AJP - Heart and Circulatory Physiology, Vol 265, Issue 6 1864-H1868, Copyright © 1993 by American Physiological Society

ARTICLES

Inhibitory role of capsaicin-sensitive afferent neurons and nitric oxide in hemostasis

I. T. Lippe, W. Sametz, K. Sabin and P. Holzer
Department of Experimental and Clinical Pharmacology, University of Graz, Austria.

Capsaicin-sensitive afferent neurons control blood flow via release of peptide transmitters and formation of nitric oxide (NO). The present study examined whether capsaicin-sensitive afferent neurons and NO interact in the control of hemostasis. Afferent nerve ablation by pretreating rats with a neurotoxic dose of capsaicin (125 mg/kg) led to a 26% reduction of the time of bleeding from punctured small mesenteric arteries in pentobarbital-anesthetized animals. Blockade of NO formation by NG-nitro-L-arginine methyl ester (L-NAME; 10 mg/kg) attenuated the bleeding time in capsaicin-pretreated rats but had no effect in vehicle-pretreated rats. Platelet aggregation induced by ADP was significantly augmented by 12% in capsaicin-pretreated rats. L-NAME did not alter platelet aggregation in vehicle-pretreated rats but enhanced it in capsaicin-pretreated animals. The prothrombin and partial thromboplastin time and the plasma levels of fibrinogen and antithrombin III remained unchanged by capsaicin or L-NAME, whereas the thrombin time was reduced in capsaicin-pretreated rats. These data indicate that capsaicin-sensitive afferent neurons play an inhibitory role in platelet aggregation and hemostasis, a function in which they interact with the NO system.

This article has been cited by other articles:

				N. Harada, K. Okajima, M. Uchiba, and T. Katsuragi Contribution of capsaicin-sensitive sensory neurons to stress-induced increases in gastric tissue levels of prostaglandins in rats Am J Physiol Gastrointest Liver Physiol, December 1, 2003; 285(6): G1214 - G1224. [Abstract] [Full Text] [PDF]