Induction (or Stimulation) of Prolactin and Growth Hormone Production in a Rat Pituitary Tumor Cell Line by Bromodeoxyuridine

Under basal conditions, a rat pituitary tumor cell line (C₈ 11RAP) does not secrete any detectable PRL, FSH, and LH, and secretes only minute amounts of GH (27.1 ± 0.5 ngThis International Symposium is sponsored by the Italian Society of Endocrinology and the Italian Society of Andrology. Topics will include: ABP in the testis, Sertoli and Leydig cell function, LHRH effects on pituitary and testis, desensitization by hCG and clinical implications, hypothalamic-pituitary-testicular function in pre-pubertal and old age, regulation of gonadotropin release, inhibin and other gonadal peptides, epididymal and spermatozoal function. Some 30 speakers have been invited. The official language is English. A limited number of free communications and poster presentations will be selected.10⁶ cells-24 h), as evaluated by RIA. Bromodeoxyuridine (BrdUrd) added to the culture medium induced the accumulation of PRL into cells and medium, increased that of GH, but did not induce that of LH or FSH. The amount of radioimmunoassayable PRL and GH accumulated in the medium increased after a lag period of 15 days and was drug concentration dependent. Maximal accumulation was 232.9 ± 36.8 and 493.6 ± 41.5 ngThis International Symposium is sponsored by the Italian Society of Endocrinology and the Italian Society of Andrology. Topics will include: ABP in the testis, Sertoli and Leydig cell function, LHRH effects on pituitary and testis, desensitization by hCG and clinical implications, hypothalamic-pituitary-testicular function in pre-pubertal and old age, regulation of gonadotropin release, inhibin and other gonadal peptides, epididymal and spermatozoal function. Some 30 speakers have been invited. The official language is English. A limited number of free communications and poster presentations will be selected.10⁶ cells-24 h for PRL and GH, respectively, at 50 μgThis International Symposium is sponsored by the Italian Society of Endocrinology and the Italian Society of Andrology. Topics will include: ABP in the testis, Sertoli and Leydig cell function, LHRH effects on pituitary and testis, desensitization by hCG and clinical implications, hypothalamic-pituitary-testicular function in pre-pubertal and old age, regulation of gonadotropin release, inhibin and other gonadal peptides, epididymal and spermatozoal function. Some 30 speakers have been invited. The official language is English. A limited number of free communications and poster presentations will be selected.ml BrdUrd. In the presence of BrdUrd (≥20 μgThis International Symposium is sponsored by the Italian Society of Endocrinology and the Italian Society of Andrology. Topics will include: ABP in the testis, Sertoli and Leydig cell function, LHRH effects on pituitary and testis, desensitization by hCG and clinical implications, hypothalamic-pituitary-testicular function in pre-pubertal and old age, regulation of gonadotropin release, inhibin and other gonadal peptides, epididymal and spermatozoal function. Some 30 speakers have been invited. The official language is English. A limited number of free communications and poster presentations will be selected.ml), the cells grew more slowly and were more strongly attached to the flasks. All of the effects induced by BrdUrd were reversible. PRL and GH were characterized by three methods: 1) radiocompetition with increasing dilution of samples; 2) Sephadex chromatography, followed by RIAs; and 3) sodium dodecyl sulfate-polyacrylamide gel electrophoresis done on the immunoprecipitate of the proteins secreted by cells incubated with [³H]leucine. Chronic treatment with TRH (3 × 10^-6 M) of cells grown without BrdUrd was unable to increase the production of GH or to induce that of PRL. On the other hand, after the same treatment of cells cultured in the presence of BrdUrd, the amounts of PRL accumulated in the culture medium or cells were increased 2- to 7-fold over unstimulated levels; under the same conditions, GH accumulation in the medium was also increased, but this augmentation was less than that of PRL.

These results indicate that BrdUrd simultaneously induces or stimulates the production of PRL and GH in C₈ 11RAP cells, and that TRH increases the production of both hormones only in BrdUrd-treated cells