Muneera M. Adlan; Munera A. Ibrahim & Faris S. Kata

The current study aimed to demonstrate the physiological and histological effects of methotrexate (MTX ) in laboratory mice's testes . 24 male laboratory mice, Mus musculus L., were used. The experimental mice were divided into three groups of equal number ,with eight mice for each group . The first group of mice was injected with 0.1 ml of distilled water and adopted (as a control group) , the second group was also injected with a low concentration of methotrexate (2 mg/kg), while the third group was injected with a high concentration of the drug (4 mg/kg) . The mice were injected into the Intraperitoneal daily for 16 days. The results of the current study showed a significant decrease in sperm count at both doses (2,4 mg/kg) with a probability level of P <0.05 compared to the control group . The drug also caused a significant decrease in the number of normal sperm in mice treated with both doses, and an increase in the number of abnormalities of the sperm's head and tail . In addition, injecting males with the drug caused a significant reduction in the concentration of testosterone at both doses. The drug also had a clear effect on testicular tissue in general and the process spermatogenesis in particular. The results of the histological examination showed that the testicular tissue was affected in the treatment group compared with the control group , to varying degrees between the group treated with the low concentration and the high concentration . It has been observed that there are vacuoles in some seminiferous tubules, the appearance of degeneration and necrosis processes of germ cells, a decrease in the thickness of the germ mass, and a narrowing of the lumen of some seminiferous tubules. It was also observed that there was exfoliated , cytolysis , loss of germ cells , infiltration of inflammatory cells in some seminiferous tubules, and the appearance of amyloid between the seminiferous tubules , significantly in the group treated with the high concentration . The current study concluded that methotrexate causes severe damage to the testicles through a decrease in the number of sperm, distortions in their external appearance, a decrease in the level of testosterone, and a significant decrease in the process of spermatogenesis.

KEY WORDS: Methotrexate; Testosterone; Sperm; Spermatogenesis.

ADLAN, M. M.; IBRAHIM, M. A. & KATA, F. S. Physiological and histological changes of the testes of laboratory mice treated with methotrexate. Int. J. Morphol., 42(6):1730-1738, 2024.