title: Induction of connexin 32 expression by potential embryonic signals in rabbit uterine epithelium.
abstract: Connexin 32 induction is found in rabbit uterine epithelium as a response to embryo recognition. Here we have chosen this connexin 32 expression as a cell biological marker to define the type of a locally acting embryonic signal. 17 beta-estradiol, onapristone, catechol estrogen (4-hydroxy-estradiol), prostaglandins E2 and F2 alpha, db-cAMP, and glass beads as mechanical stimuli were given to pseudopregnant animals on day 4, 5 or 6 posthuman chorionic gonadotropin (hCG). The induction of connexin 32 corresponded to the time of implantation at days 6-8 post-hCG by immunohistochemistry and Northern blot analysis. Untreated pseudopregnant animals started to express connexin 32 on day 8 post-hCG. In animals treated with 4-hydroxy-estradiol, 17 beta-estradiol or prostaglandins, connexin 32 expression started 1 day earlier (day 7 post-hCG) and led to an enhanced connexin 32 expression on day 8 post-hCG compared to control animals. The antigestagen, onapristone, as well as cAMP did not alter the endogenous program. Mechanical stimuli led to a high expression of connexin 32 starting at day 7 post-hCG whereas in pregnancy the blastocyst induces connexin 32 expression from day 6 postcoitum onwards. Combination of mechanical stimuli with 17 beta-estrogen advanced the induction to day 6 post-hCG. We conclude that a mechanical stimulus in combination with 17 beta-estradiol induces connexin 32 synthesis in a similar manner as compared to the blastocyst during pregnancy.
authors.affiliation: Institut für Anatomie, Universitätsklinikum Essen, Germany.
authors.forename: B
authors.initials: B
authors.lastname: Antoskiewicz
authors.forename: G
authors.initials: G
authors.lastname: Müller
authors.forename: R
authors.initials: R
authors.lastname: Grümmer
authors.forename: E
authors.initials: E
authors.lastname: Winterhager
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology; D017630:Connexins / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D000242:Cyclic AMP / Q000494:pharmacology; D015237:Dinoprost / Q000494:pharmacology; D015232:Dinoprostone / Q000494:pharmacology; D004622:Embryo, Mammalian / Q000502:physiology*; D004717:Endometrium / Q000737:chemistry / Q000378:metabolism; D004848:Epithelium / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006067:Gonanes / Q000494:pharmacology; D006727:Hormone Antagonists / Q000494:pharmacology; D007275:Injections, Intravenous; D010812:Physical Stimulation; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism / Q000502:physiology*; D011555:Pseudopregnancy / Q000378:metabolism / Q000503:physiopathology / Q000662:veterinary*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D014599:Uterus / Q000737:chemistry / Q000378:metabolism* / Q000502:physiology*; D000097002:Gap Junction beta-1 Protein
chemical_list: D015415:Biomarkers; D006063:Chorionic Gonadotropin; D017630:Connexins; D000242:Cyclic AMP; D015237:Dinoprost; D015232:Dinoprostone; D004958:Estradiol; D004967:Estrogens; D006067:Gonanes; D006727:Hormone Antagonists; D012333:RNA, Messenger; D000097002:Gap Junction beta-1 Protein; C053238:onapristone