Objectives: The aim of this study was to investigate the histological changes in uterus tissue of rats after pinealectomy at light microscopic level

Materials and Methods: For this purpose, 14 female Wistar-Albino rats were divided equally into two groups. Rats in group I were used as control (sham-pinealectomy), whereas rats in group II were pinealectomized. At the end of the one-month experimental period, all rats were killed by vascular perfusion. Uteri of all rats were weighed. Following routine histological procedures, uterus tissue specimens were examined under a light microscope.

Results: In the pinealectomized rats, there were increases in uterus weights. In light microscopic examination, it was observed that increase in endometrial connective tissue cells and dilatation in endometrial glands after pinealectomy. Additionally, myometrial blood vessels were filled as compared to control group.

Conclusion: Endometrial hyperplasia which appeared to be linked with the decrease in melatonin’s antigonadal activity due to the lack of melatonin was seen in experimental rats after surgical removal of the pineal gland. ©2005, Fırat Üniversitesi, Tıp Fakültesi