EFFECT OF ENDOTHELIUM OF PULMONARY-ARTERY VASOREACTIVITY IN MONOCROTALINE-INDUCED PULMONARY HYPERTENSIVE RATS

Citation
K. Morita et al., EFFECT OF ENDOTHELIUM OF PULMONARY-ARTERY VASOREACTIVITY IN MONOCROTALINE-INDUCED PULMONARY HYPERTENSIVE RATS, Japanese Circulation Journal, 60(8), 1996, pp. 585-592
Citations number
24
Categorie Soggetti
Cardiac & Cardiovascular System
ISSN journal
00471828
Volume
60
Issue
8
Year of publication
1996
Pages
585 - 592
Database
ISI
SICI code
0047-1828(1996)60:8<585:EOEOPV>2.0.ZU;2-H
Abstract
This study investigated vasoreactivity modulated by endothelium in pul monary arteries from isolated monocrotaline (MCT)-induced pulmonary hy pertensive rats. The responses to KCl, 5-hydroxytryptamine (5-HT), ace tylcholine (ACh), and nitroglycerin (NTG) were studied in the pulmonar y artery with and without endothelium for 3 weeks following MCT-treatm ent. The sensitivity of the contractile response to KCl markedly incre ased in the arteries with endothelium at 2 and 3 weeks after treatment , but only slightly in the arteries without endothelium. In addition, the sensitivity of the contractile response to 5-HT peaked 2 weeks aft er treatment in the arteries with endothelium, but at 1 week in those without endothelium. Although the removal of endothelium shifted the c oncentration-response curve for KCl and 5-HT to the left both in the c ontrol state and at 1 week, it did not shift the curves at 2 or 3 week s. The relaxation responses to ACh and NTG, indicative of endothelium- dependent and -independent relaxation, respectively, as well as the co ntent of tissue cGMP were reduced 2 weeks after treatment. These resul ts suggest that the impairment of both the endothelium-dependent and - independent relaxation responses contributes to hyperreactivity of the pulmonary artery, and may in part contribute to the development of MC T-induced pulmonary hypertension.