Mast cell degranulation and histamine release contribute to painful bladder syndrome, urinary tract infections, interstitial cystitis and other bladder disorders. The effects of histamine are well‐studied in other tissues, but little is known about the role of histamine and histamine receptors within the bladder. Since other smooth muscle cells express H1 (contractile) and H2 (relaxant) histamine receptors, we tested the hypothesis that histamine causes contraction of the urinary bladder smooth muscle in mice. All procedures followed institutional guidelines and were approved by the Institutional Animal Care and Use Committees of Michigan State University. Six to 12‐week‐old C57Bl/6 mice were euthanized and dissected bladders were cut into approximately 2 mm wide bladder strips, with or without the urothelium attached, for isometric contractility experiments. Both histamine H1 and H2 receptors were expressed in bladder smooth muscle cells. Increasing concentrations of histamine (100 nM – 300 μM) did not contract strips without urothelium and minimally contracted bladder strips with urothelium. However, bolus administration of 200 μM histamine caused a rapid but transient contraction in strips with and without urothelium. The H1 receptor blocker fexofenadine (5 – 10 μM) blocked these contractions (P<0.05; N=5), whereas the H2 receptor blocker cimetidine (5 – 10 μM) had no effect. In addition, transient receptor potential vanilloid 1 (TRPV1) channel blocker capsazepine significantly reduced histamine‐induced contractions only in bladder strips without urothelium, whereas the Na+ channel blocker tetrodotoxin (TTX) had no effect in any tissue (P < 0.05; N= 3–5). The mast cell activator compound 48/80 (10 μg/ml) contracted urinary bladder smooth muscle, and this contraction was also unaffected by TTX. These results indicate that H1 receptors on urinary bladder smooth cells likely modulate histamine‐induced bladder contraction, and sufficient amounts of histamine can be released from mast cells to cause a contraction. Support or Funding Information This research is supported by NIH K01‐DK103840 (NRT) and NIH R01‐DK119615 (NRT & GCM).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.