Effects Of Melatonin On The Secretion Of Hormone In Follicular Granulosa Cells And Hypophysis Cells Of Ewes In Vitro

Seasonal breeding Mongolian ewes were regarded as object in this research. The study adapted the way of cell culture and then carried different treatment. The hormone concentrations in cell culture medium were analyzed by RIA. The results were as follows: (1) Granulosa cells and hypophysis cells could be cultured with free-serum culture system in vitro, and secret corresponding hormone. (2) When follicular granulosa cells were treated with MLT or MLT and HCG, it could promote secretion of 17- β-estradiol and had the reliability of time and concentration, but progesterone was not tested in follicular granulosa cells culture medium. (3) When hypophysis cells were treated with MLT singly, the concentration of PRL, except 2000 group, was higher than that of control group, others were lower than that of control group significantly (P<0.01), but the concentration of PRL increased with the increase of MLT. The concentration of PRL in all groups at 48 hour were lower than that of control group.(4) When hypophysis cells were treated with MLT, the concentration of FSH, except 100 group, was higher than that of control group significantly at 24 hour (P<0.05), and its secretion when cultured for 48 hour were lower than those cultured for 24 hour significantly (P<0.01). This showed MLT could promote the secretion of FSH, but the function of secretion declined with the last of time. (5) There was no effect on the secretion of LH using only MLT to treat hypophysis cells. (6) Hypophysis cells were treated by MLT and HCG together, the concentration of PRL in treatment groups were lower than that of control group significantly (P<0.01) at 24 hour, but the concentration of PRL rose with the increase of MLT concentration in every treatment groups. PRL concentration only in 2000 group was higher than that of control group significantly in 24 hour (P<0.01), other treatment groups were lower than that of control group. And with the increase of MLT the level ofPRL rose in every treatment groups. This showed MLT and HCG together did not promote the secretion of PRL. The concentration of PRL in control and HCG group at 48 hour were lower than those of at 24 hour, however the concentration of PRL in treatment groups in 48 hour were higher than those of at 24 hour. It indicated MLT and HCG together could extend the function of PRL secretion in hypophysis cells. (7) When hypophysis cells were treated with MLT and HCG, we found it could promote the secretion of FSH significantly (P<0.01). Although MLT and HCG together could promote the secretion of LH, HCG played an important role in the process. (8) When hypophysis cells were treated with MLT and LHRH, we found there were no effect on the secretion of PRL at 24 hour and 48 hour. But in all groups the secretion increased with the increase of MLT concentration at 24 hour, and decreased with the increase of MLT concentration at 48 hour. (9) When hypophysis cells were treated with MLT and LHRH, the concentration of LH in 10 and 1000 group were higher than that of control group at 24 hour, and at 48 hour all treatment groups were higher than that of control group. It showed that MLT and LHRH together could possibly stimulate the secretion of LH.