Renal effects of pinane-thromboxane A2 and indomethacin in saline volume-expanded spontaneously hypertensive rats.
In 6-week old spontaneously hypertensive rats (SHR), indomethacin (5 mg/kg i.v.) and pinane-thromboxane A2 (PTA2) (50 micrograms/kg per h i.v.) a thromboxane A2 (TXA2) antagonist as well as a TXA2 synthetase inhibitor, resulted in natriuresis accompanied by an increase in p-aminohippuric acid and inulin clearances. Indomethacin acted as an antidiuretic in 6 week Wistar-Kyoto rats (WKY). PTA2 did not alter renal functions in either 6 week WKY and 18 week SHR. Basal urinary excretion of TXB2 (UTXB2V) was greater in 6 week SHR than in 6 week WKY and 18 week SHR, and that of 6-keto-PGF1 alpha (U6-keto-PGF1 alpha V) did not differ among these strains. Thus, U6-keto-PGF1 alpha V/UTXB2V was lower in the 6 week SHR. Basal urinary excretion of PGE (UPGEV) was much greater in 18 week SHR than in the 2 other groups. In the 6 week SHR, PTA2 decreased UTXB2V and increased U6-keto-PGF1 alpha V without affecting UPGEV, and indomethacin reduced UTXB2V more markedly than did U6-keto-PGF1 alpha V and UPGEV. Thus, both PTA2 and indomethacin increased U6-keto-PGF1 alpha V/UTXB2V in the 6 week SHR. These findings indicate that a disequilibrium in the biosynthesis of vasoconstrictive TXA2 and of vasodilator PGI2 may be involved in water and sodium retention in SHR during the developmental phase of hypertension.
D000818:Animals; D000081008:Bicyclic Monoterpenes; D001794:Blood Pressure / Q000187:drug effects; D004008:Diclofenac / Q000494:pharmacology; D006973:Hypertension / Q000503:physiopathology*; D007213:Indomethacin / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects*; D008297:Male; D011188:Potassium / Q000652:urine; D011453:Prostaglandins / Q000652:urine; D051381:Rats; D011919:Rats, Inbred Strains; D012964:Sodium / Q000652:urine; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000494:pharmacology*; D013931:Thromboxanes / Q000494:pharmacology*
D000081008:Bicyclic Monoterpenes; D011453:Prostaglandins; D013931:Thromboxanes; D004008:Diclofenac; D013928:Thromboxane A2; C020465:pinane-thromboxane A2; D012964:Sodium; D011188:Potassium; D007213:Indomethacin