Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/70914
Type: Artigo de periódico
Title: RENAL WATER HANDLING EVALUATED BY LITHIUM CLEARANCE FOLLOWING ADRENERGIC AND CHOLINERGIC STIMULATION OF THE LATERAL HYPOTHALAMIC AREA
Author: GONTIJO, JAR
GARCIA, WE
FIGUEIREDO, JF
SILVANETTO, CR
FURTADO, MRF
Abstract: Male Wistar rats weighing 230-300 g were used to characterize the participation of adrenergic and cholinergic receptors of the lateral hypothalamic area (LHA) in the control of renal water excretion. Since stimulation of adrenergic or cholinergic receptors has no effect on glomerular filtration rate, the antidiuresis and significant delay in urinary flow observed after lateral hypothalamic stimulation with carbachol (CCh) (0.036 +/- 0.005 to 0.019 +/- 0.003-mu-l min-1 100 g body weight-1) and noradrenaline (Nad) (0.024 +/- 0.005 to 0.025 +/- 0.004-mu-l min-1 100 g body weight-1) are secondary to an increase in distal tubular fluid reabsorption (DFR). Data are reported as means +/- SEM for ten rats in each group. Tubular water handling measured by lithium clearance demonstrated that LHA stimulation with CCh (2.8 nmol in 1-mu-l) and Nad (30.0 nmol in 1-mu-l) leads to a significant reduction in proximal water reabsorption (CCh, 93.3 +/- 2.6 to 85.4 +/- 1.4%; Nad, 92.7 +/- 0.9 to 88.6 +/- 1.3%), with a simultaneous and significant increase in fluid reabsorption along the post-proximal nephron segments when compared to control (CNa)(CCh, 6.7 +/- 0.7 to 14.5 +/- 1.1%; Nad, 8.2 +/- 0.8 to 11.4 +/- 1.6%). These effects are blocked by muscarinic (atropine, 5 nmol in 1-mu-l) and alpha-1 adrenoceptors (prazosin, 4 nmol in 1-mu-l) antagonists. The results indicate the effective participation of the post-proximal nephron in the antidiuresis occurring after cholinergic and adrenergic LHA stimulation.
Subject: RENAL WATER HANDLING
LITHIUM CLEARANCE
LATERAL HYPOTHALAMIC AREA
CHOLINERGIC SYSTEM
ADRENERGIC SYSTEM
Country: Brasil
Editor: Assoc Bras Divulg Cientifica
Rights: aberto
Date Issue: 1991
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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