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Effect of Histamine H 2 Receptor Antagonists on the Secretion of Cerebrospinal Fluid in the Cat
Author(s) -
Naveh Yehezkel,
Kitzes Ruth,
Lemberger Anshel,
BenDavid Shlomit,
Feinsod Moshe
Publication year - 1992
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1992.tb11348.x
Subject(s) - cimetidine , ranitidine , histamine , choroid plexus , histamine h2 receptor , cerebrospinal fluid , endocrinology , chemistry , medicine , receptor , pharmacology , antagonist , central nervous system
Following a recent report that epithelial cells of the choroid plexus possess histamine H 2 receptors, the effect of cimetidine and ranitidine, histamine H 2 receptor antagonists, on the secretion and electrolyte content of CSF was examined. Fifty cats were divided into one control (n = 6) and six experimental groups. CSF was collected by puncture of the cisterna magna following pentobarbital anesthesia, and its volume, concentrations of Na + , K + , Cl ‐ , and pH were determined. Cimetidine or ranitidine (50, 20, or 10 mg/kg) was injected intravenously 2 h after the start of the test, and their concentrations were measured in hourly blood samples and in 30‐min aliquots of CSF in the 50 mg/kg experimental groups. Whereas the secretion of CSF did not change over 6 h in the control group, it decreased significantly by 30–60 min after injection of cimetidine or ranitidine and remained low for the following 61/2 h in all experimental groups except the 10‐mg ranitidine group. Peak cimetidine and ranitidine concentrations in CSF in the 50‐mg experimental groups were noted 60 and 90 min, respectively, after intravenous injection. CSF electrolyte concentrations and pH did not change during the test in any group. We conclude that intravenous cimetidine or ranitidine can significantly reduce CSF secretion in the cat, possibly by competitive inhibition of the histamine effect on H 2 receptors located on the choroid plexus epithelial cell, or by a direct effect on the capillaries of the choroid plexus.