京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第21716号 / 薬科博第107号 / 新制||薬科||11(附属図書館) / 京都大学大学院薬学研究科医薬創成情報科学専攻 / (主査)教授 大野 浩章, 教授 高須 清誠, 教授 竹本 佳司 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM

The purpose of this study was to determine if endogenous tachykinins can cause bradycardia in the isolated perfused guinea pig heart through stimulation of cholinergic neurons. Capsaicin was used to stimulate release of tachykinins and calcitonin gene-related peptide (CGRP) from cardiac afferents. A bolus injection of 100 nmol capsaicin increased heart rate by 26 ± 7% from a baseline of 257 ± 14 beats/min (n = 6, P < 0.01). This positive chronotropic response was converted to a minor bradycardic effect in hearts with 1 μM CGRP (8-37) present to block CGRP receptors. The negative chronotropic response to capsaicin was markedly potentiated in another group of hearts with the further addition of 0.5 μM neostigmine to inhibit cholinesterases. In this group, capsaicin decreased heart rate by 30 ± 10% from a baseline of 214 ± 6 beats/min (n = 8, P < 0.05). This large bradycardic response to capsaicin was inhibited by 1) infusion of neurokinin A to desensitize tachykinin receptors or 2) treatment with 1 μM atropine to block muscarinic receptors. The latter observations implicate tachykinins and acetylcholine, respectively, as mediators of the bradycardia. These findings support the hypothesis that endogenous tachykinins could mediate axon reflexes to stimulate cholinergic neurons of the intrinsic cardiac ganglia.

Intravenous injection of substance P (SP) increases renal nerve firing and heart rate in spontaneously hypertensive rats (SHRs) and Wistar-Kyoto rats (WKYs) by stimulating sympathetic ganglia. Blood pressure is increased in SHRs but lowered in WKYs. This study assesses the role of neurokinin-1 (NK1) receptors in mediating the ganglion actions of SP. Rats for functional studies were anesthetized and then treated with chlorisondamine. Renal nerve, blood pressure, and heart rate responses to intravenous injection of the NK1 receptor agonist GR-73632 were similar but less than those to equimolar doses of SP in SHRs. GR-73632 only slightly increased renal nerve firing and heart rate and lowered blood pressure in WKYs. The NK1 receptor antagonist GR-82334 (200 nmol/kg iv) blocked the ganglionic actions of GR-73632 and the pressor response to SP in SHRs. It reduced the renal nerve and heart rate responses by 52 and 35%. This suggests that the pressor response to SP is mediated by ganglionic NK1 receptors and that NK1 receptors also have a prominent role in mediating the renal nerve and heart rate responses to SP. Quantitative autoradiography showed that NK1 receptors are more abundant in the superior cervical ganglia of SHRs. RT-PCR showed increased abundance of NK1 receptor mRNA in SHRs as well. These observations suggest that the greater ganglionic stimulation caused by SP in SHRs is due to upregulation of NK1 receptors.

The present study was done to characterize the effects of endogenous tachykinins on heart rate in urethane-anesthetized guinea pigs. Intravenous injection of capsaicin (32 nmol/kg) was used to evoke release of tachykinins and calcitonin gene-related peptide (CGRP) from cardiac sensory nerve fibers. Such injections caused a brief decrease in heart rate (- 37 ± 7 beats/min, n = 6) that was followed by a more prolonged increase (+ 44 ± 10 beats/min). Blood pressure was lowered by - 11 ± 2 mmHg. Bilateral vagotomy did not affect the chronotropic or depressor responses to capsaicin, but atropine (1 μmol/kg) nearly abolished the bradycardic response (- 8 ± 3 beats/min, n = 7). Combined blockade of NK2 and NK3 receptors, with SR48968 and SR14801 respectively, also caused a significant reduction of capsaicin-evoked bradycardia (- 14 ± 3 beats/min, n = 4) but did not affect bradycardia evoked by vagal nerve stimulation. Blockade of CGRP receptors eliminated capsaicin-evoked tachycardia and prolonged the capsaicin-evoked bradycardia. These findings suggest that capsaicin-evoked bradycardia in the anesthetized guinea pig is mediated by tachykinins that stimulate cardiac cholinergic neurons. This effect appears to be truncated by the positive chronotropic action of CGRP that is also released from cardiac afferents by capsaicin.

Tachykinins and their receptors are present in gustatory centers, but little is known about tachykinin function in gustation. In this study, immunohistochemical localization of substance P and two centrally prevalent neurokinin receptors, NK1 and NK3, was carried out in the rostral nucleus of the solitary tract and the caudal parabrachial nucleus to evaluate regional receptor/ligand correspondences. All three proteins showed regional variations in labeling density that correlated with distinct sites in gustatory centers. In the rostral nucleus of the solitary tract, the relative densities of substance P and NK1 receptors varied in parallel across subnuclei, with both being moderate to dense in the dorsocentral, chemoresponsive zone. NK3 receptors had a distinct distribution in the caudal half of this zone, suggesting a unique role in processing taste input from the posterior tongue. In the caudal parabrachial nucleus, substance P and NK1 receptor immunoreactivities were dense in the pontine taste area, while NK3 receptor labeling was sparse. The external medial subnucleus had substantial NK3 receptor and substance P labeling, but little NK1 receptor immunoreactivity. These findings suggest that distinct tachykinin ligand/neurokinin receptor combinations may be important in local processing of information within brainstem gustatory centers.

No description available.

Mutações inativadoras nos genes TAC3 e TACR3, os quais codificam a neurocinina B (NKB) e o seu receptor NK3R, respectivamente, foram descritas em pacientes com hipogonadismo hipogonadotrófico isolado (HHI) normósmico. A partir desse achado, hipotetizamos que mutações ativadoras na NKB e/ou NK3R resultariam na secreção prematura de GnRH e, consequentemente, no desenvolvimento de puberdade precoce dependente de gonadotrofinas (PPDG). Nesse estudo, investigamos a presença de mutações ativadoras e/ou polimorfismos nos genes TAC3 e TACR3 em pacientes com PPDG, bem como mutações inativadoras e/ou polimorfismos nesses genes em pacientes com retardo constitucional do crescimento e desenvolvimento (RCCD), e HHI normósmico. Duzentos e trinta e sete pacientes com distúrbios puberais centrais idiopáticos foram selecionados, sendo 114 com PPDG, 50 com RCCD, e 73 com HHI normósmico. Um grupo de 150 indivíduos que apresentaram desenvolvimento puberal normal foi utilizado como controle. As regiões codificadoras dos genes TAC3 e TACR3 foram amplificadas pela reação em cadeia da polimerase, seguido de purificação enzimática e seqüenciamento automático direto. Análises in silico e in vitro foram realizadas. Um nova variante foi identificada no gene TAC3, p.A63P, em uma paciente do sexo feminino com PPDG, a qual desenvolveu puberdade aos sete anos de idade. Essa variante (p.A63P) está localizada na proneurocinina B, e análises in silico sugeriram que ela não altera sítios constitutivos de splicing e é benigna para a estrutura da proteína. A análise de segregação familiar mostrou que a mãe da paciente, a qual apresentou um desenvolvimento puberal normal, também apresentava a alteração p.A63P em heterozigose, sugerindo que essa variante não desempenha um papel direto no fenótipo de PPDG. Uma nova variante em heterozigose no gene TACR3, p.A449S, foi identificada em uma paciente do sexo feminino com RCCD, que teve início puberal aos treze anos de idade. A análise do grau de conservação da alanina na posição 449 mostrou que esse aminoácido não é conservado entre as diferentes espécies, e análises in silico sugeriram que essa variante não altera os sítios constitutivos de splicing, e é benigna para a estrutura do NK3R. Três novas variantes no NK3R foram identificadas, p.G18D, p.L58L (c.172C>T) e p.W275*, em três pacientes do sexo masculino não relacionados com HHI normósmico. As variantes p.G18D e p.L58L foram identificadas em heterozigose, enquanto que a variante p.W275* foi identificada em heterozigose associada a variante silenciosa p.L58L (c.172C>T), e em homozigose em outro paciente. Análises in silico sugeriram que a variante p.G18D poderia afetar a funcionalidade do NK3R. Estudos in vitro dessa nova variante foram realizados, e mostraram que a mesma não altera a função do NK3R, visto que o aumento na produção de fosfatidil inositol não diferiu significativamente entre o receptor mutado e selvagem. Todas as novas variantes descritas nos genes TAC3 e TACR3 não foram identificadas em 300 alelos controles. Em conclusão, nosso trabalho identificou novas variantes nos genes TAC3 e TACR3 em pacientes brasileiros com distúrbios puberais centrais idiopáticos, e confirmou o envolvimento do complexo NKB/NK3R na etiologia do HHI normósmico / Inactivating mutations of the TAC3 and TACR3 genes, which encode the neurokinin B (NKB) and its receptor, NK3R, respectively, were described in patients with normosmic isolated hypogonadotropic hypogonadism (IHH). Based on these observations, we hypothesized that gain-of-function mutations in the NKB and/or NK3R might be associated with premature activation of GnRH release, leading to gonadotropin-dependent precocious puberty (GDPP). In this study, we investigated the presence of activating mutations and/or polymorphisms in the TAC3 and TACR3 genes in patients with GDPP, and inactivating mutations and/or polymorphisms in these genes in patients with constitutional delay of growth and puberty (CDGP) and normosmic IHH. It was selected 237 patients with idiopathic central pubertal disorders: 114 with GDPP, 50 with CDGP, and 73 with normosmic IHH. Indeed, a group 150 individuals who had puberty at adequate age was used as controls. The coding regions of TAC3 and TACR3 genes were amplified by polymerase chain reaction followed by enzymatic purification and direct automatic sequencing. In silico and in vitro analyses were performed. A new heterozygous variant in the TAC3 gene, p.A63P, was identified in a Brazilian girl with GDPP who had puberty onset at seven years of age. The p.A63P variant was located in the proneurokinin B and in silico analysis suggested that this variant does not alter constitutive splice sites, and it was benign to the protein. The segregation analysis revealed that her mother was heterozygous for the p.A63P variant (who had a normal pubertal development), suggesting that this variant does not play a role in the GDPP phenotype. It was identified a new heterozygous variant, p.A449S, in the TACR3 gene in a Brazilian girl with CDGP, who had puberty onset at thirteen years of age. Conservation degree analysis of alanine at position 449 showed that this amino acid is not a conserved residue among different species. In silico analyses suggested that this new variant does not alter splice sites or affects the structure of NK3R. Indeed, it was identified three new distinct variants in the TACR3 gene, p.G18D, p.L58L (c.172C>T) and p.W275*, in three unrelated males with normosmic IHH. Both p.G18D and p.L58L (c.172C>T) were identified in heterozygous state, and the p.W275* variant was identified in two of these males, since one in homozygous and in another in heterozygous state in association with the silent variant p.L58L (c.172C>T). In silico analyses suggested that p.G18D might be damaging to the NK3R. In vitro studies of this variant (p.G18D) showed that the amount of inositol phosphate (IP) was not significantly different in cells transfected with the p.G18D mutant receptor than in cells transfected with the wild type receptor, indicating that this variant did not alter the function of the neurokinin B receptor. All new variants identified in the TAC3 and TACR3 genes were absent in 300 control alleles. In conclusion, we identified new variants in the TAC3 and TACR3 genes in Brazilian patients with idiopathic central pubertal disorders. We confirm the key role of the NKB/NK3R complex in the etiology of normosmic IHH

Mutações inativadoras nos genes TAC3 e TACR3, os quais codificam a neurocinina B (NKB) e o seu receptor NK3R, respectivamente, foram descritas em pacientes com hipogonadismo hipogonadotrófico isolado (HHI) normósmico. A partir desse achado, hipotetizamos que mutações ativadoras na NKB e/ou NK3R resultariam na secreção prematura de GnRH e, consequentemente, no desenvolvimento de puberdade precoce dependente de gonadotrofinas (PPDG). Nesse estudo, investigamos a presença de mutações ativadoras e/ou polimorfismos nos genes TAC3 e TACR3 em pacientes com PPDG, bem como mutações inativadoras e/ou polimorfismos nesses genes em pacientes com retardo constitucional do crescimento e desenvolvimento (RCCD), e HHI normósmico. Duzentos e trinta e sete pacientes com distúrbios puberais centrais idiopáticos foram selecionados, sendo 114 com PPDG, 50 com RCCD, e 73 com HHI normósmico. Um grupo de 150 indivíduos que apresentaram desenvolvimento puberal normal foi utilizado como controle. As regiões codificadoras dos genes TAC3 e TACR3 foram amplificadas pela reação em cadeia da polimerase, seguido de purificação enzimática e seqüenciamento automático direto. Análises in silico e in vitro foram realizadas. Um nova variante foi identificada no gene TAC3, p.A63P, em uma paciente do sexo feminino com PPDG, a qual desenvolveu puberdade aos sete anos de idade. Essa variante (p.A63P) está localizada na proneurocinina B, e análises in silico sugeriram que ela não altera sítios constitutivos de splicing e é benigna para a estrutura da proteína. A análise de segregação familiar mostrou que a mãe da paciente, a qual apresentou um desenvolvimento puberal normal, também apresentava a alteração p.A63P em heterozigose, sugerindo que essa variante não desempenha um papel direto no fenótipo de PPDG. Uma nova variante em heterozigose no gene TACR3, p.A449S, foi identificada em uma paciente do sexo feminino com RCCD, que teve início puberal aos treze anos de idade. A análise do grau de conservação da alanina na posição 449 mostrou que esse aminoácido não é conservado entre as diferentes espécies, e análises in silico sugeriram que essa variante não altera os sítios constitutivos de splicing, e é benigna para a estrutura do NK3R. Três novas variantes no NK3R foram identificadas, p.G18D, p.L58L (c.172C>T) e p.W275*, em três pacientes do sexo masculino não relacionados com HHI normósmico. As variantes p.G18D e p.L58L foram identificadas em heterozigose, enquanto que a variante p.W275* foi identificada em heterozigose associada a variante silenciosa p.L58L (c.172C>T), e em homozigose em outro paciente. Análises in silico sugeriram que a variante p.G18D poderia afetar a funcionalidade do NK3R. Estudos in vitro dessa nova variante foram realizados, e mostraram que a mesma não altera a função do NK3R, visto que o aumento na produção de fosfatidil inositol não diferiu significativamente entre o receptor mutado e selvagem. Todas as novas variantes descritas nos genes TAC3 e TACR3 não foram identificadas em 300 alelos controles. Em conclusão, nosso trabalho identificou novas variantes nos genes TAC3 e TACR3 em pacientes brasileiros com distúrbios puberais centrais idiopáticos, e confirmou o envolvimento do complexo NKB/NK3R na etiologia do HHI normósmico / Inactivating mutations of the TAC3 and TACR3 genes, which encode the neurokinin B (NKB) and its receptor, NK3R, respectively, were described in patients with normosmic isolated hypogonadotropic hypogonadism (IHH). Based on these observations, we hypothesized that gain-of-function mutations in the NKB and/or NK3R might be associated with premature activation of GnRH release, leading to gonadotropin-dependent precocious puberty (GDPP). In this study, we investigated the presence of activating mutations and/or polymorphisms in the TAC3 and TACR3 genes in patients with GDPP, and inactivating mutations and/or polymorphisms in these genes in patients with constitutional delay of growth and puberty (CDGP) and normosmic IHH. It was selected 237 patients with idiopathic central pubertal disorders: 114 with GDPP, 50 with CDGP, and 73 with normosmic IHH. Indeed, a group 150 individuals who had puberty at adequate age was used as controls. The coding regions of TAC3 and TACR3 genes were amplified by polymerase chain reaction followed by enzymatic purification and direct automatic sequencing. In silico and in vitro analyses were performed. A new heterozygous variant in the TAC3 gene, p.A63P, was identified in a Brazilian girl with GDPP who had puberty onset at seven years of age. The p.A63P variant was located in the proneurokinin B and in silico analysis suggested that this variant does not alter constitutive splice sites, and it was benign to the protein. The segregation analysis revealed that her mother was heterozygous for the p.A63P variant (who had a normal pubertal development), suggesting that this variant does not play a role in the GDPP phenotype. It was identified a new heterozygous variant, p.A449S, in the TACR3 gene in a Brazilian girl with CDGP, who had puberty onset at thirteen years of age. Conservation degree analysis of alanine at position 449 showed that this amino acid is not a conserved residue among different species. In silico analyses suggested that this new variant does not alter splice sites or affects the structure of NK3R. Indeed, it was identified three new distinct variants in the TACR3 gene, p.G18D, p.L58L (c.172C>T) and p.W275*, in three unrelated males with normosmic IHH. Both p.G18D and p.L58L (c.172C>T) were identified in heterozygous state, and the p.W275* variant was identified in two of these males, since one in homozygous and in another in heterozygous state in association with the silent variant p.L58L (c.172C>T). In silico analyses suggested that p.G18D might be damaging to the NK3R. In vitro studies of this variant (p.G18D) showed that the amount of inositol phosphate (IP) was not significantly different in cells transfected with the p.G18D mutant receptor than in cells transfected with the wild type receptor, indicating that this variant did not alter the function of the neurokinin B receptor. All new variants identified in the TAC3 and TACR3 genes were absent in 300 control alleles. In conclusion, we identified new variants in the TAC3 and TACR3 genes in Brazilian patients with idiopathic central pubertal disorders. We confirm the key role of the NKB/NK3R complex in the etiology of normosmic IHH

A substância P (SP) é um neuropeptídeo da família das taquicininas que regula numerosas funções biológicas por meio da ligação ao seu receptor altamente específico neuroquinina-1 (NK-1R). Este complexo SP/NK-1R está envolvido em diversos processos relacionados à oncogênese, como a mitogênese, angiogênese, migração celular e metástase. O objetivo deste trabalho foi investigar a expressão de substância P e de seu receptor NK-1 e sua correlação com o índice de proliferação celular em 73 pacientes portadores de 90 carcinomas espinocelulares de boca, diagnosticados e tratados no Hospital General e Hospital de La Princesa, Jaen, Espanha, durante o período de 1995 a 2008. Todos os tumores foram corados pela técnica imunoistoquímica da estreptavidina-biotina-peroxidase com os anticorpos anti-SP, anti-NK-1R e anti-Ki-67. As alterações celulares epiteliais das margens cirúrgicas livres de doença também foram registradas. A expressão imunoistoquímica da substância P e do seu receptor neurokinina-1 foi avaliada na membrana, no citoplasma e no núcleo das células epiteliais malignas e do epitélio da mucosa bucal adjacente ao tumor, nos linfócitos e nos vasos sanguíneos dos tumores. O índice de proliferação celular tumoral foi determinado pela expressão imunoistoquímica de Ki-67 identificada no núcleo das células neoplásicas. As correlações entre as diversas localizações da SP, de seu receptor NK-1R e do índice de proliferação tumoral determinado pelo Ki-67 foram determinadas estatísticamente utilizando-se o Crosstab, Regress e Descript de SUDAAN. A expressão de SP foi identificada no estroma de 77% dos tumores, na membrana de 71% das células malignas e no citoplasma de 81,2% dos tumores. A maioria dos tumores apresentou altas taxas de proliferação das células neoplásicas com mais de 50% das células imunopositivas para o Ki-67. Ao analisar as margens cirúrgicas livres de doença, observou-se expressão da SP, sobretudo no terço inferior e médio, tanto no núcleo, como no citoplasma e na membrana celular. A expressão concomitante de substância P e do receptor neurokinina-1 no citoplasma das células neoplásicas ocorreu mais frequentemente nas células tumorais em proliferação. Verificou-se que expressão de SP no câncer bucal ocorre juntamente com o aumento da expressão de NK-1R, sugerindo que as células neoplásicas epiteliais bucais podem utilizar esta via para tornarem-se mais susceptíveis aos estímulos mediados pela SP. A expressão de substância P nos linfócitos do infiltrado inflamatório e vasos sanguíneos intratumorais e peritumorais se associaram a tumores de menor tamanho, menor estádio clínico e com menor frequência metástase ganglionar. Concluiu-se que as células neoplásicas epiteliais bucais podem utilizar a via substância P/NK-1R para tornarem-se mais susceptíveis aos estímulos mediados pela SP, particularmente aqueles associados à proliferação celular. Além disso, a expressão epitelial, citoplasmática e nuclear da substância P é um evento precoce na carcinogênese bucal podendo ser considerado um marcador da presença e intensidade de displasia epitelial. / The substance P (SP) is a neuropeptide of the tachykinin family that regulates multiple biological functions by binding to the highly specific receptor neurokinin-1. This complex SP/NK-1 is involved in several processes related to oncogenesis, such as mitogenesis, angiogenesis, cell migration and metastasis. This study investigated the expression of substance P and its receptor NK-1 and its correlation with the cell proliferation index in 73 patients with oral squamous cell carcinoma, diagnosed and treated at the General Hospital and Princess Hospital at Jaen, Spain, during the period 1995 to 2008. All tumors were stained immunohistochemically by the streptavidin-biotin-peroxidase technique using the antibodies anti-SP, anti-NK-1R and anti-Ki-67. The epithelial cell alterations on the disease-free surgical margins were registered. The immunohistochemical expression of SP and its receptor neurokinin-1 were evaluated on the membrane, cytoplasm and nucleus of malignant epithelial cells and cells of healthy oral mucosa adjacent to the tumor, as well as on the infiltrating lymphocytes and peritumoral or intratumoral blood vessels. The tumor cell proliferation index was determined by the immunohistochemical expression of Ki- 67 identified on the malignant cell nucleus. The correlations between the distinct localizations of SP, its receptor NK-1 and the proliferation index Ki-67 were statistically analyzed using the Sudaan Crosstab, Regress and Descript tests. The SP expression was identified on the stroma of 77% of tumors, on the membrane of 71% of malignant cells and cytoplasm of 81.2% of tumors. Most tumors presented high proliferation rates of neoplastic cells, with more than 50% of cells immunopositive for Ki-67. Analysis of the disease-free surgical margins revealed SP expression especially on the lower and medium third, both on the nucleus, cytoplasm and cell membrane. The simultaneous expression of substance P and its receptor NK-1 on the cytoplasm of neoplastic cells occurred more frequently in proliferating malignant cells. The expression of SP in oral cancer occurred simultaneously to an increased expression of NK-1R, suggesting that the oral malignant epithelial cells might use this pathway to become more susceptible to the stimuli mediated by the SP. The substance P expression on infiltrating lymphocytes and intratumoral or peritumoral blood vessels was associated with tumors of small size, lower clinical stage and less frequent node metastasis. It was concluded that the oral neoplastic epithelial cells may use the pathway SP/NK-1R to become more susceptible to the stimuli mediated by the SP, particularly those associated with cell proliferation. Additionally, the epithelial, cytoplasmic and nuclear expression of substance P is an early event in oral carcinogenesis and may be considered a marker of the presence and intensity of epithelial dysplasia.

A substância P (SP) é um neuropeptídeo da família das taquicininas que regula numerosas funções biológicas por meio da ligação ao seu receptor altamente específico neuroquinina-1 (NK-1R). Este complexo SP/NK-1R está envolvido em diversos processos relacionados à oncogênese, como a mitogênese, angiogênese, migração celular e metástase. O objetivo deste trabalho foi investigar a expressão de substância P e de seu receptor NK-1 e sua correlação com o índice de proliferação celular em 73 pacientes portadores de 90 carcinomas espinocelulares de boca, diagnosticados e tratados no Hospital General e Hospital de La Princesa, Jaen, Espanha, durante o período de 1995 a 2008. Todos os tumores foram corados pela técnica imunoistoquímica da estreptavidina-biotina-peroxidase com os anticorpos anti-SP, anti-NK-1R e anti-Ki-67. As alterações celulares epiteliais das margens cirúrgicas livres de doença também foram registradas. A expressão imunoistoquímica da substância P e do seu receptor neurokinina-1 foi avaliada na membrana, no citoplasma e no núcleo das células epiteliais malignas e do epitélio da mucosa bucal adjacente ao tumor, nos linfócitos e nos vasos sanguíneos dos tumores. O índice de proliferação celular tumoral foi determinado pela expressão imunoistoquímica de Ki-67 identificada no núcleo das células neoplásicas. As correlações entre as diversas localizações da SP, de seu receptor NK-1R e do índice de proliferação tumoral determinado pelo Ki-67 foram determinadas estatísticamente utilizando-se o Crosstab, Regress e Descript de SUDAAN. A expressão de SP foi identificada no estroma de 77% dos tumores, na membrana de 71% das células malignas e no citoplasma de 81,2% dos tumores. A maioria dos tumores apresentou altas taxas de proliferação das células neoplásicas com mais de 50% das células imunopositivas para o Ki-67. Ao analisar as margens cirúrgicas livres de doença, observou-se expressão da SP, sobretudo no terço inferior e médio, tanto no núcleo, como no citoplasma e na membrana celular. A expressão concomitante de substância P e do receptor neurokinina-1 no citoplasma das células neoplásicas ocorreu mais frequentemente nas células tumorais em proliferação. Verificou-se que expressão de SP no câncer bucal ocorre juntamente com o aumento da expressão de NK-1R, sugerindo que as células neoplásicas epiteliais bucais podem utilizar esta via para tornarem-se mais susceptíveis aos estímulos mediados pela SP. A expressão de substância P nos linfócitos do infiltrado inflamatório e vasos sanguíneos intratumorais e peritumorais se associaram a tumores de menor tamanho, menor estádio clínico e com menor frequência metástase ganglionar. Concluiu-se que as células neoplásicas epiteliais bucais podem utilizar a via substância P/NK-1R para tornarem-se mais susceptíveis aos estímulos mediados pela SP, particularmente aqueles associados à proliferação celular. Além disso, a expressão epitelial, citoplasmática e nuclear da substância P é um evento precoce na carcinogênese bucal podendo ser considerado um marcador da presença e intensidade de displasia epitelial. / The substance P (SP) is a neuropeptide of the tachykinin family that regulates multiple biological functions by binding to the highly specific receptor neurokinin-1. This complex SP/NK-1 is involved in several processes related to oncogenesis, such as mitogenesis, angiogenesis, cell migration and metastasis. This study investigated the expression of substance P and its receptor NK-1 and its correlation with the cell proliferation index in 73 patients with oral squamous cell carcinoma, diagnosed and treated at the General Hospital and Princess Hospital at Jaen, Spain, during the period 1995 to 2008. All tumors were stained immunohistochemically by the streptavidin-biotin-peroxidase technique using the antibodies anti-SP, anti-NK-1R and anti-Ki-67. The epithelial cell alterations on the disease-free surgical margins were registered. The immunohistochemical expression of SP and its receptor neurokinin-1 were evaluated on the membrane, cytoplasm and nucleus of malignant epithelial cells and cells of healthy oral mucosa adjacent to the tumor, as well as on the infiltrating lymphocytes and peritumoral or intratumoral blood vessels. The tumor cell proliferation index was determined by the immunohistochemical expression of Ki- 67 identified on the malignant cell nucleus. The correlations between the distinct localizations of SP, its receptor NK-1 and the proliferation index Ki-67 were statistically analyzed using the Sudaan Crosstab, Regress and Descript tests. The SP expression was identified on the stroma of 77% of tumors, on the membrane of 71% of malignant cells and cytoplasm of 81.2% of tumors. Most tumors presented high proliferation rates of neoplastic cells, with more than 50% of cells immunopositive for Ki-67. Analysis of the disease-free surgical margins revealed SP expression especially on the lower and medium third, both on the nucleus, cytoplasm and cell membrane. The simultaneous expression of substance P and its receptor NK-1 on the cytoplasm of neoplastic cells occurred more frequently in proliferating malignant cells. The expression of SP in oral cancer occurred simultaneously to an increased expression of NK-1R, suggesting that the oral malignant epithelial cells might use this pathway to become more susceptible to the stimuli mediated by the SP. The substance P expression on infiltrating lymphocytes and intratumoral or peritumoral blood vessels was associated with tumors of small size, lower clinical stage and less frequent node metastasis. It was concluded that the oral neoplastic epithelial cells may use the pathway SP/NK-1R to become more susceptible to the stimuli mediated by the SP, particularly those associated with cell proliferation. Additionally, the epithelial, cytoplasmic and nuclear expression of substance P is an early event in oral carcinogenesis and may be considered a marker of the presence and intensity of epithelial dysplasia.