Search results for "secret"
showing 10 items of 1132 documents
In vitro reprogramming of pancreatic alpha cells towards a beta cell phenotype following ectopic HNF4α expression
2015
There is currently a shortage of organ donors available for pancreatic beta cell transplantation into diabetic patients. An alternative source of beta cells is pre-existing pancreatic cells. While we know that beta cells can arise directly from alpha cells during pancreatic regeneration we do not understand the molecular basis for the switch in phenotype. The aim of the present study was to investigate if hepatocyte nuclear factor 4 alpha (HNF4α), a transcription factor essential for a normal beta cell phenotype, could induce the reprogramming of alpha cells towards potential beta cells. We utilised an in vitro model of pancreatic alpha cells, the murine αTC1-9 cell line. We initially chara…
Inhibition of Melatonin in the Plasma of Third-Generation Male Mice under the Action of ELF Magnetic Fields
1998
The pineal gland has been considered a magnetic receptor organ that regulates circadian rhythms by means of the secretion of melatonin, a potent oncostatic agent that prevents the initiation and promotion of cancer. ELF electromagnetic radiation, similar to that generated by power lines, can alter melatonin plasma levels.To study this effect, 4 OF1 mice generations have been reared subjected to a lifelong 15 μT, 50 Hz magnetic field action. This magnetic field was generated inside a Helmholtz coil system. The concentration of melatonin in the blood has been determined on 40 male mice of the third generation by means of RIA, as they reached sexual maturity (3 months).A radical decrease, more…
A Review of the Cardiovascular and Anti-Atherogenic Effects of Ghrelin
2013
Ghrelin is a peptide hormone produced mainly in the stomach that has widespread tissue distribution and diverse hormonal, metabolic and cardiovascular activities. The circulating ghrelin concentration increases during fasting and decreases after food intake. Ghrelin secretion may thus be initiated by food intake and is possibly controlled by nutritional factors. Lean subjects have increased levels of circulating ghrelin compared with obese subjects. Recent reports show that low plasma ghrelin is associated with elevated fasting insulin levels, insulin resistance and type 2 diabetes mellitus. Factors involved in the regulation of ghrelin secretion have not yet been defined; however, it is as…
Oral administration of the growth hormone secretagogue NN703 in adult patients with growth hormone deficiency
2003
Summary objective Little is known of the usefulness of GH secretagogues (GHSs) in GH-deficient (GHD) adults. The objective of this study was to determine the number of responders to treatment with NN703 in GHD adults. design A multicentre, randomized, double-blind, and placebo-controlled study. patients Ninety-seven GHD adults were included. measurements The GH response before and after 1 week of oral treatment with NN703 (n = 83) or placebo (n = 14) was determined. The first and last dose of NN703 was 3 mg/kg, whereas the dose of NN703 was 1·5 mg/kg/day during the 6 days between the first and last doses. Furthermore, all 97 patients received 1 µg/kg GH-releasing hormone (GHRH) 3 weeks afte…
Rhein stimulates active chloride secretion in the short-circuited rat colonic mucosa.
1988
In a short-circuited mucosa-submucosa preparation of the rat descending colon with preserved Meissner's plexus mounted as an everted sac rhein transiently increased the potential difference and short-circuit current (Isc) when administered serosally and mucosally, but serosal application was more effective. Maximal effects were obtained at rhein concentrations of 1.6 X 10(-4) and 3 X 10(-4) mol/l. Net chloride absorption was decreased. Indomethacin (5 X 10(-6) mol/l) did not inhibit the increase of Isc, but omission of calcium from the serosal side as well as tetrodoxin (2 X 10(-7) mol/l) decreased it by 50 and 60%. Mechanical removal of Meissner's plexus partly blocked the effect of rhein,…
Bndocrinopathic Constitutions and Pathology of War*
1919
The clinical study of the internal secretions opens a vast field of research, so far little known, notwithstanding its great value in practical medicine. Particularly important are those states of hormonic imbalance which are at the border line between health and disease, and which represent either latent or mild endocrinopathic conditions, real endocrine diatheses or endocrinopathic temperaments. It is already understood that for each of the best known endocrine glands, in addition to frank malfunctions there must be recognized minor degrees of perturbation giving rise to the endocrinopathic habitus. To the French writers, especially Levi and Rotschild, we owe much of our knowledge of the …
Effects of nicotine receptor agonists on acetylcholine release from the isolated motor nerve, small intestine and trachea of rats and guinea-pigs
1992
The effects of nicotine receptor agonists on the release of [3H]acetylcholine from the phrenic nerve, the small intestine and the trachea were investigated to characterize neuronal nicotine receptors within the peripheral nervous system. Contraction of the indirectly-stimulated hemidiaphragm was recorded to investigate desensitization of the postsynaptic muscular nicotine receptors. Nicotine, cytisine, 1,1-dimethyl-4-phenylpiperazinium and 2-(4-aminophenyl)-ethyl-trimethyl-ammoniumiodide caused a concentration-dependent (0.1-30 microM) increase in evoked [3H]acetylcholine release from the phrenic nerve, whereby bell-shaped concentration-response curves were obtained. The rank order of decre…
Cyclic AMP-dependent and independent stimulations of ovarian steroidogenesis by brain factors in the blowfly, Phormia regina.
2000
0303-7207 doi: DOI: 10.1016/S0303-7207(00)00312-9; The involvement of cyclic-AMP (cAMP) as a potential second messenger in the neurohormonal control of ovarian steroidogenesis was investigated in the adult female blowfly Phormia regina. Individual measurements of ovarian cAMP concentrations and of ovarian biosynthesis of ecdysteroids, stimulated after a protein meal, demonstrated that steroidogenesis is preceded by a peak of cAMP in the ovaries. In vitro, ovarian steroidogenesis was stimulated by cell-permeable analogues of cAMP and by forskolin. Crude brain extracts were also able to elicit a rise of cAMP in the ovaries in vitro and the secretion of ecdysteroids into the medium: such extra…
The ecdysone-induced DHR4 orphan nuclear receptor coordinates growth and maturation in Drosophila
2005
0092-8674 (Print) Journal Article Research Support, Non-U.S. Gov't; A critical determinant of insect body size is the time at which the larva stops feeding and initiates wandering in preparation for metamorphosis. No genes have been identified that regulate growth by contributing to this key developmental decision to terminate feeding. We show here that mutations in the DHR4 orphan nuclear receptor result in larvae that precociously leave the food to form premature prepupae, resulting in abbreviated larval development that translates directly into smaller and lighter animals. In addition, we show that DHR4 plays a central role in the genetic cascades triggered by the steroid hormone ecdyson…
The diabetogenic action of statins — mechanisms and clinical implications
2015
Treatment with statins has transformed primary and secondary prevention of cardiovascular disease (CVD), including thrombotic stroke. Evidence-based data demonstrate the benefits and safety of statin therapy and help to guide clinicians in the management of populations at high risk of CVD. Nevertheless, clinical trials, meta-analyses and observational studies highlight a 10-12% increase in new-onset diabetes mellitus (NODM) among patients receiving statins. The risk further increases with intensive therapy and among individuals with known risk factors for NODM. Mechanisms underpinning this effect are not yet fully understood; however, Mendelian randomization studies suggest that they are re…