RESUMO
Using the patch-clamp method in the whole cell configuration, it was shown that external potassium ions play an important role in the regulation of calcium-activated chloride channels (CaCCs). A clear dependence of the conductivity of the СаССs on the external potassium concentration was shown. The effect of external potassium in the range 0-15 mM on the conductivity of chloride channels was significantly greater than the effect it had on other ionic currents (sodium or potassium). There is reason to believe that these changes in the conductivity of CaCCs may contribute to the development of pathophysiological processes such as hypokalemia or hyperkalemia.
Assuntos
Canais de CloretoRESUMO
The photostability of Lacidipine, a dihydropyridine drug used in the treatment of mild and moderate hypertension, was studied in solutions exposed to UV-A radiations. The effects of the solvent (ethanol, acetone, dichloromethane), drug concentration and radiation wavelength on the drug photostability were evaluated. Lacidipine and its photoproducts were separated by a selective liquid chromatographic (HPLC) method, under normal phase conditions (CN-column), using n-hexane:ethanol 97:3 (v/v) as mobile phase, at a flow rate of 2.0 ml/min. The main photodegradation products were isolated and characterised and a photodegradation pathway was proposed for Lacidipine in solution. The cis-isomer and a photocyclic isomer proved to be the main photodegradation products.
Assuntos
Bloqueadores dos Canais de Cálcio/efeitos da radiação , Di-Hidropiridinas/efeitos da radiação , Raios Ultravioleta , Bloqueadores dos Canais de Cálcio/análise , Bloqueadores dos Canais de Cálcio/química , Di-Hidropiridinas/análise , Di-Hidropiridinas/química , Estabilidade de Medicamentos , Soluções Farmacêuticas/química , Soluções Farmacêuticas/efeitos da radiação , Fotoquímica , Raios Ultravioleta/efeitos adversosRESUMO
Mannans were isolated from six Candida strains and characterized. 13C-NMR spectroscopy revealed interspecific and interstrain difference of the yeasts in the structure of their mannans.
