title: Active immunization with GnRH-tandem-dimer peptide in young male rats reduces serum reproductive hormone concentrations, testicular development and spermatogenesis.
abstract: GnRH sterilization vaccines have been developed for various practical and clinical reasons. However, conjugation of GnRH peptide to carrier protein has many drawbacks, hampering the further commercialization of GnRH vaccines. In this study, a new nonconjugated GnRH vaccine, D-Lys6-GnRH-tandem-dimer peptide (TDK), emulsified in Specol adjuvant was investigated for its immunocastration efficacy in young male rats. Prepubertal male rats were randomly allocated into three groups (n = 12): control (no treatment), surgically castrated or immunized against 100 μg TDK in Specol adjuvant at 6 weeks of age (with a booster 8 weeks later). Blood samples (for antibody titers and hormone concentrations) were collected at 2-week intervals until rats were killed (18 weeks of age). Compared to intact controls, active immunization against TDK reduced (P < 0.05) serum concentrations of testosterone, inhibin B, LH and FSH, prevented the onset of spermatogenesis at puberty. Furthermore, mRNA expressions of GnRH receptor, LH-β and FSH-β in the pituitary, LH receptor, FSH receptor, inhibin α, βA and βB subunit in the testes were decreased in immunocastrated rats compared to intact controls (P < 0.05). These results demonstrate for the first time that GnRH-tandem-dimer peptide emulsified in Specol is a promising veterinary sterilization medicine.
authors.forename: Xing-Fa
authors.initials: XF
authors.lastname: Han
authors.forename: Jun-Li
authors.initials: JL
authors.lastname: Li
authors.forename: Yu-Qin
authors.initials: YQ
authors.lastname: Zhou
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Ren
authors.forename: Gong-Cheng
authors.initials: GC
authors.lastname: Liu
authors.forename: Xiao-Han
authors.initials: XH
authors.lastname: Cao
authors.forename: Xiao-Gang
authors.initials: XG
authors.lastname: Du
authors.affiliation: Isotope Research Biological Engineering and Application Biology Department, Laboratory, Sichuan Agricultural University, Ya'an 625014, People's Republic of China.
authors.forename: Xian-Yin
authors.initials: XY
authors.lastname: Zeng
mesh_terms: D000818:Animals; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D037201:Follicle Stimulating Hormone, beta Subunit / Q000187:drug effects / Q000235:genetics; D007987:Gonadotropin-Releasing Hormone / Q000276:immunology*; D028322:Inhibin-beta Subunits / Q000187:drug effects / Q000235:genetics; D007265:Inhibins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D007986:Luteinizing Hormone / Q000187:drug effects / Q000378:metabolism; D037101:Luteinizing Hormone, beta Subunit / Q000187:drug effects / Q000235:genetics; D008297:Male; D010455:Peptides; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects* / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D011962:Receptors, FSH / Q000187:drug effects / Q000235:genetics; D011974:Receptors, LH / Q000187:drug effects / Q000235:genetics; D011966:Receptors, LHRH / Q000187:drug effects / Q000235:genetics; D012741:Sexual Maturation / Q000187:drug effects*; D013091:Spermatogenesis / Q000187:drug effects*; D013737:Testis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D013739:Testosterone / Q000378:metabolism; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000494:pharmacology*
chemical_list: D037201:Follicle Stimulating Hormone, beta Subunit; C498906:Inhbb protein, rat; D037101:Luteinizing Hormone, beta Subunit; D010455:Peptides; D012333:RNA, Messenger; D011962:Receptors, FSH; D011974:Receptors, LH; D011966:Receptors, LHRH; D018074:Vaccines, Conjugate; C422364:inhibin B; C103008:inhibin beta A subunit; C094377:inhibin-alpha subunit; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D007265:Inhibins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D028322:Inhibin-beta Subunits