1. Academic Validation
  2. Ro 5-4864 has a negative inotropic effect on human atrial muscle strips that is not antagonized by PK 11195

Ro 5-4864 has a negative inotropic effect on human atrial muscle strips that is not antagonized by PK 11195

  • Eur J Pharmacol. 1994 Mar 3;253(3):231-6. doi: 10.1016/0014-2999(94)90196-1.
E Shany 1 E Hochhauser P Halpern B Vidne M Gavish E Geller A Hasharoni Y Barak V Yakirevich
Affiliations

Affiliation

  • 1 Pediatric Division, Soroka Medical Center, Beersheba, Israel.
Abstract

The effects of Ro 5-4864, a peripheral benzodiazepine receptor agonist (9 x 10(-6) M and 9 x 10(-5) M) and of PK 11195, a peripheral benzodiazepine receptor antagonist (3 x 10(-6) M and 3 x 10(-5) M), alone or together, on contraction parameters of human atrial muscle strips were studied. Atrial muscle strips were obtained from patients undergoing cardiac surgery. The strips were suspended in Krebs-Henseleit solution at 36.8 +/- 0.2 degrees C, connected to an isometric force transducer and then stimulated at 15 V above threshold and paced at 1.5 Hz. Ro 5-4864 at its higher concentration, alone or mixed with PK 11195 at both concentrations, depressed the contraction amplitude to 80% of the control value (P < 0.05). In conclusion, Ro 5-4864 had a small but significant depressant effect on the contraction amplitude of human atrial strips. Surprisingly, this effect was not reversed by the peripheral benzodiazepine receptor antagonist PK 11195.

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