[Effect of captopril on platelet cytosolic [Ca2+]i and plasma TXA2/PGI2 in renovascular hypertensive rats].
OBJECTIVE
To study the effect of captopril (Cap) on platelet cytosolic free calcium concentration ([Ca2+]i), platelet aggregation (PAg), and plasma TXA2/PGI2 ratio in the renovascular hypertensive rats.


METHODS
Blood pressure was measured once a week by tail-cuff microphonic manometer. Platelet [Ca2+]i was measured by Fura 2-AM. Plasma angiotensin II (Ang), thromboxane A2 (TXA2), and prostacycline (PGI2) were measured by radioimmunoassay.


RESULTS
Platelet [Ca2+]i and PAg increased (P < 0.01), while plasma Ang and TXA2/PGI2 ratio elevated (P < 0.05) in the renovascular hypertensive rats; platelet [Ca2+]i and plasma TXA2/PGI2 ratio reduced markedly after i.g. Cap 100 mg.kg-1.d-1 compared with saline for 2 wk.


CONCLUSIONS
The altered TXA2/PGI2 after Cap treatment contributed to the improvement of the platelet [Ca2+]i and PAg.
Wei
X R
XR
Department of Cardiology, Zhujiang Hospital, Guangzhou, China.
Hu
L
L
Du
J
J
D000804:Angiotensin II / Q000097:blood; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D001792:Blood Platelets / Q000378:metabolism; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000097:blood*; D002216:Captopril / Q000494:pharmacology*; D011464:Epoprostenol / Q000097:blood*; D005260:Female; D006978:Hypertension, Renovascular / Q000097:blood*; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013928:Thromboxane A2 / Q000097:blood*
D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D000804:Angiotensin II; D013928:Thromboxane A2; D002216:Captopril; D011464:Epoprostenol; D002118:Calcium