title: Suppression of spermatogenesis by testosterone undecanoate-loaded injectable in situ-forming implants in adult male rats.
abstract: We have investigated the feasibility of administration of testosterone undecanoate (TU)-loaded injectable in situ-forming implant (ISFI) for contraception in adult male Sprague-Dawley rats. Male rats were treated with vehicle, TU-loaded ISFIs (540, 270 and 135 mg TU kg-1 ) or TU injections (45 mg TU kg-1 every 30 days) for 120 days. Fertility tests served for determining infertility or restoration of fertility in treated rats. Serum testosterone concentration, epididymal sperm count, motility, morphology, and histology of the testis were monitored. The TU-loaded ISFIs increased serum testosterone levels in rats steadily without fluctuation over 3 months. One month after TU administration, the epididymal sperm count decreased significantly in all experimental groups. After 3 months, the animals treated with 270 and 135 mg kg-1 TU-loaded ISFIs were 100% infertile, and no implantation sites were produced in the mated females. However, some of males treated with 540 mg kg-1 ISFI or TU injections were still fertile but numbers of implantation sites were also significantly lower than control values. TU-loaded ISFI at an appropriate dose has potential as a long-acting male contraceptive drug that suppresses spermatogenesis consistently over a period of 3 months.
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Zhang
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Yang
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Meng
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Wang
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Guo
authors.affiliation: Drug Research Laboratory, Liaoning Research Institute of Family Planning, Huanggu District, Shenyang, China.
authors.forename: Dan-Hua
authors.initials: DH
authors.lastname: Liu
mesh_terms: D000818:Animals; D048430:Cell Shape / Q000187:drug effects; D003272:Contraceptive Agents, Male / Q000008:administration & dosage*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013076:Sperm Count; D013081:Sperm Motility / Q000187:drug effects*; D013091:Spermatogenesis / Q000187:drug effects*; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects*; D013739:Testosterone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: D003272:Contraceptive Agents, Male; D013739:Testosterone; C010792:testosterone undecanoate