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At least 109 records · Page 6Linked to original sources

Distinct endocrine effects of chronic haloperidol or risperidone administration in male rats.

Antipsychotic drugs have been used effectively for the treatment of schizophrenia symptoms, but they are often associated with metabolic side effects such as weight gain and endocrine disruptions. To investigate the possible mechanisms of antipsychotic-induced metabolic effects, we studied the impact of chronic administration of a typical antipsychotic drug (haloperidol) and an atypical antipsychotic (risperidone) to male rats on food intake, body weight, adiposity, and the circulating concentrations of hormones and metabolites that can influence energy homeostasis. Chronic (28days) haloperidol administration had no effect on food intake, weight gain or adiposity in male rats, whereas risperidone treatment resulted in a transient reduction in food intake and significantly reduced body weight gain compared to vehicle-treated control rats. Whereas neither antipsychotic had any effect on serum lipid profiles, glucose tolerance or the circulating concentrations of hormones controlled by the hypothalamo-pituitary-thyroid (free T4), -adrenal (corticosterone), -somatotropic (IGF-1), or -gonadotropic axes (testosterone), haloperidol increased circulating insulin levels and risperidone increased serum glucagon levels. This finding suggests that haloperidol or risperidone induce distinct metabolic effects. Since metabolic disorders such as obesity and type 2 diabetes mellitus represent serious health issues, understanding antipsychotic-induced endocrine and metabolic effects may ultimately allow better control of these side effects.

Adipose Tissue↗

L-thyroxine treatment of preterm newborns: clinical and endocrine effects.

Preterm newborns have low serum thyroxine (T4) levels compared with late-gestational fetuses. Low thyroid hormone levels are associated with increased severity of neonatal illness and neurodevelopmental dysfunction. We assessed the endocrine and clinical effects of increasing serum T4 levels in preterm newborns with a gestational age <31 wk. Forty newborns were randomized in a double blind protocol: 20 infants received a daily dose of 20 microg/kg L-T4 for 2 wk, whereas 20 control infants received saline. Serum concentrations of T4, triiodothyronine (T3), reverse T3 (rT3), thyroglobulin (TG), and TSH were measured weekly as well as serum levels of GH, prolactin, and IGF-I. After 2 wk, a TSH-releasing hormone (TRH) test was performed. Neonatal illness and outcome was evaluated by noting heart rate, oxygen requirement, duration of ventilation, development of chronic lung disease, oral fluid intake, and weight gain; a Bayley score was done at the corrected age of 7 mo. L-T4 administration induced a marked increase in serum T4 without apparent change in T3 levels, whereas the postnatal decline in serum rT3 was more gradual. L-T4 treatment was associated with a decrease in serum TG and TSH levels. TRH injection induced a definite rise in serum TSH and T3 in controls, but not in L-T4 treated newborns. Neither L-T4 treatment, nor TRH administration appeared to alter circulating levels of prolactin, GH, or IGF-I. In contrast to the pronounced endocrine effects, no clinical effects of L-T4 administration were detected.

Dopamine↗

Long-term endocrine effects of cancer treatment: experience of the Royal Children's Hospital, Melbourne.

OBJECTIVES: To evaluate the frequency and degree of severity of endocrine late effects in patients treated for childhood cancer and to assess the value of the late effects clinic for continued monitoring of these patients. METHOD: Data was collected on all patients who attended the late effects clinic at the Royal Children's Hospital (RCH) between 1998-2003. Endocrine function was assessed by clinical and biochemical evaluation at the time of presentation and at ongoing intervals of 3-12 months as clinically indicated. RESULTS: A total of 249 children attended the late effects clinic. Two hundred and thirty five endocrine diagnoses were made in 155 (62%) patients, of whom 63 patients had multiple endocrinopathies. CONCLUSION: Our audit supports the need for ongoing prospective surveillance in survivors of childhood cancer. Appropriate and timely interventions in such patients can help to reduce morbidity and improve quality of life.

Antineoplastic Agents↗

Endocrine effects of a 24-hour intravenous infusion of interleukin-2 in the immunotherapy of cancer.

Several experiments have demonstrated that there is a relationship between neuroendocrine and immune systems. Despite these interesting findings, only few studies have been performed up to now to evaluate the possible importance of neuroimmune interactions in influencing the biological efficacy and toxicity of cancer immunotherapy with IL-2. To analyze the effects of IL-2 on endocrine secretions, we have measured by RIA serum levels of cortisol, beta-endorphin, GH, PRL and of the pineal hormone melatonin in metastatic renal cancer patients, treated with 5-day courses of IL-2 at a daily dose of 3 x 10(6) U/m2, given through a 24-hour intravenous infusion. Six IL-2 courses were evaluated, by collecting blood samples at 4-hour intervals for 24 hours and by comparing the hormonal values with those observed in baseline conditions. Both cortisol and beta-endorphin mean values significantly increased during IL-2 infusion. GH and PRL also increased, but not in a significant manner. Finally, melatonin mean levels significantly decreased during the infusion. The IL-2-induced effects on cortisol, beta-endorphin and melatonin resulted in a complete abolition of their physiological circadian rhythm. These results show that IL-2 infusion induces important changes in endocrine secretions. Because of the immunosuppressive effect of cortisol and the stimulatory one of melatonin, their changes during IL-2 infusion might influence the biological activity of immunotherapy itself. Further studies will be required to define better the clinical importance of IL-2 induced hormonal changes.

Carcinoma, Renal Cell↗

Repeated 28-day oral toxicity study of vinclozolin in rats based on the draft protocol for the "Enhanced OECD Test Guideline No. 407" to detect endocrine effects.

We performed a 28-day repeated-dose toxicity study of vinclozolin, a widely used fungicide, based on the draft protocol of the "Enhanced OECD Test Guideline 407" (Enhanced TG407) to investigate whether vinclozolin has endocrine-mediated properties according to this assay. Seven-week-old SD rats were administered with vinclozolin daily by oral gavage at dose rates of 0, 3.125, 12.5, 50 and 200 mg/kg/day for at least 28 days. The vinclozolin-treated male rats showed a reduction of epididymis and accessory sex organ weights and an alteration of hormonal patterns. A slight prolongation of the estrous cycle and changes in the estrogen/testosterone ratio and luteinizing hormone level were observed in vinclozolin-treated female rats. Thyroxin concentrations were decreased and thyroid-stimulating hormone concentrations were increased in both sexes; however, there were no compound-related microscopic lesions in the thyroid gland or changes in the thyroid weight. The endocrine-related effects of vinclozolin could be detected by the parameters examined in the present study based on the OECD protocol, suggesting the Enhanced TG407 protocol should be a suitable screening test for the detection of endocrine-mediated effects of chemicals.

Administration, Oral↗

Repeated 28-day oral toxicity study of ketoconazole in rats based on the draft protocol for the "Enhanced OECD Test Guideline No. 407" to detect endocrine effects.

We performed a 28-day repeated-dose toxicity study of ketoconazole, a widely used an antimycotic drug, based on the draft protocol of the "Enhanced OECD Test Guideline 407" (Enhanced TG407) to investigate whether ketoconazole has endocrine-mediated properties according to this assay. Seven-week-old SD rats were administered with ketoconazole daily by oral gavage at doses of 0, 6.25, 25 or 100 mg kg(-1) day(-1) for at least 28 days. The ketoconazole-treated male rats showed reduction of epididymis and accessory sex organ weights, spermatid retention in the seminiferous tubules, decrease of testosterone and increases of estradiol, luteinizing hormone (LH) and follicular stimulating hormone (FSH). A prolongation of the estrous cycle and increases of estradiol, LH and FSH were observed in the treated female rats. Thyroxin and triiodothyronine were decreased and thyroid-stimulating hormone was increased in both sexes; however, there were no compound-related microscopic lesions in the thyroid gland or changes in the thyroid weight. The endocrine-related effects of ketoconazole could be detected by the parameters examined in the present study based on the Organization for Economic Cooperation and Development (OECD) protocol, suggesting that the Enhanced TG407 protocol should be a suitable screening test for detection of endocrine-mediated effects of chemicals.

Administration, Oral↗

Health effects classification and its role in the derivation of minimal risk levels: reproductive and endocrine effects.

The Agency for Toxic Substances and Disease Registry (ATSDR) derives health-based guidance values called minimal risk levels (MRLs) to assist with assessment of risks posed by exposures to hazardous chemicals. From the total of 326 MRLs currently posted on ATSDR's web site (www.atsdr.cdc.gov), 14 and 5 MRLs are based on reproductive and endocrine endpoints, respectively. The paper also describes the ranking of effects into less serious and serious categories according to ATSDR's Guidance for Developing Toxicological Profiles, endpoints used for the MRLs derivation, and the use of uncertainty factors.

Animals↗

Endocrine effects of granulocyte colony-stimulating factor in cancer patients.

AIMS AND BACKGROUND: In addition to well-documented endocrine properties of interleukins, hemopoietic growth factors could also exert hormonal activities. In fact, our previous studies have shown that GM-CSF may stimulate cortisol and GH release. In contrast, few data only are available about the possible effects of G-CSF. This study was carried out to investigate endocrine effects of G-CSF in cancer patients. METHODS: The study included 8 cancer patients who were investigated after G-CSF (0.3 mg subcutaneously) or during saline infusion alone as control by collecting venous samples at zero time and after 2, 4, 6 and 8 h. Serum levels of cortisol, GH, PRL, FSH. LH, TSH and melatonin were measured by the RIA method. RESULTS: The circadian rhythm of cortisol was not influenced by G-CSF. No significant differences in mean levels of GH, PRL, FSH or LH were seen after G-CSF and during saline infusion. Both TSH and melatonin decreased after G-CSF, without, however, significant differences with respect to the values seen on saline alone. CONCLUSIONS: The study showed that G-CSF has no substantial endocrine affects in humans. Therefore, G-CSF would differ from GM-CSF not only for its hemopoietic properties, but also from an endocrine point of view.

Granulocyte Colony-Stimulating Factor↗

Effects of nandrolone decanoate or testosterone decanoate on murine lupus: further evidence for a dissociation of autoimmunosuppressive and endocrine effects.

Nandrolone decanoate injections (20, 40 or 80 mg/kg/3 weeks) in female or castrated male New Zealand black/white mice, starting at various ages (4, 9, 17 or 26 weeks) prolong survival, reduce proteinuria and affect the weights of various endocrine and non-endocrine organs. Nandrolone decanoate is at least equally potent as testosterone decanoate with respect to its beneficial effects on lupus-associated symptoms; in contrast, its effects on some other androgen-sensitive endocrine parameters are significantly less. These observations show that the autoimmunosuppressive effects of steroids are not quantitatively correlated to endocrine properties.

Animals↗

The endocrine effects of visual erotic stimuli in normal men.

Endocrine responses to erotic stimulation in the laboratory were assessed in eight normal subjects. Each subject was tested on two occasions. On one occasion only neutral stimuli were involved. After 15 min baseline, 30 min of films were shown. For the erotic condition on the other occasion, two 10-min erotic films were interspersed with 10 min of neutral film. Fifteen-minute blood samples were taken from the start of each test and continued for 5 hr after the films. Plasma was assayed for testosterone, LH, prolactin, cortisol, ACTH and beta-endorphin. Urine was collected for 4 hr before and 4 hr after the films; this was assayed for adrenaline, noradrenaline and dopamine. Sexual arousal occurred in response to the erotic films in all subjects, as shown by erectile and subjective responses. There were no significant changes in hormone or catecholamine levels following either the erotic or the neutral stimuli, except for a rise in cortisol during the neutral but not the erotic film. These results indicate that in the laboratory, substantial sexual response can occur without accompanying endocrine or biochemical changes.

Adrenocorticotropic Hormone↗

Endocrine effects of examination stress.

1. We have studied endocrine function in nine healthy young men 16 weeks before and immediately after Final degree examinations. Factors other than psychological stress which might have affected hormone levels were excluded. 2. The presence of psychological stress at the time of examinations was confirmed by finding increased values for two self-rating anxiety scales. 3. Urine metadrenaline excretion was increased in all subjects at the time of examination. Serum and early morning urine cortisol as well as pituitary-testicular and pituitary-thyroid function and prolactin levels were unaffected by examination stress. 4. This study questions the popular belief that psychological stress stimulates prolactin secretion and suppresses pituitary-testicular function.

Adult↗

17alpha-methyltestosterone: 28-day oral toxicity study in the rat based on the "Enhanced OECD Test Guideline 407" to detect endocrine effects.

A 28-day oral gavage toxicity study in the rat with 17alpha-methyltestosterone was conducted as part of the international validation exercise on the modified Enhanced OECD Test Guideline 407 (Organisation for Economic Co-operation and Development, Paris). Special emphasis was placed on the endocrine mediated effects exerted by 17alpha-methyltestosterone, a potent androgen agonist. The test compound was administered daily by oral gavage for at least 28 days to groups of 7-week-old-Wistar rats. Dose levels were 0, 10, 40 and 200 mg/kg body weight per day for males and 0, 10, 100 and 600 mg/kg body weight per day for females. In addition, and outside the remit of the enhanced protocol, testosterone levels in males, oestradiol levels in females and luteinizing hormone (LH) levels in both sexes were measured, to provide a broader profile on the hormonally mediated effects of 17alpha-methyltestosterone. Furthermore, stage-specific quantification of Terminal deoxynucleotidyl transferase-mediated dUTP Nick-End Labeling (TUNEL)-labeled germ cells (apoptotic germ cells) in the seminiferous tubules was also performed, in an effort to demonstrate the precise stages in the spermatogenic cycle 17alpha-methyltestosterone exerts its effect. In this study, the most critical additional parameters contained in the Enhanced OECD Test Guideline 407 for the detection of endocrine disruption were considered to be the histopathological assessment and organ weight data of endocrine-related tissues. Beyond the scope of this validation exercise, an increase in apoptosis in specific germ cell types was detected using the TUNEL assay in male rats treated at 200 and 40 mg/kg.

Administration, Oral↗

Saturnism in the male rat: endocrine effects.

The effect of exposure to lead on endocrine function was studied in pubertal rats treated with 1.0 g/l lead acetate (PbAc) in drinking water for 20 days (subacute group) or 9 months (chronic group) in addition to iv injections of PbAc (0.1 mg/100 g body weight) every 10 (subacute group) or 15 days (chronic group). Although basal levels of testosterone were higher both in the plasma and in the testes of acutely intoxicated animals, the circulating levels of luteinizing hormone (LH) were not affected in either group, nor was the LHRH content of the median eminence. The density of [125I]LH/hCG binding sites in testicular homogenates was reduced by saturnism in both groups. However, the apparent affinity constant of the hormone-receptor complex significantly increased. These data can be viewed as the result of a mixture of specific lead toxicity (e.g., at the enzyme level) with other more general actions (e.g., at the level of the hypothalamus-pituitary-testicular axis).

Animals↗

Clinical and endocrine effects of ovulation induction with FSH and hCG supplementation in low responders in the midfollicular phase. A pilot study.

OBJECTIVE: To assess the endocrine and clinical effects of luteinizing hormone (LH) activity supplementation administered in the midfollicular phase during controlled ovarian hyperstimulation to poor responders who were candidates for in vitro fertilization (IVF)--embryo transfer. STUDY DESIGN: Prospective, controlled, nonrandomized trial with historical controls. Twenty-five IVF patients who had shown a poor response to standard, long-protocol GnRH-a and FSH only in a preceding cycle (cycle A), were stimulated in the next cycle after six months with hCG supplementation (50 I.U. subcutaneously daily) starting on day 7 during standard, long-protocol GnRH-a and FSH (cycle B). The comparative analysis of clinical effects (duration of stimulation, total highly purified (HP)-FSH dose, number of oocytes retrieved and pregnancy rate) and endocrine responses (serum E2, follicular E2 and androstenedione levels) were determined between cycles A and B. RESULTS: Maximum serum E2 levels and clinical pregnancy rate were higher in cycle B, with hCG supplementation. Also, the follicular E2 and androstenedione levels were higher in cycle B. No differences were noted between cycles as regards the duration of stimulation, total HP-FSH dose and number of oocytes retrieved. CONCLUSION: LH activity supplementation in the midfollicular phase yields favorable pregnancy results in low responders. This may be due to enhanced release of follicular precursors for greater synthesis of E2.

Chorionic Gonadotropin↗

Investigations on Dieffenbachia amoena Gentil. I: Endocrine effects and contraceptive activity.

Contraceptive activity and the correlated endocrine alterations of an aqueous extract of the leaves of Dieffenbachia amoena were investigated. In female Wistar rats the extract, given for 4 days during the estrous cycle, induced significant variations of luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL) progesterone and 17 beta-estradiol levels. It also determined a reversible interruption of the estrous cycle with consequent temporary inhibition of ovulation.

Animals↗

Treatment of metastatic breast cancer patients with different dosages of megestrol acetate; dose relations, metabolic and endocrine effects.

Megestrol acetate (MA) is of therapeutic value in breast cancer patients. This study was designed to evaluate the effects of different dosages of MA on endocrine events potentially influenced by the drug in relation to plasma level of MA and clinical effects in patients with advanced breast cancer. Eighteen postmenopausal patients were randomly distributed over six groups to receive daily 90, 180 or 270 mg of MA (niagestin) orally in a cross-over study consisting of 3 periods of 6 weeks. Complete remission was observed in 1 patient, partial remission in 9, no change in 4 and failure in 4 patients. During the 18 weeks of treatment plasma levels of MA gradually increased, irrespective of the dose administered. Significant rises of the basal and TRH-stimulated plasma PRL and basal insulin levels were observed, whereas LH and FSH, estradiol, SHBG and the pituitary-adrenal axis were suppressed. None of these metabolic effects showed a correlation with the clinical response. We concluded that treatment of metastatic breast cancer with 180 mg MA/day is effective and causes minimal adverse effects.

Administration, Oral↗

Sleep endocrine effects of antigluco- and antimineralocorticoids in healthy males.

In several mammalian species the responsiveness of brain neurons to corticosteroids is mediated by mineralo- (MR) and glucocorticoid (GR) receptors. These receptors play a key role not only in the endocrine adaptation to stress but also in corticosteroid-induced changes of behavior, including sleep. We further explored the specific physiological role of this binary receptor system in the human brain by studying electroencephalogram (EEG) sleep and changes in plasma concentrations of adrenocorticotropic hormone (ACTH), cortisol, and growth hormone from 1800 to 0700 h in a series of investigations in healthy men pretreated the previous evening with the nonselective GR agonist dexamethasone (Dex) and then receiving at 1400 h either placebo, spironolactone (Spi), an MR antagonist, or mifepristone (Mif), a GR antagonist. The Dex-induced suppression of ACTH and cortisol was unaltered after Spi (200 mg) but attenuated by Mif treatment (400 mg). The sleep-associated plasma growth hormone surge was increased by Dex, an effect that remained unchanged by Spi but was reduced by Mif treatment. Pretreatment with Dex did not by itself induce recognizable effects on EEG sleep, but the Dex combination with Spi reduced the amount of rapid-eye-movement (REM) sleep. With Dex plus Mif, both REM sleep and slow wave sleep (SWS) were reduced compared with placebo. The Dex-induced endocrine effects on plasma ACTH, cortisol, and growth hormone concentrations could not be antagonized by Spi, which acts via MRs mainly located in the hippocampus, but were compensated for in part by Mif, which antagonizes GR at the pituitary and in the central nervous system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocorticotropic Hormone↗