PARENT SESSION
SLIDE SESSION 13: GONADAL FUNCTION
Chairs: Robert Burghart, Francisco Moran (Trainee)
Univ Ottawa-Monpetit 203
1:30 PM-3:30 PM

INTERCELLULAR COMMUNICATION BETWEEN THE SERTOLI AND LEYDIG CELLS IN THE ABSENCE OF FOLLICLE-STIMULATING HORMONE RECEPTOR SIGNALING.

Krishnamurthy, H¹, Kats, Rouslan¹, Danilovich, Natalia¹, Sairam, M.R.¹, ¹

ABSTRACT- Close interactions among the various compartments are necessary to sustain efficiency of the spermatogenic process. To study the intercellular communication between the Sertoli and Leydig cells in the complete absence of FSH receptor signaling, we have examined the serum testosterone, inratesticular testosterone levels, LH receptor and 3betaHSD levels in response to different doses of oLH in FSH receptor knock out (FORKO) mice. The serum testosterone levels were significantly reduced in the adult FORKO males compared to wild type mice. Treatment with oLH resulted in a dose-dependent increase in the testosterone levels in all the three genotypes and the response in FORKO males was significantly reduced. Similarly, the total intratesticular testosterone per testis was also lower in the FOKRO males but interestingly the intratesticular testosterone per mg testis was significantly elevated in the FORKO males. Western blot analysis revealed higher activity of 3betaHSD activity and LH receptor content in the testis FORKO males. Immunohistochemistry also showed a dramatic increase in the 3betaHSD positive cells in the FORKO males. Taken together the results of the current study suggests that in the absence of FSH receptor signaling the Leydig cells may undergo hypertrophy as well as exhibit hyperactivity in terms of testosterone production but the question why circulating testosterone is low remains to be answered. Studies are underway in our laboratory to understand the mechanisms underlying this phenomenon. (Supported by grants from CIHR, Canada).

KEY WORDS: Sertoli Cell, Leydig Cell, Gonadotropins, Gonadotropin Receptors