AJP - Endocrinology and Metabolism, Vol 252, Issue 6 E765-E771, Copyright © 1987 by American Physiological Society
Stimulation of dog gastropancreatic hormone release by neuromedin B and its analogues
H. Mukai, K. Kawai, Y. Suzuki, K. Yamashita and E. Munekata
The effects on gastrin, insulin, and glucagon release of neuromedin B
(NMB), the C-fragment decapeptide of gastrin-releasing peptide-10 (GRP-10),
seven analogues replacing amino acid positions 3, 6, and 9, and two
C-terminal desamide analogues were examined in conscious dogs using
intravenous bolus injection of these peptides study the structure-activity
relationship of two bombesin-related peptides identified in mammals. The
replacement from valine of position 6 of GRP-10 to threonine effectively
reduced the stimulatory potency of these hormone secretions. Removal of the
C-terminal amide of NMB and GRP-10 resulted in an almost complete loss of
their stimulatory effect on gastrin secretion. [Leu3]GRP-10 elicited the
most potent stimulatory activity on three hormone secretions among the
analogues including NMB and GRP-10. These results indicate that valine in
position 6 of GRP-10 and C-terminal amide of two peptides play an important
role in the bioactivities of bombesin family peptides.
