Skip to main content
Open Access Publications from the University of California

The cyclo-oxygenase pathway in the avascular heart of the frog, Rana esculenta L.

  • Author(s): Ghiara, P
  • Parente, L
  • Piomelli, D
  • et al.

1. A modification of Vane's cascade is reported, allowing the superfusion bioassay of prostaglandin-like substances (PLS) in the outflow of isolated and perfused heart of the frog Rana esculenta L. 2. Using both this technique and radioimmunoassay determination, the cyclo-oxygenase pathway in perfused frog heart has been investigated. 3. Arachidonate (AA) (2-20 μg) injected into the perfusing fluid, was transformed by the heart into PLS, as shown by the response of the bioassay tissues (rat stomach strip, chick rectum, rat colon). A compound capable of relaxing rabbit mesenteric artery and a rabbit aorta contracting substance were also generated. The release was inhibited by indomethacin (1.0 × 10-5M). 4. Radioimmunoassay determination of PGE2, TXB2and 6-keto-PGF1αin frog heart effluent, before and after AA injection (20 μg), gave the following yields (ng/ml of effluent). Basal: PGE2= 0.45 ± 0.15; TXB2= 0.46 ± 0.13; 6-keto-PGF1α- 2.21 ± 0.3. Following AA: PGE2= 1.55 ±0.35; 6-keto-PGF1α= 3.4 ± 0.4; TXB2= 1.00 ± 0.06. 5. Our results suggest that prostacyclin is a major product of the cyclo-oxygenase pathway in frog perfused heart. The biological significance of this finding is discussed in relation to both the absence of a coronary circulation in amphibians and to the spongy nature of frog myocardium. © 1984.

Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.

Main Content
Current View