Some might call it a kind of Holy Grail for reproductive science: the development of a long-term, inexpensive, completely reversible and nonhormonal male contraceptive, one that’s suitable for use in developing to first world countries.
And that is exactly the long-term goal that two UNC scientists have set out to accomplish. How? By using ultrasound from therapeutic instruments commonly found in sports medicine or physical therapy clinics. And their quest is well underway, with very promising results.
James Tsuruta, PhD, assistant professor in the Laboratories for Reproductive Biology in UNC’s Department of Pediatrics and Paul Dayton, PhD, associate professor and director of graduate studies in the Department of Biomedical Engineering successfully depleted testicular sperm in laboratory rats using therapeutic ultrasound.
And just this month, the pair received a $100,000 Grand Challenges Exploration grant from the Bill & Melinda Gates Foundation. The project, aimed at further fine-tuning this technique for maximum effect and safety, could provide men with six months of reliable, low cost, non-hormonal contraception from a single round of treatment.
Tom Hughes in our news office tells us that Tsuruta and Dayton’s project is one of 78 grants announced by the Gates Foundation in the fourth funding round of Grand Challenges Explorations, an initiative to help scientists around the world explore bold and largely unproven ways to improve health in developing countries. The grants were provided to scientists in 18 countries on six continents.
The testis is composed of many tubes called “seminiferous tubules.” In the accompanying image here, the seminiferous tubule on the left is from a testis that was not treated with ultrasound while the tubule on the right is from a testis that was treated with ultrasound.
The tubule from the control testis has many darkly stained germ cell nuclei. Most germ cell nuclei are round; the long, thin nuclei closest to the center of the tubule belong to germ cells called spermatids and they will soon be released as testicular sperm. In contrast, the ultrasound-treated tubule is completely lacking testicular sperm and has lost almost all immature germ cells, decreasing its overall diameter while greatly increasing the amount of “empty” space in the center of the tubule.
“Once the testis has stopped producing sperm and all “sperm reserves” have been depleted, it is impossible to be fertile,” Tsuruta says. “Our Grand Challenges Exploration project will determine the appropriate ultrasound treatment to temporarily interrupt the supply of testicular sperm yet allow the testis to regenerate itself from the germ cells remaining after treatment.”
May the good vibes continue….
Les Lang
hard science 