Substance P is released from the endothelium of normal and capsaicin-treated rat hind-limb vasculature, in vivo, by increased flow.
The rat hind-limb vasculature releases substance P when subjected to a rapid increase in flow through the vascular bed. This release also occurs during high flow after rats have been capsaicinized, when loss of substance P-containing nerve fibers was verified by immunohistochemistry. Air treatment, a procedure shown by transmission electron microscopy to have removed endothelial cells from the arteries but not arterioles or capillaries of the hind-limb preparations, eliminated this release. Thus, the substance P released is unlikely to arise from perivascular nerves but rather from arterial endothelial cells.
Department of Anatomy and Developmental Biology, University College London, United Kingdom.
V
V
Ralevic
P
P
Milner
O
O
Hudlická
F
F
Kristek
G
G
Burnstock
D000818:Animals; D002211:Capsaicin / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D006614:Hindlimb / Q000098:blood supply*; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D012039:Regional Blood Flow; D013373:Substance P / Q000378:metabolism*
D013373:Substance P; D002211:Capsaicin