Induction of possible male sterility in laboratory rats by gossypol was examined by microscopic observations on sperm motility, sperm morphology following silver staining, and meiosis. The rats were force-fed with gossypol acetate once with 400mg/kg body weight. In a span of 2-5 weeks post-feeding, a marked reduction of sperm motility was observed with a concurrent increase of abnormal spermatozoa Silver staining of the spermatozoa showed various tail abnormalities, including disrupted connecting piece, bent tails, looped tails, and cracked midpiece, Sperm head structure appeared to be not affected. Beginning 6 weeks post-feeding, there was a complete recovery. Short-term in vitro experiments showed similar but weaker response. In all samples, histologieal sections and cytogenetic preparations of testes revealed no abnormalities in the activity and normally of meiotic divisions. In animals 2-4 weeks after feeding with gossypol, no argentophilic accessary structures in developing mammalian spermatids were observed.

The application of human embryonic stem cell(hES cell) contributes a lot to the disease treatment,and shows a great potentiality especially in organ transplantation and tissue engineering.Although hES cell therapy has not reached clinical application,some newly achieved results are encouraging.This review mainly presents results recently published in applying hES cell for disease treatment.

A ready-made Chinese herb containing the glycosides of Tripteri-gium wilfordii ( GTW ) have been reported to cause testicular atrophy in men. Various fractions isolated from GTW were screened in experiments on rats and mice to observe their antifertility effects and found that the monomer T9 among the requirements for male contraceptive need to be elucidated. T9 was administered through gastric intubation at a dose of 0.1mg/kg?d-1 7w? All the T9 treated rats exhibited minimal testicular damage at the end of seventh week of treatment, but causes severe damages mainly the epididymal, the spermatozod showed various structural abnormalities, including cracked midpiece, decapitation of the sperm head commonly ( above 90% ) . It is no malformed round or tadpoleshapes head sperms discernible, no significant changes were seen in main visceral organs, no immunosuppressive actions was observed. The potencies of anti-sperm activity of T9 is 100 times stronger than GTW.

The clinical trials of gossypol at the dosage of 15 mg and 22.5 mg per day were carried out in the city and the rural area respectively. The results of cytological, cytochemical as well as ultrastructural studies of the semen obtained before and during gossypol administration were as follows:1. It was shown that a decrease in sperm count and the occurrence of abnormal sperm in semen was detectable 4 weeks after gossypol administration. By the 8th week the sperm count being reduced markedly in semen, while exfoliated spermatogenic cells (including mainly spermatids and spermatocytes) increased concomitantly, the date indicated that the site of gossypol action was at the spermiogenic spermatids as well as the mid-and late stage spermatocytes.2. Decrease in the activity of SDH in the middle piece of the sperm and damage to the spiral mitochondrial sheath including derangement, vacuolation, and loss of mitochndrial cristae were observed following gossypol treatment. Such changes suggested that gossypol might suppress the energy matoblism of sperm. The effect of gosspol on the PLE of acrosome system appeared to be secondary.3. The ultrastructural changes of sperm nuclear chrmatin after gosspol treament suggested the possibility that gosspol might exert effect on the matoblism of the nuclic acid.

Mutagenesis of several male contraceptives in sperm bead anomalies was investigated. Results show that glycosides of tripterygium wilfordii hook (GTW) and its monomer T13, microwave induce sperm head anomalies. However, gossypol and monomer T4 and GTW do not induce sperm head anomalies. Adult male mice and rats were given orally GTW, monomer T4, T13 and gossypol. These chemical agents were delivered in 1% methylcellulose. Result indicated that frequency of abnormal sperm heads in GTW, T13 groups were significantly increased, while frequency of abnormal sperm heads in T4 and gossypol-treated animals were similar to that of normal controls. When male mice were exposed to microwaves of 0.5 kW for 1-2 min, for five weeks abnormal shape of spermatozoa could be found.