Toshiko Imamura

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Prostaglandins (PGs) have been recently proven essential for parturition in mice. To dissect the contributions of the two cyclooxygenase (COX) isoforms to the synthesis of PGs during pregnancy, we have characterized the parturition phenotype of COX-1-deficient mice. We find that mice with targeted disruption of the COX-1 gene have delayed parturition(More)
Prostaglandins (PGs) have proven important during parturition, but inhibition of PG production treating preterm labor (PTL) results in significant maternal and fetal side effects. We hypothesize that specific inhibition of either cyclooxygenase (COX)-1 or -2 may result in separation of therapeutic and toxic effects. We demonstrate that COX-2, but not COX-1,(More)
O,O,S-Trimethyl phosphorothioate (OOS-TMP) is an impurity present in a number of widely used organophosphorus insecticides and has been recognized as a potent lung toxicant. OOS-TMP was given p.o. to pregnant rats on gestation day (G) 20 at 0.5, 2.5, 10 and 40 mg/kg. Control dams or pair-fed dams (pair-fed to 40 mg/kg) received 2 ml/kg corn oil. Neonates(More)
OBJECTIVE To review recent studies of parturition control in mice with relevance to understanding the control of human parturition. METHODS Assimilation of published studies of gene knockout mice with mutations in neuropeptides, prostaglandin synthetic enzymes and receptors, and other molecules implicated in parturition. RESULTS The central role of(More)
OBJECTIVE This study was designed to determine the effect of umbilical cord occlusion (UCO) on fetal endocrine responses in the long-term hypoxemic (LTH) ovine fetus. METHODS Pregnant ewes were maintained at high altitude (3820 m) from day 30 of gestation. Normoxic control and LTH fetuses were catheterized, and an inflatable occluder was placed on the(More)
Recent analysis of mice deficient in both oxytocin (OT) and cyclooxygenase-1 has shown that OT exerts significant effects on both the ovarian corpus luteum and the uterine myometrium during pregnancy. To better define the roles of OT during pregnancy, we evaluated OT action and OT receptor regulation in wild-type and OT-deficient knockout (KO) mice.(More)
O,O,S-trimethyl phosphorothioate (OOS-TMP), an impurity present in widely used organophosphorus insecticides, has been shown to induce lung injury after oral administration. To date, very little is known about the hemorheological changes which may occur during the inflammation of lung caused by OOS-TMP. The present study has demonstrated that oral(More)
Two different strains of congenic mice were used to study the influence of the H-2 complex on the age-associated decline of different parameters of the immune function. Aged C57BL/10 and C57BL/10.BR mice demonstrated significantly reduced plaque forming cell (PFC) responses to both T-dependent and-independent antigens. However, the response to sheep red(More)
Mice of the C57BL/10.RIII strain (B10.RIII) and C57BL/10.F strains (B10.F) are congenic, differing genetically at the H-2 complex. The former is H-2r and the latter H-2n. The strains differ greatly in mean survival times, with values for females being about 33 months for B10.RIII and 14 months for B10.F. In the present study, we found that B10.F mice had(More)
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