V. K. Ganjam, B.V.Sc., M.S., PhD

Email: GanjamV@missouri.edu

Research Interests: Testicular steroidogenesis, sperm maturation

Teaching: Endocrinology and reproductive physiology

Dr. Ganjam has continued his work in elucidating the precise mechanisms involved in mammalian sperm maturation. Sperm acquire or develop the capacity for fertilization only during their transit through the epididymis, and knowledge of the sperm maturation process should enable its manipulation. The reversible prevention of sperm maturation, induction of premature cell death, or the binding of an "antifertilizing compound" to sperm within the epididymis might afford alterative methods for contraception.

The major functions carried out by the epididymis are the transport of spermatozoa, their maturation (acquisition of fertilizing potential), and their storage. The maturation of spermatozoa occurs by passage through the epididymis, and, depending on the species, is complete between the distal caput and the proximal cauda epididymis.

This process is active in that germ cells need to be exposed to the changing epididymal environment in order to become mature. Regarding the regulation of epididymal functions, several lines of evidence have come together to indicate that the primary androgen(s) responsible for maintaining epididymal histology and functions, is (are) the 5_-reduced metabolite(s) of testosterone, namely dihydrotestosterone (DHT) and/or its 3_-reduced form (3_-diol).

We are continuing our studies on 1) factors regulating epididymal 5_-reductase activity, 2) distribution and kinetics of epididymal androgen receptors, and 3) to establish the interaction of androgen receptors and the gene expression of 5_-reductase.

Selected publications:
Nonneman DJ, Ganjam VK, Welshons WV, and vom Saal FS. Intrauterine position effects on steroid receptors of reproductive organs in male mice. Biology of Reproduction, 47:723-729, 1992.

Slight S, Ganjam VK, Nonneman DJ, and Weber KT. Glucocorticoid metabolism in the cardiac interstitium: 11 beta-hydroxysteroid dehydrogenase activity in cardiac fibroblasts. J. Lab. Clin. Med., 122:180-187, 1993.

Mann FA, Nonneman DJ, Pope ER, Boothe HW, Welshons WV, and Ganjam VK. Androgen receptors in the pelvic diaphragm muscles of dogs with and without perineal hernia. Am. J. Vet. Res., 56:134-139, 1995.

Messer NT, Johnson PJ, Refsal KR, Nachreiner RF, Ganjam VK, and Krause GF. Effect of food deprivation on baseline iodothyronine and cortisol concentrations in healthy, adult horses. Am. J. Vet. Res., 56:116-121, 1995.