The effect of progesterone and progesterone + estradiol on the morphology of the pineal gland in immature female pigs.

Pineal gland of the immature female pigs treated with progesterone and progesterone and estradiol simultaneously were investigated with light and electron microscopy. Both of the applied hormones influenced the structure of the pineal glands. Inhibitory effect of progesterone on the relative volume of mitochondria, granular vesicles and dense bodies of type one was observed. Administration of progesterone and estradiol simultaneously caused more complicated influence statistically significant increase of pinealocyte nuclei volume and at the same time significant decrease of mitochondria and granular vesicles.