Korean J Physiol Pharmacol.
2000 Feb;4(1):55-61.
Effects of norepinephrine and neuropeptide Y on the contractility of
small mesenteric artery from 2K1C and DOCA-salt hypertensive rats
- Affiliations
-
- 1Department of Physiology, Chonnam University Medical School, 5
Hak-Dong, Dong-Gu, Kwangju, South Korea.
Abstract
- The present study was conducted to investigate the possible role of the
sympathetic nervous system in two-kidney, one clip (2K1C) and
deoxycorticosterone acetate (DOCA)-salt hypertension. 2K1C and
DOCA-salt hypertension were made in Sprague-Dawley rats. Four weeks
after induction of hypertension, systolic blood pressure measured in
conscious state was significantly higher in 2K1C (216+/-18 mmHg) and
DOCA-salt (205+/-29 mmHg) groups than that in control (128+/-4 mmHg). The
third branches (<300 micrometer in outer diameter) of the mesenteric artery
were isolated and cut into ring segments of 2apprx3 mm in length. Each
ring segment was mounted in tissue bath and connected to a force
displacement transducer for measurement of isometric tension. The
arterial rings were contracted by application of norepinephrine (NE) in
a dose-dependent manner. The amplitude of the NE-induced contraction of
the vessels was significantly larger in hypertension than in control.
The NE-induced contraction was significantly enhanced by neuropeptide Y
(NPY) in hypertension. Reciprocally, NPY-elicited vasocontraction was
increased by NE in hypertension. These results suggest that the
sympathetic nervous system contributes to the development of 2K1C and
DOCA-salt hypertension.