NEW YORK - Why does stress cause a man's sperm count to plummet? Research led by Population Council endocrinologist Matthew Hardy found that stress hormones overpower the enzymes responsible for ensuring that cells in the testes produce testosterone, which is necessary for sperm formation.
Offering the first evidence that stress acts locally within the testes, via the Leydig cells, the report by Hardy and his colleagues is the lead article in the December Endocrinology and is accompanied by an editorial comment.
"It's well known that stress exerts a profound suppression on the male reproductive system, but we really haven't understood until now where or how in the complex process of spermatogenesis it happens," Hardy says. "This is also a new way of understanding how enzymes work in Leydig cells."
While Hardy's work provides insight into male reproduction, it may also aid the design of new male contraceptives. He comments, "I am ultimately interested in the control of testosterone production. Anytime you look at the biosynthesis of testosterone, you are looking at a potential way to regulate sperm production."
Hardy found receptors in adult Leydig cells that mediate the action of glucocorticoid hormone. In small amounts, glucocorticoid helps cells grow and thrive, but in the large amounts produced during times of stress, it disrupts normal body processes. Too much glucocorticoid overwhelms the Leydig cell defense mechanism, which is controlled by an enzyme called, for short, 11ßHSD-1. The cell produces only enough 11ßHSD-1 to cope with normal amounts of glucocorticoid. The surfeit of hormone overwhelms the capacity of 11ßHSD-1 to neutralize it, shortcircuiting testosterone production. Without testosterone, other sperm-making cells do not begin to manufacture sperm.
Enzyme acts as a double agent
11ßHSD-1 assists and neutralizes glucocorticoid as necessary. As Leydig cells
develop, the amount of enzyme increases in para
Contact: Christina Hourzepa