title: [Interactions of PAF and its antagonists in the guinea pig atrial myocardium].
abstract: The effects of platelet activating factor (PAF) and three its antagonists on the transmembrane intracellular potentials and stimulated (0.5 Hz) contraction amplitude (CA) of the left auricle has been studied. PAF (1-5 X 10(-7) M) was added to the standard Tyrode solution or the same perfusing solution with 15 mM K+, and 6 mM Ca++ (t = 30 degrees C, pH = 7,2). PAF induced the straight cardio-depressing action: the CA always was suppressed during 20 min. The electrical activity was depressed in parallel; in the Tyrode the action potential (AP) duration was lowered, but in the atrial depolarized preparations PAF resulted in a decrease of the slow calcium potential (Ca-AP) amplitude from 100% to 20.2 +/- 2.0%. After 20 min PAF-acting the perfusing solutions contained also one of PAF-antagonists. Antagonist U-66985 led to the weakening of the PAF-depressing effects in the myocardium U-66985 is also able to increase electrical and mechanical activity in myocardium depressed by the blood serum from patients with virulent infections.
authors: E G
authors: EG
authors: Vornovitskiĭ
authors: V B
authors: VB
authors: Ignat'eva
authors: M
authors: M
authors: Gollash
authors: V I
authors: VI
authors: Kulikov
authors: T I
authors: TI
authors: Kuznetsova
authors: B I
authors: BI
authors: Khodorov
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D001381:Azepines / Q000494:pharmacology; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006325:Heart Atria / Q000187:drug effects; D006801:Humans; D006993:Hypnotics and Sedatives / Q000494:pharmacology; D066298:In Vitro Techniques; D007239:Infections / Q000097:blood; D009200:Myocardial Contraction / Q000187:drug effects*; D010477:Perfusion; D010972:Platelet Activating Factor / Q000037:antagonists & inhibitors / Q000494:pharmacology* / Q000031:analogs & derivatives; D011817:Rabbits
chemical_list: D001381:Azepines; D006993:Hypnotics and Sedatives; D010972:Platelet Activating Factor; C020960:brotizolam; C046779:U 66985
vernacular_title: Vzaimodeĭstvie PAF i ego antagonistov v miokarde predserdiia morskoĭ svinki.