Post-occlusive reactive hyperaemia in the heart, skeletal muscle and skin of control and capsaicin-pre-treated pigs.
In the present study we have tried to characterize and quantify the post-occlusive hyperaemia in the pig heart, skeletal muscle and skin circulation. In addition, the possible involvement of caspaicin-sensitive sensory nerves in the reactive hyperaemia was investigated. Reperfusion after total stop-flow ischaemia for 1, 5 or 15 min elicited a marked hyperaemia in all vascular beds studied. The post-occlusive hyperaemia after 5 min ischaemia was 512 +/- 74%, 328 +/- 94% and 444 +/- 87% in the heart, femoral artery and saphenous artery respectively. Also, in the skin the blood flow following 5 min ischaemia was increased fivefold. Furthermore, the duration of the hyperaemia after 5 min ischaemia was significantly (P less than 0.01) longer in the heart (382 +/- 32 s) than that in the femoral artery (192 +/- 27 s), saphenous artery (182 +/- 48 s) and skin (95 +/- 14 s). Increasing the ischaemic time period prolonged the duration as well as elevated the peak increase of the hyperaemia. Capsaicin pre-treatment significantly reduced (by about 70%) the tissue levels of calcitonin gene-related peptide (CGRP)-like immunoreactivity (-LI), which is present in sensory nerves, but not neuropeptide Y-LI, which is of sympathetic origin, in the left ventricle of the heart, quadriceps muscle and skin in the pig. However, there were no differences in the post-occlusive hyperaemia in control and capsaicin-pre-treated pigs. Capsaicin administered intracutaneously caused a long-lasting (about 20 min) increase in skin blood flow in the pig. This enhanced blood flow was completely abolished after systemic capsaicin pre-treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Franco-Cereceda
A
A
Department of Pharmacology, Karolinska Institute, Stockholm, Sweden.
Lundberg
J M
JM
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002211:Capsaicin / Q000008:administration & dosage*; D003326:Coronary Circulation / Q000187:drug effects*; D006940:Hyperemia / Q000503:physiopathology*; D009132:Muscles / Q000098:blood supply*; D009478:Neuropeptide Y / Q000378:metabolism; D012867:Skin / Q000098:blood supply*; D013552:Swine
D009478:Neuropeptide Y; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin