Search results for "Insulin receptor"
showing 10 items of 54 documents
Bisoprolol and captopril effects on insulin receptor tyrosine kinase activity in essential hypertension.
1998
Angiotension converting enzyme (ACE) inhibitors and beta-blockers have been reported to possess disparate effects on insulin sensitivity. The aim of this study was to study the effects of the selective beta-1 blocker bisoprolol and of the ACE inhibitor captopril on cellular insulin action in hypertensive individuals. After washout, 12 mild to moderate essential hypertensives were randomized in a double-blind manner to 5 mg bisoprolol daily or 25 mg captopril twice daily for 8 weeks. Erythrocyte insulin binding and insulin-stimulated tyrosine kinase (TK) activity were measured before and after therapy. Both agents decreased diastolic blood pressure significantly (bisoprolol 96.5+/-0.9 to 87.…
Genetic and environmental aspect of polycystic ovary syndrome.
2004
Polycystic ovary syndrome (PCOS) is a heterogeneous syndrome determined in most patients by the association of two main factors: hyperandrogenism and insulin resistance. These characters are probably independent of each other and seem to be inherited by several different mechanisms. In some patients homozygous gene alteration has been found but in most patients PCOS seems to be determined by the association of gene polymorphisms that are common in the general population but alone are unable to determine phenotypic consequences. Alteration of genes that regulate the initial steps of ovarian steroidogenesis is probably the main causal factor of hyperandrogenism. Insulin resistance may be the …
Hypertension, diabetes mellitus, and insulin resistance: the role of intracellular magnesium.
1997
Magnesium is one of the most abundant ions present in living cells and its plasma concentration is remarkably constant in healthy subjects. Plasma and intracellular magnesium concentrations are tightly regulated by several factors. Among them, insulin seems to be one of the most important. In fact, in vitro and in vivo studies have demonstrated that insulin may modulate the shift of magnesium from extracellular to intracellular space. Intracellular magnesium concentration has also been shown to be effective on modulating insulin action (mainly oxidative glucose metabolism), offset calcium-related excitation-contraction coupling, and decrease smooth cell responsiveness to depolarizing stimul…
The estrogen receptor α:insulin receptor substrate 1 complex in breast cancer: structure–function relationships
2007
Background: Insulin receptor substrate 1 (IRS-1) is a signaling molecule that exerts a key role in mediating cross talk between estrogen receptor a (ERa) and insulin-like growth factor 1 (IGF-1) in breast cancer cells. Previously, we demonstrated that a fraction of IRS-1 binds ERa, translocates to the nucleus, and modulates ERa-dependent transcription at estrogen response elements (ERE). Here, we studied structure-function relationships of the ER-a:IRS-1 complex under IGF-1 and/or estradiol (E 2 ) stimulation. Materials and methods: ERa and IRS-1 deletion mutants were used to analyze structural and functional ERα/IRS-1 interactions. IRS-1 binding to ERE and IRS-1 role in ERa-dependent ERE t…
Toll-like receptor 5 in obesity: The role of gut microbiota and adipose tissue inflammation
2015
Objective This study aimed at establishing bacterial flagellin-recognizing toll-like receptor 5 (TLR5) as a novel link between gut microbiota composition, adipose tissue inflammation, and obesity. Methods An adipose tissue microarray database was used to compare women having the highest (n = 4, H-TLR) and lowest (n = 4, L-TLR) expression levels of TLR5-signaling pathway genes. Gut microbiota composition was profiled using flow cytometry and FISH. Standard laboratory techniques were used to determine anthropometric and clinical variables. In vivo results were verified using cultured human adipocytes. Results The H-TLR group had higher flagellated Clostridium cluster XIV abundance and Firmicu…
IRS-2 deficiency impairs NMDA receptor-dependent long-term potentiation
2011
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License.-- et al.
Control of ovarian steroidogenesis by insulin-like peptides in the blowfly (Phormia regina).
2004
0022–0795/04/0181–147; This study investigated the ability of insulin and of insect insulin-like peptides (ILPs) to stimulate ovarian steroidogenesis in the blowfly Phormia regina. Bovine insulin was active on ovaries isolated in vitro, which showed an age-dependent sensitivity; this peptide progressively stimulated steroidogenesis in ovaries isolated from the third day after adult molt, but not in younger ones, and had maximal activity after the fifth day. This stimulatory effect was observed equally from females reared in the presence or in the absence of males, excluding a regulatory effect of mating. The mode of action of insulin in blowflies did not involve cAMP, but triggered a specif…
Chick embryo retina development in vitro: the effect of insulin.
1995
In this paper we study the development of chick embryo retina cultured in vitro and the effects exerted by insulin. Retinas were removed from 7-day embryos and cultured in serum- and hormone-free medium for 7 additional days. Under these conditions retinal cells survived and underwent cholinergic differentiation, as previously ascertained by Hausman et al. (Dev. Brain Res., 1991, 59: 31-37). However, a great retardation of development was noted compared to uncultured control, 14-day retina. In fact both wet weight and DNA and protein content increased much slower than in ovo and the tubulin content decreased below even the starting value. In addition, although after 7 days in culture retina…
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…
MAGNESIUM METABOLISM IN INSULIN RESISTANCE, METABOLIC SYNDROME, AND TYPE 2 DIABETES MELLITUS
2007
Magnesium plays a key role in regulating insulin action, insulin-mediated glucose uptake, and vascular tone. Intracellular magnesium depletion may result in a defective tyrosine—kinase activity at the insulin receptor level, in a postreceptorial impairment in insulin action, and clinically in a worsening of insulin resistance. Intra- and extracellular alterations of magnesium metabolism have been identified in clinical states characterized by insulin resistance, such as metabolic syndrome, hypertension, altered glucose tolerance, type 2 diabetes, and aging. Several studies, from our and other’s groups, have confi rmed the clinical relevance of alterations of magnesium homeostasis in these c…