Enhanced generation of vascular thromboxane A2 in spontaneously hypertensive rats and its role in the rapid proliferation of vascular smooth muscle cells.
We examined vascular thromboxane A2 (TXA2) generation and its relation to a proliferation of vascular smooth muscle cells (VSMCs) in spontaneously hypertensive rats (SHRs). Aortic TXA2 release was significantly enhanced in 5-week-old SHRs, as compared with Wistar-Kyoto strain rats (WKY). The cultured VSMCs of SHRs exhibited a shorter doubling time and a greater [3H]thymidine uptake than those of WKY rats. OKY 046 a thromboxane synthetase inhibitor, tempered proliferation of VSMCs in SHRs, but not in WKY rats. STA2, a stable analog of TXA2, stimulated VSMC growth in WKY rats more than in SHRs. It is indicated that vascular TXA2 generation is enhanced, and partially participates in the rapid proliferation of VSMCs in SHRs.
Ishimitsu
T
T
Second Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
Uehara
Y
Y
Ishii
M
M
Sugimoto
T
T
D000818:Animals; D001808:Blood Vessels / Q000378:metabolism*; D002455:Cell Division; D006973:Hypertension / Q000378:metabolism* / Q000473:pathology; D066298:In Vitro Techniques; D008689:Methacrylates / Q000494:pharmacology; D009131:Muscle, Smooth, Vascular / Q000473:pathology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013928:Thromboxane A2 / Q000031:analogs & derivatives / Q000096:biosynthesis* / Q000494:pharmacology / Q000502:physiology; D013930:Thromboxane-A Synthase / Q000037:antagonists & inhibitors
D008689:Methacrylates; D013928:Thromboxane A2; C037866:STA 2; D013930:Thromboxane-A Synthase; C034364:ozagrel