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A male contraceptive targeting germ cell adhesion


Throughout spermatogenesis, developing germ cells remain attached to Sertoli cells via testis-specific anchoring junctions. If adhesion between these cell types is compromised, germ cells detach from the seminiferous epithelium and infertility often results. Previously, we reported that Adjudin is capable of inducing germ cell loss from the epithelium. In a small subset of animals, however, oral administration of Adjudin (50 mg per kg body weight (b.w.) for 29 d) resulted in adverse effects such as liver inflammation and muscle atrophy. Here, we report a novel approach in which Adjudin is specifically targeted to the testis by conjugating Adjudin to a recombinant follicle-stimulating hormone (FSH) mutant, which serves as its 'carrier'. Using this approach, infertility was induced in adult rats when 0.5 μg Adjudin per kg b.w. was administered intraperitoneally, which was similar to results when 50 mg per kg b.w. was given orally. This represents a substantial increase in Adjudin's selectivity and efficacy as a male contraceptive.

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Figure 1: The hormonal and receptor-binding activity of the M3 FSH mutant.
Figure 2: Reaction scheme for conjugating Adjudin to the M3 FSH mutant.
Figure 3: Pharmacokinetics of Adjudin–M3 FSH conjugate in rats.
Figure 4: Effects of the Adjudin–M3 FSH conjugate on the testis and fertility.


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This work was supported in part by grants from the NIH (National Institute of Child Health and Human Development, U01 HD045908 and U54 HD029990 Project 3 to C.Y.C.) and the CONRAD Program (Consortium for Industrial Collaboration in Contraceptive Research, CIG 01-74 to D.D.M. and CIG 01-72 to C.Y.C.).

Author information

Authors and Affiliations



D.D.M. and C.Y.C. designed research; D.D.M., C.H.W. and C.Y.C. performed research; B.S., C.H.W., D.D.M. and C.Y.C. contributed reagents/analytical tools; D.D.M. and C.Y.C. analyzed data, wrote the paper, and established the in vivo model to study anchoring junction dynamics using Adjudin and the Adjudin-FSH mutant conjugate that was used in the study.

Corresponding authors

Correspondence to Dolores D Mruk or C Yan Cheng.

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Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Table 1

Results of toxicity study for Adjudin. (PDF 77 kb)

Supplementary Table 2

The primary sequence of rat FSH subunits and mutants. (PDF 74 kb)

Supplementary Table 3

Effects of different mutations on FSH action. (PDF 100 kb)

Supplementary Table 4

Primers used for production of the M1 FSH mutant. (PDF 84 kb)

Supplementary Table 5

Primers used for production of the M3 FSH mutant. (PDF 84 kb)

Supplementary Note 1

Synthesis of Adjudin [AF-2364, 1-(2,4-dichlorobenzyl)-1H-indazole-3-carbohydrazide]. (PDF 70 kb)

Supplementary Note 2

Subchronic toxicity report of Adjudin (AF-2364). (PDF 1684 kb)

Supplementary Note 3 (PDF 1932 kb)

Supplementary Methods (PDF 124 kb)

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Mruk, D., Wong, CH., Silvestrini, B. et al. A male contraceptive targeting germ cell adhesion. Nat Med 12, 1323–1328 (2006).

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