Search results for "HORMONES"
showing 10 items of 1169 documents
Differential effects of potassium channel blockers on neurohypophysial release of oxytocin and vasopressin. Evidence for frequency-dependent interact…
1988
Isolated rat neurohypophyses were fixed by their stalks to a platinum wire electrode and superfused with Krebs-HEPES solution. Vasopressin and oxytocin released into the medium were determined by specific radioimmunoassays. Hormone secretion was increased by electrical stimulation of the pituitary stalk at different frequencies. The effects of several potassium channel blockers, tetraethylammonium (TEA) ions, 4-aminopyridine (4-AP) and 3,4-diaminopyridine (3,4-DAP) were tested. The release of vasopressin and oxytocin evoked by electrical stimulation with 900 pulses at 15 Hz (about 900 and 1,000 μU, respectively) was about 10 times higher than that evoked by 900 pulses at 3 Hz. Both 10 and 3…
The hypothalamic magnocellular neurosecretory system in developing rats
2009
Studies concerning the development of the magnocellular system are scarce and discordant in literature. We carried out an immunohistochemical study on supraotic and paraventricular hypothalamic nuclei using antivasopressin and antioxytocin antibodies in developing rats between the 15th day of intrauterine life and the 6th day of postnatal life. In addition, we performed RT-PCR experiments to establish the stage at which these hormones appear and neurosecretory activity commences. The results showed that supraoptic and paraventricular nuclei appear, respectively, on the 16th and the 18th day of intrauterine life and both immediately synthetize vasopressin neurohormone. By contrast, synthesis…
Chemosensory signalling pathways involved in sensing of amino acids by the ghrelin cell
2015
AbstractTaste receptors on enteroendocrine cells sense nutrients and transmit signals that control gut hormone release. This study aimed to investigate the amino acid (AA) sensing mechanisms of the ghrelin cell in a gastric ghrelinoma cell line, tissue segments and mice. Peptone and specific classes of amino acids stimulate ghrelin secretion in the ghrelinoma cell line. Sensing of L-Phe occurs via the CaSR, monosodium glutamate via the TAS1R1-TAS1R3 while L-Ala and peptone act via 2 different amino acid taste receptors: CaSR & TAS1R1-TAS1R3 and CaSR & GPRC6A, respectively. The stimulatory effect of peptone on ghrelin release was mimicked ex vivo in gastric but not in jejunal tissue …
Vitellogenesis inhibition in Oncopeltus fasciatus females (Heteroptera: Lygaeidae) exposed to cadmium
2005
Abstract Newly moulted females of the insect Oncopeltus fasciatus were exposed to cadmium (Cd) dissolved in the drinking water (50–400 mg l −1 Cd) for 5 days. Cd exposure delayed ovarian maturation and inhibited egg production. Exposure to Cd, moreover, decreased hemolymph levels of the two major vitellogenin polypeptides of O. fasciatus , VG1 and VG2, in a concentration-dependent way, probably by a reduction in their synthesis. The ovarian levels of VG1 and VG2 were also decreased in Cd-exposed females. It was next investigated whether Cd effects might be a consequence of the endocrine disruption of vitellogenin synthesis, which is controlled by juvenile hormone (JH). JH replacement therap…
Ovicidal Activity of Maternally Applied Ecdysteroids in the Large Milkweed Bug (Heteroptera: Lygaeidae)
1982
Exogenous ecdysteroids (ecdysone, 20-hydroxyecdysone and makisterone A) administered to reproducing females of Oncopelus fasciatus (Dallas) reduced egg hatch drastically. The ovicidal activity apparently stemmed from ecdysteroids—unchanged hormone or metabolites—transferred from mother into oocyte. Different stages of embryogenesis were affected. Makisterone A, the predominant ecdysteroid in normal embryos, is by far the most effective ecdysteroid.
Presence of thyroid hormones in ascidian larvae and their involvement in metamorphosis
2001
In this study we investigated the presence and localization of thyroxine in Ciona intestinalis larvae and its involvement in metamorphosis. To date, the mechanisms regulating the metamorphosis of ascidians remain largely unknown. In vivo treatment of swimming larvae with exogenous L-thyroxine and thiourea, and in vitro experiments utilizing high performance liquid chromatography, radioimmunoassay, and immunoperoxidase staining demonstrate the presence of thyroxine at the larval stage. This suggests that this hormone may participate in the control of metamorphosis and thus play a different role from that observed in adults.
Disease control and treatment pathways of asthma patients after initiating ICS/LABA
2019
Introduction: GINA guidelines recommend medium dose (MED) and high dose (HD) ICS/LABA as the preferred controller for step 4 asthma patients and clinicians should consider step up/down based on their patients’ asthma control. Limited data is available on how step 4 patients respond to ICS/LABA and how they step up/down in clinical practice. Methods: We conducted a retrospective cohort study using UK Clinical Practice Research Datalink to assess control status of asthma patients in one year after initiating a MED or HD ICS/LABA between 2007 and 2015, and examined their treatment pathways within one year after the treatment initiation. Results: 29,229 and 16, 575 patients initiated MED and HD…
Darstellung und Reaktionen von 2-Methylen-canrenon
1995
Ausgehend vom Mannich-Salz 1 des Aldosteronantagonisten Canrenon oder von 2-Methylen-canrenon (2) wurden die am A-Ring anellierten Hetero- und Carbocyclen 5, 6, 8–13 dargestellt. Mit den Verbindungen 2, 3, 4b, 5, 6b, 8 und 12 wurden Bindungsstudien am Estradiol-, Progesteron-, Androgen-, Glucocorticoid- und Mineralocorticoid-Rezeptor sowie an den Serumproteinen Sexualhormonbindendes Globulin (SHBG) und Corticosteroidbindendes Globulin (CBG) durchgefuhrt. Die relativen Bindungsaffinitaten lagen bei CBG unter 1%, in allen anderen Fallen niedriger als 0.01%. Synthesis and Reactions of 2-Methylene-canrenone Starting from the Mannich salt 1 of the aldosterone antagonist canrenone or from 2-methy…
Systemic therapies for Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: a SCORTEN-based systematic review and meta-analysis.
2020
Background The SCORTEN score is a specific predictor of mortality for patients with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). There is little evidence in support of the common immunomodulating therapies for SJS/TEN. Objectives To systematically assess the effectiveness of several therapies for SJS/TEN through the SCORTEN score. Methods Databases were searched for original studies on the use of SCORTEN. Six meta-analyses were carried out on patients with SJS/TEN who received supportive care only or in combination with immunomodulating drugs: corticosteroids, cyclosporine, etanercept, immunoglobulins or a combination of corticosteroids with immunoglobulins. A multivaria…
Cardiorespiratory fitness is not associated with risk of venous thromboembolism: a cohort study
2019
Objectives. The inverse and independent association between cardiorespiratory fitness (CRF) and arterial thrombotic disease is well established. However, the potential association between CRF and venous thromboembolism (VTE) is not well known. We aimed to assess the prospective association of CRF with the risk of VTE. Design. Cardiorespiratory fitness, as measured by maximal oxygen uptake (VO2max), was assessed using a respiratory gas exchange analyser in 2,249 men aged 42-61 years without a history of VTE at baseline in the Kuopio Ischemic Heart Disease prospective cohort. Cox-regression models were used to calculate hazard ratios (HR) with 95% confidence interval (CI) for VTE. We correcte…