PT  - JOURNAL ARTICLE
AU  - K MacCannell
AU  - K Lederis
TI  - Dilatation of the mesenteric vascular bed of the dog produced by a peptide, urotensin I.
DP  - 1977 Oct 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 38--46
VI  - 203
IP  - 1
4099  - http://jpet.aspetjournals.org/content/203/1/38.short
4100  - http://jpet.aspetjournals.org/content/203/1/38.full
SO  - J Pharmacol Exp Ther1977 Oct 01; 203
AB  - Urotensin I, a peptide derived from the urophysis of bony fish, produced hypotension when administered intravenously in small doses to pentobarbital-anesthetized dogs. The mechanism of this hypotensive response was mainly, if not exclusively, due to dilatation of the cephalic and caudal mesenteric arteries. Neither the hypotensive response nor the mesenteric vasodilator response was prevented by adrenergic, histaminergic or muscarinic receptor blockade. In the doses employed, urotensin I constantly caused minimal increases in heart rate and left ventricular dp/dt; these changes could be prevented by prior administration of propranolol, indicating that they were probably reflex in origin. The authors suggest that the unique mechanism of action of the peptide may make it a valuable tool in studies of the mesenteric circulation, particularly in experimental shock; moreover, the peptide may prove useful in situations in which afterload reduction in the absence of cardiac stimulation is desired.