In this study, we demonstrate the in vivo labeling by [3H]nitrendipine ([3H]NTD) of peripheral tissues and the brain in Sprague-Dawley rats. Specific binding is decreased in a dose-dependent manner by nifedipine, with a mean inhibitory dose of 2-10 mg/kg (i.p.). Thin-layer chromatography of the particulate-bound radioactivity reveals that the predominant tritiated drug bound in the left ventricle and the cerebral cortex is [3H]NTD, whereas metabolites constitute the main species in the liver. Peak radioactivity is seen at 15 min following an intravenous injection of [3H]NTD. Highly perfused tissues such as the heart, brain, and lung have significant [3H]NTD binding. In contrast to previously reported in vitro studies, [3H]NTD binding is low in the aorta, skeletal muscle, and ileum. This in vivo animal model is suitable for pharmacokinetic and physiological studies of the calcium channel in intact animals.
|Original language||English (US)|
|Number of pages||12|
|Journal||Advances in myocardiology|
|State||Published - Jan 1 1985|
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