Occurrence of VIP and peptide HM in human pancreas and their influence on pancreatic endocrine secretion in man.
By immunohistochemistry it was found that VIP- and peptide HI/peptide HM (PHI/PHM)-like immunoreactivity occurred in autonomic neurons in the human pancreas. Antisera against both VIP and PHI/PHM reacted with neuronal cells in local ganglia and these ganglia also contained PHI/PHM- and VIP-immunoreactive fibre plexuses. VIP- and PHI/PHM-positive fibres were also seen close to the Langerhans' islets. In addition, PHI/PHM- but not VIP-like immunoreactivity was observed in the endocrine cells often located in the periphery of the islets. The nature of these PHI/PHM-positive cells remains to be established. I.v. infusion of VIP at constant rates of 300 and 900 pmol/kg X h for 30 min in 6 healthy volunteers resulted in plateau values of 102 +/- 26 and 291 +/- 25 pM, respectively. These levels of VIP which are above those found in the circulation under physiological conditions stimulated secretion of insulin, C-peptide and pancreatic glucagon dose-dependently. On the contrary prolonged (60 min) infusion of PHM in doses resulting in plasma levels up to 1340 +/- 405 pM had no effect on pancreatic hormone secretion. These findings suggest that VIP is a likely neurotransmitter in the control of endocrine pancreatic secretion while PHM has a less prominent role, if any.
Fahrenkrug
J
J
Pedersen
J H
JH
Yamashita
Y
Y
Ottesen
B
B
Hökfelt
T
T
Lundberg
J M
JM
D000328:Adult; D002096:C-Peptide / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D005934:Glucagon / Q000378:metabolism; D006651:Histocytochemistry; D006801:Humans; D007328:Insulin / Q000378:metabolism; D000078790:Insulin Secretion; D008297:Male; D010179:Pancreas / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D010451:Peptide PHI / Q000032:analysis* / Q000494:pharmacology; D014018:Tissue Distribution; D014660:Vasoactive Intestinal Peptide / Q000032:analysis* / Q000494:pharmacology
D002096:C-Peptide; D007328:Insulin; D010451:Peptide PHI; D014660:Vasoactive Intestinal Peptide; D005934:Glucagon