PT  - JOURNAL ARTICLE
AU  - Burcher, Elizabeth
AU  - Garlick, David
TI  - ANTAGONISM OF VASOCONSTRICTOR RESPONSES BY EXERCISE IN THE GRACILIS MUSCLE OF THE DOG
DP  - 1973 Oct 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 78--85
VI  - 187
IP  - 1
4099  - http://jpet.aspetjournals.org/content/187/1/78.short
4100  - http://jpet.aspetjournals.org/content/187/1/78.full
SO  - J Pharmacol Exp Ther1973 Oct 01; 187
AB  - Responses to lumbar sympathetic stimulation. and to intra-arterial injections of norepinephrine, vasopressin and angiotensin were elicited in the vascularly isolated dog gracilis muscle, perfused with blood at constant flow and by autoperfusion. Sympathetic stimulation was antagonized by exercise, the degree of inhibition being dependent on the level of exercise. Responses to norepinephrine, vasopressin and angiotensin were also antagonized by exercise, suggesting that the inhibition is nonspecific. A comparison of norepinephrine and sympathetic stimulation showed that sympathetic responses were significantly more reduced by exercise than responses to norepinephrine. This suggests either that endogenous and exogenous norepinephrine activate different populations of receptors, or more likely that during exercise there may be some inhibition to sympathetic neurotransmission in addition to the nonspecific inhibition of circulating vasoconstrictors. © 1973 by The Williams & Wilkins Company