title: Histamine lipolysis II: effects of histamine and related compounds on membrane potentials of rat adipocytes.
abstract: The effects of histamine (Hi) and related compounds on rat mesenterial adipocytes were investigated using electrophysiological techniques. Hi caused a concentration-related depolarization and significant effect was observed at concentrations higher than 5 x 10(-6) M. Effective membrane resistance was also decreased by Hi. The H1-agonists 2-methylHi and 2-thiazolylethylamine caused no depolarization even at a concentration of 5 x 10(-4) M, but the H2-agonists, 4-methylHi and impromidine decreased resting membrane potentials. While 4-methylHi was less potent than Hi, impromidine was more potent. The H1-antagonists diphenhydramine and pyrilamine did not affect Hi-induced depolarization. However, H2-antagonists like cimetidine and ranitidine caused a significant inhibition even at a concentration of 10(-6) M. As in the case of isoproterenol, the decrease in resting membrane potentials induced by Hi was significantly potentiated by theophylline. Dibutyryl cyclic AMP treatment and intracellular application of cyclic AMP also caused a marked depolarization.
authors.affiliation: Department of Pharmacology, Faculty of Pharmaceutical Sciences, Okayama University, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Akiyama
authors.forename: C
authors.initials: C
authors.lastname: Kamei
authors.forename: K
authors.initials: K
authors.lastname: Tasaka
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects*; D000818:Animals; D004347:Drug Interactions; D004594:Electrophysiology; D006632:Histamine / Q000031:analogs & derivatives / Q000494:pharmacology*; D006633:Histamine Antagonists / Q000494:pharmacology*; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects* / Q000502:physiology; D010042:Ouabain / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D006633:Histamine Antagonists; D010042:Ouabain; D006632:Histamine; D007545:Isoproterenol