NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Effects of Hypergravity Exposure on Prolactin Levels in Pre-parturient , Parturient and Lactating Rat DamsWe analyzed the effects of 2.0-g, 1.75-g and 1.5-g hypergravity exposure on plasma concentrations of the lactotrophic hormone, prolactin (PRL), in female rats on pre-parturient (Gestation Day 20), parturient (Post-natal day 0) and lactating (P10) days. PRL levels have been found to be reduced in rat dams around the time of birth following exposure to gravitational loads varying from 2.16 to 3.14-g (Megory et. al., Aviation, Space and Environs 1129-1135, 1984). It has also been reported that at these high gravitational loads, neonatal mortality has been extremely high, suggesting a possible interaction between dam PRL concentration and neonatal outcome. We have previously reported no significant differences in PRL levels of parturient (PO) and lactating (P6 & P 15) dams when exposed to 1.5-g hypergravity, but did observe a slight elevation of PRL on PO and P 15, with a decrease on P6. In the present study, time-bred pregnant dams were exposed to either continuous 2.0-g, 1.75-g or 1.5-g centrifugation, beginning on Gestational day (G) 11 of the rats' 22-day pregnancy. We observed no significant differences in PRL concentrations between SC and any of the HG conditions. On G20 and PO, PRL concentrations of the 2.0-g and 1.5-g groups were slightly elevated as compared to SC. Similar to what we previously reported. PRL secretion was elevated in both HG and SC conditions on the day of birth relative to later during lactation, but on P10 it appeared to be reduced in HG relative to SC dams. These findings suggests that hypergravity slightly elevates plasma concentration of PRL in pre-parturient and lactating rat dams, with effects most pronounced during the periparturitional period and in a direction opposite to that observed following microgravity exposure.
Document ID
20010056902
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Baer. Lisa A.
(Lockheed Martin Corp. Moffett Field, CA United States)
Wade, Charles E.
(NASA Ames Research Center Moffett Field, CA United States)
Ronca, April E.
(NASA Ames Research Center Moffett Field, CA United States)
Sun, Sid
Date Acquired
August 20, 2013
Publication Date
January 1, 2001
Subject Category
Life Sciences (General)
Meeting Information
Meeting: Annual Experimental Biology Meeting
Location: Orlando, FL
Country: United States
Start Date: March 29, 2001
End Date: April 4, 2001
Funding Number(s)
CONTRACT_GRANT: MH-46485
PROJECT: RTOP 121-10-40
PROJECT: RTOP 121-40-10
PROJECT: RTOP 121-10-50
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available