Adjudin targeting rabbit germ cell adhesion as a male contraceptive: a pharmacokinetics study.
Adjudin (1-(2,4-dichlorobenzyl)-1H-indazole-3-carbohydrazide; formerly called AF-2364) has been shown to inhibit spermatogenesis by disrupting anchoring junctions at the Sertoligerm cell interface. This, in turn, leads to germ cell loss from the seminiferous epithelium, and transient infertility. Adjudin's efficacyin inhibiting spermatogenesis, the recovery of spermatogenesis after cessation of the drug, and side effects were examined in adult male Japanese rabbits. The pharmacokinetics profiles of adjudin in rabbits after oral administration and after intravenous injection were compared. Rabbits received 25 mg/kg adjudin once weekly for 4 consecutive weeks either by intravenous injection or by gavage. Vehicle-treated rabbits were used as controls. At 1, 2, 3, 4, and 8 weeks after treatment, testes were removed for microscopic examination to assess the status of spermatogenesis. Four weeks after intravenous cessation of adjudin, the recovery of spermatogenesis also was monitored. Blood was withdrawn after first administration to measure plasma concentrations of adjudin by high-performance liquid chromatography. Four weeks after intravenous treatment, examination of testis sections showed rapid exfoliation of elongated/elongating spermatids and the presence of large multinucleated cells; more than 95% of germ cells were absent from the seminiferous epithelium. Intravenous treatment showed a more severe disturbance of spermatogenesis compared with gavage treatment, which was correlated with bioavailability of the drug. The areas under the curve for intravenous injection and gavage were 20.11 +/- 1.90 and 2.23 +/- 0.45 mg x h x L(-1), respectively. These results illustrate the potential of adjudin as a male contraceptive, and the efficacy is associated with the bioavailability of the drug.
Hu
Guo-Xin
GX
Institute of Molecular Toxicology and Pharmacology, School of Pharmacy, Wenzhou Medical College, Wenzhou, China.
Hu
Lu-Feng
LF
Yang
Dai-Zheng
DZ
Li
Jun-Wei
JW
Chen
Guo-Rong
GR
Chen
Bing-Bing
BB
Mruk
Dolores D
DD
Bonanomi
Michele
M
Silvestrini
Bruno
B
Cheng
C Yan
CY
Ge
Ren-Shan
RS
D000284:Administration, Oral; D000818:Animals; D005298:Fertility / Q000187:drug effects*; D006834:Hydrazines / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000633:toxicity; D007191:Indazoles / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000633:toxicity; D007275:Injections, Intravenous; D008297:Male; D011817:Rabbits; D013091:Spermatogenesis / Q000187:drug effects*; D013092:Spermatogenesis-Blocking Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000633:toxicity
C432482:1-(2,4-dichlorobenzyl)indazole-3-carbohydrazide; D006834:Hydrazines; D007191:Indazoles; D013092:Spermatogenesis-Blocking Agents