Infertility accounts for problems associated with conceiving and about 15% of couples worldwide are affected due to this condition. Male infertility rate has increased more than that of female infertility rate; heat stress of the scrotum majorly affecting spermatogenesis and cryptorchidism, a condition characterized by the loss of one or both of the testes in the scrotum are the contributors of male infertility.
A team from the Yong Loo Lin School of Medicine at the National University of Singapore (NUS) headed by Prof. B.C. Wong demonstrate for the first time the physiological, pharmacological role of hydrogen sulphide (H2S) in testicular germ cells and unraveled how H2S aids in protecting the germ cells by preserving mitochondrial function and stimulates anti-oxidant activity.
H2S known to cause the smell of rotten eggs could be a potential cure to male infertility someday. It plays an important role in generating anti-oxidant effects in the brain, heart, kidney and bone. Endogenous H2S is produced in small amounts by the enzymes cystathionine β-synthase (CBS), cystathionine γ-lysase (CSE) in the testes.
Heat stress can be caused by saunas, excessive exercise and heat exposure working environment. Sperm cells having a limited cellular cytoplasm are easily susceptible to oxidative stress. During excessive heat stress, reactive oxygen species (ROS) are generated which then attack the lipids of the mitochondrial membrane and hence sperm apoptosis is triggered. Mitochondrial controls the process of apoptosis via the intrinsic pathway increasing the ratio of Bax/Bcl-2, release of cytochrome C and the extrinsic pathway involving caspase 8 activation. Mitochondrial dysfunction is the major source of ROS contributing to high oxygen consumption, decrease in ATP levels, finally leading to oxidative stress.
In the study, they applied carefully calculated does of NaHS (Sodium hydrosulphide), a contributor of H2S exogenously to sperm cells. The results observed were that it decreased oxygen consumption, reversed heat-induced ATP depletion, and led to less production of intracellular ROS i.e. it prevented the intrinsic apoptotic pathway of mitochondria getting activated in sperm cells. Furthermore, NaHS treatment also ameliorated the activity of SOD, one of the most important anti-oxidative enzymes on scavenging of free radicals.
Results obtained in these studies suggest that the H2S protected testicular germ cells against heat-induced apoptosis via an anti-oxidant mechanism and Prof. P. C. Wong’s team believes H2S could potentially be a treatment to male infertility, provided the carefully designed studies have to be performed to optimize the perfect dose concentration of H2S to replicate similar effects in humans.
Source: The Straits Times.