title: Galanin antagonist increases insulin resistance by reducing glucose transporter 4 effect in adipocytes of rats.
abstract: Seeing that galanin increases animal body weight on the conditions of inhibiting insulin secretion and animals with metabolic disorder of galanin easily suffer from diabetes, we postulate that endogenous galanin is necessary to reduce insulin resistance in adipocytes. To test this hypothesis, we compared four groups of rats to examine whether an increase in galanin secretion stimulated by swimming may reduce insulin resistance. The rats from sedentary and trained drug groups were injected by M35, a galanin antagonist. The rats from trained control and trained drug groups swam after each injection for four weeks. We found that exercise significantly elevated plasma galanin contents and glucose transporter 4 (GLUT4) mRNA levels in adipocytes. Meanwhile, M35 treatment reduced GLUT4 and GLUT4 mRNA levels, and glucose infusing rates in euglycemic-hyperinsulinemic clamp tests. The ratios of GLUT4 concentrations at plasma membranes to total cell membranes in both drug groups were lower compared with each control group, respectively. These observations suggest that endogenous galanin reduces insulin resistance by increasing GLUT4 contents and promoting GLUT4 transportation from intracellular membranes to plasma membranes in adipocytes. Galanin is an important hormone to reduce insulin resistance in rats.
authors.affiliation: Department of Physical Education, Chuzhou College, Chuzhou, Anhui Province 239012, PR China.
authors.forename: Lili
authors.initials: L
authors.lastname: Guo
authors.forename: Mingyi
authors.initials: M
authors.lastname: Shi
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Li
authors.forename: Lingxiang
authors.initials: L
authors.lastname: Zhang
authors.forename: Hu
authors.initials: H
authors.lastname: Shao
authors.forename: Penghua
authors.initials: P
authors.lastname: Fang
authors.forename: Yingping
authors.initials: Y
authors.lastname: Ma
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Qiaojia
authors.initials: Q
authors.lastname: Shi
authors.forename: Yumei
authors.initials: Y
authors.lastname: Sui
mesh_terms: D017667:Adipocytes / Q000187:drug effects* / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D001920:Bradykinin / Q000031:analogs & derivatives* / Q000494:pharmacology; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D019004:Galanin / Q000037:antagonists & inhibitors* / Q000378:metabolism* / Q000494:pharmacology; D015309:Glucose Clamp Technique; D051275:Glucose Transporter Type 4 / Q000235:genetics / Q000378:metabolism*; D007333:Insulin Resistance / Q000502:physiology*; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D051275:Glucose Transporter Type 4; D010446:Peptide Fragments; C074069:galanin-(1-13)-bradykinin-(2-9)-amide; D019004:Galanin; D001920:Bradykinin