Human prolactin physiology

The overall aim of the work to be presented in this thesis was to investigate the biology of the protein hormone prolactin (PFL) in two areas of reproductive endocrinology: hypothalamic-pituitary control of PRL secretion and the possible origin of amniotic fluid PRL. For these studies, a reliable homologous PRL double antibody radioimmunoassay was developed using materials supplied by the NIAMDD. Serum PRL concentrations in 60 normal men were 12.8 ± 3.2 ng/ml (mean± 2 SO) and in 24 premenopausal women 13.6 ± 5.4 ng/ml. Depending onthe iodination procedure used, the mean assay sensitivity was 0.55 -0.61 ng/ml, the within-assay precision (expressed as a coefficient of variation) was between 5.6 - 6.6 per cent and the between-assay precision for medium pool samples was 16 - 19%. Factors crucial to the development of a reliable assay were the use of minimal oxidation conditions for PRL iodination, complete separation of the iodinated species so formed, use of a highly dilute PRL antiserum to increase assay sensitivity, careful titration of the amount of non-immune serum used to increase ant genic bulk for the second antibody step and a long incubation time to ensure maximal immunoprecipitation. [...]