The effect of growth hormone on granulosa cell function during in-vitro fertilization.

The effect of growth hormone addition to human menopausal gonadotrophin (HMG), after pituitary down-regulation, on granulosa cell function, in in-vitro fertilization (IVF) was evaluated. Growth hormone or placebo were added in a prospective, randomized and double-blind manner to an existing IVF stimulation protocol. Forty-two normal ovulatory women (< or = 38 years old) with mechanical factor infertility and normal male factor were included in the study. Gonadotrophin-releasing hormone agonist (GnRHa) was given from day 21 of the previous cycle until human chorionic gonadotrophin (HCG) administration. Follicular stimulation with HMG was started after pituitary down-regulation. Growth hormone 12 IU/day or placebo were administered on alternate days, beginning day 1 until day 7 of HMG treatment. Granulosa cell function was evaluated, in all patients, by follicular fluid levels of ovarian steroids and insulin-like growth factor-I (IGF-I). In 14 patients, chosen arbitrarily granulosa lutein cells were cultured in the presence and absence of additional HCG. Follicular fluid levels of oestradiol, progesterone, testosterone and IGF-I were similar in both growth hormone and placebo groups. Basal and post-HCG levels of oestradiol and progesterone did not differ significantly between the two groups of granulosa lutein cell cultures. We conclude that after pituitary down-regulation, in-vivo administration of growth hormone with HMG in young ovulatory women does not seem to affect granulosa cell function when compared to the administration of HMG alone.

Effects of melatonin on progesterone production by human granulosa lutein cells in culture.

OBJECTIVE: To test the hypothesis that melatonin modulates steroid synthesis in the human ovary. DESIGN: Granulosa lutein cells obtained from in vitro fertilization cycles were cultured in medium containing melatonin and human chorionic gonadotropin (hCG). RESULTS: Progesterone (P) secretion by granulosa lutein cells increased progressively in both basal and hCG-stimulated conditions, up to 96 hours in culture, plateaued at 144 and decreased thereafter. Melatonin (10(-7), 10(-9), 10(-11) M) had no effect on basal P or 17 beta-estradiol production. The addition of melatonin to the hCG-treated granulosa lutein cells significantly (P less than 0.05) potentiated the stimulatory effect of hCG on P production. The effect was most prominent after 144 and 196 hours of incubation. CONCLUSION: This observation suggests a role for melatonin in the intraovarian control of P production in the human ovary.

Isolation and characterization of HL-60 cell variants with different potentials for spontaneous differentiation.

Although HL-60 cells, an in vitro established cell line derived from a patient with acute promyelocytic leukemia, are blocked at the promyelocytic stage of myeloid differentiation, certain chemicals can induce the cells to undergo terminal differentiation into either granulocytes or macrophages. Moreover, a small fraction of the cell population undergoes differentiation spontaneously without the addition of any inducing agent. In this paper it is demonstrated that this cell line is heterogeneous with respect to the ability of the cells to differentiate spontaneously: some clones (SD+) have a higher tendency to do so than others (SD-). In semi-solid medium, SD+ cells developed diffused colonies containing mature monocytes and macrophages, whereas SD- cells developed compact colonies of promyelocytes. Based on these morphological differences the various clones were isolated and analysed. Although only a small fraction of the population actually became differentiated at any particular time, practically all the cells in the SD+ clones had the potential to differentiate spontaneously. The clones also differ in their response to differentiation inducers; whereas some agents induced complete differentiation in both types of clones, others (e.g. actinomycin C and cytosine arabinoside) induced only SD+ clones, suggesting that differentiation induced by the latter agents is related to the ability of the cells to differentiate spontaneously. Thus the potential of leukemic cells to undergo spontaneous differentiation may be an important factor when considering differentiation-inducing therapy for leukemic patients.