Porcine VIP is more potent than guinea pig VIP in relaxing the guinea pig uterine artery.
The vasodilator potency of guinea pig VIP (gp VIP) on the guinea pig uterine artery was compared with the potency of porcine VIP (p VIP), which differs in amino acid sequence at four locations. When antioxidants were not used, the two peptides were approximately equipotent in causing relaxation of precontracted vessel segments. Use of the antioxidants ascorbic acid and dithiothreitol resulted in significantly increased potency of both peptides. Porcine VIP was 15 times more potent than gp VIP synthesized by the same method (tBoc), and gp VIP synthesized by tBoc methodology was 2 times more potent than gp VIP synthesized by Fmoc methodology. Therefore, care should be taken in the choice and handling of synthetic peptides when aiming to mimic actions of endogenous peptides.
Morris
J L
JL
Department of Anatomy and Histology, School of Medicine, Flinders University of South Australia, Bedford Park.
Murphy
R
R
D000818:Animals; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009126:Muscle Relaxation / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects*; D013045:Species Specificity; D013552:Swine; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D014660:Vasoactive Intestinal Peptide