Effects of different dosages of ethephon on testicular tissues of male pups under different duration of action / 中华实用儿科临床杂志

ABSTRACT

Objective:To explore the effects of different doses of Ethephon on testes of male pups.Methods:Thirty-two 45-day-old healthy female Sprague-Dawley (SD) rats were randomly divided into the control group and the low dose, middle dose and high dose Ethephon groups by the random figure table.The female rats in the low dose, middle dose and high dose Ethephon groups were given 200, 400, and 800 mg/kg Ethephon solution, respectively.The control group was treated with 9 g/L saline.After the birth of the offspring, the mother rats were not administrated with any medications, and the male offspring rats were given Ethephon solution instead.Twelve offspring male rats were randomly selected from each group and killed at the age of 0, 14 and 28 days after birth.Fresh testicular tissues were stained with hematoxylin eosin (HE), and the morphological changes of testicular tissues were observed under light microscope.The apoptotic cells were labeled by terminal dexynucleotidyl transferase (TdT) mediated dUTP nick end labeling (TUNEL) method and the apoptosis index (AI) of spermatogenic cells was detected by fluorescence microscope.Results:(1) Compared with the newborn rats in the middle dose group, low dose group and control group, se-miniferous tubules in the newborn rats of the high dose group were slightly thicker, and seminiferous cells were arranged slightly in disorder.The AI of the newborn rats in high dose group was significantly higher than that in the control group (1.00±0.06 vs.0.41±0.03, P<0.01). The AI of the newborn rats in the middle dose group was not significantly different from that in the control group and the low dose group ( P>0.05). (2) The seminiferous tubules of the 14-day-old rats in the low dose, middle dose and high dose Ethephon groups were significantly thicker and arranged more loosely than those in the control group.Compared with the control group, there were very few seminiferous cells, which were arranged disorderly in the low dose, middle dose and high dose Ethephon groups.The AI of the 14-day-old rats in the low dose, middle dose and high dose Ethephon groups was (2.13±0.10), (2.18±0.10) and (3.90±0.23), respectively, which were significantly higher than that in the control group (1.00±0.02) ( F=2 508.36, P<0.01). There was no significant difference in the AI between the middle dose and low dose groups ( P>0.05). (3) Compared with the control group, the seminiferous tubules of the 28-day-old rats in the low dose, middle dose and high dose groups were significantly thicker and arranged much more loosely, and spermatogenic cells were even less and arranged in a severely disordered way.The AI of 28-day-old rats in the low dose group (5.52±0.13), the middle dose group (9.44±0.07) and the high dose group (14.56±0.27) was significantly higher than that in the control group (3.11±0.13) ( F=10 784.69, P<0.01). Conclusions:Ethephon can thicken the seminiferous tubules of newborn and young rats, cause the germ cells to arrange disorderly, promote the apoptosis of spermatogenic cells and reduce the ability of spermatogenesis.Moreover, a longer exposure of the rats to a higher concentration of Ethephon will result in more serious damage to testicular tissues.