Wistar-Imamichi male rats were slowly infused with synthetic TRH (T), LRH(L) and T +L in combination for of 1, 3, 24, 48 and 72hr. Doses of the releasing hormones were 1ƒÊg/hr. For each duration of infusioi,pituitary and serum TSH, LH and FSH concentrations were radioimmunoassayed. , When T is infused, the pituitary TSH concentration increases at 72hr. When L is infused, it increases at 48hr bu...

Background: To attain whether the effects of low and high doses of estrogen, progesterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) in acute and chronic administration were related to oxidant and antioxidant parameters in rat uterine tissue as well as cyclooxygenase-1 (COX-1) activity. Materials and Methods: Acute and chronic administration of estrogen (1 and 5 mg/ kg), ...

BACKGROUND The role of exogenous LH supplementation in ovarian stimulation is a matter of debate. Here we evaluate the impact of exogenous LH on oocyte yield and developmental competence in an oocyte donation programme. METHODS Oocyte donors were randomized (computer-generated randomization list) to groups stimulated with FSH alone or with a combination of FSH and LH after pituitary down-regu...

BACKGROUND In men, the feedback of gonadotropins is regulated by estrogens that come from the aromatization of testosterone, but the relative contribution to the inhibition of LH and FSH secretion by the amount of locally produced estrogens within the hypothalamus and/or the pituitary, and the amount of circulating estrogens still remains unknown. OBJECTIVE In order to evaluate the effect of ...

Thyroid disorders both hypo and hyperthyroidism are frequently seen in women, the incidence of hypothyroidism is being much higher than hyperthyroidism. Reported studies in these two conditions on reproductive physiology in women and in experimental female animals have shown that both hypo and hyperthyroidism are associated with delay in onset of puberty, anovulation, various menstrual irregula...

To study the plasma gonadotrophin profiles of 9 cows after parturition, blood samples were obtained every 20 min for 12 hrs on three occasions between 5 and 50 days postpartum and analysed by RIA techniques. The time of the first ovulation, as judged by plasma progesterone levels, varied from 30 to more than 60 days postpartum. Variations in mean levels of FSH and LH were not significantly corr...

The effects of unilateral castration (UC) and induced unilateral cryptorchidism (UCR) on basal plasma luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone, and on the responses of these hormones to gonadotropin releasing hormone (GnRH), were investigated in bulls altered at 3, 6 or 9 months of age. Blood plasma was collected before and after GnRH (200 micrograms) stimul...

BACKGROUND The gonadotropins (GtHs), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) are produced in the pituitary gland and regulates gametogenesis through production of gonadal steroids. However, respective roles of two GtHs in the teleosts are still incompletely characterized due to technical difficulties in the purification of native GtHs. METHODS Native FSH and LH were pu...