrasonography was performed in ten pediatric cases of hypohidrotic ectodermal dysplasia to investigate the status of parotid and submandibular salivary gland. Results- Three patients presented aplasia/hypoplasia of at least one gland examined. The other 7 patients did not present any alterations in parotid and submandibular glands. Limitations- Although ultrasonography exam is adequate to investigate the presence and status of major salivary glands, other important glands such as sublingual and minor mucous salivary glands are not well-visualized using this technique. Conclusions- Aplasia or hypoplasia of the major salivary gland is strongly related to ectodermal dysplasia and we suggest routine evaluation of the major salivary gland using ultrasound to monitor and manage the possible impact of xerostomia in oral health.

Avaliamos o perfil dos portadores de Mucoceles bucais e estudamos microscopicamente suas características para correlacioná-las com as possíveis etiopatogenias, especialmente as obstruções ductais promovidas por proliferações epiteliais hiperplásicas e neoplásicas como o papiloma intraductal, Papiloma Ductal Invertido e Sialadenoma Papilífero. Realizamos o levantamento das informações registradas de 987 casos clínicos e suas respectivas peças cirúrgicas foram re-analisadas microscopicamente em cortes teciduais corados em HE. Os dados foram registrados e tabulados para comparações e correlações. A faixa etária mais comprometida foi a segunda e terceira décadas (399 e 345 casos) e o local mais afetado foi o lábio inferior (707 casos). A distribuição entre os gêneros foi praticamente igual. Em 262 casos os pacientes relacionaram a lesão com o traumatismo prévio. Dos 987 casos, 77 (7,8%) foram diagnosticados como Cisto de Retenção Mucosa e (910) como cisto por extrasamento mucoso. Os Cistos de Retenção Mucosa aconteceram predominantemente pacientes acima da quinta década de vida. Algumas situações simultâneas foram identificadas com frequência nas glândulas salivares associadas às Mucoceles, como a Sialadenite Crônica Inespecífica, Sialadenite Crônica Esclerosente ou Tumor de Kuttner, Oncocitose e Sialolitíase. Foram diagnosticados ainda, 21 Papilomas Intraductais, 6 Papilomas Ductais Invertidos e 3 Sialadenomas Papilíferos, além de 27 Proliferações Epiteliais Intraductais de diagnóstico não determinado. Concluímos que: a) além dos traumatismos, na etiopatogenia das Mucoceles bucais deve-se considerar a presença dos Papilomas Ductais como uma importante possibilidade a ser analisada especificamente nas observações microscópicas das peças cirúrgicas enviadas para análise histopatológica, considerando-se a sua natureza neoplásica. b) a Sialolitíase e a Oncocitose devem ser consideradas como causas obstrutivas ductais de Mucoceles bucais em suas análises clínicas e microscópicas. c) as causas obstrutivas parciais e totais podem estar associadas à etiopatogenia das Mucoceles bucais do tipo Cisto por Extravasamento Mucoso, especialmente quando ocorrem próximo ou no interior do corpo glandular. A retenção de muco pode promover a ruptura dos delicados ductos proximais e dos ácinos, promovendo o derramamento de muco no tecido conjuntivo do estroma glandular, iniciando-se o processo no interior da mesma. Quando mais próximas da mucosa bucal, as causas obstrutivas podem não romper o ducto pela sua estrutura epitelial e conjuntiva ser mais espessa e resistente, gerando Cistos de Retenção Mucosa com revestimento epitelial. / This study evaluated the profile of individuals with oral Mucoceles and investigated their microscopic characteristics with a view to correlate them to the possible etiopathogenesis, especially ductal obstructions caused by hyperplastic and neoplastic epithelial proliferations such as Intraductal Papilloma, Inverted Ductal Papilloma and Sialoadenoma Papilliferum. The study surveyed the records of 987 clinical cases and respective specimens, which were microscopically reanalyzed on tissue sections stained with hematoxylin and eosin. Data were recorded and tabulated for comparisons and correlations. The most affected age range was the second and third decades of life (399 and 345 cases), and the lower lip was the most affected site (707 cases). The distribution between genders was nearly equal. In 262 cases the patients related the lesion to a previous trauma. Among the 987 cases, 77 (7.8%) were diagnosed as mucus retention cyst and (910) as mucus extravasation cyst. The Mucus Retention Cysts affected mainly patients above the fifth decade of life. Simultaneous disorders were often identified in salivary glands associated to the Mucoceles, such as Nonspecific Chronic Sialadenitis, Chronic Sclerosing Sialadenitis or Kuttner Tumor, Oncocytosis and Sialolithiasis. There were also diagnoses of 21 Intraductal Papillomas, 6 Inverted Ductal Papillomas and 3 cases of Sialoadenoma papilliferum, besides 27 Intraductal Epithelial Proliferations of undetermined diagnosis. It was concluded that: a) in addition to trauma, the etiopathogenesis of oral Mucoceles should consider the presence of Ductal Papillomas as an important possibility to be specifically analyzed on the microscopic analysis of specimens submitted to histopathological analysis, considering its neoplastic nature. b) Sialolithiasis and Oncocytosis should be considered as causes of ductal obstruction of oral Mucoceles in the clinical and microscopic analyses. c) the partial and total causes of obstruction may be associated to the etiopathogenesis of oral Mucoceles involving Mucus Extravasation Cysts, especially when they occur close to or inside the gland body. The mucus retention may cause the rupture of fragile proximal ducts and acini, causing the outflow of mucus in the connective tissue of the gland stroma, giving rise to the process inside it. When closer to the oral mucosa, the obstructive causes may not disrupt the duct because its epithelial and connective structure is thicker and more resistant, giving rise to Mucus Retention Cysts with epithelial lining.

A proteína Akt modula a função de numerosos substratos envolvidos na regulação da sobrevivência celular, progressão do ciclo celular e crescimento celular. Estudos prévios realizados em nosso laboratório demonstraram a superexpressão de Akt em adenoma pleomórfico, mioepitelioma e carcinoma adenóide cístico. O objetivo deste estudo foi analisar a via da proteína Akt através da avaliação da expressão das proteínas NFkB e PTEN em neoplasias benignas e malignas de glândulas salivares através das técnicas de imunohistoquímica, western blotting e imunofluorescência, e a possível interação protéica direta entre p-Akt/Mdm2 e p-Akt/PTEN em linhagem de carcinoma adenóide cístico. A superexpressão nuclear na proteína PTEN foi encontrada nas duas neoplasias malignas estudadas. Além disso, não foi observada interação direta entre as proteínas p-Akt/Mdm2 e p-Akt/PTEN, as quais apresentam localização nuclear em neoplasias de glândulas salivares. / The Akt protein modulates the function of numerous substrates involved in the regulation of cell survival, cell cycle progression and cell growth. Previous studies from our laboratories showed overexpression of Akt and Mdm2 followed by the lack of p53 expression in pleomorphic adenoma, myoepithelioma and adenoid cystic carcinoma. The aim of this study was to analyze the Akt pathway through evaluation of expression of NFkB and PTEN proteins in pleomorphic adenoma, carcinoma ex pleomophic adenoma and adenoid cystic carcinoma by western blotting, immunofluorescence and immunohistochemical techniques, and we have intended to analyse a possible direct interaction between p-Akt/Mdm2 and p-Akt/ PTEN protein in salivary gland tumours. Overexpression of nuclear PTEN was present in both carcinomas studied. In addition, there was no direct interaction between p-Akt/Mdm2 and p-Akt/ PTEN protein, which presents a nuclear localization in salivary gland tumours.

The Australian paralysis tick, Ixodes holocyclus causes a potentially fatal paralysis in domestic animals, livestock and humans with companion animals (mainly dogs) most commonly affected. Current treatment regimes include administration of a commercial tick anti-serum (TAS), prepared as hyperimmune serum in dogs, to neutralise the effects of the toxin. However, each new batch must be standardised using an expensive and highly subjective bioassay performed in neonatal mice. There is currently an urgent need for a more cost effective and rapid in vitro assay that can be more objectively and accurately quantified. Further understanding of the composition of the toxin molecule is also required to develop toxin-specific reagents necessary for these assays. One of the main objectives of this study was to develop a suitable immunoassay to replace the existing mouse bioassay for assessing batches of tick anti-sera for use in tick paralysis therapy in dogs. Initially an enzyme-linked immunosorbent assay (ELISA) was established to detect and quantify antibody specific for I. holocyclus toxin in dog sera. Using a partially purified antigen extracted from I. holocyclus salivary glands, good discrimination was achieved between reactive (hyperimmune) and non-reactive (naïve) sera. The hyperimmune dog sera reacted very strongly with the antigen compared to negligible reactions of serum from dogs not exposed to I. holocyclus. The reactions of hyperimmune sera were also significantly weaker to a non-toxin antigen control extracted from the salivary glands of the non-toxic tick Rhipicephalus microplus, indicating the assay was detecting toxin-specific responses. Furthermore, each of the hyperimmune sera that reacted strongly and specifically with the I. holocyclus antigen in the ELISA also strongly neutralised toxin in the mouse bioassay. Together these findings support the suitability of this ELISA for assessing the potency of batches of commercial dog hyperimmune sera for use as therapy for tick paralysis in dogs. Sera from dogs that were experimentally infested with ticks and sera from patient dogs, presenting at veterinary clinics with signs of tick paralysis, were also screened for antibodies to I. holocyclus antigen using the ELISA. Twenty-eight out of 29 sera from animals with single or multiple exposures to ticks failed to recognise the I. holocyclus antigen indicating the ELISA is not suitable as a diagnostic test to detect toxin-specific antibodies in animals with limited exposure to I. holocyclus infestation. A panel of toxin-specific monoclonal antibodies (mAbs) was produced as research tools to analyse and purify tick toxin components. Rats were successfully immunised against tick toxin using a combination of inoculation of partially purified salivary gland antigen and exposure to tick infestation. The latter approach preserved the native confirmation of the toxin using a natural route of immunisation and rats were chosen due to their high tolerance of multiple tick infestations over several days. While fusion of rat spleen cells with mouse myeloma cells has been reported several times in the literature, the resulting hybridomas are unstable with fastidious culture requirements. Optimisation of the culture conditions revealed that most rat-mouse hybridoma lines grew best in serum-free medium supplemented with 5% foetal bovine serum. Of 600 hybridomas produced, only 12 were shown to be specific for the Ixodes antigen, as determined by ELISA. A selection of these hybridomas representing various patterns of affinity and/or antigen specificity were further analysed for toxin-neutralising ability in a mouse bioassay. Notably, the most potent toxin-neutralising mAb in mice, showed a specific but relatively moderate reaction to Ixodes antigen in the ELISA. The most potent toxin-neutralising mAbs inactivated toxin as strongly as the commercial TAS used for immunotherapy in dogs with tick paralysis. This suggests that mAbs may present an alternative source of immunotherapy, providing a potentially endless supply of a highly consistent reagent and negating the need to use live animals for both the production of tick antiserum and the continual testing of reagent batches. The toxin-neutralising mAbs were also used to analyse I. holocyclus toxin in polyacrylamide gel electrophoresis (PAGE) and Western blot to identify specific toxin proteins. The most potent neutralising mAbs consistently recognised high MW proteins (100-200 kDa) in a smeared pattern. Although this was contrary to previous reports of low molecular weight components (3-5 kDa) in holocyclotoxin, this study was the first to use mAbs prepared to native toxin. The large molecular weight structures likely represent presucursors to, or complexes of the smaller peptides, previously identified. When the Toxin-neutralising mAbs were assessed as ligands to affinity purify toxin components from crude Ixodes SG extracts, toxin components of 110 and 32 kDa were consistently identified. These purified proteins represent good candidates for N-terminal sequencing to further identify the toxin components in I.holocyclus salivary glands.

Die acinösen Speicheldrüsen der Schabe Periplaneta americana sind reich durch serotonerge, dopaminerge und GABAerge Fasern innerviert. Die biogenen Amine Serotonin (5-HT) und Dopamin (DA) induzieren die Sekretion eines NaCl-haltigen Primärspeichels. Die physiologische Rolle der GABAergen Innervation des Drüsenkomplexes war bislang unbekannt. Weiterhin wurde vermutet, dass Tyramin (TA) und Octopamin (OA) an der Speichelbildung beteiligt sind. Mittels intrazellulärer Ableitungen von sekretorischen Acinuszellen mit und ohne Stimulierung des Speicheldrüsennervs (SDN) sollte daher die Wirkung von GABA, TA und OA im Speicheldrüsenkomplex untersucht werden. Intrazelluläre Ableitungen aus Acinuszellen zeigten, dass sowohl DA als auch 5 HT biphasische Änderungen des Membranpotentials induzierten. Diese bestanden aus einer initialen Hyperpolarisation und einer darauf folgenden transienten Depolarisation. Stimulierung des SDN mittels einer Saugelektrode verursachte ebenfalls biphasische Änderungen des Membranpotentials der Acinuszellen, die mit den DA- bzw. 5-HT-induzierten Änderungen kinetisch identisch waren. Dieses Ergebnis zeigte, dass die elektrische Stimulierung des SDN im Nerv-Speicheldrüsenpräparat eine verlässliche Methode zur Untersuchung der Wirkungen von Neuromodulatoren auf die dopaminerge und/oder sertotonerge Neurotransmission ist. Die Hyperpolarisation der DA-induzierten Potentialänderungen wurde durch eine intrazelluläre Ca2+-Freisetzung und die Öffnung basolateral lokalisierter Ca2+-gesteuerter K+-Kanäle verur-sacht. Die DA- und 5-HT-induzierte Depolarisation hing kritisch von der Aktivität eines basolateral lokalisierten Na+-K+-2Cl--Symporters ab. GABA, TA und OA potenzierten die elektrischen Antworten der Acinuszellen, wenn diese durch SDN-Stimulierung hervorgerufen wurden. Dabei war OA wirksamer als TA. Dieses Ergebnis zeigte, dass diese Substanzen als im Drüsenkomplex präsynaptisch und erregend als Neuromodulatoren wirken. Pharmakologische Untersuchungen ergaben, dass die erregende Wirkung von GABA durch einen G-Protein-gekoppelten GABAB-Rezeptor vermittelt wurde. Messungen der durch SDN-Stimulierung induzierten Flüssigkeits- und Proteinsekretionsraten zeigten, dass beide Parameter in Anwesenheit von GABA verstärkt waren. Dies ließ auf eine verstärkte serotonerge Neurotransmission schließen, da nur 5-HT die Bildung eines Protein-haltigen Speichels verursacht. Immuncytochemische Untersuchungen zeigten, dass die Drüsen tyraminerge und octopaminerge Innervation empfangen. Weiterhin wurde der erste charakterisierte TA-Rezeptor (PeaTYR1) der Schabe auf einem paarigen, lateral zur Drüse ziehenden Nerv markiert, der auch tyraminerge Fasern enthielt. Die vorliegende Arbeit trug zum Verständnis der komplexen Funktionsweise der Speicheldrüse der Schabe bei und erweiterte das lückenhafte Wissen über die neuronale Kontrolle exokriner Drüsen in Insekten. / The cockroach Periplaneta americana has acinar type salivary glands. The secretory acini consist of P-cells, responsible for electrolyte and water secretion and C-cells that secrete protein into the saliva. Salivation is controlled by the dopaminergic and GABAergic salivary neurons SN1 and SN2, and by several smaller serotonergic neurons. Dopamine (DA) and serotonin (5-HT) induce the secretion of a NaCl-rich saliva. The physiological role of the GABAergic innervation was unknown. Furthermore, the cellular actions of the biogenic amines DA and 5-HT were poorly understood. Based on studies on other insect salivary glands a role for octopamine (OA) and tyramine (TA) acting as neuromodulators was suggested. In this study, intracellular recordings of the basolateral membrane potential of acinar cells were performed to examine direct and modulating actions of the biogenic amines DA, 5-HT, OA, TA and of GABA. A nerve-gland preparation was developed and used to investigate the actions of neuromodulators, namely GABA, OA and TA. DA and 5-HT induced biphasic membrane potential changes, consisting of an initial hyperpolarization and a transient depolarization. The DA-induced hyperpolarization was mediated by intracellular Ca2+-release and subsequent opening of basolateral Ca2+-dependent K+-channels. The DA- and 5-HT-induced depolarization was dependent on the presence of extracellular Na+ and the activity of a basolateral Na+-K+-2Cl--cotransporter. Electrical stimulation of the salivary duct nerve (SDN) by means of a suction electrode induced membrane potential changes with the same kinetics as those induced by bath application of DA and 5-HT. These results suggested that electrical nerve stimulation is a adequate method to investigate presynaptic effects of neuromodulators. GABA, OA and TA affected neither the resting membrane potential of the acinar cells, nor the DA- or 5 HT- induced potential changes. When GABA was applied during SDN-stimulation, it enhanced the amplitudes of the membrane potential changes of the acinar cells as well as fluid- and protein secretion rates of the glands. Pharmacological experiments revealed that the excitatory action of GABA in the gland complex is mediated by a metabotropic GABA receptor (GABAB-type). OA and TA enhanced the membrane potential changes of the acinar cells when these were induced by SDN-stimulation, suggesting presynaptic excitatory roles for both amines in the gland complex. Immunocytochemistry revealed rich innervation of the salivary glands with octopamine- immunoreactive fibers that were also stained by the tyramine-antibody, and with tyramine-immunoreactive fibers lacking octopamine-immunoreactivity. Since the tyramine receptor PeaTYR1 is expressed in the salivary gland complex, its distribution was investigated by using a specific antibody. Immunoreactivity was detected in a paired nerve of unknown root. This nerve innervated only few acini lying in the periphery of the gland complex and contained tyraminergic fibers. This study extends our knowledge about the complex neuronal control and function of insect salivary glands.

The acinar salivary gland of the cockroach, Periplaneta americana, is innervated by dopaminergic and serotonergic nerve fibers. Stimulation of the glands by serotonin (5-hydroxytryptamine, 5-HT) results in the production of a protein-rich saliva, whereas stimulation by dopamine results in saliva that is protein-free. Thus, dopamine acts selectively on ion-transporting peripheral cells within the acini, and 5-HT acts on protein-producing central cells. We have investigated the pharmacology of the 5-HT-induced secretory activity of isolated salivary glands of P. americana by testing several 5-HT receptor agonists and antagonists. The effects of 5-HT can be mimicked by the non-selective 5-HT receptor agonist 5-methoxytryptamine. All tested agonists that display at least some receptor subtype specificity in mammals, i.e., 5-carboxamidotryptamine, (+/-)-8-OH-DPAT, (+/-)-DOI, and AS 19, were ineffective in stimulating salivary secretion. 5-HT-induced secretion can be blocked by the vertebrate 5-HT receptor antagonists methiothepin, cyproheptadine, and mianserin. Our pharmacological data indicate that the pharmacology of arthropod 5-HT receptors is remarkably different from that of their vertebrate counterparts. (C) 2007 Elsevier Ltd. All rights reserved.

The phenolamines octopamine and tyramine control, regulate, and modulate many physiological and behavioral processes in invertebrates. Vertebrates possess only small amounts of both substances, and thus, octopamine and tyramine, together with other biogenic amines, are referred to as “trace amines.” Biogenic amines evoke cellular responses by activating G-protein-coupled receptors. We have isolated a complementary DNA (cDNA) that encodes a biogenic amine receptor from the American cockroach Periplaneta americana, viz., Peatyr1, which shares high sequence similarity to members of the invertebrate tyramine-receptor family. The PeaTYR1 receptor was stably expressed in human embryonic kidney (HEK) 293 cells, and its ligand response has been examined. Receptor activation with tyramine reduces adenylyl cyclase activity in a dose-dependent manner (EC50 350 nM). The inhibitory effect of tyramine is abolished by co-incubation with either yohimbine or chlorpromazine. Receptor expression has been investigated by reverse transcription polymerase chain reaction and immunocytochemistry. The mRNA is present in various tissues including brain, salivary glands, midgut, Malpighian tubules, and leg muscles. The effect of tyramine on salivary gland acinar cells has been investigated by intracellular recordings, which have revealed excitatory presynaptic actions of tyramine. This study marks the first comprehensive molecular, pharmacological, and functional characterization of a tyramine receptor in the cockroach.

Die nichtproteinogene Aminosäure GABA (γ-Aminobuttersäure) gilt als der wichtigste inhibitorische Neurotransmitter im Zentralnervensystem von Vertebraten sowie Invertebraten und vermittelt ihre Wirkung u. a. über die metabotropen GABAB-Rezeptoren. Bisher sind diese Rezeptoren bei Insekten nur rudimentär untersucht. Für die Amerikanische Großschabe als etablierter Modellorganismus konnte pharmakologisch eine modulatorische Rolle der GABAB-Rezeptoren bei der Bildung von Primärspeichel nachgewiesen werden. Ziel dieser Arbeit war eine umfassende Charakterisierung der GABAB-Rezeptor-Subtypen 1 und 2 von Periplaneta americana. Unter Verwendung verschiedenster Klonierungsstrategien sowie der Kooperationsmöglichkeit mit der Arbeitsgruppe von Prof. Dr. T. Miura (Hokkaido, Japan) in Hinsicht auf eine dort etablierte P. americana EST-Datenbank gelang die Klonierung von zwei Rezeptor-cDNAs. Die Analyse der abgeleiteten Aminosäuresequenzen auf GB-spezifische Domänen und konservierte Aminosäure-Reste, sowie der Vergleich zu bekannten GB Sequenzen anderer Arten legen nahe, dass es sich bei den isolierten Sequenzen um die GABAB-Rezeptor-Subtypen 1 und 2 (PeaGB1 und PeaGB2) handelt. Für die funktionelle und pharmakologische Charakterisierung des Heteromers aus PeaGB1 und PeaGB2 wurden Expressionskonstrukte für die Transfektion in HEK-flpTM-Zellen hergestellt. Das Heteromer aus PeaGB1 und PeaGB2 hemmt bei steigenden GABA-Konzentrationen die cAMP-Produktion. Die Substanzen SKF97541 und 3-APPA konnten als Agonisten identifiziert werden. CGP55845 und CGP54626 wirken als vollwertige Antagonisten. Das in vitro ermittelte pharmakologische Profil im Vergleich zur Pharmakologie an der isolierten Drüse bestätigt, dass die GABA-Wirkung in der Speicheldrüse tatsächlich von GBs vermittelt wird. Für die immunhistochemische Charakterisierung konnte ein spezifischer polyklonaler Antikörper gegen die extrazelluläre Schleife 2 des PeaGB1 generiert werden. Ein weiterer Antikörper, welcher gegen den PeaGB2 gerichtet ist, erwies sich hingegen nicht als ausreichend spezifisch. Western-Blot-Analysen bestätigen das Vorkommen beider Subtypen im Zentralnervensystem von P. americana. Zudem wird der PeaGB1 in der Speicheldrüse und in den Geschlechtsdrüsen der Schabenmännchen exprimiert. Immunhistochemische Analysen zeigen eine PeaGB1-ähnliche Markierung in den GABAergen Fasern der Speicheldrüse auf. Demnach fungiert der PeaGB1 hier als Autorezeptor. Weiterhin konnte eine PeaGB1-ähnliche Markierung in nahezu allen Gehirnneuropilen festgestellt werden. Auch die akzessorischen Drüsen der Männchen, Pilzdrüse und Phallusdrüse, sind PeaGB1-immunreaktiv. / The non-proteinogenic amino acid GABA (γ-aminobutyric acid) is the major inhibitory neurotransmitter in the central nervous system of vertebrates and invertebrates, and GABA mediates its action among others via metabotropic GABAB receptors (GBs). So far, these receptors are only rudimentary characterized in insects. In the American Cockroach, which is an established model organism, pharmacological studies have pointed out a modulatory role of GBs in the production of primary saliva in the salivary gland. Therefore, the aim of this study is the profound characterization of the GABAB receptor subtypes 1 and 2 of Periplaneta americana. Diverse cloning strategies and the access to a Periplaneta EST-database enabled the cloning of two receptor-cDNAs. The analysis of the deduced amino acid sequences for GB-specific domains and conserved amino acid-residues, and the comparison to known GB-sequences of other species revealed that the sequences correspond to GABAB receptor subtypes 1 and 2 (PeaGB1 and PeaGB2). Next, we functionally and pharmacologically characterized the receptor-heteromer of PeaGB1 and PeaGB2. Therefore, we established expression constructs for the transfection of HEK-flpTM-cells. The PeaGB1/PeaGB2 heteromer inhibits dose-dependently the production of cAMP. The substances SKF97541 and 3-APPA imitate the GABA effect. In contrast, CGP54626 and CGP55845 are considered to be proper antagonists. The comparison of the in vitro with the known pharmacology of isolated glands reveals that GBs indeed mediate the effect of GABA in the salivary gland. For immunohistochemical localization, a specific polyclonal antibody was raised against the extracellular loop 2 of PeaGB1. A second antibody, which was raised against the analogous region of the PeaGB2, must be considered to be non-specific. Western blot analyses demonstrate the localization of both subtypes in the central nervous system of P. americana. Additionally, PeaGB1 is expressed in the salivary gland and in male accessory glands. Immunohistochemical analyses reveal the expression of PeaGB1 in GABAergic nerve fibers of the salivary gland. As a consequence, PeaGB1 must act as an autoreceptor in this organ. A widespread distribution of PeaGB1 in almost all neuropiles was detected in the cockroach brain. In the male accessory glands mushroom gland and phallic (conglobate) gland, an intense PeaGB1-like immunoreactivity was measured.