Salvia miltiorrhiza (SM) preconditioning was reported to be helpful in the early recovery of gastrointestinal motility in the intestinal congestion of rats with hepatic ischemia reperfusion. The aim of this study was to determine whether SM stimulates contraction of isolated terminal ileum of Sprague-Dawley rat ex vitro and the mechanisms which regulates that. The roots of SM were extracted by ethanol. One of the indicative marker of SM, Tanshinone IIA, was identified and quantified with high performance liquid chromatography (HPLC), and the results showed that Tanshinone IIA was 1190 £gg/ml in SM extract. The effects of contractile activity of SM extract at various cumulative dosages on the rat isolated terminal ileum were studied in organ bath. The area under curve above the baseline of contractile graphy of SM extract on isolated terminal ileum was recorded. In order to explore the contractile mechanism of SM extract on isolated terminal ileum, the individual pretreatment or use of atropine (a muscarinic receptor antagonist), tetrodotoxin (a sodium channel blocker), nifedipine (a calcium channel blocker), Ca2+ free Kreb¡¦s solution with EGTA, or trifluoperazine (a calmodulin blocker) was given and then cumulative dosages (40 £gL, 100 £gL, 180 £gL, 280 £gL) of SM extract were added. In addition, we used Fura-2 pentakis acetoxymethyl ester to detect the change of intracellular calcium concentration of intestinal epithelial cell-6 (IEC-6) induced in 1/1000-time or 1/10000-time dilution of SM extract. The result indicated SM extract significantly simulated the contraction of isolated terminal ileum in a dose-dependent manner. The individual addition or use of atropine, tetrodotoxin, nifedipine, or Ca2+ free Kreb¡¦s solution with EGTA all could not down-regulate significantly the contraction of SM extract on isolated terminal ileum. Trifluoperazine significantly down-regulated the contraction of SM extract on isolated terminal ileum. In addiation, SM extract was able to increase cytosolic calcium concentration of IEC-6 cells. In conclusion, the mechanisms of contraction of SM extract on isolated terminal ileum of rat were involved in calmodulin/Ca2+ associated contraction pathway.

Orientador: Maria Regina Sposto / Banca: Cláudia Maria Navarro / Banca: Enilson Antônio Sallum / Resumo: O objetivo deste trabalho foi avaliar a prevalência e severidade do crescimento gengival em pacientes brasileiros sob terapia com nifedipina, por meio do uso do "Novo Índice Clínico para Crescimento Gengival Induzido por Drogas(Índice DIGO)". O estudo foi realizado em 35 pacientes sob terapia com nifedipina (grupo teste ) e em um grupo controle de 35 pacientes. Foram feitos os registros das variáveis demográficas (idade e sexo do paciente), farmacológicas (dose e tempo de uso da nifedipina) e das variáveis periodontais (índice de placa, índice gengival, profundidade de sondagem, nível de inserção clínico, sangramento à sondagem) e do crescimento gengival. O teste Z (nível de significância a 5% e p<0.05) e a correlação de Spearman foram usados para a comparação dos resultados entre os grupos teste e controle. Os resultados mostraram que o crescimento gengival foi observado em 68% dos pacientes e que não houve associação entre o crescimento gengival e as variáveis demográficas e as variáveis farmacológicas. No entanto, houve associação entre o crescimento gengival e as variáveis periodontais, exceto para o índice de placa. Podemos concluir que a inflamação gengival apresentou influência no crescimento gengival associado à nifedipina. / Abstract: The aim of this study was to evaluate the occurrence of nifedipine induced GO in patients and the risk factors associated using a New Clinical Index for Drug Induced Gingival Overgrowth (DIGO) and the relation between The study was carried out with 35 patients under treatment with nifedipine (test group) and 35 patients without treatment (control group). There was assessed the characteristics of demographic (age, gender), pharmacological (dose, time of use), periodontal variables (plaque index, gingival index, probing depth, attachment level, bleeding on probing) and gingival overgrowth of the sample. The test Z (significance level at 5% - p< 0.05) and the Spearman correlation were used to compare data in test and control groups. Gingival overgrowth was noticed in 68% of patients. The statistical analyses showed no association between the gingival overgrowth and demographic and pharmacological variables, except for the plaque index. However, there was an association between the gingival overgrowth and periodontal variables. Further, it is possible to conclude that the presence of gingival inflammation was the main factor of risk to promote nifedipine-induced gingival overgrowth. / Mestre

A venlafaxina é um fármaco usado no tratamento da depressão e dos transtornos de ansiedade generalizada. É disponível na clínica na forma de mistura racêmica dos enantiômeros S-(+) e R-(-) em formulação de liberação controlada. O enantiômero S-(+) inibe a recaptação da serotonina, enquanto o enantiômero R-(-) inibe a recaptação da serotonina e da norepinefrina. A venlafaxina é biotransformada pelo CYP2D6 e CYP2C19 em seu principal metabólito, O-desmetilvenlafaxina, o qual apresenta atividade farmacológica semelhante à venlafaxina. Outros metabólitos da venlafaxina, dependentes do CYP3A4, incluem a N-desmetilvenlafaxina e a N,O-di-desmetilvenlafaxina. A absorção e a distribuição da venlafaxina são moduladas pela ação da glicoproteina-P. O nifedipino, um fármaco da classe dos inibidores dos canais de cálcio, é descrito como inibidor da glicoproteina-P. O presente estudo investiga a influência do nifedipino na disposição cinética e no metabolismo da venlafaxina em voluntários sadios caracterizados como portadores de atividade normal do CYP3A (omeprazol como fármaco marcador) e fenotipados como metabolizadores rápidos do CYP2C19 (omeprazol como fármaco marcador) e do CYP2D6 (metoprolol como fármaco marcador). Os voluntários investigados receberam, em estudo cruzado e randomizado, dose única oral de 150 mg de venlafaxina racêmica (Fase 1) e 40 mg de nifedipino associada com dose única oral de 150 mg de venlafaxina racêmica (Fase 2). Foram coletadas amostras seriadas de sangue até 72 horas após a administração dos fármacos para o estudo farmacocinético. As concentrações plasmáticas dos enantiômeros da venlafaxina e de seus metabólitos foram determinadas por LC-MS/MS utilizando a coluna Chirobiotic V com fase móvel constituída de mistura de metanol: solução aquosa de acetato de amônio 15 mmol/L pH 6,0 (80:20, v/v). A farmacocinética da venlafaxina mostrou-se enantiosseletiva com acúmulo plasmático (AUC 526,0 vs 195,7 ng.h/mL) e menores valores de clearance (Cl/f 142,67 vs 408,01 L/h) para o enantiômero S-(+). A disposição cinética do metabólito ativo O-desmetilvenlafaxina apresentou enantiosseletividade apenas no parâmetro concentração plasmática máxima com observação de maiores valores para o enantiômero R-(-) (Cmax 69,33 vs 56,94 ng/mL). A disposição cinética da N,O-di-desmetilvenlafaxina também mostrou-se enantiosseletiva apenas para o parâmetro concentração plasmática máxima, mas com observação de maiores valores para o enantiômero S-(+) (Cmax 7,08 vs 4,61 ng/mL). A administração de dose única oral de 40 mg de nifedipino não alterou a farmacocinética de ambos os enantiômeros da venlafaxina e de seus metabólitos O-desmetilvenlafaxina e N,O-di-desmetilvenlafaxina, seja utilizando teste estatístico não paramétrico (teste de Wilcoxon para dados pareados, p < 0,05), seja avaliando o IC 90% das razões das médias geométricas de AUC e Cmax (Fase 2/Fase 1). Os dados obtidos evidenciam que o nifedipino na dose de 40 mg não age como um inibidor da P-gp / Venlafaxine is a drug used to treat depression and generalized anxiety disorders. It is available in clinical practice in the form of a racemic mixture of S-(+) and R-(-) enantiomers, in controlled release formulation. The S-(+) enantiomer inhibits the reuptake of serotonin, while the R-(-) enantiomer inhibits the reuptake of both serotonin and norepinephrine. Venlafaxine is biotransformed by CYP2D6 and CYP2C19 in its major metabolite, O-desmethylvenlafaxine, which has similar pharmacological activity when compared to venlafaxine. Other metabolites of venlafaxine, dependent of CYP3A4, include N-desmethylvenlafaxine and N, O-di-desmethylvenlafaxine. The absorption and distribution of venlafaxine are modulated by the action of P-glycoprotein. Nifedipine, a calcium channel blocker drug, is described as an inhibitor of P-glycoprotein. The present study investigates the influence of nifedipine on the kinetic disposition of venlafaxine enantiomers and its metabolites in healthy volunteers characterized as having normal activity of CYP3A (omeprazole as a probe drug) and phenotyped as rapid metabolizers of CYP2C19 (omeprazole as a probe drug) and CYP2D6 (metoprolol as a probe drug). The enrolled volunteers received, in a randomized, two-way study, a single 150 mg oral dose of racemic venlafaxine (Phase 1) and 40 mg oral dose of nifedipine associated with a single 150 mg oral dose of racemic venlafaxine (Phase 2). Serial blood samples were collected until 72 hours after drug administration to the pharmacokinetic study. Plasma concentrations of venlafaxine enantiomers and its metabolites were determined by LC-MS/MS using a Chirobiotic V column and a mobile phase constituted of methanol: aqueous 15 mmol/L ammonium acetate solution pH 6.0 (80:20, v/v). The venlafaxine pharmacokinetics is enantioselective with plasma accumulation (AUC 526.0 vs 195.7 ng h/mL) and lower clearance values (CL/f 142.67 vs 408.01 L/h) for the S-(+) enantiomer. The kinetic disposition of the active metabolite O-desmethylvenlafaxine exhibits enantioselectivity only in the maximum plasma concentration parameter with higher values for the R-(-) enantiomer (Cmax 69.33 vs 56.94 ng/mL). The kinetic disposition of N,O-di-desmethylvenlafaxine is also enantioselective only for the maximum plasma concentration parameter, but with higher values for the S-(+) enantiomer (Cmax 7.08 vs 4.61 ng/ml). Administration of a 40 mg single oral dose of nifedipine do not alter the pharmacokinetics of both enantiomers of venlafaxine and its metabolites O-desmethylvenlafaxine and N,O-di-desmethylvenlafaxine, using non-parametric statistical test (Wilcoxon test for paired data, p <0.05), or evaluating the 90% CI of the AUC and Cmax geometric mean ratios (Phase 2/Phase 1). The obtained data show that nifedipine in a 40 mg oral dose does not act as a P-gp inhibitor.

No description available.

Yes / Microemulsion is a stable, isotropic clear solution consisting of oil based substance, water surfactant and cosurfactant. There are two types of microemulsion which are used as a mobile phase; water in oil (w/o) and oil in water (o/w).Microemulsion has a strong ability to solubilize both hydrophobic and hydrophilic analytes, therefore reducing the pre-treatment of the sample which is needed for the complex sample. Recent reports found that separating the analytes by using microemulsion high performance liquid chromatography can be achieved with superior speed and efficiency compared to conventional HPLC modes. In this work, Oil in water (o/w) microemulsion has been used for the determination of nifedipine in pharmaceutical preparation. The effect of each parameter on the separation process was examined. The samples were injected into C18, analytical columns maintained at 30°C with a flow rate 1 ml/min. The mobile phase was 87.1% aqueous orthophosphate buffer 15 mM (adjusted to pH 3 with orthophosphoric acid), 0.8% of octane as oil, 4.5 SDS, and 7.6% 1-butanol, all w/w. The nifedipine and internal standard peaks were detected by UV detection at λ max 237 nm The calibration curve was linear (r2=0.9995) over nifedipine concentrations ranging from 1 to 60 μg/ml (n=6). The method has good sensitivity with limit of detection (LOD) of 0.33 μg/ml and limit of quantitation (LOQ) of 1.005 μg/ ml. Also it has an excellent accuracy ranging from 99.11 to 101.64%. The intra-day and inter-day precisions (RSD %) were <0.45% and <0.9%, respectively.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Neste estudo foram preparados polimorfos do fármaco tolbutamida, um hipoglicemiante oral usado no tratamento dos Diabetes Mellitus tipo II. Foram também preparados polimorfos da nifedipina, fármaco usado no tratamento das desordens cardiovasculares, como angina pectoris e hipertensão. A preparação dos polimorfos foi mediada por solvente, ou seja, foi em função do solvente usado nas etapas de cristalização e de precipitação das espécies. Um método de resfriamento rápido por nitrogênio líquido também foi utilizado. Técnicas analíticas como a espectrofotometria de infravermelho, a calorimetria diferencial de varredura, a difratometria de raio-X e a microscopia eletrônica de varredura foram úteis para a caracterização dos produtos obtidos experimentalmente. Os resultados comprovaram que dois polimorfos da tolbutamida foram preparados, ambos com estrutura cristalina. No caso da nifedipina, dois polimorfos foram preparados e a caracterização mostrou que um destes foi obtido num estado amorfo enquanto o outro estava sob forma cristalina. A instabilidade da nifedipina no estado amorfo foi monitorada pela técnica de calorimetria diferencial de varredura que, através de diferentes curvas, mostrou uma transformação rápida para uma estrutura cristalina. Esta mesma técnica aliada à termogravimetria confirmou a obtenção de um terceiro produto da nifedipina, de estrutura cristalina, que foi considerado um pseudopolimorfo por ser uma espécie solvatada. Ao final do procedimento experimental e da avaliação dos resultados foi sugerido um esquema, passo a passo, para obtenção e caracterização de polimorfos de uma substância / In this study the polymorphs of tolbutamide, an oral hypoglicemiant used on Diabetes Mellitus type II treatment, and of nifedipine, a drug used in the cardiovascular disorders treatment, were prepared. All crystalline forms were obtained by crystallization from different solvents. Tolbutamide was isolated only in crystalline forms and nifedipine in two crystalline forms and in the amorphous form prepared by melting and subsequent cooling. The polymorphs from each drug were characterized by powder x-ray diffraction (PDRX), infrared spectroscopy (IR), Raman spectroscopy (FT-RAMAN), scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results proved that two different crystalline forms of tolbutamide were obtained and two crystalline form to nifedipine, one of them as a pseudo-polymorph. The characterization confirmed that melting and quickly cooling procedure prepared amorphous nifedipine. Differential scanning calorimetry technique generated curves whose data proved that the amorphous nifedipine is a very unstable form. Thermogravimetry confirmed a pseudo-polymorphs preparation of nifedipine. In spite of the modification observed on the profile of X-ray diffraction, because of the solvent present, was possible to prove that this solvated form have an crystalline structure. A methodology was proposed step by step to prepare and characterize polymorphs of a substance

Includes 4 published papers by the author as part of appendix 9 / Bibliography: leaves 1-19 (second sequence) / System requirements for accompanying computer disk: IBM-compatible computer. Other requirements: Dbase. / 1 v. (various pagings) ; / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Summary: describes and evaluates an economical method of collecting a large amount of data on thousands of patients suffering from essential hypertension and establishes the reliability of the data collected in this way. Also provides information on the tolerability and effectiveness of nifedipine / Thesis (M.D)--Dept. of Clinical and Experimental Pharmacology, University of Adelaide, 1993

Τα οξύαιχμα κύματα-ριπιδισμοί αποτελούν μία σημαντική και ενδογενή νευρική δραστηριότητα του ιπποκάμπου που εμφανίζεται κυρίως κατά το στάδιο των βραδέων κυμάτων του ύπνου και σε φάσεις ακινησίας κατά την εγρήγορση και πιστεύεται ότι διαδραματίζει κρίσιμο ρόλο στην διαδικασία της παγίωσης της μνήμης, που εμπλέκεται στη μεταφορά της πληροφορίας από τον ιππόκαμπο στον νεοφλοιό. Στην παρούσα μελέτη χρησιμοποιώντας καταγραφές των δυναμικών πεδίου από την CA1 περιοχή τομών του κοιλιακού πόλου του ιπποκάμπου, εξετάσαμε την επίδραση της νιφεδιπίνης, ενός ανταγωνιστή των L-τύπου τασεοελεγχόμενων διαύλων ασβεστίου, στην δραστηριότητα των οξύαιχμων κυμάτων-ριπιδισμών. Παρατηρήσαμε ότι η νιφεδιπίνη αύξησε το πλάτος των ριπιδισμών χωρίς να επηρεάζει σημαντικά την διάρκεια και τη συχνότητα της ριπιδικής ταλάντωσης. Επίσης η νιφεδιπίνη αύξησε το πλάτος των οξύαιχμων κυμάτων και προκάλεσε μία μετρημένη αύξηση στην εμφάνιση των επεισοδίων των οξύαιχμων κυμάτων. Αυτά τα αποτελέσματα καταδεικνύουν ότι η ροή ασβεστίου διαμέσου των L-τύπου διαύλων συμμετέχει στην τροποποίηση των οξύαιχμων κυμάτων-ριπιδισμών. / Sharp wave-ripples (SWRs) are a prominent and endogenous network activity in the hippocampus occurring during slow-wave sleep, and awake immobility, and it is thought to play a critical role in process of memory consolidation implicated in the transfer of information from the hippocampal to neocortex. In the present study using recordings of field potentials from the CA1 field of ventral hippocampal slices we examined the effect of nifedipine, a blocker of voltage-dependent calcium channels of L-type, in the activity of SWRs. We observed that nifedipine increased the amplitude of ripples without significantly affecting the duration and frequency of the ripple oscillation. Also, nifedipine increased the amplitude of sharp waves and produced a moderate increase in the incidence of episodes of SWRs. These results indicate that calcium influx through L-type calcium channels participate in the modulation of SWRs.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2018-07-09T16:12:59Z No. of bitstreams: 2 Tese- Maysa Aparecida de Oliveira - 2013.pdf: 2303389 bytes, checksum: d6b1b0186001f327c5e50809b8d401fb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-07-10T11:10:17Z (GMT) No. of bitstreams: 2 Tese- Maysa Aparecida de Oliveira - 2013.pdf: 2303389 bytes, checksum: d6b1b0186001f327c5e50809b8d401fb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-07-10T11:10:17Z (GMT). No. of bitstreams: 2 Tese- Maysa Aparecida de Oliveira - 2013.pdf: 2303389 bytes, checksum: d6b1b0186001f327c5e50809b8d401fb (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2013-07-16 / A simple and accurate stability-indicating high-performance liquid chromatography (HPLC-DAD) method was developed to measure nifedipine (NIF) in plasma in the presence of its degradation products. The chromatographic separation was performed on a C18 column using H3PO4 0.01%:CH3CN:CH3OH (60:20:20, v/v/v) as the mobile phase and a 1.0ml/min flow rate. The analytical validation was performed according to FDA, EMA and ANVISA (Brazilian Health Surveillance Agency) guidelines and was linear between 100.0 and 2000.0 ng/ml, precise (1.9 to 11.3%) and accurate (86.0 to 113.1%). Under the evaluated conditions, NIF in plasma samples were stable after processing and freeze-thaw cycles. The average liquid-liquid extraction recovery was 101.3 ± 5.4%. After validation, this method was applied to evaluate the influence of nitrosophenylpyridine (NO-NIF) in the pharmacokinetic of NIF in plasma of Wistar rats. This method was also validated for quality control of NO-NIF obtained after photodegradation of NIF in photostability chamber. The method showed selectivity, linearity (0.4 to 2.4mg/ml), as well as precision and accuracy. Nitrophenylpyridine (NINIF) was synthesized from the NIF. These degradation products were characterized by NMR and mass spectroscopy. In addition, a breakdown product of NO-NIF due to its contact with plasma was identified and characterized. / Um método simples, rápido e preciso por cromatografia líquida de alta eficiência (HPLC-DAD) foi desenvolvido para determinação de nifedipino (NIF) na presença de seus produtos de degradação em amostras de plasma. A separação cromatográfica foi realizada em coluna C18 empregando H3PO4 0,01%:CH3CN:CH3OH (60:20:20 v/v/v) como fase móvel e vazão de 1,0mL/min. A validação procedeu-se segundo as recomendações dos guias editados pela ANVISA, EMA e FDA e apresentou linearidade no intervalo de 100,0 a 2000,0ng/mL com precisão (1,9 a 11,3%) e exatidão 86,0 a 113,1%) adequadas. Nas condições avaliadas, as amostras de NIF mostraram-se estáveis tanto em plasma como após processamento e ciclos de congelamento e descongelamento. A eficiência do método de extração líquido-líquido demonstrou recuperação média de 101,3 ± 5,4%. Após a etapa de validação, o método foi aplicado em estudos farmacocinéticos para avaliação da influência do nitrosofenilpiridino (NO-NIF) na farmacocinética do NIF. Este método também foi validado para o controle de qualidade do NO-NIF obtido após fotodegradação do NIF em câmara de fotoestabilidade e apresentou seletividade, linearidade (0,4 a 2,4μg/mL), assim como precisão e exatidão. Além da obtenção do NO-NIF por fotodegradação, nitrofenilpiridino (NI-NIF) foi sintetizado a partir do NIF. Esses produtos de degradação foram caracterizados por RMN e espectrometria de massas. Além disso, um produto de degradação do NO-NIF decorrente do seu contato com plasma foi identificado e caracterizado.

Submitted by Jaqueline Silva (jtas29@gmail.com) on 2014-11-07T17:14:00Z No. of bitstreams: 2 Dissertacao - Luciano Alberto de Castro - 2006.pdf: 817678 bytes, checksum: e83324d3753e3c2449197b0379e4981a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-11-07T17:14:21Z (GMT) No. of bitstreams: 2 Dissertacao - Luciano Alberto de Castro - 2006.pdf: 817678 bytes, checksum: e83324d3753e3c2449197b0379e4981a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-11-07T17:14:21Z (GMT). No. of bitstreams: 2 Dissertacao - Luciano Alberto de Castro - 2006.pdf: 817678 bytes, checksum: e83324d3753e3c2449197b0379e4981a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2006-02-28 / Drug induced gingival overgrowth (DIGO) is an adverse effect associated with the chronic use of three main drugs: phenytoin, an anticonvulsant, cyclosporin, an immunosuppressant drug and the pharmacological agents known as calcium channel blockers (CCB). Nifedipine is a calcium channel blocker, which because of its strong vessel dilating action has become widely used in cardiotherapy, in particular for the control of arterial hypertension. The aim of this study is to evaluate the microscopic characteristics and the epithelial proliferation index of gingival tissue in patients undergoing chronic treatment with nifedipine. To do so, twenty samples of gingival tissue of patients undergoing chronic treatment with nifedipine were obtained. The majority of these patients did not present clinically detectable gingival overgrowth. For comparative purposes, nine samples of gingival tissues of healthy patients who did not use drugs associated with gingival overgrowth (control) were used. The samples were microscopically analyzed using hematoxylin-eosin staining, to determine the size of the epithelial rete pegs. To carry out the epithelial proliferation index evaluation, a cellular identification of the Ki-67 and B1 Cyclin proteins was done using the immunohistochemical technique (streptavidin-biotin-peroxidase), as well as the quantification of positive cells (+cells) in mm².The results showed that the epithelial tissue of nifedipine users has considerably longer rete pegs that of the control group (Mann-Whitney, p=0.02). However, with regard to the proliferating activity of the keratinocytes, no significant difference was observed between the two groups (Mann-Whitney, p>0.05). The findings show that the microscopic alterations observed in the epithelium of nifedipine users are not caused by the mitotic activity of the keratinocytes but taking data from the literature into consideration, it is suggested that this increase might be caused by an inhibition of apoptosis rate of these same cells. / O crescimento gengival induzido por drogas (CGID) é um efeito adverso associado ao uso crônico de três medicamentos principais: a fenitoína, um anticonvulsivante, a ciclosporina, uma droga imunossupressora e os agentes farmacológicos conhecidos como bloqueadores dos canais de cálcio (BCC). A nifedipina é um bloqueador dos canais de cálcio que, por sua potente ação vasodilatadora, tornou-se uma droga largamente utilizada em cardioterapia, especialmente, para controle da hipertensão arterial. O presente trabalho teve como objetivo avaliar as características microscópicas e o índice proliferativo epitelial do tecido gengival de pacientes sob terapia crônica com nifedipina. Para este fim, foram obtidas vinte amostras de tecido gengival de usuários crônicos de nifedipina, sendo que, a maioria dos pacientes não apresentava CG clinicamente detectável. Para fins comparativos, foram utilizadas nove amostras de tecido gengival de pacientes saudáveis e não usuários de drogas indutoras de CG (controle). As amostras foram avaliadas microscopicamente, por meio da coloração de hematoxilina-eosina, quanto ao tamanho das cristas epiteliais. Para a avaliação do índice proliferativo epitelial, foi realizada a identificação celular das proteínas Ki-67 e Ciclina B1 pela técnica da imunoistoquímica (streptavidina-biotina-peroxidase), bem como a quantificação das células positivas (células +) por mm2. Os resultados revelaram que os pacientes usuários de nifedipina exibiram um tecido epitelial com cristas significativamente mais longas do que os pacientes do grupo controle (Mann-Whitney, p=0,02). No entanto, quanto à atividade proliferativa dos queratinócitos, não pôde ser observada diferença significante entre os dois grupos (Mann-Whitney, p>0,05). Os achados revelaram que as alterações microscópicas observadas no epitélio de pacientes usuários de nifedipina não ocorreram por aumento da atividade mitótica dos queratinócitos, mas considerando dados da literatura, sugere-se que este aumento possa ocorrer devido a uma inibição da taxa de apoptose destas células.