Effects of atrial natriuretic factor on maternal ovine vascular resistance.
J Dev Physiol
; 11(1): 25-8, 1989 Jan.
Article
en En
| MEDLINE
| ID: mdl-2529307
Atrial natriuretic factor (ANF) is a potent endogenous vaso-dilator and diuretic peptide of uncertain physiologic relevance. In this study, the effects of ANF on normal and angiotensin II constricted placental, uterine and renal vessels were examined in pregnant sheep. Ewes were equipped with catheters to monitor vascular pressures, infuse drugs and measure blood flow by the microsphere technique. An electromagnetic flow sensor was placed around the middle uterine artery and electromyogram electrodes were attached to the uterus. ANF was administered into a branch of the uterine artery to minimize its systemic effects. The experiment included two protocols. First, blood flows and pressures were measured after a 5-min period of saline infusion into the uterine artery. These measurements were repeated at the end of a 5-min infusion of ANF (6.25 micrograms.min-1) into the uterine artery. During the second protocol, angiotensin II (AII) was infused via the jugular vein at 5 micrograms.min-1 for 10 min and ANF (6.25 micrograms.min-1) was infused through the uterine artery during the second half of the AII infusion. In the absence of AII, ANF lowered blood pressure from 97 +/- 6 to 90 +/- 6 mmHg (P less than 0.05); and placental resistance from 67.8 +/- 11.3 to 57.3 +/- 10.4 mmHg.min.ml-1 per g (P less than 0.01). Uterine resistance did not change.(ABSTRACT TRUNCATED AT 250 WORDS)
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Placenta
/
Útero
/
Resistencia Vascular
/
Vasodilatación
/
Preñez
/
Factor Natriurético Atrial
/
Riñón
Límite:
Animals
/
Pregnancy
Idioma:
En
Revista:
J Dev Physiol
Año:
1989
Tipo del documento:
Article
Pais de publicación:
Reino Unido