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Results for “Pituitary Hormones--analysis”

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[Effect of clomiphene on the restoration of ovulation in androgen-sterile rats].

In the androgen-sterile rats given 10-250 mug of testosterone-propionate there was observed at the early postnatal period a reduction in the LH-RP level in the hypothalamus, of the LH in the hypophysis and the blood, of the weight of the ovaries and of the corporal luteum count in them, as well as an increase in the dopamine level in the anterior portion of the hypothalamus. Klomiphen administration for 5 days in a dose of 20 mug led to the normalization of these indices and to the appearance of ovulation, but failed to restore the capacity to pregnancy. Prolonged klomiphen administration (20 mug every 3 days for a period of 1 month) also failed to restore this capacity.

Animals↗
PubMed1976

A radioimmunoassay for corticosterone and its application to the measurement of stress in poultry.

A radioimmunoassay for corticosterone was developed using an antibody to corticosterone-21-hemisuccinate:bovine serum albumin. The assay possessed good specificity, sensitivity and reproducibility and required minimal sample preparation. Tests of adrenal function showed that stimulation of the adrenal with exogenous ACTH and with dexamethasone caused an increase and decrease, respectively, in plasma concentrations of corticosterone. Exposure to cold environmental temperatures caused an increase in plasma corticosterone. Handling and the removal of blood samples by venepuncture had no effect upon the concentration of corticosterone. It was concluded that this assay would accurately measure the response to stresses which affect the pituitary-adrenal axis.

Adrenal Glands↗
PubMed1977

Effects of aging on the hypothalamic-hypophyseal-gonadal axis in female rats.

The failure of reproductive function in aged rats could be due to deficiencies at the level of the ovary, pituitary, hypothalamus, or higher brain centers. The classic explanation that the ovary is depleted of follicles does not receive adequate support on the basis of histologic studies of aged ovaries. Basal serum gonadotropin levels change with increasing age in female rats. Serum follicle-stimulating hormone (FSH) levels rise while serum luteinizing hormone (LH) levels fall. Likewise, the characteristic response to castration is markedly altered in aged female rats with a reduced secretion of FSH and a minimal elevation of LH. However, the pituitaires of these animals are still caapable of responding to exogenous LH-releasing hormone with a delayed LH response whose magnitude simulates that seen in younger female animals. With increasing age there is decreased pituitary and/or hypothalamic sensitivity to the feedback action of estradiol. These data are consistent with the postulation that there is an altered hypothalamic-hypophyseal function in aged rats.

Aging↗
PubMed1977

Recovery of preimplantation blastocysts in the squirrel monkey by a laparoscopic technique.

A laparoscopic uterine flushing technique has been developed for the recovery of preimplantation embryos from the squirrel monkey. Fourteen adult female squirrel monkeys were induced to ovulate with 4 or 5 days' treatment with follicle-stimulating hormone (1 mg) followed by human chorionic gonadotropin (HCG) (500 IU). Natural mating with a fertile male or artificial insemination was performed near the time of ovulation. Thirty-six hours and eleven days after HCG administration, the females were laparoscoped to determine whether ovulation had occurred. Under laparoscopic control, 1.2 to 3 ml of warmed saline were flushed through the uterine lumen 4 to 7 and 15 to 17 days after HCG administration. Flushed fluid was recovered with a plyethylene catheter or a Pasteur pipette inserted into the cleaned vagina. Fifty-eight uterine flushings were performed, with an average of 65.4% fluid recovery. Six nonfertilized ova and two preimplantation blastocysts were recovered by this technique.

Animals↗
PubMed1979

Plasma levels of adrenocorticotropin and cortisol in women receiving oral contraceptive steroid treatment.

The secretion rate and plasma concentration of the adrenocortical steroid cortisol is modified in subjects treated with estrogenic and/or progestational steroids. The effects of contraceptive steroids on the secretion of ACTH are poorly documented, however, In the current investigation, we found that concentrations of ACTH and cortisol in plasma obtained at 0800--0900 h from a group of women with normal cyclic menses (n = 4) ranged from 78--120 pg/ml and 77--137 ng/ml, respectively. Although significant cyclic changes in the plasma levels of LH, FSH, 17 beta-estradiol, and progesterone occurred during the ovarian cycle, no obvious cyclic fluctuations in plasma levels of ACTH or cortisol were observed. In women treated with Norinyl 1 + 80 (1.0 mg norethindrone plus 0.08 mg mestranol), plasma concentrations of LH, FSH, 17 beta-estradiol, and progesterone were significantly lower (P less than 0.001) than plasma levels of these hormones in normal women during the ovarian cycle. The mean daily plasma concentrations of ACTH were significantly lower (P less than 0.001), whereas plasma cortisol levels were significantly higher (P less than 0.001) in women treated with oral contraceptive steroids compared to the levels of these hormones in the untreated ovulatory women.

Adrenocorticotropic Hormone↗
PubMed1977

Immunoglobulins, proteinase inhibitors, albumin, and lysozyme in human cervical mucus. I. Communication: hormonal profiles and cervical mucus changes--methods and results.

The serum levels of luteinizing hormone (LH), estradiol-17beta, and progesterone were determined simultaneously with the concentrations of immunoglobulin (Ig) G, IgA, C'3, alpha1-antitrypsin, inter-alpha-trypsin inhibitor, alpha1x-antichymotrypsin, albumin, and lysozyme in cervical mucus during nine ovulatory cycles. Spinnbarkeit and ferning were also assessed, and the basal body temperature was measured and recorded during these cycles. The profiles were synchronized according to the LH peak. The midcycle period, characterized by the rapid increase and decline of estrogen and the beginning rise of progesterone, shows a prounced minimum of immunoglobulins, C'3, proteinase inhibitors, albumin, and lysozyme in cervical mucus, which is known to be most receptive to sperm penetration at this time. Although the variation of cervical mucus values is considerable during the early proliferative and the luteal phases, the midcycle values appear to be constantly low, showing slight differences among the profiles of the different parameters. The statistical evaluation and the assessment of the significance of parameters for ovulation detection and the assessment of the fertile period as well as the correlation of these parameters with basal body temperature will be the subject of the second communication of this series.

Adult↗
PubMed1979

The endocrine effects of vasectomy: a prospective five-year study.

A prospective study of plasma luteinizing hormone (LH) and testosterone in 54 men for 5 years following vasectomy revealed no significant continuing alteration in either testosterone or LH. Plasma LH levels 1 year after operation were higher than preoperative levels but did not increase further. Stimulation studies (4 years postvasectomy) using human chorionic gonadotropin confirmed acceptable Leydig cell functional reserve.

Adult↗
PubMed1975

Guanidination of ovine luteinizing hormone and effects on activity.

The free amino groups in oLH, oLHalpha and oLHbeta were guanidinated by O-methylisourea. The epsilon-NH2 groups of lysine residues reacted bo substitute these positions in the sequence with the more basic homoarginine residue. The alpha-NH2 groups did not react under the conditions used. Guanidinated oLH or the products of guanidinated oLHalpha + native oLHbeta or guanidinated oLHalpha + guanidinated oLHbeta were inactive in two bioassay systems. Native oLHalpha + guanidinated oLHbeta, however, showed potencies of 39% to 55% of that observed with the native subunit recombinant or native oLH. Possible structural implications for hormone-receptor site interactions are discussed.

Amino Acids↗
PubMed1978

Detection of ovulation by a radioreceptor assay for human luteinizing hormone.

A specific, sensitive, and rapid radioreceptor assay (RRA), employing membranes from bovine testes as receptor and [125I]hLH as radioligand, has been developed for measurement of human LH in serum. This RRA was used to determine the time of ovulation in seven women. For comparison, four hourly values around midcycle were measured by RIA. The sensitivity of the RRA was 0.78 ng/ml serum and could be increased by prolonged incubation. The coefficient of within and between assay variation at the 50% inhibition level was 7% and 13%, respectively. The mean index of discrimination (RRA/RIA) was 1.02, expressed by the slope of the regression curve. The coefficient of correlation was 0.97. In all women, the LH surge was detected by RRA, and the subsequent ovulation was verified within 30 h by endoscopic examination of the ovaries, as well as serum progesterone concentrations of more than 5 ng/ml on the fifth day after ovulation. As shown, prospective ovulation timing can be done by this simple and accurate method. The RRA can be useful in infertility therapy such as artificial insemination.

Adult↗
PubMed1978

Pregnancy-specific beta 1-glycoprotein and chorionic gonadotropin-like immunoreactivity during the latter half of the cycle in women using intrauterine contraception.

In a cross-sectional study, the serum levels of pregnancy-specific beta 1-glycoprotein (PSBG), hCG, human LH, and progesterone were measured by RIAs during 94 mid or late luteal phases of 69 women using oral contraceptives. Subsequent spontaneous menstruation took place in every cycle. None of the women using oral contraceptives had any PSBG or hCG-like immunoreactivity in serum. In women with intrauterine devices, PSBG was found in six cycles (6.4%) and hCG-like immunoreactivity was demonstrated in one cycle only, where PSBG also was present. In two out of six PSBG-positive cycles, menstruation was delayed by 5 and 16 days. Although rare, the transient occurrence of trophoblastic antigens in women using intrauterine contraception is taken as evidence for an occult pregnancy in these apparently infertile cycles.

Chorionic Gonadotropin↗
PubMed1979

Transitory hypoadrenalism due to long-term treatment with antiovulatory compounds.

A considerable number of women receiving antiovulatory compounds or estrogens complain of weakness and fatigability, suggesting a state of clinical hypoadrenalism. For this reason, levels of plasma ACTH and plasma cortisol were determined in 25 women with such complaints both during treatment and at various intervals after cessation of this treatment. The results obtained showed that there was a significant inhibition of ACTH secretion during long-term treatment with antiovulatory compounds or estrogens, and in half of the cases, there was a delay in normalization of the pituitary-adrenal axis following interruption of the drug, supporting a state of transitory hypoadrenalism.

Adrenal Insufficiency↗
PubMed1977

Bovine cystic ovarian disease: plasma hormone concentrations and treatment.

Ovarian function in 91 dairy cows with cystic ovarian disease was assessed by rectal palpation and by plasma hormone analysis before and after treatment. Plasma analysis showed that 84% of the cysts were correctly classified clinically and only these cows are considered further. Luteinised cysts occurred in 59 cows whereas only 18 had non-luteinised cysts. The mean plasma concentrations of luteinising hormone (LH), follicular stimulating hormone (FSH), progesterone, oestradiol and testosterone were not significantly different when compared with values at relevant stages of the oestrous cycle in normal cows. Success of treatment with progesterone, a synthetic prostaglandin, human gonadotrophin (HCG), or gonadotrophin releasing hormone (GnRH) was not dependent upon prior hormone concentrations, except for the prostaglandin which required active luteal tissue. LH and FSH concentrations in cows with luteinised cysts were not significantly different before and after successful treatment with GnRH or progesterone. Normal luteal function was not always established after treatment of non-luteinised cysts with GnRH.

Animals↗