[Effects of short-term treatment with trandolapril on vasodilatator responses mediated by receptors or on blood flow in the coronary arteries in SHR].
The aim of the study was to assess the effects of a one-month treatment period with the ACE inhibitor trandolapril (0.3 mg/kg/day) on the endothelial reactivity in epicardial right coronary arteries (CA) of 26-30 week-old SHRs. For this purpose, segments of CA were mounted in an arteriograph where wall thickness and internal diameter (ID) were continuously monitored while intraluminal pressure (IP) was controlled. In the absence of flow and under an IP of 30 mmHg, IDs were not significantly different in control compared to those of treated SHR arteries (microns, 250 +/- 8 vs 240 +/- 7). In preconstricted preparations (5HT, 10 microns extraluminally) C/E curves were constructed by adding acetylcholine (AC, 0.01-10 microM) or bradykinin (BK, 0.01-10 microM) in the bath. On the other hand, the effect of a stepwise increase in intraluminal flow (50-450 microliters/min; IP = 30 mmHg) of perfusion solution was observed. The effects of subsequent additions of sodium nitroprusside (SNP) were assessed. Maximal relaxations were expressed as percent of maximal contractions. Results were as follows: [table: see text] These results show that the endothelium-dependent relaxation induced by AC and BK were significantly increased in coronary arteries of treated compared to control SHRs whereas the flow-induced relaxation seemed to remain unaffected in our experimental conditions. From these data, it can be concluded that a short period of ACE inhibition in SHRs is able to improve the endothelium-dependent vasodilation induced by agonists in the coronary arterial bed.
Pourageaud
F
F
Laboratoire de pharmacodynamie, faculté de pharmacie, université de Bordeaux II.
Freslon
J L
JL
D000109:Acetylcholine / Q000494:pharmacology; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use; D003331:Coronary Vessels / Q000187:drug effects* / Q000503:physiopathology; D004334:Drug Administration Schedule; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000473:pathology; D006439:Hemodynamics / Q000187:drug effects*; D006973:Hypertension / Q000188:drug therapy* / Q000503:physiopathology; D007211:Indoles / Q000494:pharmacology* / Q000627:therapeutic use; D051381:Rats; D011918:Rats, Inbred SHR; D014665:Vasodilator Agents / Q000627:therapeutic use
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D007211:Indoles; D014665:Vasodilator Agents; C052035:trandolapril; D000109:Acetylcholine
Effets d'un traitement court par le trandolapril sur les réponses vasodilatatrices médiées par des récepteurs ou le débit au niveau d'artères coronaires chez le SHR.