Studies on Canine Pancreatic Secretion

Tankel, Henry I (1958) Studies on Canine Pancreatic Secretion. PhD thesis, University of Glasgow.

Abstract

THE RESPONSE TO HISTAMINE. The pancreatic response to histamine and to control injections of secretin have been studied in 8 dogs. To exclude any fallacy due to activation of the endogenous secretin mechanism by gastric acid, 3 of the dogs had total gastrectomies carried out, and 5 dogs had gastrostomies through which the stomach could be kept empty. Histamine is a potent stimulator of pancreatic secretion in the absence of the endogenous secretin mechanism. The volume, bicarbonate concentration, and total bicarbonate output in response to histamine are on the average about 70% of the response to secretin in the doses used, and on occasion may even be greater than it. The concentrations of chloride and nitrogen in response to histamine are about 2-J times the corresponding concentrations in response to secretin, but the total outputs are approximately equal. The profiles of the responses to histamine and secretin are very similar as regards latent period, duration of response, and the timing of the peak of the response. 'Histamine is a true pancreatic secretagogue. Its action cannot be explained by activation of the endogenous secretin mechanism by gastric HCl, by direct secretin release, or by lowering of the threshold to secretin. It is not due to the concomitant secretion of bile, to vasodilatation, to lowering of the blood pressure, or to an increase in blood, flow through the pancreas. THE EFFECT OF ATROPINE. The effect of atropine on the response to histamine has been studied on 3 dogs with total gastrectomies and 4 dogs with gastrostomies. Atropine inhibits the volume and bicarbonate output in response to histamine and tnis inhibition may be complete when one hour is allowed to elapse between the injection of atropine and the subsequent injection of histamine. When an interval of only half an hour is allowed, inhibition does not invariably occur. The effect of atropine on the pancreatic response to secretin has been studied in one dog. Atropine produces a small but important reduction in the volume response to secretin. Atropine produces a significant increase in the bicarbonate concentration, but little change in the total bicarsbonate output in response to secretin. Both the concentration and total output of nitrogen are significantly decreased by atropine. The concentration and total output of chloride were not significantly affected by atropine. Vagotomy reduced the inhibitory effect of atropine on the concentration and total output of nitrogen to a significant degree, and reduced the increase in the bicarbonate concentration. Atropine appears to act directly on the secretory cell as well as blocking the secretory fibres of the vagus. (Abstract shortened by ProQuest.).

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Physiology, Veterinary science
• Date of Award: 1958
• Depositing User: Enlighten Team
• Unique ID: glathesis:1958-79263
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 31 Mar 2020 09:09
• Last Modified: 31 Mar 2020 09:09
• URI: https://theses.gla.ac.uk/id/eprint/79263