Cytotoxic effects of local anesthesia through lidocaine/ropivacaine on human melanoma cell lines / Efeitos citotóxicos de anestesia local com lidocaína/ropivacaína em linhagens celulares de melanoma humano

Abstract Background: Local anesthetics (LAs) are generally considered as safe, but cytotoxicity has been reported for several local anesthetics used in humans, which is not well investigated. In the present study, the cytotoxicity of lidocaine, ropivacaine and the combination of lidocaine and ropivacaine were evaluated on human melanoma cell lines. Melphalan, a nitrogen mustard alkylating agent, was used as a control agent for comparison of cytotoxic activity. Methods: Melanoma cell lines, A375 and Hs294T, were exposed to 1 h to different concentrations of above agents. Cell-viability after exposure was determined by flow cytometry. Results: Investigated LAs showed detrimental cytotoxicity on studied melanoma cell lines in time- (p < 0.001), concentration- (p < 0.001), and agent dependant. In both A375 and Hs294T cell lines, minimum cell viability rates were found after 72 h of exposure to these agents. Lidocaine 2% caused a reduction of vital cells to 10% ± 2% and 14% ± 2% in A375 and Hs294T, respectively after 72 h of exposure. Ropivacaine 0.75% after 72 h reduced viable cells to 15% ± 3% and 25% ± 3% in A375 and Hs294T, respectively. Minimum cell viability after 72 h exposure to the combination was 10% ± 2% and 18% ± 2% in A375 and Hs294T, respectively. Minimum cell viability after 72 h exposure to melphalan was 8% ± 1% and 12% ± 2%, in A375 and Hs294T, respectively. Conclusion: LAs have cytotoxic activity on human melanoma cell lines in a time-, concentration- and agent-dependant manner. Apoptosis in the cell lines was mediated through activity of caspases-3 and caspases-8.

Resumo Justificativa: Os anestésicos locais (ALs) são geralmente considerados como seguros, mas citotoxicidade foi relatada em vários anestésicos locais usados em seres humanos, a qual não é bem investigada. No presente estudo, a citotoxicidade de lidocaína e ropivacaína e da combinação de lidocaína e ropivacaína foi avaliada em linhagens celulares de melanoma humano. Melfalano, um agente alquilante de mostarda nitrogenada, foi usado como um agente de controle para a comparação da atividade citotóxica. Métodos: Linhagens celulares de melanoma, A375 e Hs294T foram expostas por uma hora a concentrações diferentes dos agentes mencionados acima. A viabilidade celular após a exposição foi determinada por citometria de fluxo. Resultados: Os ALs investigados mostraram citotoxicidade prejudicial nas linhagens celulares de melanoma estudadas dependente do tempo (p < 0,001), da concentração (p < 0,001) e do agente. Em ambas as linhagens de células A375 e Hs294T, níveis mínimos de viabilidade celular foram encontrados após 72 horas de exposição a esses agentes. Lidocaína a 2% provocou uma redução das células vitais para 10% ± 2% e 14% ± 2% em A375 e Hs294T, respectivamente, após 72 horas de exposição. Ropivacaína a 0,75% após 72 horas reduziu as células viáveis para 15% ± 3% e 25% ± 3%, em A375 e Hs294T, respectivamente. A viabilidade celular mínima após exposição de 72 horas para a combinação foi de 10% ± 2% e 18% ± 2% em A375 e Hs294T, respectivamente. A viabilidade celular mínima após exposição de 72 horas ao melfalano foi de 8% ± 1% e 12 ± 2, em A375 e Hs294T, respectivamente. Conclusão: Os ALs têm atividade citotóxica em linhagens de celulares de melanoma humano de modo dependente do tempo, da concentração e do agente. A apoptose nas linhagens celulares foi mediada por meio da atividade das caspases-3 e caspases-8.

Effect of hypokalemia on glucose metabolism in primary hyperaldosteronism / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the effect of potassium deficiency on glucose and insulin metabolism in primary hyperaldosteronism, including aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA).</p><p><b>METHODS</b>Totally 178 patients who were diagnosed as primary hyperaldosteronism (103 patients with APA and 75 with IHA) were divided into hypokalemia group and normal potassium group according to their serum potassium levels. All patients received 3 hours of oral glucose tolerance test and aldosterone test to observe the relationship among glucose, insulin and serum potassium.</p><p><b>RESULTS</b>Area under curve of serum potassium, area under curve of plasma insulin, and fasting serum insulin were significantly lower in the hypokalemia group than in the normal potassium group (P <0. 05, P <0. 01); area under curve of glucose and aldosterone level were significantly higher in the hypokalemia group than in the normal potassium group ( P < 0. 05 ) . The prevalence of metabolic syndrome was significantly higher in IHA than in APA (57. 3% vs 38. 8% ; P < 0. 05).</p><p><b>CONCLUSION</b>Hypokalemia may play an important role in inhibiting insulin secretion in primary hyperaldosteronism.</p>

Expression of renin-angiotensin-aldosterone system in human adipose tissues / 中国医学科学院学报

<p><b>OBJECTIVE</b>To compare the mRNA expression of renin-angiotensin-aldosterone system in human subcutaneous and visceral adipose tissues.</p><p><b>METHODS</b>Total RNA was extracted from 12 human subcutaneous adipose tissues, 12 perirenal adipose tissue and 9 periadrenal adipose tissues. The expressions of angiotensinogen ( AGT) , renin, angiotensin converting enzyme ( ACE) , angiotensin converting enzyme 2 (ACE2), angiotensin I1 receptor type 1 (AT1), angiotensin II receptor type 2 (AT2 ), CYP11 B2, and their internal reference glyceraldehyde phosphate (GAPDH) were studied by reverse transcription-polymerase chain reaction. The ratios of each target genes were used to evaluate the expression levels of AGT, renin, ACE, ACE2, AT1, AT2, and CYP11B2 in different adipose tissues.</p><p><b>RESULTS</b>The mRNA expressions of AGT, ACE, ACE2, AT1, and AT2 were detected in human subcutaneous, perirenal, and periadrenal adipose tissues. However, CYPI B2 mRNA expression was not found in these three adipose tissues. The mRNA expressions of renin was only detected in perirenal and periadrenal adipose tissues, which was significantly higher in perirenal adipose tissues than in periadrenal adipose tissues ( P < 0. 05 ). The mRNA expressions of ACE and ACE2 in perirenal adipose tissues were significantly higher than that in subcutaneous adipose tissues ( P < 0. 05). The mRNA expressions of ACE were significantly higher than that of ACE2 in subcutaneous, perirenal, and periadrenal adipose tissues (P <0. 05). The mRNA expressions of AT1 were significantly lower than that of AT2 in periadrenal adipose tissues (P < 0. 05).</p><p><b>CONCLUSION</b>Local renin-angiotensin system exists in the adipose tissues; however, aldosterone is not synthesized in the adipose tissues.</p>