Researchers led by teams at the Johns Hopkins Bloomberg School of Public Health and Wenzhou Medical University of China have discovered a way to keep adult stem cells that are destined to become testosterone-producing cells multiplying and on track to fulfill their fate, a new study reports.
The findings could eventually help scientists develop transplantable cells that can churn out testosterone, avoiding the multitude of drawbacks associated with other ways to administer this quintessential male hormone. A report on the research is published online in the Proceedings of the National Academy of Sciences.
Scientists have long known that testosterone, produced by Leydig cells in the testicles, is necessary for the male reproductive system to develop in fetuses and to maintain male reproductive function later in life. More recent research has shown that testosterone performs a host of other critical jobs in the body, with deficiencies contributing to increased body fat, decreased muscle mass, increased fatigue, depressed mood, decreased cognitive function and reduced immune response. Low testosterone has also been linked to increased mortality risk in older men.
To combat these issues, and to synchronize secondary sexual characteristics with gender identity in transgendered men, doctors often prescribe testosterone supplements that can be administered a variety of ways, including injection or topically. But these methods have a number of side effects, including increased risk of heart attacks and strokes, prostate enlargement, breast enlargement and acne. These issues, says study leader Dr. Haolin Chen, senior scientist in the department of biochemistry and molecular biology at the Bloomberg School, stem from the dramatic peaks and valleys in blood concentrations of the hormone that result from artificial administration.