Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.20 (alpha-glucosidase)
 4,237 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have studied the influence of nitric oxide (NO) and carbon monoxide (CO), putative messenger molecules in the brain as well as in the islets of Langerhans, on glucose-stimulated insulin secretion and on the activities of the acid alpha-glucoside hydrolases, enzymes which we previously have shown to be implicated in the insulin release process. We have shown here that exogenous NO gas inhibits, while CO gas amplifies glucose-stimulated insulin secretion in intact mouse islets concomitant with a marked inhibition (NO) and a marked activation (CO) of the activities of the lysosomal/vacuolar enzymes acid glucan-1,4-alpha-glucosidase and acid alpha-glucosidase (acid alpha-glucoside hydrolases). Furthermore, CO dose-dependently potentiated glucose-stimulated insulin secretion in the range 0.1-1000 microM. In intact islets, the heme oxygenase substrate hemin markedly amplified glucose-stimulated insulin release, an effect which was accompanied by an increased activity of the acid alpha-glucoside hydrolases. These effects were partially suppressed by the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one. Hemin also inhibited inducible NO synthase (iNOS)-derived NO production probably through a direct effect of CO on the NOS enzyme. Further, exogenous CO raised the content of both cGMP and cAMP in parallel with a marked amplification of glucose-stimulated insulin release, while exogenous NO suppressed insulin release and cAMP, leaving cGMP unaffected. Emiglitate, a selective inhibitor of alpha-glucoside hydrolase activities, was able to markedly inhibit the stimulatory effect of exogenous CO on both glucose-stimulated insulin secretion and the activityof acid glucan-1,4-alpha-glucosidase and acid alpha-glucosidase, while no appreciable effect on the activities of other lysosomal enzyme activities measured was found. We propose that CO and NO, both produced in significant quantities in the islets of Langerhans, have interacting regulatory roles on glucose-stimulated insulin secretion. This regulation is, at least in part, transduced through the activity of cGMP and the lysosomal/vacuolar system and the associated acid alpha-glucoside hydrolases, but probably also through a direct effect on the cAMP system.
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PMID:Nitric oxide inhibits, and carbon monoxide activates, islet acid alpha-glucoside hydrolase activities in parallel with glucose-stimulated insulin secretion. 1700 69

The present study was conducted to test the hypothesis that dietary supplementation with a nano chitosan-zinc complex (CP-Zn, 100 mg/kg zinc) could alleviate weaning stress in piglets challenged with ETEC K88 by improving growth performance and intestinal antioxidant capacity. The in vivo effects of CP-Zn on growth performance variables (including gastrointestinal digestion and absorption functions and the levels of key proteins related to muscle growth) and the antioxidant capacity of the small intestine were evaluated in 72 weaned piglets. The porcine jejunal epithelial cell line IPEC-J2 was used to further investigate the antioxidant mechanism of CP-Zn in vitro. The results showed that CP-Zn supplementation increased the jejunal villus height and decreased the diarrhoea rate in weaned piglets. CP-Zn supplementation also improved growth performance (ADG and ADFI), increased the activity of carbohydrate digestion-related enzymes (amylase, maltase, sucrase and lactase) and the mRNA expression levels of nutrient transporters (SGLT1, GLUT2, PEPT1 and EAAC1) in the jejunum, and upregulated the expression levels of mTOR pathway-related proteins (IRS1, phospho-mTOR and phospho-p70S6K) in muscle. In addition, CP-Zn supplementation increased glutathione content, enhanced T-SOD and GSH-px activity, and reduced MDA content in the jejunum. Furthermore, CP-Zn decreased the content of MDA and ROS, enhanced the activity of T-SOD and GSH-px, and upregulated the expression levels of Nrf2 pathway-related proteins (Nrf2, NQO1 and HO1) in LPS-stimulated IPEC-J2 cells. Collectively, these findings indicate that CP-Zn supplementation can improve growth performance and the antioxidant capacity of the small intestine in piglets, thus alleviating weaning stress.
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PMID:Nano chitosan-zinc complex improves the growth performance and antioxidant capacity of the small intestine in weaned piglets. 3325 56