title: Effect of ovariectomy followed by administration of ovarian steroid hormones on the pig pinealocyte ultrastructure.
abstract: The ultrastructure of female pig pinealocytes was studied after ovariectomy alone and ovariectomy followed by administration of estradiol, progesterone, or both. Administration of estradiol as well as a combination of estradiol and progesterone induced qualitative ultrastructural changes in pinealocytes relative to Golgi apparatus and cytoplasmic dense bodies as well as quantitative ones, such as a decrease in relative volume of cytoplasmic dense bodies and lysosomes. Administration of progesterone caused the formation of dense bodies and a decrease in the relative volume of lysosomes. The results point to a relationship between the pineal gland and gonads in the pig and suggest that gonadal steroids, particularly estradiol, could be involved in a feedback mechanism of the hypothalamic-hypophyseal-gonadal system to the pineal gland.
authors.affiliation: Department of Histology and Embryology, Veterinary Faculty University of Agriculture and Technology, Olsztyn, Poland.
authors.forename: B
authors.initials: B
authors.lastname: Przybylska
authors.forename: Z
authors.initials: Z
authors.lastname: Wyrzykowski
authors.forename: J
authors.initials: J
authors.lastname: Kaleczyc
mesh_terms: D000818:Animals; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006056:Golgi Apparatus / Q000187:drug effects / Q000648:ultrastructure; D008247:Lysosomes / Q000187:drug effects / Q000648:ultrastructure; D015388:Organelles / Q000187:drug effects / Q000648:ultrastructure; D010052:Ovariectomy; D010870:Pineal Gland / Q000187:drug effects / Q000648:ultrastructure*; D011374:Progesterone / Q000494:pharmacology*; D013552:Swine / Q000033:anatomy & histology*
chemical_list: D011374:Progesterone; D004958:Estradiol