Comparison of the responses to thrombin in monkey renal and uterine arteries.
OBJECTIVE
Thrombin is known to regulate vascular tone. We analyzed and compared mechanisms of thrombin action in primate renal and uterine arteries.


METHODS
Isolated Japanese monkey renal and uterine arteries were suspended in Ringer-Locke solution for tension recordings.


RESULTS
Renal arteries responded to thrombin with relaxation, which was inhibited by N(G)-nitro-L-arginine or indomethacin and reversed to contractions by the combination. The relaxations were also reversed to contractions by endothelial denudation. Conversely, thrombin caused uterine arterial contractions that were unaffected by endothelial denudation. Relaxations in both renal arteries and contractions in uterine arteries were suppressed by hirudin (a specific thrombin inhibitor). Relaxant responses to A23187 (Ca(2+) ionophore), nitroprusside sodium (nitric oxide donor), and beraprost sodium (prostacyclin analogue) did not differ between renal and uterine arteries.


CONCLUSIONS
Thrombin-induced relaxation of renal arteries appears to be mediated by nitric oxide and vasodilator prostaglandins liberated from the endothelium, whereas uterine arterial contraction is caused by an endothelium-independent mechanism.
Kimura
Toshio
T
Department of Obstetrics and Gynecology, Shiga University of Medical Science, Seta, Ohtsu 520-2192, Japan.
Ayajiki
Kazuhide
K
Noda
Yoichi
Y
Okamura
Tomio
T
D000818:Animals; D001158:Arteries / Q000187:drug effects / Q000502:physiology*; D000001:Calcimycin / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D011464:Epoprostenol / Q000031:analogs & derivatives* / Q000494:pharmacology; D005260:Female; D007213:Indomethacin / Q000494:pharmacology; D007537:Isometric Contraction / Q000187:drug effects / Q000502:physiology; D008251:Macaca; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D019335:Nitroarginine / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D009928:Organ Specificity; D012077:Renal Artery / Q000187:drug effects / Q000502:physiology*; D013917:Thrombin / Q000494:pharmacology*; D014599:Uterus / Q000098:blood supply*; D014665:Vasodilator Agents / Q000494:pharmacology
D014665:Vasodilator Agents; D009599:Nitroprusside; D019335:Nitroarginine; C048081:beraprost; D000001:Calcimycin; D011464:Epoprostenol; D013917:Thrombin; D007213:Indomethacin