Substance P mechanisms in the regulation of striated muscle microcirculation.
The effects of substance P (SP) on microvessels in the cremaster of sodium pentobarbital-anesthetized male, Sprague-Dawley rats were investigated using closed-circuit television microscopy. Topically added SP (bath concentrations of 10(-13) to 10(-8) M) caused significant dilation of small arterioles. SP vasodilation was sensitive to pretreatment of the muscle tissue with SP analogues, [D-Arg1, D-Pro2, D-Trp7,9, Leu11]-substance P (APTL-SP) and [D-Pro2, D-Trp7,9]-substance P (PT-SP). Attenuation of the responses by pyrilamine suggests that part of the SP-induced dilation involves the release of histamine. The vasodilation was abolished by hydroquinone, suggesting an intermediate role for endothelium-derived relaxing factor in the response to SP.
Brock
J W
JW
Department of Physiology and Biophysics, School of Medicine, University of Louisville, Kentucky 40292.
Joshua
I G
IG
D000818:Animals; D002196:Capillaries / Q000187:drug effects; D004730:Endothelium, Vascular / Q000378:metabolism; D006636:Histamine Release; D006873:Hydroquinones / Q000494:pharmacology; D008297:Male; D008833:Microcirculation / Q000187:drug effects; D009132:Muscles / Q000098:blood supply*; D009569:Nitric Oxide / Q000378:metabolism; D011738:Pyrilamine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter / Q000187:drug effects; D013373:Substance P / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology / Q000502:physiology*; D014664:Vasodilation / Q000187:drug effects
D006873:Hydroquinones; D018040:Receptors, Neurokinin-1; D017981:Receptors, Neurotransmitter; D009569:Nitric Oxide; D013373:Substance P; C032132:substance P, prolyl(2)-tryptophan(7,9)-; C038073:substance P, Arg(1)-Pro(2)-Trp(7),(9)-LeuNH(2)(11)-; D011738:Pyrilamine; C031927:hydroquinone