Premature birth is one of the principal causes of perinatal morbidity and mortality. In order of to aid in the understanding and prevention of this problem, it is imperative to elucidate the factors involved in the regulation of myometrial contractility and the initiation of parturition. Due to ethical considerations, data obtained from human studies are incomplete. This proposal will examine the role of CATS in the initiation of labor by studying the qualitative and quantitative changes in CAT concentrations in the chronically catheterized rhesus monkey. Studies will include measurements of epinephrine, and dopamine in maternal and fetal plasma and amniotic fluid. In addition, PG concentrations (PGEM-II, PGFM, and 6-keto-PGF1alpha) will be quantitated. How these changes are related to alterations in uterine activity and the initiation of labor will also be assessed. In vitro superfusion studies will examine the interaction between CATS and PGs in reproductive tissues collected from pregnant rhesus monkeys. Specifically, what are the stimulatory effects of CATS on PG biosynthesis by decidua, myometrium, amnion, and chorion? PG (PGF2, PGE2 and 6-keto-PGF1alpha) production will be quantitated before and after exposure of the tissue to CATs. These studies will be directed to answer the following questions: 1) Is there a causal relationship between changes in CATS and uterine activity rhythms? 2) Do CATs exert their effects indirectly by first stimulating PG biosynthesis? These studies are in line with the long-term goals of the present research program, namely, to clarify the mechanisms involved in the regulation of uterine contractility and the initiation of labor.

Agency
National Institute of Health (NIH)
Institute
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29HD022865-02
Application #
3469458
Study Section
Human Embryology and Development Subcommittee 2 (HED)
Project Start
1987-09-01
Project End
1991-08-31
Budget Start
1988-09-01
Budget End
1989-08-31
Support Year
2
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Loma Linda University
Department
Type
School of Medicine & Dentistry
DUNS #
City
Loma Linda
State
CA
Country
United States
Zip Code
92350
Nnamani, C; Godwin, A; Ducsay, C A et al. (1994) Regulation of cell-cell communication mediated by connexin 43 in rabbit myometrial cells. Biol Reprod 50:377-89
Koos, B J; Mason, B A; Ducsay, C A (1993) Cardiovascular responses to adenosine in fetal sheep: autonomic blockade. Am J Physiol 264:H526-32
Umezaki, H; Valenzuela, G J; Hess, D L et al. (1993) Fetectomy alters maternal endocrine and uterine activity rhythms in rhesus macaques during late gestation. Am J Obstet Gynecol 169:1435-41
Germain, A M; Valenzuela, G J; Ivankovic, M et al. (1993) Relationship of circadian rhythms of uterine activity with term and preterm delivery. Am J Obstet Gynecol 168:1271-7
Seron-Ferre, M; Ducsay, C A; Valenzuela, G J (1993) Circadian rhythms during pregnancy. Endocr Rev 14:594-609
Matsuda, K; Ducsay, C; Koos, B J (1992) Fetal breathing, sleep state and cardiovascular adaptations to anaemia in sheep. J Physiol 445:713-23
Matsumoto, T; Ducsay, C A (1992) Maternal plasma catecholamines in the rhesus macaque during late gestation: effect of photoperiod and timed melatonin infusion. Biol Reprod 47:582-7
Valenzuela, G J; Norburg, M; Ducsay, C A (1992) Acute intrauterine hypoxia increases amniotic fluid prostaglandin F metabolites in the pregnant sheep. Am J Obstet Gynecol 167:1459-64
Ducsay, C A; Ervin, M G; Kaushal, K M et al. (1992) Myometrial contractile responsiveness to oxytocin after dexamethasone suppression of circadian uterine activity in pregnant rhesus macaques during late gestation. Am J Obstet Gynecol 167:1636-41
Matsumoto, T; Hess, D L; Kaushal, K M et al. (1991) Circadian myometrial and endocrine rhythms in the pregnant rhesus macaque: effects of constant light and timed melatonin infusion. Am J Obstet Gynecol 165:1777-84

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