D. Guemene et al., DEVELOPMENT AND VALIDATION OF A HOMOLOGOUS RADIOIMMUNOASSAY USING A BIOLOGICALLY-ACTIVE RECOMBINANT TURKEY PROLACTIN, British Poultry Science, 35(5), 1994, pp. 775-787
1. A new homologous radioimmunoassay has been developed for the measur
ement of turkey prolactin. 2. A 25000 kDa purified recombinant derived
turkey prolactin (rtPRL), the biological activity of which was tested
using a crop sac assay, was used as immunogen for the production of r
abbit antiserum. In this biological test, the rtPRL was as active as t
he ovinePRL. 3. The radioligand (rtPRL) was labelled with I-125 and th
e assay allowed the detection of standard doses of rtPRL ranging from
400 pg/tube to 50 ng/tube. 4. No cross reaction with chicken luteinisi
ng hormone and recombinant chicken growth hormone was detected. 5. The
within and between assay coefficients of variability were 5.0 +/- 2.7
% and 16.3%, respectively. The overall mean recovery ratio was 1.01. 6
. The dose-response curves obtained with serial dilution of plasma and
pituitary from turkey hens at different physiological stages and from
male turkeys were parallel to those obtained with standard rtPRL. 7.
The measured concentration of prolactin was 5 times higher in plasma f
rom incubating than laying turkey hens, and the pituitaries from incub
ating hens contained 2 and 4 times more prolactin than those of laying
and out of lay hens or males, respectively. 8. To further assess the
validity of the assay, we measured changes in plasma concentration of
prolactin in turkeys following stimulation with chicken vasointestinal
peptide (cVIP). A single injection of 1 or 10 mu g/kg body weight of
cVIP to laying hens produced a large and rapid increase in plasma prol
actin. 9. This new radioimmunoassay appears to be highly specific and
sensitive for the measurement of turkey prolactin.