Developmental patterns of bioactive and immunoreactive FSH in the female rabbit: effects of ovariectomy.
A longitudinal study was performed to determine the relationship between immunoreactive and biologically active FSH in the serum of sham-operated and ovariectomized female rabbits. Twenty-two-day-old female rabbits, 8 per group, were sham-operated or bilaterally ovariectomized on day 23. Blood was taken every 3-4 days from each rabbit until they achieved a weight of 3 kg or age 100 days. Sera were analysed by radioimmunoassay for LH and FSH or for bioactive FSH. In sham-operated animals, immuno-FSH levels showed a 10-fold increase from 0.36 +/- 0.04 ng/ml to greater than 35 ng/ml between days 45 and 80. By contrast, bio-FSH levels increased more gradually from a baseline of 5.4 +/- 0.4 ng/ml to about 8 ng/ml. Bilateral ovariectomy resulted in a significant increase in both bio-FSH, 5.5 +/- 0.4 ng/ml to 12.6 +/- 1.5 ng/ml and immuno-FSH levels from 0.4 ng/ml to 5.2 +/- 1.4 ng/ml 24 h later. These levels of FSH remained elevated throughout the sampling period in both groups of animals and then decreased after day 100. Peripheral LH levels showed much more variation but were 2-fold higher in ovariectomized rabbits, 0.4-1.4 ng/ml in sham-operated vs. 0.8-2.4 ng/ml in ovariectomized rabbits. These results emphasize the marked variations in FSH levels according to the method of analysis. They also suggest that extra-ovarian factors may play a role in inhibiting gonadotropin release especially LH.
YoungLai
E V
EV
Department of Obstetrics & Gynecology, McMaster University, Hamilton, Ontario, Canada.
Yie
S M
SM
Yeo
J
J
D000375:Aging / Q000378:metabolism*; D000704:Analysis of Variance; D000818:Animals; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006801:Humans; D008137:Longitudinal Studies; D007986:Luteinizing Hormone / Q000097:blood; D010052:Ovariectomy; D010053:Ovary / Q000378:metabolism*; D011817:Rabbits; D011863:Radioimmunoassay
D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone