[Effect of the time of theophylline administration on the intensity of diuresis and natriuresis in the rat].
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.
D000818:Animals; D002940:Circadian Rhythm; D004231:Diuresis / Q000187:drug effects*; D007678:Kidney Glomerulus / Q000502:physiology; D007687:Kidney Tubules, Proximal / Q000502:physiology; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D051381:Rats; D013806:Theophylline / Q000008:administration & dosage* / Q000494:pharmacology; D013997:Time Factors
D013806:Theophylline
Influence de l'heure d'administration de la théophylline sur l'intensité de la diur èse et de la natriurèse chez le rat.