Related Experiment Video

Updated: Jul 9, 2026

Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents.
09:29

Fabrication and Implantation of Miniature Dual-element Strain Gages for Measuring In Vivo Gastrointestinal Contractions in Rodents.

Published on: September 18, 2014

Stimulatory effect of (R) alpha-methylhistamine on duodenal HCO3- secretion in anaesthetized rats

G Coruzzi1, E Gambarelli, G Bertaccini

  • 1Istituto di Farmacologia, Università di Parma, Italy.

The Italian Journal of Gastroenterology
|December 1, 1996
PubMed

Insights

The histamine H3 receptor agonist (R) alpha-methylhistamine stimulates duodenal bicarbonate secretion in rats. This effect is mediated by H3 receptors and may contribute to gastroprotection.

Area of Science:

  • Gastroenterology
  • Pharmacology
  • Physiology

Background:

  • Histamine H3 receptors play a role in regulating gastrointestinal functions.
  • The gastroprotective effects of (R) alpha-methylhistamine have been previously observed.
  • Understanding the mechanisms of duodenal bicarbonate secretion is crucial for gastrointestinal health.

Purpose of the Study:

  • To investigate the effect of the histamine H3 receptor agonist (R) alpha-methylhistamine on duodenal bicarbonate secretion in rats.
  • To determine if the observed effects are mediated through histamine H3 receptors.
  • To explore the potential contribution of this mechanism to the gastroprotective properties of (R) alpha-methylhistamine.

Main Methods:

  • Administered varying doses of (R) alpha-methylhistamine intravenously to anesthetized rats.
  • Utilized the H3 receptor antagonist clobenpropit to block receptor activity.
  • Measured duodenal alkaline secretion in response to drug administration.
  • Assessed the effect of the antagonist on PGE2-induced secretion.

Main Results:

  • (R) alpha-methylhistamine induced a dose-dependent increase in duodenal alkaline secretion.
  • The H3 receptor antagonist clobenpropit completely blocked the secretory response to (R) alpha-methylhistamine.
  • Clobenpropit slightly reduced the secretory response to PGE2 (19%).

Conclusions:

  • The alkaline secretion induced by (R) alpha-methylhistamine is mediated by the activation of histamine H3 receptors.
  • Histamine H3 receptor activation represents an additional mechanism contributing to the gastroprotective effects of (R) alpha-methylhistamine.
  • These findings provide insights into the pharmacological regulation of duodenal bicarbonate secretion.

More Related Videos

A Method of Nodose Ganglia Injection in Sprague-Dawley Rat09:28

A Method of Nodose Ganglia Injection in Sprague-Dawley Rat

Published on: November 25, 2014

In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats08:19

In Vitro Characterization of the Electrophysiological Properties of Colonic Afferent Fibers in Rats

Published on: September 27, 2017

Related Concept Videos

Hormonal Regulation01:40

Hormonal Regulation

Hormones regulate a significant portion of digestion through activation of the neuroendocrine system. The neuroendocrine system of digestion contains many different hormones all with multiple functions that are both, directly and indirectly, involved in digestion.
Pathophysiology of Peptic Ulcer Disease: Injurious Factors01:22

Pathophysiology of Peptic Ulcer Disease: Injurious Factors

Peptic ulcers are sores on the stomach's inner lining and the upper small intestine, which are the result of disruptions in the mucosal layer that houses parietal cells which produce gastric acid, and chief cells which secrete pepsinogen.
In the antrum region, G cells secrete the gastrin hormone that binds to gastrin-cholecystokinin-B (CCK2) receptors on parietal and enterochromaffin-like (ECL) cells in the fundic glands. Simultaneously, the vagus nerve releases acetylcholine, which binds to M3...
Acid Suppressive Drugs for Peptic Ulcer Disease: Histamine H2-Receptor Antagonists01:28

Acid Suppressive Drugs for Peptic Ulcer Disease: Histamine H2-Receptor Antagonists

Histamine H2 receptors, which are intricately located on the basolateral membrane of parietal cells, play a crucial role in modulating gastric acid secretion. When released from enterochromaffin-like cells, histamine engages H2 receptors, initiating the cyclic AMP (cAMP) pathway. In this pathway, adenylyl cyclase converts ATP into cAMP, elevating intracellular cAMP levels. The activation of protein kinase A follows, stimulating the proton pump. This stimulation prompts the secretion of hydrogen...
Regulation of the Digestive System01:25

Regulation of the Digestive System

Digestive activity regulation hinges on three primary components. Activation is prompted by a multitude of mechanical and chemical indicators, primarily detected by receptors within the stomach and intestines' walls. These receptors predominantly respond to factors such as mechanical stretching of the organ walls, changes in pH and osmolarity, and the presence of digesting materials and their by-products.
The effectors in this regulation system are glands and smooth muscles. Activation of these...
Gastric Phase of Digestion01:26

Gastric Phase of Digestion

The gastric phase of digestion begins as soon as food enters the stomach. The incoming food bolus triggers neural and hormonal mechanisms, which last approximately 3 to 4 hours. During this phase, the stomach undergoes significant changes to prepare the food for further digestion and absorption.
When food enters the stomach, it stretches the stomach walls and activates stretch receptors. This triggers local reflexes of the enteric nervous system, mediated through the myenteric plexus. These...
Intestinal Phase of Digestion01:29

Intestinal Phase of Digestion

The intestinal phase of digestion is the third and final stage of the digestive process, occurring after the cephalic and gastric phases. It begins when chyme, a partially digested mixture of food and digestive enzymes, enters the small intestine from the stomach. This phase is crucial for nutrient absorption and involves complex hormonal and enzymatic interactions.
The arrival of the chyme in the small intestine distends the duodenum, which triggers the enterogastric reflex. This distension...