title: Aminophylline pretreatment modulates the nitric oxide system of the isolated rat diaphragm: the role of frequency of the electrical stimulation.
abstract: The effect of different frequencies of direct subtetanic electrical stimulation (14, 20, and 30 Hz) and aminophylline (AMPh) pretreatment on the effect of N(G)-nitro-L-arginine methyl ester (L-NAME) (1 mM) on isolated rat diaphragm was investigated. L-NAME potentiated tension developed (Td) in the diaphragm pretreated with a single concentration of AMPh (1.08 mM) in a frequency-dependent manner. The effect was significantly different in comparison with muscle incubated 30 min with Tyrode solution only. In the muscle pretreated with cumulative concentrations of AMPh (0.36 - 3.60 mM), the frequency-dependent potentiation of Td induced by L-NAME and the difference between L-NAME-treated and untreated muscle were lost.
authors.affiliation: Department of Pharmacology, Clinical Pharmacology and Toxicology, School of Medicine University of Belgrade, Serbia.
authors.forename: Radan
authors.initials: R
authors.lastname: Stojanovic
authors.forename: Zoran
authors.initials: Z
authors.lastname: Todorovic
authors.forename: Zorica
authors.initials: Z
authors.lastname: Nesic
authors.forename: Sonja
authors.initials: S
authors.lastname: Vuckovic
authors.forename: Milica
authors.initials: M
authors.lastname: Prostran
mesh_terms: D000628:Aminophylline / Q000494:pharmacology*; D000818:Animals; D003964:Diaphragm / Q000187:drug effects* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004558:Electric Stimulation; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000628:Aminophylline; D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester