Search results for "antagonists"
showing 10 items of 1346 documents
Time Course of 5-HT2A Receptor Occupancy in the Human Brain after a Single Oral Dose of the Putative Antipsychotic Drug MDL 100,907 Measured by Posit…
1997
MDL 100,907 is a potent and selective antagonist of 5-HT2A serotonin receptors. Animals studies suggest that MDL 100,907 may behave as an atypical antipsychotic drug. Positron emission tomograph (PET) using [11C]NMSP as the radiotracer was used to define the time course of 5-HT2 receptor occupancy in the human frontal cerebral cortex after a single oral dose of MDL 100,907 (10 or 20 mg) in nine healthy subjects. After the baseline scan each subject was studied three times post dosing at various time points. 5-HT2 occupancies were in the range of 70 and 90% after each dose. While the occupancy remains in this range over 24 hours after 20 mg MDL 100,907, it decreases by about 20% at 24 hours …
Contractile responses of human thyroid arteries to vasopressin
2013
Abstract Aims In the present study we investigated the intervention of nitric oxide and prostacyclin in the responses to vasopressin of isolated thyroid arteries obtained from multi-organ donors. Main methods Paired artery rings from glandular branches of the superior thyroid artery, one normal and the other deendothelised, were mounted in organ baths for isometric recording of tension. Concentration–response curves to vasopressin were determined in the absence and in the presence of either the vasopressin V 1 receptor antagonist d(CH 2 ) 5 Tyr(Me)AVP (10 − 8 M), the nitric oxide synthase inhibitor N G -monomethyl- l -arginine ( L -NMMA, 10 − 4 M), or the inhibitor of prostaglandins indom…
Effects of vasopressin on human renal arteries
1996
The effects of vasopressin were studied in isolated rings from branches (2-3 mm in external diameter) of human renal arteries obtained from 18 patients undergoing nephrectomy for non-obstructive neoplasia. In arterial rings under resting tension, vasopressin produced concentration-dependent and endothelium-independent contractions with an EC 50 of 9.1 x 10 -10 mol L -1 . The vasopressin V 1 receptor antagonist d(CH 2 ) 5 Tyr(Me)AVP (10 -6 mol L -1 ) displaced the control curve to vasopressin 564-fold to the right in a parallel manner. In precontracted arterial rings and previously treated with the V 1 antagonist (10 -6 mol L -1 ) vasopressin caused endothelium-independent relaxation. The re…
Testosterone-Lowering Medication and Its Association With Recidivism Risk in Individuals Convicted of Sexual Offenses
2020
For a particular subgroup of individuals with severe paraphilic disorders and a high risk of sexual recidivism, the combination of sex drive–reducing medications and psychotherapy is a promising treatment approach. The present quasi-experimental study aims at comparing differences in clinical characteristics and dynamic risk factors between persons receiving (+TLM, n = 38) versus not receiving (−TLM, n = 22) testosterone-lowering medications (TLMs). Individuals receiving TLM were more frequently diagnosed with paraphilic disorders. Neither the criminal history nor average risk scores differed between the two groups. In the +TLM, Stable-2007 scores showed a stronger decrease after TLM treat…
Thyroid function and release of thyroid-stimulating hormone and prolactin from the pituitary in human obesity
1991
Thyroid function, basal serum thyroid-stimulating hormone (TSH) and prolactin concentrations, and the effects of 200 micrograms TSH-releasing hormone (TRH) given intravenously on TSH (delta TSH) and prolactin (delta prolactin) were investigated in 25 euthyroid obese subjects and 20 lean controls. No significant differences in serum thyroid hormone concentrations, glucose metabolism parameters, or basal TSH and prolactin concentrations were detected between groups, but a significant (P less than 0.01) increase in delta TSH and a significant (P less than 0.01) decrease in delta prolactin were observed in obese subjects. No significant differences in basal TSH and prolactin were observed in ob…
Study of pituitary secretion in relation to retinopathy in patients with juvenile diabetes mellitus.
1981
Fifteen juvenile diabetic patients with normal eye fundus, 6 with non proliferative retinopathy, 5 with proliferative retinopathy and 5 healthy control subjects were studied in order to investigate pituitary function in relation to diabetic retinopathy. ACTH values at 08(00) and 18(00), hPRL and TSh secretion in response to 200 microgram TRH i.v., and GH secretion in response to 500 mg oral L-dopa were evaluated. In all diabetic subjects, 08(00) ACTH levels were lower than in controls. Basal hPRL, TSH and GH values of the diabetics did not differ from those of the controls. No significant differences were found in hPRL levels in response to TRH, whereas significantly lower TSH responses wer…
Reference interval by the indirect approach of serum thyrotropin (TSH) in a Mediterranean adult population and the association with age and gender.
2019
Abstract Background The serum concentration of thyrotropin (TSH) represents a first-line test in diagnostic algorithms. The estimation of TSH reference intervals (RIs) is still a matter of debate due to the high prevalence of subclinical disease making difficult the definition of truly healthy subjects. The aim of this study was to estimate TSH RIs in healthy subjects and to evaluate the effect of age and gender on TSH concentration. Methods Forty-four thousand one hundred and fifty-six TSH data were collected between July 2012 and April 2018 at the Department of Laboratory Medicine, University-Hospital, Palermo. Common and sex-specific RIs were estimated by Arzideh’s indirect method after …
Prevalence and clinical relevance of thyroid stimulating hormone receptor-blocking antibodies in autoimmune thyroid disease
2017
Summary The prevalence and clinical relevance of thyroid stimulating hormone (TSH) receptor (TSHR) blocking antibodies (TBAb) in patients with autoimmune thyroid disease (AITD) was investigated. Serum TBAb were measured with a reporter gene bioassay using Chinese hamster ovary cells. Blocking activity was defined as percentage inhibition of luciferase expression relative to induction with bovine TSH alone (cut-off 40% inhibition). All samples were measured for TSHR stimulatory antibody (TSAb) and TSHR binding inhibiting immunoglobulins (TBII). A total of 1079 unselected, consecutive patients with AITD and 302 healthy controls were included. All unselected controls were negative for TBAb and…
Plasma levels of benperidol, prolactin, and homovanillic acid after intravenous versus two different kinds of oral application of the neuroleptic in …
2009
Plasma levels of prolactin (PRL) and the butyrophenone neuroleptic benperidol (BPD) were closely followed 0 to 48 h after acute application of 6 mg BPD as intravenous injection, orally as liquid, and orally as tablets in 12 schizophrenic patients using a partially randomized cross over design. Drug concentrations showed application specific pharmacokinetic behavior with complete elimination within 48 h. All three applications led to a biphasic PRL response with pronounced initial plasma PRL peaks returning to baseline levels within 48 h. The results suggest that after acute neuroleptic challenge BPD plasma levels as low as 2-3 ng/ml can be sufficient for complete depletion of pituitary PRL …
Effects of corticotropin-releasing hormone on respiratory parameters during sleep in normal men.
2009
Corticotropin-releasing hormone (CRH) is well-known to be a centrally acting respiratory stimulant after systemic application both in healthy subjects and in patients suffering from respiratory failure. In order to study the effects of CRH on sleep EEG and respiratory parameters during sleep, 14 healthy male volunteers were investigated in a single-blind placebo controlled design. After an adaptation night, polysomnography was performed during two successive nights between 23.00 hrs. and 7.00 hrs. During one night placebo was applied, on the other 50 μg ovine CRH was administered intravenously as a bolus every hour from 0.00 hrs. to 6.00 hrs. For the assessment of respiration, blood oxygen …