Conclusions

Abstract

This review highlights new and controversial ideas about the mechanism of testicular descent and indicates how these ideas may be relevant for future clinical practice. The concept of two independent steps in testicular descent has allowed many previous studies that were apparently in conflict to be resolved. The possible role of MIS in initiating the first step has been discussed and now awaits definitive experiments to resolve the opposing studies. Central to the argument is the genetic mutation causing persisting müllerian duct syndrome, which clearly implicates MIS in gubernacular development. Reassessment of the way testosterone is involved in the second step of descent led to the idea that androgens may direct gubernacular migration via release of a second messenger from the GFN. CGRP has been found not only to have a pivotal role in normal testicular descent in rodents, but also in cryptorchid rodents, suggesting that it may be an important factor in many species. This has led to speculation that CGRP treatment may be used therapeutically in causing descent of undescended testes. Investigation of germ cell development in the immature mouse has revealed a putative role for MIS in germ cell maturation, which also could be important clinically in treatment of cryptorchid boys.KeywordsGerm CellGenetic MutationPutative RoleUndescended TestisGerm Cell DevelopmentThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.