AJP - Heart and Circulatory Physiology, Vol 253, Issue 5 1325-H1329, Copyright © 1987 by American Physiological Society

ARTICLES

Altered endothelial cell-mediated arterial dilation in dogs with D. immitis infection

L. Kaiser, J. F. Williams, E. A. Meade and H. V. Sparks
Department of Physiology, Michigan State University, East Lansing 48824-1101.

Vascular endothelial cells regulate arterial diameter in vivo and in vitro. Stimulation of endothelial cell muscarinic receptors by acetylcholine results in the production and release of a nonprostaglandin metabolite of arachidonic acid that causes vascular smooth muscle relaxation. We examined femoral artery endothelium-dependent vasodilator responses in normal dogs and dogs with heartworm (Dirofilaria immitis) infection. Endothelium-dependent vascular reactivity was attenuated in dogs with D. immitis infection studied in the spring but not in the fall. The dilator response was inversely related to the number of female worms but not related to the presence of circulating microfilariae. Indomethacin markedly depressed responses to acetylcholine in dogs with D. immitis but did not alter acetylcholine-induced dilation in normal dogs. These data suggest that D. immitis releases substances that alter distal arterial endothelial cell arachidonic acid metabolism. The seasonal pattern may reflect the onset of maximal reproductive activity in the spring and its decline as the vector season ends in the fall.

This article has been cited by other articles:

				M. Mupanomunda, J. F. Williams, C. D. Mackenzie, and L. Kaiser Dirofilaria immitis: heartworm infection alters pulmonary artery endothelial cell behavior J Appl Physiol, February 1, 1997; 82(2): 389 - 398. [Abstract] [Full Text] [PDF]