ISSN:
1573-2568
Keywords:
clonidine
;
α-adrenergic receptors
;
sympathetic nervous system
;
central nervous system
;
water absorptionin vivo
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract This study examined the role of central adrenergic receptors in the regulation of water absorption by the rat ileum. Clonidine, an α2 -adrenergic receptor agonist, increased water absorptionin vivo following intracerebroventricular but not intravenous injection. Intracerebroventricular injection of prazosin, an α1 -adrenergic receptor antagonist, did not alter basal water absorption. Prazosin did not prevent the clonidine effect. In contrast, the α2 -adrenergic receptor antagonist, yohimbine, reduced basal absorption and prevented the intracerebroventricular clonidine effect. Treatment with reserpine reduced ileal norepinephrine content by 98%, reduced basal water absorption consistent with a loss of sympathetic outflow to the mucosa, but did not prevent the increase in water absorption due to intracerebroventricular clonidine. These results suggest that central α2 receptors regulate water absorption by the rat ileum. The clonidine-induced increase in water absorption is not mediated by the sympathetic nerves innervating the intestine.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01540177
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