Effect of the time of theophylline administration on the intensity of diuresis and natriuresis in the rat
Cambar, J.; Toussaint, C.; Lemoigne, F.
Comptes Rendus des Seances de la Societe de Biologie et de ses Filiales 173(5): 898-903
1979
ISSN/ISBN: 0037-9026 PMID: 161185 Document Number: 144947
The present study originates in two experimental data: circadian variations evidence of water, electrolytes and solutes urinary excretion and theophylline diuretic and salidiuretic effects knowledge; we purpose to evidence theophylline-induced water and sodium renal excretion in rats as modified by the time of drug administration. Theophylline single dose is injected in 100 animals (20 lots of 5 rats) at 8 h, 14 h, 20 h or 2 h and urines are collected during a consecutive to injection hours long period: 8 h-14 h (I), 14 h-20 h (II), 20 h-2 h (III) or 2 h-8 h (IV). Diuresis increases in + 40,4 p. cent (I), in + 123,7 p. cent (II), in + 123,3 p. cent (III) in + 65,4 p. cent (IV). So, natriuresis increases in 39,6 p. cent (I), in 223,2 p. cent (II), in 114,3 p cent (III) and in 109,6 p. cent (IV). These results evidence that theophylline diuretic and natriuretic effects change strongly with injection time, being largest if it is injected at 14 h and slightest if injected at 8 h. Such observations prompt to study if the other pharmacological properties of theophylline, especially at pulmonary level, response also with a time-dependant intensity.