title: On the role of 'in vivo' injected progesterone and of the 'in vitro' presence of oxytocin, modulating Ca2+ uptake by the rat uteri from spayed animals and as controllers of the production of arachidonic acid metabolism.
abstract: We attempted to explore possible mechanism(s) subserving the influence of oxytocin (O) and of progesterone (P) in the isolated rat uterus studying the action of these hormones on: the synthesis and release of prostaglandins (PGs), the metabolism of labelled arachidonic acid and the uptake of Ca2+ by the tissue from ovariectomized animals. The experiments were done with uterine preparations isolated from spayed rats treated or not with P prior to sacrifice and afterward incubated or not with O 'in vitro'. While uterine strips from untreated spayed rat uterus exhibited a basal release into the incubating medium of approximately the same amounts of PGF2 alpha, and PGE2, the 'in vitro' addition of O (50 mU/ml) increased significantly (p < 0.05) the output of PGF2 alpha without changing the release of PGE2. In tissue from rats injected with P prior to sacrifice the output of PGF2 alpha rose significantly (p < 0.01) as it did after the addition of O to preparations obtained from spayed rats treated with P in comparison to findings in uteri from spayed rats but not in comparison to uteri from spayed rats treated with P alone. Moreover, the 'in vitro' addition of O (50 mU/ml) only increased the formation of PGF2 alpha (p < 0.05) and of 5-HETE (p < 0.05); nevertheless the administration of P to spayed rats diminished significantly (p < 0.05) the formation of 6-keto-PGF1 alpha from uteri, but increased that of PGF2 alpha (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Centro de Estudios Farmacológicos y Botánicos (CEFYBO), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Buenos Aires, Argentina.
authors.forename: A
authors.initials: A
authors.lastname: Motta
authors.forename: A M
authors.initials: AM
authors.lastname: Franchi
authors.forename: A
authors.initials: A
authors.lastname: Faletti
authors.forename: A L
authors.initials: AL
authors.lastname: Gimeno
authors.forename: M A
authors.initials: MA
authors.lastname: Gimeno
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D015237:Dinoprost / Q000096:biosynthesis; D005260:Female; D010052:Ovariectomy; D010121:Oxytocin / Q000494:pharmacology*; D011374:Progesterone / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects* / Q000378:metabolism
chemical_list: D016718:Arachidonic Acid; D011374:Progesterone; D010121:Oxytocin; D015237:Dinoprost; D002118:Calcium