Performance of quinoa (Chenopodium quinoa Willd) flour in the manufacture of gluten-free spaghetti

The objective of this work was to assess the performance of mixtures of corn and quinoa (Chenopodium quinoa Willd) flours in the development of a spaghetti-type product. Cooking quality (loss of solids, volume increase, weight increase), texture (adhesiveness, elasticity), peak and final viscosities and moisture content of the pre-gelatiniised hour mixtures were the physical parameters studied. The mean values for loss of solids, weight increase, volume increase, adhesiveness and moisture were 162 g kg(-1), 2.3 times, 2.6 times, 2090.7 g and 384 g kg(-1) respectively. Peak viscosity and elasticity provided information relevant, yet not definitive, to both formulation and processing of the product. However, the model developed was predictive for final viscosity. The combination of independent variables that resulted in higher elasticity values, desirable for spaghetti, were short thermal treatment and low-to-medium quinoa additions. All peak viscosities were low with respect to the untreated hour. For final viscosity, however, the best combinations were short heat treatments across the entire range of quinoa contents. Sensory acceptability testing of the spaghetti by a consumer panel was also included. (C) 2000 Society of Chemical Industry.8119510

The phosphatidylinositol/AKT/atypical PKC pathway is involved in the improved insulin sensitivity by DHEA in muscle and liver of rats in vivo

DHEA improves insulin sensitivity and has anti-obesity effect in animal models and men. However, the molecular mechanisms by which DHEA improves insulin action have not been clearly understood. In the present study, we examined the protein levels and phosphorylation state of insulin receptor (IR), IRS-1 and IRS-2, the association between IRSs and PI3K and SHP2, the insulin-induced IRSs associated PI 3-kinase activities, and the phosphorylation status of AKT and atypical PKCzeta/lambda in the liver and the muscle of 6 month-old Wistar rats treated with DHEA. There was no change in IR, IRS-1 and IRS-2 protein levels in both tissues of treated rats analysed by immunoblotting. On the other hand, insulin-induced, IRS-1 tyrosine phosphorylation was increased in both tissues While IRS-2 tyrosyl phosphorylation was increased in liver of DHEA treated group. The PI3-kinase/AKT pathway was increased in the liver and the PI3K/atypical PKCzeta/lambda pathway was increased in the muscle of DHEA treated rats. These data indicate that these regulations of early steps of insulin action may play a role in the intracellular mechanism for the improved insulin sensitivity observed in this animal model. (C) 2004 Elsevier Inc. All rights reserved.761577

In vivo activation of insulin receptor tyrosine kinase by melatonin in the rat hypothalamus

Melatonin is the pineal hormone that acts via a pertussis toxin-sensitive G-protein to inhibit adenylate cyclase. However, the intracellular signalling effects of melatonin are not completely understood. Melatonin receptors are mainly present in the suprachiasmatic nucleus (SCN) and pars tuberalis of both humans and rats. The SCN directly controls, amongst other mechanisms, the circadian rhythm of plasma glucose concentration. In this study, using immunoprecipitation and immunoblotting, we show that melatonin induces rapid tyrosine phosphorylation and activation of the insulin receptor beta-subunit tyrosine kinase (IR) in the rat hypothalamic suprachiasmatic region. Upon IR activation, tyrosine phosphorylation of IRS-1 was detected. In addition, melatonin induced IRS-1/PI(3)-kinase and IRS-1/SHP-2 associations and downstream AKT serine phosphorylation and MAPK (mitogen-activated protein kinase) phosphorylation, respectively. These results not only indicate a new signal transduction pathway for melatonin, but also a potential cross-talk between melatonin and insulin.90355956

Novel signal transduction pathway for luteinizing hormone and its interaction with insulin: Activation of janus kinase/signal transducer and activator of transcription and phosphoinositol 3-kinase/akt pathways

The actions of LH are mediated through a single class of cell surface LH/human chorionic gonadotropin receptor, which is a member of the G protein-coupled receptor family. In the present study we showed that LH induced rapid tyrosine phosphorylation and activation of the Janus kinase 2 (JAK2) in rat ovary. Upon JAK2 activation, tyrosine phosphorylation of signal transducer and activator of transcription-1 (STAT-1), STAT-5b, insulin receptor substrate-1 (IRS-1), and Src homology and collagen homology (Shc) were detected. In addition, LH induced IRS-1/phosphoinositol 3-kinase and Shc/growth factor receptor-binding protein 2 (Grb2) associations and downstream AKT (protein kinase B, homologous to v-AKT) serine phosphorylation and ERK tyrosine phosphorylation, respectively. The simultaneous infusion of insulin and LH induced higher phosphorylation levels of JAK2, STAT5b, IRS-1, and AKT compared with each hormone alone in the whole ovary of normal rats. By immunohistochemistry we demonstrated that these late events take place in follicular cells and both external and internal theca. These results indicate a new signal transduction pathway for LH and show that there is positive cross-talk between the insulin and LH signaling pathways at the level of phosphoinositol 3-kinase/AKT pathway in this tissue.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.144263864

ERK3 associates with MAP2 and is involved in glucose-induced insulin secretion

The adaptation of pancreatic islets to pregnancy includes increased P cell proliferation, expansion of islet mass, and increased insulin synthesis and secretion. Most of these adaptations are induced by prolactin (PRL). We have previously described that in vitro PRL treatment increases ERK3 expression in isolated rat pancreatic islets. This study shows that ERK3 is also upregulated during pregnancy. Islets from pregnant rats treated with antisense oligonucleotide targeted to the PRL receptor displayed a significant reduction in ERK3 expression. Immunohistochemical double-staining showed that ERK3 expression is restricted to pancreatic P cells. Transfection with antisense oligonucleotide targeted to ERK3 abolished the insulin secretion stimulated by glucose in rat islets and by PMA in RINm5F cells. Therefore, we examined the participation of ERK3 in the activation of a cellular target involved in secretory events, the microtubule associated protein MAP2. PMA induced ERK3 phosphorylation that was companied by an increase in ERK3/MAP2 association and MAP2 phosphorylation. These observations provide evidence that ERK3 is involved in the regulation of stimulus-secretion coupling in pancreatic P cells. (c) 2006 Elsevier Ireland Ltd. All rights reserved.25141671334