S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 20 No.1 (1979)
HCG가 자궁운동성에 미치는 영향 -2. 흰쥐 발정 주기간의 혈장 성호르몬농도에 미치는 영향
Effect of Human Chorionic Gonadotrophin on Uterine Motility II. Effect on plasma sex hormone level during estrous cycle of rat
- Issue Date
- 서울대학교 의과대학
- Seoul J Med, Vol.20 No.1, pp. 27-35
- In the previous experiment. one of authors reported
that diminished effect af exogenous hCG on the uterine
motility is probably due to the alteration of ovarian
In this study. the experiment was designed ta determine
whether diminished uterine motility induced
by hCG is mediated through the altered secretian of
The cyclic changes in the concentration of plasma
estradiol, progesterone and testosterone during estrous
cycle were measured in the rats having a regular 5
day-cycle. and the effects of previous hCG administrations
on the concentrations were observed. The rats were divided into three groups, namely,
the control, the rats stimulated with hCG on the day
of proestrus and the rats stimulated with hCG continuously
during the entire estrous cycle.
Peripheral blood collections were performed arbitrarily
at 10: 00 a.rn. on the day of proestrus because
of a wide diurnal variation and to fix sampling time
throughout the remainder of the estrous cycle.
Values obtained on each day of the cycle were
compared with the values observed during another
day of the cycle on the one hand, and with the values
of another groups on the other hand.
Following were the results:
1. Plasma progesterone levels of normal rats varied
somewhat from day to day: the concentration tended
to increase on the day of estrus and it was further
elevated on the morning of mctaestrus and then declined
2. Single stimulation of hCG on the day of proestrus
showed a slight increase in plasma progesterone
concentration of estrus and metaestrus but the differences
were not significant as compared to the control
3. Continuous stimulation of hCG resulted in a marked
increase in plasma progesterone concentration
especially on the day of metaestrus. Stimulation could
still be effective on the day of diestrus although the
changes wer~ not so wide.
4. During the latter half of the estrous cycle, there
were no significant differences in plasma estradiol
levels between the rats with both single or continuous
hCG stimulation and control rats, although the levels
tended to be higher in the rats with stimulation than
in the control animals.
5. There were no significant variations in the mean
concentration of testosterone in peripheral blood during
the entire estrous cycle of the control rats.
6. Single injection of hCG on the day of proestrus
induced an insignificant rise in plasma testosterone
level, however, marked elevation was observed by
7. From above results, the followings are suggested:
a) hCG acts on the ovulated ovary promoting progesterone
and testosterone release and to a lesser ex- tent estrogen.
b) A significant effect of hCG on progesterone secretion
rather than estrogen may contribute to the
diminished uterine motility.
c) A significant effect of hCG on plasma testosterone
concentration could probably modify the estrogen