Alpha2-adrenoceptor control of ion and water transport in the newt renal distal tubule

Title:

Alpha2-adrenoceptor control of ion and water transport in the newt renal distal tubule

Creator:

Goncharevskaya, O. A. and Monin, Yu. G.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:21bddda9-c6b5-4868-927b-7c7995661b6d
uuid:21bddda9-c6b5-4868-927b-7c7995661b6d

Subject:

norepinephrine, dibenamine, propranolol, idazoxan, prazosin, distal tubule, and electrolytes

Type:

article, model:article, and TEXT

Description:

To study the nature of adrenergic stimulation of ions and water reabsorption in the newt renal distal tubule, stationary microperfusion of the nephron and electron probe analysis were used. After application of norepinephrine (NE 10'6 M) to the tubule surface, the fractional reabsorption of fluid increased from 15.0±3.1 to 41.30±10.4 % (n = 7, p<0.01), of Na+ from 69.30 ±6.6 to 79.10±7.5 % (p<0.05), CT from 63.30±7.6 to 72.40 ±7.9 % (p<0.05). Instead of secretion (control), there was reabsorption of K+. Fractional reabsorption of Ca2+ decreased from 51.00±6.0 to 43.00±7.0 % (p<0.05). The nonspecific alpha-adrenergic antagonist dibenamine 10"6 M completely inhibited the effect of NE while, under the action of propranolol (2xl(76 M) NE increased ion and water reabsorption significantly. When applied alone, or with NE, the specific alpha2-adrenoblocker idazoxan, 2xl0‘6 M, did not interfere with reabsorption in the distal tubule. At the same time, under the action of alphai-adrenoblocker prazosin 2xl0'6 M NE, increased the fractional reabsorption of fluid from 24.10 ±3.4 to 44.40 ±4.0 % (n = 6, p<0.001). These results serve as evidence that there exist specific alpha^adrenoceptors in the newt distal tubule the stimulation of which increases membrane permeability of the distal tubule to water, Na+, K+, Cl', but not to Ca2+.

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 1992 Volume:41 | Number:3

Harvested from:

CDK

Metadata only:

false