Uptake and effects of thiopental in isolated heart preparations of the rat in the presence of halothane.
The uptake of thiopental (CAS 76-75-5) (0.13-0.27 mmol.l-1) into tissue of rat hearts (Langendorff's preparation) was studied in the presence of halothane (CAS 151-67-7). Up to a thiopental concentration of 0.19 mmol.l-1 in the perfusion medium its concentration in heart tissue was significantly increased vs. control when halothane (0.8 vol%) simultaneously was present; using 0.13 mmol.l-1 thiopental and 0.8, 1.5 or 2.0 vol% halothane this increase amounted +12%, +29% and +43%, respectively. Frequency of spontaneously beating rat hearts decreased in the presence of increasing thiopental concentrations. 0.8 vol% halothane (without thiopental) did not influence heart rate; in the presence of thiopental it attenuated heart rate reduction. This attenuation was absent in hearts of rats pretreated with reserpine. 1.5 vol% halothane (itself also without influence on heart rate) increased the negative chronotropic action of thiopental. In isolated right and left atria of rat hearts frequency and contractility decreased concentration-dependently in the presence of thiopental; simultaneously present halothane additionally increased this negative chronotropic and negative inotropic effect of thiopental.
Büch
U
U
Klinik für Anästhesiologie und Intensivmedizin, Universität des Saarlandes, Homburg/Saar, Fed. Rep. of Germany.
Isenberg
J C
JC
Baldauf
J
J
Altmayer
P
P
Büch
H P
HP
D000818:Animals; D002855:Chromatography, Thin Layer; D005260:Female; D006221:Halothane / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012110:Reserpine / Q000494:pharmacology; D013874:Thiopental / Q000493:pharmacokinetics* / Q000494:pharmacology*
D012110:Reserpine; D013874:Thiopental; D006221:Halothane