EVOLUTION OF THE PLASMA-LEVELS OF GLYCOPROTEIC GONADOTROPIN AND 17-ALPHA HYDROXY-20-BETA DIHYDROPROGESTERONE DURING MATURATION AND OVULATION IN THE RAINBOW-TROUT, SALMO-GAIRDNERII

  • 1 January 1981
    • journal article
    • research article
    • Vol. 293  (15) , 817-820
Abstract
The plasma concentrations of the glycoproteic gonadotropin (GTH) and of the 17.alpha.hydroxy-20.beta. dihydroprogesterone (17.alpha.20.beta.OHP) were followed in the course of ovulation in 6 rainbow trout, using radioimmunoassays on samples taken every 2 days. A 1st slow and limited GTH increase (10-20 ng/ml) is detected before and during ovulation, while the 17.alpha.20.beta.OHP rises sharply (up to 300-500 ng/ml). The progestagen levels drop back to their previous values, .apprx. 3 wk after ovulation. At the same time, a 2nd higher GTH increase (25-30 ng/ml) is taking place. The relations between these 2 hormones, maturation and ovulation are discussed.