Intrinsic tone and passive mechanics of isolated renal arteries from virgin and late-pregnant rats.
Am J Physiol
; 273(1 Pt 2): R22-7, 1997 Jul.
Article
em En
| MEDLINE
| ID: mdl-9249528
ABSTRACT
The purpose of this study was to investigate whether there are alterations in the intrinsic properties of renal interlobar arteries during pregnancy. Renal interlobar arteries (internal diameter approximately 250 microns) from virgin and late-pregnant rats were mounted in a pressurized arteriograph system. Intrinsic tone was quantified as the percent difference in luminal diameter of each artery in the presence of physiological saline solution and while pharmacologically relaxed with papaverine. At pressures between 75 and 125 mmHg, tone was 35-50% less in arteries from pregnant rats (P < 0.05). Endothelial removal reduced tone in arteries from virgin rats but had no effect on arteries from pregnant rats. Analysis of stress-strain curves (rate constants pregnant, 6.31 +/- 0.38; virgin, 7.81 +/- 0.78; P < 0.05) indicate that there is a decrease in arterial stiffness in gestation. Thus pregnancy is associated with a reduced intrinsic tone, possibly because of a reduction in an endothelial constrictor influence on the vascular smooth muscle in isolated rat renal interlobar arteries. This effect, coupled with the decreased arterial stiffness, demonstrates the significant arterial adaptation occurring during pregnancy.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Artéria Renal
/
Prenhez
/
Músculo Liso Vascular
/
Tono Muscular
Limite:
Animals
/
Pregnancy
Idioma:
En
Revista:
Am J Physiol
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Estados Unidos