Showing papers in "Domestic Animal Endocrinology in 1987"

TL;DR: A monoclonal antibody for LH has been produced which can be used to develop sensitive and specific RIAs in many different mammalian species and validated the use of 518B7 in detecting LH in serum.

TL;DR: It is clear that postpartum administration of exogenous prolactin during the period of lactation prior topeak milk yield or after peak milk yield does not alter lactational performance in high producing dairy cows.

TL;DR: In this article, a heterologous radioimmunoassay system was validated for the determination of IGF1 concentrations in swine sera, which indicated that IGF1 is involved in the regulation of swine growth in vivo and that its physiologic regulation is similar to that in humans.

TL;DR: The decrease in adipose tissue growth of pigs treated chronically with pGH is due in large part to the suppression of fatty acid synthesis and a decrease in the ability of insulin to stimulate lipid synthesis in pig adipocytes.

TL;DR: It is shown that both endogenous GH secretion and pGRF(1-29)NH2-induced GH release declines with age, suggesting a decreased sensitivity of the somatotroph cells to GRF with age; and that the high variability of the GH response to p GRF( 1-29]NH2 stimulation depends greatly on the timing of the episodic endogenous GH release, thus implying a possible episodic internal somatostatin secretion by the hypothalamus.

TL;DR: Results suggest that either some forms of bPL are more stable or that the hormone isolated from placental tissue is not representative of the final secreted product.

TL;DR: Wethers receiving the toxic fescue ration exhibited elevated plasma DA concentrations which was associated with depressed prolactin secretion in wethers, and MAO levels in pituitaries were higher (P less than .01) for Spiperone-treated wether's.

TL;DR: No differences in the circulating concentrations of any of the hormones were observed between piglets of different sizes, however, there were changes in circulate concentrations of hormones during postnatal development.

TL;DR: Hormone secretory responses to TRH and HAL suggest that the effects on PRL are mediated through dopamine-like activity in toxic fescue, and Alterations in pituitary hormone secretion due to toxic factors in fescues were confined to PRL.

TL;DR: Infusion of GRF increased episodic GH secretion in spite of limited pulsatile activity in saline-infused calves and boosted baseline GH and area under the GH response curve.

TL;DR: It is concluded that LH release in the early postpartum cow is partially regulated by endogenous opioid peptides.

TL;DR: The regional distribution and relative concentrations of LHRH and beta-endorphin immunoreactivity in the hypothalamus were compared in sexually active and sexually inactive Soay rams, consistent with the hypothesis that beta- endorphin is a physiologically important endogenous opioid involved in the modulation of L HRH secretion.

TL;DR: Results indicate that LH release is not inhibited by gonadal factors from 6 to 9 weeks of age in the bull calf, however, estradiol negative feedback on LH secretion is evident during this same developmental period.

TL;DR: Uterine contractions were studied in two experiments utilizing ultrasonography and seasonally anovulatory mares to produce longitudinal real-time images of the uterine body and an overall uterine contractile activity score was assigned to each scan.

TL;DR: It is concluded that serum prolactin concentrations in stallions are seasonal, as in many other seasonally breeding species, and in general are highest in older stallions and lowest in young stallion and are not affected by active immunization against estrogens.

TL;DR: Chicks which developed antibodies against somatostatin following active immunization exhibited a 7.1% increase in growth rate which was associated with a significant decrease in abdominal fat, however, neither GH nor IGF-I concentrations were elevated in the chicks which developed somatstatin antibodies.

TL;DR: The E1S test was accurate in the detection of pregnancy in sows using both plasma and urine during the optimal sampling period of 20 to 30 days post mating, and the test was slightly more accurate using plasma than urine in detecting non-pregnant sows.

TL;DR: The results of this study support previously accepted values for time-action characteristics of regular insulin, but suggest that NPH insulin may have an earlier peak and shorter duration of action than has previously been proposed in the dog.

TL;DR: It is demonstrated that GH response of bovine anterior pituitary cells to GRF was modulated negatively by SRIF, and augmentation of GRF-induced GH release by cortisol was evident only when cells were cultured in media supplemented with untreated FCS.

TL;DR: Parachlorophenylalanine, quipazine, and cyproheptadine studies indicated that serotonergic mechanisms are likely involved in the regulation of GH and ACTH secretion in steers.

TL;DR: Dose-response relationships and the magnitude of the prolactin release following domperidone or TRH varied with time, but did not affect the timing of the LH surge or the increase in progesterone associated with the subsequent cycle.

TL;DR: It is indicated that NPY, at in vitro dosages of .01 to 100 nM, does not modulate the release of LH or PRL at the pituitary level in castrate cattle.

TL;DR: Monodeiodination activity 2 hr after TRH or TSH injection was not significantly different from control values in either stimulated or unstimulated conditions of each group, while peroxidase activity measured in the thyroid gland was significantly higher in embryos and growing chickens treated with MMI.

TL;DR: The differences in structure of TBG may in part be responsible for the low serum T4 levels and rapid T4 metabolism seen in dogs, and many similarities were found between man and dog regarding TBPA, but not TBG.

TL;DR: Sixteen male Holstein calves averaging 168 kg body weight (BW) were used to determine the effects of human growth hormone-releasing factor (1-29)NH2 (hGRF), thyrotropin-re releasing factor (TRF) or hGRF plus TRF (.22 and .165 micrograms/kg BW, respectively) on growth hormone (GH) release in animals exposed to 16 hr of light (L).

TL;DR: Data are consonant with the view that hypothalamic inhibition as well as LHRH stimulation regulate gonadotropin release by the pituitary.

TL;DR: Twenty ovariectomized pony mares were used to determine if dihydrotestosterone propionate (DHTP) administration, with or without estradiol benzoate (EB) pretreatment, would have the same effects on follicle stimulating hormone (FSH) and luteinizing hormone (LH) secretion as testosterone propionates (TP) administration.

TL;DR: The procedures described for cell dissociation and culture of suspended cells provide a useful tool for studying release of LH from the bovine AL cell, and longer treatments may be required to investigate effects of agents that inhibit therelease of LH.

TL;DR: The results suggest that the anabolic action of zeranol does not occur by directly regulating muscle protein synthesis or degradation, or by altering the glucocorticoid-induced catabolic response in muscle.