Cheng CY, & Mruk DD (2012). The Blood-Testis Barrier and Its Implications for Male Contraception. Pharmacological Reviews, 64(1), 16-64. https://doi.org/10.1124/pr.110.002790
Cheng CY, Mruk DD. The Blood-Testis Barrier and Its Implications for Male Contraception. Pharmacological Reviews. 2012;64(1):16-64. doi:10.1124/pr.110.002790
Cheng CY, and Mruk DD. "The Blood-Testis Barrier and Its Implications for Male Contraception." Pharmacological Reviews, vol. 64, no. 1, 2012, pp. 16-64.
How the Blood-Testis Barrier Blocks Male Contraceptive Drugs
This is a 2012 lab review of rat studies. The review looks at the blood-testis barrier, a tight seal that protects growing sperm cells. Less than 1% of one test drug reached the testis when rats took it by mouth. The finding shows how strongly the barrier blocks new male birth control drugs that skip hormones.
Key Findings
In rats given either a low or high dose of the experimental drug adjudin, all sperm-forming cells except stem cells disappeared from the testis within about 2 weeks.
At the lower dose, normal sperm production started returning around 20 weeks, and more than 70% of tubules were producing sperm normally again by 30 weeks; the higher dose failed to recover.
Less than 1% of adjudin given orally to rats reached the testis, leaving little room between a dose strong enough to work and one that could cause harm.
Reducing one drug transport protein by about 70% cut the drug's delivery into the testis's inner compartment by about 30%; blocking four such proteins together cut delivery by more than 70%.
Roughly 60% of the about 800 known drug transporter proteins in mammals are built into cell membranes, and many sit in the cells that form the blood-testis barrier.
Interpretation
This is a lab review. The review is not a study of men. The authors bring together years of rat and cell research on how the blood-testis barrier forms and how drugs cross it. No contraceptive here was tested in men. The review does not say if a new drug would be safe or work well in people. The drug-delivery findings come from rat dosing and lab-grown cell barriers. They do not come from patients. What it does show is that this barrier is a real, well-studied block to getting drugs into the testis, for birth control or for treating other problems there.
RRM Context
RRM Academy treats this as background science. The review is not care advice. The review also shows how things like cadmium and bisphenol A can hurt the blood-testis barrier and lower sperm counts. That is one way male infertility can start. The drugs studied here are not an RRM method. They work by shutting down sperm production on purpose. RRM instead looks for the cause of infertility in both partners and treats it.
Our editorial summary of this paper, not the article's abstract.
Abstract not indexed.
C. Yan Cheng, Dolores D. Mruk
D Mruk
DOI 10.1124/pr.110.002790 10.1124/pr.110.002790 Cheng et al. 2012, Cheng 2012
03zjj0p70