Effect of pancreastatin on cerulein-stimulated pancreatic blood flow and exocrine secretion in anaesthetized rats.
BACKGROUND
Pancreastatin (PST) is an inhibitor of pancreatic exocrine secretion in vivo but not in vitro, which suggests that the inhibitory effect of PST is indirect, that is, not mediated by a specific receptor on pancreatic acinar cells. In this study, we investigated the effects of PST on pancreatic exocrine secretion and local pancreatic blood flow in anaesthetized rats to elucidate the participation of PST in indirect regulation of pancreatic exocrine function through blood supply.


METHODS
Pancreastatin (100, 200 or 500 pmol/kg per h) was administered intravenously under background infusion of cerulein (0.5 microg/kg per h), a cholecystokinin analogue. Pancreatic exocrine secretion was monitored by volume and protein output of the pancreatic juice and local pancreatic blood flow was measured by the hydrogen gas clearance method.


RESULTS
Pancreastatin significantly reduced cerulein-induced local pancreatic blood flow in a dose-dependent manner. Pancreatic exocrine secretion was also reduced significantly by PST dose-dependently. Pancreastatin did not change systemic blood pressure. These results suggested that the reduction of pancreatic blood flow is associated with the reduction of pancreatic exocrine secretion.


CONCLUSIONS
We conclude that the mechanism of PST-induced inhibition of pancreatic exocrine secretion is, at least, partly mediated by the reduction of local pancreatic blood flow through blockade, caused by the action of cerulein on pancreatic blood flow.
Migita
Y
Y
Third Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Nakano
I
I
Goto
M
M
Ito
T
T
Nawata
H
H
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002108:Ceruletide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D053379:Chromogranin A; D004305:Dose-Response Relationship, Drug; D005765:Gastrointestinal Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D010179:Pancreas / Q000098:blood supply / Q000187:drug effects* / Q000378:metabolism*; D010187:Pancreatic Hormones / Q000494:pharmacology*; D010189:Pancreatic Juice / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012039:Regional Blood Flow / Q000187:drug effects
D053379:Chromogranin A; D005765:Gastrointestinal Agents; D010187:Pancreatic Hormones; C050836:pancreastatin; D002108:Ceruletide