ABSTRACT
OBJECTIVE: To evaluate the effects of metoclopramide-induced hyperprolactinemia on the prolactin receptor of murine endometrium. DESIGN: Experimental study using the RNA extraction to detect tissue prolactin receptor isoforms by reverse-transcriptase polymerase chain reaction (RT-PCR). SETTING: University-based laboratory. ANIMAL(S): Seventy-two female swiss albino mice (Mus musculus), approximately 100 days old, were divided into six 12-animal groups: (GI) nonoophorectomized mice given vehicle; (GII) nonoophorectomized mice treated with metoclopramide; (GIII) oophorectomized mice treated with metoclopramide; (GIV) oophorectomized mice treated with metoclopramide and 17beta-estradiol; (GV) oophorectomized mice treated with metoclopramide and micronized progesterone; (GVI) oophorectomized mice treated with metoclopramide and a solution of 17beta-estradiol and micronized progesterone. INTERVENTION(S): Drugs were administered for 50 days. Following euthanasia, the middle portions of the uterine horns were removed, sectioned, and immediately frozen for RT-PCR procedures. Blood was collected for the dosage of prolactin and serum estrogen and progesterone using radioimmune assay. MAIN OUTCOME MEASURE(S): Identification of uterine prolactin receptor isoforms. RESULT(S): The PRL receptor and its isoform L were identified only in GI (control group) and GII (metoclopramide), the two groups with nonoophorectomized animals. The amount of PRL receptor mRNA and that of its isoform L from GII were the largest. No other isoforms of the prolactin receptor were identified in any of the groups. CONCLUSION(S): Our results suggest that replacement of estrogen and progestin may not increase the mRNA of endometrial PRL receptor in metoclopromide-induced hyperprolactinemia in rats after castration.
Subject(s)
Endometrium/metabolism , Hyperprolactinemia/genetics , Receptors, Prolactin/genetics , Animals , Disease Models, Animal , Endometrium/drug effects , Estradiol/administration & dosage , Estradiol/blood , Female , Gene Expression Regulation , Hormone Replacement Therapy , Hyperprolactinemia/chemically induced , Hyperprolactinemia/metabolism , Metoclopramide , Mice , Ovariectomy , Progesterone/administration & dosage , Progesterone/blood , Protein Isoforms , RNA, Messenger/metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
OBJECTIVE: To quantify and study the immunoexpression of hyaluronic acid (HA) in the uterine horns of the mouse throughout the estrous cycle phases. DESIGN: Experimental study using an ELISA-like fluorometric assay to quantify HA and an avidin-biotin immunoperoxidase method using biotinylated hyaluronan-binding protein for histochemical studies. SETTING: University-based laboratory. ANIMAL(S): Forty regularly cycling adult female mice were divided into four groups according to the diagnosed phase of the cycle: proestrus, estrus, metaestrus, and diestrus. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Histologic samples of the uterine horns. Immunohistochemical reaction was evaluated by detection of HA and CD44 distribution within the uterine horn. Tissue HA content was determined through an ELISA-like fluorometric assay with the same hyaluronan-binding protein and with europium-labeled streptavidin. RESULT(S): The immunohistochemical HA and CD44 reactions were most intense during diestrus, mainly below the luminal epithelium. HA was strongly stained in the connective tissue near the myometrium layer during metaestrus. The biochemical data showed that the highest concentration of HA in uterine horns occurred during diestrus (4053.0 +/- 651.4 ng/g dry tissue) compared with other phases. CONCLUSION(S): Our data show that the expression of HA in mouse uterine horns is highest during the diestrous phase. The fluctuations of HA in the mouse uterus during the estrous phase may be related to the varying estrogen and P levels during the cycle and may be important as far as embryo implantation is concerned.
