We investigated the effects of histamine on the motility of isolated segments from canine ureters and characterized pharmacologically the histamine receptors involved. We also evaluated the effects of various autacoids (5-HT, carbachol, noradrenaline, thromboxane, prostaglandin F2alpha) on the motility of canine ureters. Histamine as well as the H1 receptor agonist 2-(2-pyridyl)ethylamine elicited a concentration-dependent contraction. This contractile response was antagonized by dimethindene, causing a rightward shift (pA2 8.30) and a reduction of the slope and the maximal effect (pD'2 6.01) of the concentration-response curve. The histamine H2 receptor antagonist cimetidine in a concentration of 10(-5) mol/l was ineffective concerning the concentration-response curve for histamine. After precontraction of the ureter segments (5-HT, carbachol, prostaglandin F2alpha), a concentration-dependent relaxant effect was evaluated in the presence of histamine or the histamine H2 receptor agonist impromidine. The histamine H2 receptor antagonist cimetidine attenuated the relaxant response, causing a rightward shift of the concentration-response curve. All autacoids except thromboxane were capable of increasing contractility in canine ureters. Comparing the absolute contractile force in the presence of prostaglandin F2alpha, 5-HT, carbachol, noradrenaline and potassium, we found that histamine exhibits the most marked effect on this parameter in the canine ureter. It is concluded that there are two types of histamine receptors modulating contractile activity in the canine ureter: histamine H1 receptors, which mediate contraction, and histamine H2 receptors, which mediate relaxation (in the precontracted tissue).
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0014-2999(96)00765-0 | DOI Listing |
Med Chem
January 2025
Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan.
Introduction: Histamine Type I Receptor Antagonists (H1 blockers) are widely used to mitigate histamine-induced inflammation, particularly in allergic reactions. Histamine, a biogenic amine found in endothelial cells, vascular smooth muscle, bronchial smooth muscle, and the hypothalamus, is a key player in these responses. H1 blockers are essential in cough syrups and flu medications and are divided into two generations: first-generation H1 blockers, which are sedating and have numerous side effects, and second-generation blockers, which are non-sedating and generally less toxic but may still exhibit cross-reactivity with other receptors.
View Article and Find Full Text PDFCell Mol Gastroenterol Hepatol
January 2025
Center for Advanced Biotechnology and Medicine, Rutgers University, Piscataway, NJ, USA. Electronic address:
Background & Aims: Erythropoietic protoporphyria (EPP) is caused by mutations in ferrochelatase which inserts iron into protoporphyrin-IX (PP-IX) to generate heme. EPP is characterized by PP-IX accumulation, skin photosensitivity, cholestasis, and end-stage liver disease. Despite available drugs that address photosensitivity, treatment of EPP-related liver disease remains an unmet need.
View Article and Find Full Text PDFDrug Dev Res
February 2025
Department of Gastroenterology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, China.
Famotidine is an H2 receptor antagonist and is currently used on a large scale in gastroenterology. However, Famotidine may also cause severe toxicity to organ systems, including the blood system, digestive system, and urinary system. The objective of this study was to scientifically and systematically investigate the adverse events (AEs) of Famotidine in the real world through the FDA Adverse Event Reporting System (FAERS) database.
View Article and Find Full Text PDFJ Therm Biol
January 2025
College of Marine Science and Engineering, Nanjing Normal University, Jiangsu Province Engineering Research Center for Aquatic Animals Breeding and Green Efficient Aquacultural Technology, Nanjing, 210023, PR China. Electronic address:
Climate warming and frequent incidents of extreme high temperatures are serious global concerns. Heat stress induced by high temperature has many adverse effects on animal physiology, especially in aquatic poikilotherms. Chinese mitten crab (Eriocheir sinensis) is sensitive to high temperatures, this study evaluated the harmful effects of heat stress on the neurotoxicity, intestinal health, microbial diversity, and metabolite profiles.
View Article and Find Full Text PDFFood Sci Nutr
January 2025
Department of Nutrition and Food Hygiene, School of Public Health Jilin University Changchun China.
BackgroundAllergic diseases have become one of the major public health problems to be addressed in the world today. As a tissue resident cell, mast cells are crucial in the pathogenesis of allergic diseases. Vitamin A is an important fat-soluble vitamin with immunomodulatory functions.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!