SENSITIVITY AND REACTIVITY TO ENDOTHELIN-1 IN MESENTERIC BEDS AND AORTIC RINGS OF 4-WEEK-OLD SPONTANEOUSLY HYPERTENSIVE RATS

被引:7
作者
CRISCIONE, L
THOMANN, H
LUU, TD
机构
[1] Cardiovascular Research Department, Pharmaceuticals Division, CIBA-GEIGY Ltd
关键词
ENDOTHELIN; HYPERTENSION; MESENTERIC ARTERY; VASCULAR REACTIVITY; AGE; SPONTANEOUSLY HYPERTENSIVE RATS; WISTAR KYOTO RATS;
D O I
10.3109/10641969209036200
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
The vasconstrictor effects of endothelin-1 were studied in perfused mesenteric vascular beds (MVB) and aortic rings of 4-week-old spontaneously hypertensive rats (SHR) and age-matched Wistar Kyoto rats (WKY). Mean blood pressure (124 +/- 4 vs. 97 +/- 3 mmHg) and initial perfusion pressure in the MVBs (25 +/- 2 vs. 19.7 +/- 1.2) were significantly higher in SHR. Reactivity to endothelin-1 was increased in MVBs of SHR, as indicated by the maximum perfusion pressure obtained (223 +/- 8 vs 155 +/- 7 mmHg, p < 0.001), whereas there was no significant difference in sensitivity between the two strains (EC50 values: 50 +/- 12 and 80 +/- 15 pmol, respectively). By contrast, in aortic rings respectivity and sensitivity to endothelin-1 were similar in both strains. (EC50S: 1.8 +/- 0.12 and 1.4 +/- 0.1 nM). Reactivity to norepinephrine was increased in MVBs, but reduced in aortic rings of SHR. The unchanged sensitivity to endothelin-1 and the unspecificially increased reactivity in the MVBs of SHR to endothelin-1 and norepinephrine indicate rather a change in vascular structure and not a functional abnormality. These results suggest that hyperreactivity to endothelin-1 may not be a primary hypertensive mechanism in genetic hypertension.
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页码:453 / 467
页数:15
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