Based on the research results of Professor Shigenobu Tona, a special full-time professor at Tokyo Denki University, it was found that temperature is the only cause of sperm formation in "undescended testis".
The testes of mammals, including humans (excluding elephants and whales), descend into the scrotum before birth and air-cooled to allow sperm to form normally.However, it is known that a few percent of newborns have "undescended testes" in which the testes stay in the abdominal cavity, and sperm is not formed, which is one of the causes of male infertility and the risk of developing testicular cancer. It will increase.
Numerous studies have been conducted on why sperm cannot be formed in cryptorchidism, but the definitive cause has not been clarified.Therefore, in this study, we conducted an experiment in which the testes of mice were cultured in vitro at different temperatures, and found that sperm could not be produced at 37 ° C, which is the same as in the abdominal cavity, but sperm could be produced only at 34 ° C. ..
Upon closer examination, it was found that cells that become sperm cannot replicate DNA when cultured at 37 ° C, which is the main cause of sperm failure in cryptorchidism.On the other hand, when the temperature in the test tube was lowered from 37 ° C to 34 ° C, it was found that the cells that became sperm awakened as if they were switched on and formed sperm. It was confirmed that the cells that become sperm do not die at 37 ° C, but that DNA replication stops (the cells that become sperm are only sleeping).
In the future, by clarifying the target in which the DNA replication apparatus of cells that become sperm is inactivated at 37 ° C, it is possible that spermatogenesis can be promoted by supplementing the molecule. Is also expected to develop into one of the future fertility treatments.
