Search results for "PROLACTIN"
showing 10 items of 71 documents
Selective bilateral blood sampling from the inferior petrosal sinus in Cushing's disease: effects of corticotropin-releasing factor and thyrotropin-r…
1993
We sought to enhance the sensitivity of selective bilateral blood sampling to determine adrenocorticotropin (ACTH) and prolactin levels in the inferior petrosal sinus (IPS) by administering two stimulatory agents--corticotropin-releasing factor (CRF) and thyrotropin-releasing hormone (TRH). We then determined the ACTH and prolactin levels in the IPS of 10 patients with Cushing's disease. After peripheral administration of both CRF and TRH, ACTH levels were significantly higher on the tumor side in all patients. The prolactin level was significantly higher on the tumor side when CRF or TRH was used to stimulate pituitary secretion. Postsurgical immunohistochemistry studies revealed productio…
The Effects of Chlorotrianisene (Tace) on Kinetics of 3H-testosterone Metabolism in Patients with Carcinoma of the Prostate
1982
Summary— Alterations in the metabolism of testosterone and plasma levels of testosterone, luteinising hormone (LH), follicle stimulating hormone (FSH), prolactin and oestradiol were studied in 6 patients with newly diagnosed prostatic carcinoma before and during treatment with chlorotrianisene at a daily dosage of 48 mg for 14 days. Parameters of plasma kinetics were determined according to the single injection technique and the 2-compartment model, and the plasma hormones by radioimmunoassay. Chlorotrianisene altered neither plasma levels of testosterone, gonadotrophins, prolactin and oestradiol, nor metabolic clearance rate, production rate and other kinetic parameters of testosterone. Th…
The effects of sex hormones, prolactin, and chorionic gonadotropin on pineal electrical activity in guinea pigs.
1981
Microelectrophoretic application of sex hormones onto pineal cells in guinea pigs has shown different responses in pregnant females as compared to males. In pregnant females estrone caused excitation in 74% of the cells tested, while progesterone and testosterone, prolactin, and HCG were inhibitory in a majority of the cells tested, while progesterone and testosterone, prolactin, and HCG were inhibitory in a majority of the cells. In contrast, in males estrone caused excitation of only 19% but inhibition of 37%. A smaller percentage of cells was inhibited by progesterone, while the predominant response to testosterone was excitation. These results suggest that the pineal gland may be under …
Testosterone metabolism in patients with advanced carcinoma of the prostate: a comparative in vivo study of the effects of oestrogen and antiprolacti…
1978
In the light of the high incidence of cardiovascular side effects with oestrogen therapy in patients with prostatic cancer, other medications altering androgen metabolism are under investigation. The influence of the anti-prolactin bromocriptine (CB154) on plasma kinetics of testosterone and on endogenous hormones was studied and compared with the effect of ethinyl oestradiol in 25 patients with prostatic carcinoma. Bromocriptine significantly suppressed both prolactin and testosterone, inhibited the transfer of androgen from the inner pool into the deep compartment and favoured its degradation. Ethinyl oestradiol decreased testosterone, LH and FSH, and prolonged the biological half-life of…
Alterations of peripheral testosterone metabolism after induced hypoprolactinemia in patients with prostatic carcinoma
1979
In 12 patients with advanced prostatic carcinoma the effect of bromocriptine-induced hypoprolactinemia on the peripheral androgen metabolism was investigated after 3H-testosterone injection under conditions that each individual served as his own control. After a 5-day significant prolactin suppression, the elimination of 3H-label 1 h after testosterone injection was about 45% and equal to pre-bromocriptine values. The recovery of dihydrotestosterone separated by silica gel T.L.C., however, was significantly augmented, resulting in a marked decrease of the testosterone/dihydrotestosterone ratio from 12.2 to 6.3. This induced 5alpha-reductase activity after prolactin suppression is in accorda…
Renal and neurologic effects of cadmium, lead, mercury, and arsenic in children: evidence of early effects and multiple interactions at environmental…
2006
We read with great interest the article by de Burbure et al. (2006) on health effects in children who live near nonferrous smelters in France, the Czech Republic, and Poland. We were especially interested in the inverse relationship found between levels of urinary mercury and serum prolactin. We found a similar result in an Italian multicenter crosssectional survey with adult subjects (Alessio et al. 2002) using a different statistical approach based on regression analysis with mixed linear models. We found that serum prolactin decreased as a function of both urinary mercury and occupational exposure to inorganic mercury (Lucchini et al. 2003). In another study (Carta et al. 2003), our grou…
Bromocriptine and Prostatic Carcinoma: Plasma Kinetics, production and Tissue Uptake of3H-Testosterone in Vivo
1978
The influence of the anti-prolactin bromocriptine on plasma kinetics, production rate and tissue uptake of testosterone was investigated in 15 patients with newly diagnosed stages C and D prostatic carcinoma. Bromocriptine was given for 5 days in a daily dose of 15 mg. orally. The studies were performed with the single injection technique using the 2-compartment model. Plasma testosterone, serum prolactin, and luteinizing and follicle-stimulating hormones were determined initially. Blood samples were drawn up to 5 hours after the injection of 3H-testosterone. For tissue studies a transrectal needle biopsy was done 3 hours post-injection. Bromocriptine suppressed prolactin and the endogenous…
Prolactin secretion before, during, and after chronic gonadotropin-releasing hormone agonist treatments in children.
2005
Objective To examine the effect of long-term administration of GnRH agonists (GnRHa) on PRL secretion in children affected by central precocious puberty (CPP) and growth hormone deficiency (GHD). Design Prospective analysis of blood sampling before, during, and after GnRHa treatments. Setting Pediatric endocrine center. Patient(s) One hundred nineteen and 93 children with a diagnosis of CPP and GHD, respectively. Intervention(s) Monthly depot injections of GnRHa drugs (leuprorelin acetate 3.75 mg [LA] and triptorelin 3.75 mg [TR]) administered to CPP and GHD patients for 40 and 24 months, respectively. Main Outcome Measure(s) Serum PRL levels at baseline and after 6, 12, 18, 24, 30, 36, and…
Effect of prolactin and the anti-prolactin bromocriptin on the testosterone uptake and metabolism in androgen-sensitive and insensitive canine organs
1976
Prolactin promotes the growth and function of the prostate in low doses, whereas high doses or previous castration reduce this effect. The antiprolactin bromocriptin should reverse the prolactin action. In the castrated dog the highest accumulation of H3-testosterone given i.v. occurred in the prostate as compared with muscle, urethra, penis, liver and kidney. Prolactin pretreatment increased the radiosteroid uptake only in the liver. Converseley, bromocriptin suppressed the tracer incorporation into the liver, but increased prostatic accumulation. The highest testerone reduction occurred in the prostate of the untreated castrated dogs as compared with other organs. Prolactin suppressed 5 a…
Studies of the Hypothalamus-Pituitary-Adrenocortical System: An Example of Progress in Psychoneuroendocrinology
1986
Psychobiological study of affective disorders has passed through several phases during the last three decades. With the discovery of thymoleptic drugs and our partial understanding of their pharmacological properties, a dominant theme in psychiatric research came to be the pathophysiology underlying depressive illness. Since enhancement of monoamine neurotransmission was found to be a common characteristic of most antidepressants, several attempts were made to test the hypothesis of a defective cerebral monoamine transmission as the prime cause of depression. In this context, neuroendocrinology became an area that was of particular interest to investigators, for several reasons. Basic resea…