Accession Number:

ADB233865

Title:

Hormonal Contraception, Body Water Balance and Thermoregulation

Descriptive Note:

Annual rept. 15 Sep 1996-14 Sep 1997

Corporate Author:

JOHN B PIERCE FOUNDATION LAB NEW HAVEN CT

Personal Author(s):

Report Date:

1997-10-01

Pagination or Media Count:

35.0

Abstract:

To test the hypothesis that estrogen enhances water and sodium retention, we compared the fluid regulatory responses to 150 min of exercise-induced dehydration, followed by 180 min of ad libitum drinking during the follicular and luteal phases of the menstrual cycle, and following treatment with an estrogenprogestin oral contraceptive oCP and a progestin-only oCP, in a double-blind, randomized, cross-over design. The women n9, 25 1 yr, 62.5 3.6kg, had a mean blood volume of 67.3 2.l mlkg, and a VO2 peak of 30.6 2.4 ml- min on the recumbent bicycle ergometer Due to the double- blind design, the pills have been identified only as OCP-A or B at this point. Preliminary data on 6 women who have completed testing with oCP-A and S women with oCP-B reveal a downward sh,,ft in osmotic regulation of plasma arginine vasopressin during the luteal phase and both oCPs compared to the follicular phase, which was present during rest and exercise. However, this shift was not accompanied by plasma volume expansion. Fluid and electrolyte loss during exercise were unaffected by phase of the menstrual cycle or oCP treatment. Fluid and electrolyte retention was greatest during ad libitum drinking the follicular phase, however, overall fluid balance was similar across all trials.

Subject Categories:

  • Biology
  • Medicine and Medical Research
  • Pharmacology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE