Related Experiment Videos
Morphological pattern elicited by agents affecting spermatogenesis by stimulation
Abstract:
A variety of agents (clomiphene citrate, cyproterone acetate, estradiol 17-beta, medrogestone, medroxyprogesterone, and methoxychlor) thought to disrupt the normal pathway by which hormones stimulate the testis were tested in rats to determine the early morphologic changes in the testis. After initial trial experiments at which dose and sacrifice intervals were determined, the earliest morphological abnormalities were assessed quantitatively and related to the particular spermatogenic stage in which these defects were initiated. All agents tested produced an identical morphological pattern of response displaying a significant increase in Stage VII degenerating cells (pachytene spermatocytes, step 7 and step 19 spermatids) as compared with vehicle-administered rats. The number of degenerating cells in other stages did not significantly change. The rise in degenerating cells in Stage VII, as seen in this study, was similar to that reported in Russell and Clermont (1972) utilizing hypophysectomized rats, and that reported by other investigators who have used a variety of agents to disrupt the hormonal stimulation of the seminiferous tubules. The data indicate that no matter how, or at what level the hormonal stimulation of the testis is interrupted, the morphological pattern of response is the same, and that such a pattern is useful in predicting the mechanism of action of agents suspected of interfering with hormone action.
Insights
Agents disrupting testicular hormone stimulation cause identical early morphologic changes in rats. This consistent pattern of increased Stage VII degenerating cells aids in predicting the mechanism of action for endocrine-disrupting chemicals.
Area of Science:
- Endocrinology
- Reproductive Biology
- Toxicology
Background:
- Hormonal regulation of the testis is crucial for spermatogenesis.
- Various agents can disrupt normal testicular function.
- Understanding early cellular changes is key to identifying mechanisms of disruption.
Purpose of the Study:
- To identify early morphological changes in rat testes induced by agents disrupting hormonal stimulation.
- To correlate these changes with specific spermatogenic stages.
- To establish a predictive pattern for agents interfering with testicular hormone action.
Main Methods:
- Rats were administered various agents (e.g., clomiphene citrate, estradiol 17-beta) or vehicle.
- Dose and sacrifice intervals were optimized through initial trials.
- Morphological abnormalities in testes were quantitatively assessed and linked to spermatogenic stages.
Main Results:
- All tested agents induced a significant increase in Stage VII degenerating cells (pachytene spermatocytes, step 7 and step 19 spermatids).
- No significant changes were observed in degenerating cells in other spermatogenic stages.
- The observed pattern of Stage VII degeneration was consistent across different disruptive agents.
Conclusions:
- Disruption of testicular hormonal stimulation, regardless of the agent or level, results in a uniform morphological response.
- The specific increase in Stage VII degenerating cells serves as a reliable indicator for predicting the mechanism of action of agents affecting hormone pathways.