We have established a dispersed bovine pituitary cell culture system to study the effects of charcoal-extracted bovine follicular fluid (BFF) or bovine inhibin, partially purified by immunoaffinity chromatography (IPI), on the spontaneous release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Pituitary cells were plated at 0.25, 0.5 or 1 x 10(6) viable cells/well (c/w) and ...

Lactating, primiparous Landrace x Yorkshire sows were used to characterize LH secretion during lactation in sows that experienced an early (less than 9 d; n = 14) or late (greater than 15 d; n = 9) return to estrous postweaning and to evaluate the relationship between LH secretion and blood metabolites. Twenty-three sows were fed one of nine corn-soybean meal diets to achieve a matrix of lysine...

The objectives of this study were to characterize the LH secretion pattern and the follicular development of anestrous beef heifers during early exposure (first 30 d of exposure) to androgenized steers (AS) and to determine if exposure to AS for 80 d (includes the first 30 d and 50 d more) advances the onset of ovarian cyclic activity. Twenty-nine anestrous Hereford heifers (20.2 ± 4.1 mo old a...

Bovine thyroid-stimulating hormone (thyrotropin, TSH) has been separated into two different subunits by gel filtration in ammonium bicarbonate solution after prior treatment with 1 M propionic acid. The two subunits, which have been designated TSH-a! and TSH-0, resemble each other more closely in amino acid composition than do the two subunits of luteinizing hormone (LH, interstitial cell-stimu...

Women harbouring inactivating mutations in luteinizing hormone (LH) beta subunit ( LHB ) or LH receptor ( LHCGR ) genes have similar clinical manifestations characterized by female external genitalia, spontaneous breast and pubic hair development at puberty, and normal or late menarche followed by oligo-amenorrhea and infertility. Oestradiol and progesterone levels are normal for the early to m...

OBJECTIVE To evaluate the efficacy of earlier oocyte retrieval in IVF patients with a premature LH surge on hCG day. METHODS One hundred forty IVF patients (164 cycles) with premature LH surge on hCG day were included, retrospectively. We divided them into 2 study groups: LH surge with timed ovum pick-up (OPU) 36 hours after hCG injection (group B, 129 premature cycles), and LH surge with ear...

Lameness, hoof lesion development and behaviour were compared for two groups of 10 heifers: one in early pregnancy (PH), the other in early lactation (LH). Both groups were housed in the summer in cubicles under identical conditions. Behavioural observations commenced immediately after housing, and then at 2, 4 and 6 weeks post-housing. Locomotion scores were assessed weekly, and feet were exam...

Monoamine synthesis inhibitors have been used extensively to unravel the role of neurotransmitters in the hypothalamic regulation of pituitary LH release (Coppola, Leonardi & Lippmann, 1966; Kordon & Glowinski, 1972; Kalra, P.S. & McCann, 1973). Inhibition of tyrosine hydroxylase by \g=a\-methyl-paratyrosine(Corrodi & Hansen, 1966) or dopamine-\g=b\-hydroxylaseby sodium diethyldithiocarbamate (...

-Experiments were undertaken with DMBA -induced mammary tumours of the rat to determine the anti-tumour properties of a new and potent luteinizing hormone-releasing hormone (LH-RH) agonist, [D-Ser(But) 6AzglylO]-LH-RH (ICI 118630). Tumours were classified according to their oestrogen-receptor (ER) content. Twice daily i.m. injections of either 5 ,ug or 0-5 ,ug ICI 118630 in saline were as effec...

This study was designed to determine the prevalence of bipolar disorder in women with polycystic ovarian syndrome (PCO). One hundred and ten women with definite diagnosis of PCO and one hundred and ten age-matched infertile women due to other reasons except for PCO were enrolled in this case-control study. Ten ml fasting venous blood sample obtained to measure fasting glucose, LH and FSH. Heigh...