Changes in estrogen receptor expression and cell activity of lactotropes in female mink (Mustela vison) pituitary in response to variations in the gonadal steroid environment.
This study was undertaken to get new information on the role played by estrogen (E) on the activity of mink lactotropes. Immunocytochemistry for estrogen receptor (ER) and prolactin (PRL) was applied to assess modifications in the protein production that occur as a result of in vivo changes in the gonadal steroid environment. Variations in the functional activity of lactotropes were demonstrated from the ultrastructural characteristics and morphometric parameters (cellular area, numerical density, and secretory granular size). The present study documents the presence of ER in mink lactotropes revealing the ability of E to regulate the expression of ER in the mink pituitary. Furthermore, all morphological and morphometric parameters of lactotropes activity appeared significantly increased in intact females, killed during the mating period, compared with castrated females under the same photoperiodic conditions. Castration thus blocks the stimulatory effect of photoperiod on metabolic activity of mink lactotropes suggesting that E may participate in the photoperiodic regulation of PRL.
Vidal
S
S
Department of Anatomy, University of Santiago de Compostela, Lugo, 27002, Spain.
del Mar Yllera
M
M
Román
A
A
Moya
L
L
D000818:Animals; D003593:Cytoplasm / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D004967:Estrogens / Q000502:physiology*; D005260:Female; D007150:Immunohistochemistry; D007774:Lactation / Q000502:physiology; D008907:Mink / Q000378:metabolism*; D010052:Ovariectomy; D010902:Pituitary Gland / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D011247:Pregnancy; D011388:Prolactin / Q000032:analysis / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000032:analysis / Q000378:metabolism*
D004967:Estrogens; D011960:Receptors, Estrogen; D011388:Prolactin