Hypervitaminosis A and Its Histologic Effects on Mice Testes

In order to study the therapeutic effects of high doses of vitamin A on male fertility, its histologic effects on mice testes were investigated. In this study, 48 adult white male mice in the same age (60±3 days) were used. The animals were divided into control and experimental groups and were kept in controlled conditions. The experimental group received daily dosage of 25,000 IU vitamin A (retinol palmitate) intramuscularly for seven days. After the last injection, at two-, four-, and eight- day intervals, changes in testicular weight, volume, consistency, and histologic sections of the testes were studied. In addition, each time, epididymal spermatozoa were observed. The first control group received 0.05 mL normal saline and the second one received 0.05 mL palmitic acid intramuscularly. The results indicated that the testes’ weight (P≤0.002), volume (P≤0.03), and consistency (P≤0.001) decreased significantly. Histologic studies also revealed a severe loss of connective tissue in tunica albuginea and tunica vascularis. Leydig cells and seminiferous tubes showed degeneration. These findings indicated that hypervitaminosis A could affect the male fertility in mice.