Regulation of K+ transport in the rat distal colon via angiotensin II subtype receptors and K+ -pathways.
Acta Physiol Scand
; 171(2): 145-51, 2001 Feb.
Article
em En
| MEDLINE
| ID: mdl-11350274
ABSTRACT
The role of angiotensin subtype-1 (AT1) and -2 (AT2) receptors in mediating the effects of angiotensin II (ANG II) on several K+ transporters was studied in rat distal colon using an Ussing chamber. Angiotensin II induced K+ secretion at two different doses. Secretion occurred at 10-(8) and 10-(4) M, as a result of an increase in serosal-to-mucosal flux (Js-m). The ANG II-induced stimulation of Js-m at a low dose (10-(8) M) was abolished by PD123319 while losartan did not alter the low-dose ANG II-dependent increase in Js-m. In contrast, the increase in Js-m induced by a high-dose of ANG II (10-(4) M) was blocked by losartan, whereas PD123319 partially reduced the stimulatory effect. In the presence of both blockers, high-dose ANG II induced an inhibition of basal Js-m. Low-dose ANG II activated the barium-sensitive K+ channels, whereas the Na+, K+, 2Cl- cotransporter and the Na+, K+ -ATPase pump were unchanged. At the high dose, ANG II activated the barium-sensitive K+ channels and the Na+, K+, 2Cl- cotransporter and inhibited the Na+, K+ -ATPase pump. These data indicate that ANG II stimulates serosal-to-mucosal K+ flux in the rat distal colon at high and low doses via different receptors and K+ transporters.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potássio
/
Angiotensina II
/
Receptores de Angiotensina
/
Colo
Limite:
Animals
Idioma:
En
Revista:
Acta Physiol Scand
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Suécia