Parallel bioassay of 27 bombesin-like peptides on 9 smooth muscle preparations. Structure-activity relationships and bombesin receptor subtypes.
Thirteen natural bombesin-like peptides and 14 synthetic analogues were submitted to parallel bioassay on 9 smooth muscle preparations in order to determine their relative potency, in comparison to bombesin and litorin. The natural peptides of the bombesin subfamily showed a uniformly high or moderate potency on all preparations. However, synthetic bombesins of shorter chain length (hepta- and octapeptides) manifested a good potency only on the rat uterus preparation. Among the peptides of the litorin and phyllolitorin subfamilies, only litorin and ranatensin presented a full spectrum of potency, equalling or even surpassing that of bombesin. All other natural and synthetic members of the two subfamilies showed a sharply dissociated spectrum of potency on the different smooth muscle preparations. The only exception was the rat urinary bladder and, in part, the chicken intestine, on which the peptides displayed a uniformly high potency, comparable to, or even greater than that of bombesin. The present results help to explain structure/activity relationships and suggest the probable existence, in the periphery, of multiple bombesin receptor subtypes.
Falconieri Erspamer
G
G
Institute of Medical Pharmacology, University of Rome La Sapienza, Italy.
Severini
C
C
Erspamer
V
V
Melchiorri
P
P
Delle Fave
G
G
Nakajima
T
T
D000818:Animals; D001839:Bombesin / Q000031:analogs & derivatives* / Q000494:pharmacology* / Q000502:physiology; D005260:Female; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter / Q000502:physiology*; D013329:Structure-Activity Relationship; D014590:Uterine Contraction / Q000187:drug effects
D018004:Receptors, Bombesin; D017981:Receptors, Neurotransmitter; D001839:Bombesin