One major research focus is on the molecular regulation of Leydig cell steroidogenic function and DNA damage/repair during aging; and in particular on the role oxidative stress resulting from increased production of reactive oxygen and decreases in cellular antioxidant defenses. A second research focus on the stem cells that ultimately give rise to adult Leydig cells, and on the issue of whether and how stem cells age. A third focus is on the regulation of mammalian spermatogenesis and its tranlation to male infertility and contraception. Finally, we are examining the effect of fetal exposure to phthalates on steroidogenic function later in life.

Leydig cell, aging, spermatogenesis, reproductive toxicology

Midzak AS, Chen H, Papadopoulos V, Zirkin BR. 2009. Leydig cell aging and the mechanisms of reduced testosterone synthesis. Mol Cell Endocrinol. 299:23-31.

Chen H, Ge RS, Zirkin BR. 2009. Leydig cells: From stem cells to aging. Mol Cell Endocrinol. 306:9-16.

Culty M, Thuillier R, Li W, Wang Y, Martinez-Arguelles DB, Gesteira Benjamin C, Triantafilou KM, Zirkin BR, Papadopoulos V. 2008. In utero exposure to di-(2-ethylhexyl) phthalate exerts both short-term and long-lasting suppressive effects on testosterone production in the rat. Biol Reprod. 78:1018-1028.

Ge, R.-S., Dong, Q., Sottas, C.M., Papadopoulos, V., Zirkin, B.R. and Hardy, M.P. 2006. In search of rat stem Leydig cells: identification, isolation and lineage specific development. Proc. Natl. Acad. Sci. 103: 2719-2724.

Jarow, J.P. and Zirkin, B.R. 2006. The androgen microenvironment of the human testis and hormonal control of spermatogenesis. Ann. N.Y. Acad. Sci. 1061: 208-220.