Abstract

This study was designed to test the hypothesis that: 1) maternal and/or amniotic fluid catecholamines or prostaglandins display nocturnal activity rhythms similar to those of the myometrial contractility in the pregnant rhesus macaque and, 2) catecholamines stimulate prostaglandin production by fetal membranes. Paired maternal arterial blood and amniotic fluid samples were collected at 0900 h (AM) and 2100 h (PM) from chronically catheterized rhesus macaques until delivery and analyzed for prostaglandin metabolites (PGFM and PGEM-II) and catecholamines (norepinephrine, epinephrine, and dopamine). Uterine activity data was continuously recorded. A rhythm in uterine contractility was observed, with peak activity between 1900 and 0100 h (p < 0.01). No AM-PM differences were observed in maternal plasma or amniotic fluid prostaglandins. Additional samples were collected at 3 h intervals for 24 h at selected times from surgery to delivery. Maximal plasma concentrations across the 24 h experimental periods observed at 2100 h for norepinephrine and dopamine and at 1200 h for epinephrine, but these elevations were not significant. Amniotic fluid catecholamine concentrations across 24 h did not differ. Despite the lack of AM-PM differences, amniotic fluid PGFM and PGEM - II increased significantly as delivery approached (p < 0.01). No correlation was observed between either prostaglandins or catecholamines and uterine activity.

In vitro superfusion studies examined prostaglandin production from amnion and chorion in response to catecholamines. Samples were analyzed for PGF2α and PGE2 following perfusion with norepinephrine, epinephrine and dopamine. Catecholamines had no effect on tissues from 65-156 days gestation. PGE2 production from 158d amnion increased following 10-9M treatment, but changes did not reach statistical significance. No trends in PGF2α production were observed. Late gestation amnion was also treated with adrenergic agonists, or adrenergic agonist with antagonists. These data suggest that catecholamines do not stimulate prostaglandin production from 65-156d amnion or chorion, and that uterine activity rhythms are not related to changes in maternal plasma or amniotic fluid prostaglandins or catecholamines. Although prostaglandins and catecholamines are involved in labor, other factors may be involved in the generation of uterine activity rhythms prior to the initiation of labor.

LLU Discipline

Physiology

Department

Physiology

School

Graduate School

First Advisor

Charles A. Ducsay

Second Advisor

Raymond D. Gilbert

Third Advisor

James F. Padbury

Fourth Advisor

Beatriz J. Vasquez

Fifth Advisor

Steven M. Yellon

Degree Name

Doctor of Philosophy (PhD)

Degree Level

Ph.D.

Year Degree Awarded

1991

Date (Title Page)

3-1991

Language

English

Library of Congress/MESH Subject Headings

Catecholamines -- analysis; Macaca Mulatta; Uterine Contraction

Type

Dissertation

Page Count

vi; 85

Digital Format

PDF

Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.

Collection

Loma Linda University Electronic Theses and Dissertations

Collection Website

http://scholarsrepository.llu.edu/etd/

Repository

Loma Linda University. Del E. Webb Memorial Library. University Archives

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