Histamine receptors in unstimulated pancreatic exocrine secretion of the rabbit

Abstract

Histamine H2-receptor antagonists cimetidine and oxmetidine, H2-receptor agonist dimaprit, H1-receptor antagonist chlorpheniramine and H1-receptor agonist 2-thiazolylethylamine were tested for their effects on unstimulated pancreatic exocrine secretion in anaesthetized rabbits fitted with an acute pancreatic cannula. Intravenous administration of H1 agonist induces a dose-dependent increase in pancreatic secretion but H1 antagonist have the opposite effects. Intravenous administration of H2 antagonists induces effects similar the ones produced after H1 agonist infusion. The implications of H1 and H2 receptors on exocrine pancreatic secretion are discussed.

Role of histamine receptors in rabbit pancreatic exocrine secretion stimulated by cholecystokinin and secretin

“…The sensitivity of the rabbit pancreas to histamine (Liebow & Franklin, 1982), along with a preliminary observation showing the secretagogue character of cimetidine in this same species (Pariente, Pozo, Madrid & Salido, 1987), and the observation that resting pancreatic exocrine secretion is affected by administration of both agonists and antagonists of HI and H2 receptors (Pariente et (Pariente et al 1989) and confirm that HI receptors have stimulatory actions on exocrine rabbit pancreas (Liebow & Franklin, 1982). In addition, our results demonstrate that the CI-/HCO3-ratio also varies after 2-thiazolylethylamine administration.…”

“…In a previous study (Pariente, Madrid & Salido, 1989), we examined the role of the histamine receptors in the resting pancreatic secretion of anaesthetized rabbit using selective agonists and antagonists. The use of an HI agonist, 2-thiazolylethylamine, reveals its dose-dependent stimulatory action on the volume of pancreatic juice.…”

“…The role of H2 receptors seems more doubtful, although Liebow & Franklin (1982) did not assign them a role as mediators of histamine actions. We had previously demonstrated (Pariente et al 1989) that both cimetidine and oxmetidine (H2 antagonists) induce a dose-dependent increase of electrolyte, water and enzyme output of the pancreas.…”

Histamine‐evoked amylase secretion is associated with small changes in calcium mobilization in isolated guinea‐pig pancreas

“…There is some evidence that histamine can act as a secretagogue in both the anaesthetized dog and rabbit (Tankel, Lester, Richman & Hollander, 1957;Pariente, Madrid & Salido, 1989) as well as on the rabbit pancreas in vitro (Leibow & Franklin, 1982). In contrast, histamine is less effective as a secretagogue in the anaesthetized rat (Chariot, Roz6 & Vaille, 1979) and has no detectable effect on digestive enzyme secretion in lobules of the guinea-pig pancreas (Leibow & Franklin, 1982).…”

Activation of Histamine Receptors is Associated with Amylase Secretion and Calcium Mobilization in Guinea-Pig Pancreatic Acinar Cells

“…In ail these studies little or no attempt was made to determine the cellular mechanism of action of histamine on pancreatic acinar cells. Fur thermore, studies on in vivo preparations which attempt to characterise the types of histaminergic receptors associated with pan creatic juice secretion are less conclusive [8,13]. In the isolated dog pancreas, the Hi antagonist metiamide completely blocked the effect of histamine [7], whereas in the anaesthetised rabbit the H2 antagonist cimetidine caused an increase in the pan creatic juice flow by itself [8,14] and a marked potentiation of the secretory effect of the paracrine hormone [9].…”