Search results for "hormone"
showing 10 items of 2056 documents
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 …
Transferrin gene expression in the mammary gland of the rat. The enhancing effect of 17 beta-oestradiol on the level of RNA is tissue-specific.
1993
We have investigated the physiological factors which regulate transferrin gene expression in the mammary gland of the rat. Our studies by dot blot analysis have demonstrated that multiple doses of 17β-oestradiol (OE2; 0·5 mg/kg per day for 3 days) elicit a specific 3·5-fold increase in the transferrin mRNA levels in the mammary glands of virgin rats. The hormonal action of OE2 in mammary tissue was specific for the transferrin gene, as judged by hybridization with β-actin cDNA. The accmulation of transferrin mRNA induced by OE2 treatment was similar to the developmentally regulated expression of the gene observed during the reproductive cycle. The steady-state level of mammary transferrin m…
The effect of L-thyroxine on the metamorphosis of Ascidia malaca
1981
Larvae of Ascidia malaca, both before and after hatching, were treated with L-thyroxine solutions. The effect of the thyroid hormone was to induce the onset of metamorphosis and then to cause the rate at which body reorganization occurred to increase. In treated larvae the resorption of the tail occurred only few hours after hatching, and a beating heart appeared form 10 to 15 h earlier than in the control larvae. These results are discussed in the context of a probable relationship between the occurrence of a hormonal metamorphic factor and the button cells of the trunk.
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.
Identification of a discrete neuronal circuit that relays insulin signaling into the brain to regulate glucose homeostasis
2021
Abstract26RFa (QRFP) is a biologically active peptide that regulates glucose homeostasis by acting as an incretin and by increasing insulin sensitivity at the periphery. 26RFa is also produced by a neuronal population localized in the hypothalamus. In the present study, we have investigated whether the 26RFa neurons may be involved in the hypothalamic regulation of glucose homeostasis. Our data indicate that 26RFa, i.c.v. injected, induces a robust antihyperglycemic effect associated with an increase of insulin production by the pancreatic islets. In addition, we found that insulin strongly stimulates 26RFa expression and secretion by the hypothalamus. RNAscope experiments revealed that neu…
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…
The non-appearance of female-specific proteins in male Spilostethus pandurus)
1990
1. 1. Female-specific peptides can be detected by SDS-PAGE in the haemolymph when the female insects are 48 hr old. 2. 2. The age of the male insect at the moment of treatment with juvenile hormone I (JH I), JH III or ecdysone has no influence on the induction of the female-specific bands in male S. pandurus. 3. 3. Male insects exposed to the hormones for periods of time longer than 24 hr were also unable to show female-specific bands in their haemolymph. Consecutive treatments with JH were unable to induce these peptides in the males.