Medical Journal of the Islamic Republic Of Iran
مجله پزشکی جمهوری اسلامی ایران
Med J Islam Repub Iran
Medical Sciences
http://mjiri.iums.ac.ir
2
journal2
1016-1430
2251-6840
8
10.18869/mjiri
14
8888
13
en
jalali
1382
5
1
gregorian
2003
8
1
17
2
online
1
fulltext
en
EFFECTS OF LEVOTHYROXINE ADMINISTRATION ON OVULATION RATE AND SEX HORMONE LEVELS IN PREPUBERTAL AND ADULT RATS
Physiology
Physiology
Original Research: Basic Science in Medicine
Original Research: Basic Science in Medicine
Thyroid gland dysfunction is associated with disorders of female reproductive
functions. The aim of this study was to examine the effects of hyperthyroidism
on ovulation rate and peripheral sex steroid levels in prepubertal and adult
rats.
Two groups of female rats aging 30 days (prepubertal rats) and 60 days (adult
rats) were made hyperthyroid by oral administration of levothyroxine daily. In the
two control groups (n=lO) rats with the same ages received the same volume of
normal saline. After 10 days the serum levels of T3, T4, LH, FSH, estradiol and
progesterone were measured by RIA technique and also sections of ovaries were
prepared for histological studies. All ovarian follicles and corpora lutea were
counted to estimate ovulation rate.
The results indicated that serum estradiol and progesterone levels of adult
hyperthyroid rats were significantly lower than those of the control group (p<0.05).
However, there was no significant difference between estradiol levels in the prepubertal
hyperthyroid group and its control group. In the hyperthyroid groups the
mean number of primary, secondary and antral follicles and corpora lutea was
significantly less than those of control groups.
It was concluded that high levels of plasma thyroid hormones resulted in
lowered body weight and disturbed ovarian follicle development and differentiation
leading to reduction in ovarian steroidogenesis and ovulation.
Ovulation, Levothyroxine, Hyperthyroidism, Prepubertal rats
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157
http://mjiri.iums.ac.ir/browse.php?a_code=A-10-298-164&slc_lang=en&sid=1
A
A. ZARIFKAR
20031947532846003817
20031947532846003817
Yes
From the Department of Physiology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
P
HOOSHMAND
20031947532846003818
20031947532846003818
No