Altered Calcium Current of the Vascular Smooth Muscle in Renal Hypertension .
- Author:
Sang Chae NAM
1
;
Hye Jeon JEONG
;
Wonjae KIM
;
JongUn LEE
Author Information
1. Department of Physiology, Chonnam University Medical School, 5 Hak-Dong, Dong-Gu, Kwangju, 501-190 South Korea.
- Publication Type:Original Article
- Keywords:
Two-kidney;
One clip hypertension;
Deoxycorticosterone acetate-salt hypertension;
Vascular smooth muscle;
Calcium current
- MeSH:
Animals;
Basilar Artery;
Blood Pressure;
Calcium Channels;
Calcium*;
Desoxycorticosterone;
Desoxycorticosterone Acetate;
Hypertension;
Hypertension, Renal*;
Microscopy;
Muscle, Smooth, Vascular*;
Rats;
Rats, Sprague-Dawley;
Renal Artery
- From:The Korean Journal of Physiology and Pharmacology
1999;3(3):351-356
- CountryRepublic of Korea
- Language:English
-
Abstract:
The present study was aimed at investigating whether the calcium current in the vascular smooth muscle (VSM) cells is altered in renal hypertension. Two-kidney, one clip (2K1C) and deoxycorticosterone acetate (DOCA)-salt hypertension were made in Sprague-Dawley rats. Rats without clipping the renal artery or implanting DOCA were used as control for 2K1C and DOCA-salt hypertension, respectively. Four weeks after clipping, systolic blood pressure was significantly higher in 2K1C rats than in control (192+/-24 and 119+/-4 mmHg, respectively, n=16 each). DOCA-salt rats also showed a higher blood pressure (180+/-15 mmHg, n=18) compared with control (121+/-6 mmHg, n=14). VSM cells were enzymatically and mechanically isolated from basilar arteries. Single relaxed VSM cells measured 5 ~ 10 mum in width and 70 ~ 150 mum in length were obtained. VSM cells could not be differentiated in size and shape between hypertensive and normotensive rats under light microscopy. High-threshold (L-type) calciumcurrents were recorded using whole-cell patch clamp technique. The amplitude of the current recorded from VSM cells was larger in 2K1C hypertension than in control. Neither the voltage-dependence of the calcium current nor the cell capacitance was significantly affected by 2K1C hypertension. By contrast, the amplitude of the calcium current was not altered in DOCA-salt hypertension. These results suggest that high-threshold calcium current of the VSM cells is altered in 2K1C hypertension, and that calcium channel may not be involved in calcium recruitment of VSM in DOCA-salt hypertension.
