A HETEROLOGOUS RADIOIMMUNOASSAY FOR AVIAN PROLACTIN: APPLICATION TO THE MEASUREMENT OF PROLACTIN IN THE TURKEY

Abstract

A specific heterologous double-antibody RIA [radioimmunoassay] has been developed to measure turkey prolactin (PRL) using a guinea pig anti-h[human]PRL antiserum and 125I-labeled ovine PRL, [125I]oPRL. Turkey pituitary PRL and serum give parallel dose-response curves and no cross-reaction is seen with turkey growth hormone [GH], LH [lutropin] or FSH [follitropin] or mammalian LH, FSH, TSH [thyrotropin], GH or placental lactogens. The RIA is accurate and precise and is sufficiently sensitive to measure PRL in all physiological situations investigated in the turkey. The RIA will measure PRL in several avian species including the chicken, duck, goose, pheasant, pheasant .times. chicken F1 hybrid, pigeon, quail and rook. Plasma PRL concentrations in laying and broody turkey hens were not significantly different (46.5 .+-. 2.5 vs. 39.7 .+-. 3.8 ng/ml) but both were significantly higher (P < 0.001) than in non-laying turkey hens (4.6 .+-. 0.7 ng/ml). Estradiol injection into laying hens did not alter PRL levels while the same injection in non-laying hens caused a significant 3-fold increase in plasma PRL levels.