A radioimmunoassay for ovine LH is described in which the plasma values are lower than those reported most other studies. Simultaneous measurements of estrogen and ovarian venous effluent sheep were performed by radioimmunoassay. Levels both hormones elevated during follicular phase. The first rise levels was detected 1 day before rise. measurement peripheral blood collected from same at time (± 5 min) indicated no significant lowering when compared to jugular levels.

A series of experiments were conducted which involved the exogenous administration progesterone and estrogens to 15 ovariectomized ewes. Plasma LH levels measured by radioimmunoassay occurrence behavioral estrus was determined vasectomized rams. Injection estradiol benzoate (EDB) either at 2 or 16 days after end priming produced effects. Initially, a depression (0-12 hr post injection) plasma LH, followed an surge (12-24 injection). EDB (50 μg) injected 2, 8 14 resulted in typical surges all...

A serum-free ovine granulosa cell culture system is described that allows the induction of FSH-responsive oestradiol production by undifferentiated cells from small (< 3.5 mm) follicles (P < 0.001) and maintenance differentiated large (≥3.5 follicles. Physiological doses FSH stimulated 0.01) proliferation cultured both The synthesis immunoreactive inhibin progesterone increased with time culture, was not dependent on FSH. Inhibin secretion expressed a per basis responsive. Insulin...

An experiment in which a lupin grain supplement was fed to ewes (n = 11) over days 2-13 of the oestrous cycle carried out. A group 12 used as control and not supplement. Plasma concentrations LH GH (20 min intervals) FSH, insulin prolactin (hourly were determined plasma samples collected every 20 24 h on day 11 cycle. The changes related increases ovulation rate. Ovulation rate increased (2.5 +/- 0.2 versus 1.9 for lupin-supplemented groups, respectively; P 0.073) that received supplement,...

SUMMARY Corpora lutea of ewes bearing ovarian autotransplants were infused for 4 h with prostaglandin F 2α (PGF ) (10 μg/h), PGF + PGE 2 μg/h each), μg/h) or saline on day 10 the cycle. Ovarian venous blood obtained before, during, and up to 12 after infusion period, was assayed progesterone. Prostaglandin produced an immediate, rapid sustained decline in progesterone secretion, but together prevented until infusion. Progesterone secretion unaffected by alone. Oestrous behaviour observed...

The peripheral concentration of LH and the secretion rates estradiol-17beta androstenedione were measured every 10 min for 4 h during anestrus in six ewes with utero-ovarian autotransplants. basal was 0.45 +/- 0.06 ng//ml (NIH S14; mean SEM), pulses (6.0 0.3 ng/ml; N = 5) occurring an average frequency one per 5 h. rate 0.5--1.3 ng/min. Each pulse followed by a rise estradiol-17beta. Maximum 5.18 0.72 ng/min reached 25 after discharge. Basal higher than at about 1.5 to 3.4 ng/min, increased...

The concentration of LH and pro-gesterone in jugular venous plasma the secre-tion steroids by ovary were measured every 10 minutes for 2 hours on days 12, 14, 16 ofthe estrous cycle 5 ewes with utero-ovarian auto-transplants. A pulse occurred about onceevery hours, when rose froma basal level 0.5J7 ± 0.08 ng/ml to a peak 2.97± 0.57 ng/ml. Within LH,the secretion Qstradiol (an exclusive productof follicle) rapidly from 0.75 0.12 ng/miiij reach value 2.16± 0.33 ng/min 30 minutes. In...

The concentrations of oestradiol, androstenedione, progesterone and prostaglandin F2alpha (PGF2alpha) were measured in utero-ovarian autotransplants. secretion oestradiol was closely correlated with that androstenedione (r = 0-67, P less than 0-001) indicating a common origin from the Graafian follicle. concentration these two steroids fluctuated at random throughout luteal phase maximum occurring about 2 days before onset oestrus. Functional regression corpus luteum, as indicated by fall...

The infusion of 50 µ g norepinephrine (NE) into the third ventricle brain was found to be highly effective in stimulating release an ovulatory surge LH from pituitary gland estrogen-primed rabbits. Intraventricular dopamine (D), dosages 5 and g, not only completely ineffective inducing ovulation, but higher dosage actually blocked effect NE, often for a month or more after infusion. In experimentts which measured by radioimmunoassay, intraventricular NE stimulated marked rise starting within...

SUMMARY The concentrations of progesterone, oestrogen and luteinizing hormone (LH) in ovarian venous plasma, follicle-stimulating hormone, LH prolactin peripheral plasma were measured 47 Welsh Mountain sheep at accurately timed stages around oestrus. histology ultrastructure the pre-ovulatory newly ruptured follicles these animals also examined. highest vein levels invariably obtained from ovary containing largest non-atretic follicle. A significant amount was already being secreted by day...

The ob/ob mouse has a complete absence of circulating leptin, resulting in obesity and infertility. Using the minimum daily dose leptin required to maintain normal body weight sexual maturation (5 mg/kg, ip), leptin-treated females were mated with either wild-type (+/+) or males. treatment continued throughout pregnancy until weaning was withdrawn at 0.5, 3.5, 6.5, 14.5 d post coitum (dpc). Normal parturition pups resulted when +/+ males (6 8 pregnancies), dpc 6.5 (9 12 pregnancies)....

The effects of season and diet on LH, FSH testosterone concentrations, testicular mass, sebaceous gland volume male odour were examined in mature Australian cashmere goat bucks fed ad libitum with diets low or high quality for 16 months under natural photoperiod at 29°S, 153°E (n = 6 per treatment). Each week plasma was sampled, the weighed, scored assessed mass based scrotal circumference. month a skin sample taken from occipital region histological assessment volume. For each variable...

The stimulatory effect of nutritional supplementation on ovarian activity in sheep has been linked to an increase glucose availability that, with insulin, directly decreases follicular steroidogenesis. Glucose uptake occurs by transporters, but it is not known which transporters are present the ovary or whether they affected stimulation. aim this study was determine widely distributed transporter 1 (GLUT1) insulin-responsive GLUT4 granulosa theca cells follicles, and their concentrations...