Effect of nitrendipine on urine volume, osmolality, and electrolyte excretion in normal, adrenal-enucleate, and mononephrectomized rats.
Female Sprague-Dawley rats were sham operated, adrenal-enucleated, or mononephrectomized. Half of each group received 30 mg/kg of nitrendipine; the remainder were given equal volumes of vehicle, and all rats were then injected i.p. with 40 ml/kg of 0.9% NaCl solution. Urine was collected over a 6-h period. Nitrendipine-treated intact rats excreted slightly more water and Na+ and less K+ than controls, but none of the differences were significant statistically. Adrenal-enucleate controls displayed oliguria and Na+ retention, but normal K+ excretion and reduced Na+/K+. Nitrendipine did not modify oliguria or antinatriuresis or affect Na+/K+. Mononephrectomized rats behave similarly, but in these nitrendipine abolished oliguria and improved Na+ excretion. The most characteristic nitrendipine effect in all three cases was a reduction in urine osmolality. This was particularly evident in adrenal-enucleated and mononephrectomized rats, in which control urine displayed a relative hyperosmolarity as compared with normal control values.
D000315:Adrenalectomy; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004231:Diuresis / Q000187:drug effects*; D004573:Electrolytes / Q000652:urine*; D005260:Female; D005919:Glomerular Filtration Rate; D007685:Kidney Tubules, Collecting / Q000187:drug effects; D009392:Nephrectomy; D009399:Nephrons / Q000378:metabolism; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D009568:Nitrendipine; D009994:Osmolar Concentration; D011188:Potassium / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000652:urine
D002121:Calcium Channel Blockers; D004573:Electrolytes; D009568:Nitrendipine; D012964:Sodium; D009543:Nifedipine; D011188:Potassium