Hormone associated with obesity also plays a key role in male fertility

Researchers in the University of Warwick’s Department of Biological Sciences have found that a hormone associated with obesity is actually also very active in the male genitals where it plays a key role in male fertility and may even influence the erection response in male sexual arousal.

The research, published today (Tuesday 6th April 2004) in the “Journal of Clinical and Endocrinology and Metabolism” focuses on a protein called orexin. Orexin is named after the Greek word for appetite as previous researchers found it stimulates the human adrenal gland to produce cortisol which in turn can cause obesity. The University of Warwick researchers have now, for the first time, found clear evidence that orexin activity can be found in several areas of the male genitals where it has a more positive affect.

The University of Warwick research team (Dr. Emmanuel Karteris, Dr Jing Chen, Dr Harpal Randeva), led by Dr Harpal Randeva (Senior Lecturer) found receptors for orexins in a number of areas within the testis and penis. These areas include the:

• Testicular cells responsible for making testosterone, the primary male sex hormone, and in tubules that are responsible for producing sperm.
• They are also present in an area called the epididymis, implicating orexins in events that include transport and storage of sperm cells.
• Finally, the research team also found orexin receptors in the penis, which implicates orexin in the control of penile function including the maintenance of penile erection.