AJP - Endocrinology and Metabolism, Vol 253, Issue 1 E40-E44, Copyright © 1987 by American Physiological Society
Effects of fasting on serum lactogenic hormone concentrations during mid- and late pregnancy in mice
P. J. Fielder, L. Ogren, D. Edwards and F. Talamantes
Hormonal and metabolic responses to fasting were studied in pregnant Swiss
Webster mice. Food was removed from pregnant mice 12, 24, 36, or 48 h
before death on day 12 or 15 of pregnancy. Serum mouse placental
lactogen-II (mPL-II), mouse growth hormone (mGH), mouse prolactin (mPRL),
free fatty acids (FFA), and glucose concentrations were determined for each
group. In comparing fasted animals with fed controls, there was a
significant increase in the serum mPL-II concentration after 24 and 48 h of
fasting on day 12 and after 12, 36, and 48 h of fasting on day 15. Fasting
significantly decreased the glucose and increased the FFA concentration of
the serum at all fasting periods. Fasting had no effect on serum mPRL or
mGH concentrations. In the second part of this study, pregnant mice were
fasted for 24 h and then refed for an additional 24 h before being killed
on day 12 of pregnancy. The changes in serum mPL-II, glucose, and FFA
concentrations that occurred after a 24-h fast on day 12 of pregnancy were
completely reversed by refeeding the animals for 24 h. Results from both
studies indicate the involvement of mPL-II in the maternal response to
fasting in pregnant mice.
