Insulin is a hormone secreted by pancreaticβcells.The concentration of glucose in circulation is proportional to the secretion of insulin by these cells.In target cells,insulin binds to its receptors and activates ph...Insulin is a hormone secreted by pancreaticβcells.The concentration of glucose in circulation is proportional to the secretion of insulin by these cells.In target cells,insulin binds to its receptors and activates phosphatidylinositol-3-kinase/protein kinase B,inducing different mechanisms depending on the cell type.In the liver it activates the synthesis of glycogen,in adipose tissue and muscle it allows the capture of glucose,and in the hypothalamus,it regulates thermogenesis and appetite.Defects in insulin function[insulin resistance(IR)]are related to the development of neurodegenerative diseases in obese people.Furthermore,in obesity and diabetes,its role as an anorexigenic hormone in the hypothalamus is diminished during IR.Therefore,hyperphagia prevails,which aggravates hyperglycemia and IR further,becoming a vicious circle in which the patient cannot regulate their need to eat.Uncontrolled calorie intake induces an increase in reactive oxygen species,overcoming cellular antioxidant defenses(oxidative stress).Reactive oxygen species activate stress-sensitive kinases,such as c-Jun Nterminal kinase and p38 mitogen-activated protein kinase,that induce phosphorylation in serine residues in the insulin receptor,which blocks the insulin signaling pathway,continuing the mechanism of IR.The brain and pancreas are organs mainly affected by oxidative stress.The use of drugs that regulate food intake and improve glucose metabolism is the conventional therapy to improve the quality of life of these patients.Currently,the use of antioxidants that regulate oxidative stress has given good results because they reduce oxidative stress and inflammatory processes,and they also have fewer side effects than synthetic drugs.展开更多
文摘Insulin is a hormone secreted by pancreaticβcells.The concentration of glucose in circulation is proportional to the secretion of insulin by these cells.In target cells,insulin binds to its receptors and activates phosphatidylinositol-3-kinase/protein kinase B,inducing different mechanisms depending on the cell type.In the liver it activates the synthesis of glycogen,in adipose tissue and muscle it allows the capture of glucose,and in the hypothalamus,it regulates thermogenesis and appetite.Defects in insulin function[insulin resistance(IR)]are related to the development of neurodegenerative diseases in obese people.Furthermore,in obesity and diabetes,its role as an anorexigenic hormone in the hypothalamus is diminished during IR.Therefore,hyperphagia prevails,which aggravates hyperglycemia and IR further,becoming a vicious circle in which the patient cannot regulate their need to eat.Uncontrolled calorie intake induces an increase in reactive oxygen species,overcoming cellular antioxidant defenses(oxidative stress).Reactive oxygen species activate stress-sensitive kinases,such as c-Jun Nterminal kinase and p38 mitogen-activated protein kinase,that induce phosphorylation in serine residues in the insulin receptor,which blocks the insulin signaling pathway,continuing the mechanism of IR.The brain and pancreas are organs mainly affected by oxidative stress.The use of drugs that regulate food intake and improve glucose metabolism is the conventional therapy to improve the quality of life of these patients.Currently,the use of antioxidants that regulate oxidative stress has given good results because they reduce oxidative stress and inflammatory processes,and they also have fewer side effects than synthetic drugs.
