Diabetes-induced suppression of IGF-1 and its receptor mRNA levels in rat superior cervical ganglia.
Insulin-like growth factor-I (IGF-I) is implicated in the development, survival and maintenance of function of sympathetic and sensory neurons. These neurons are affected at an early stage during the course of diabetes. Reverse transcriptase polymerase chain reaction (RT-PCR) based assay revealed that rat superior cervical ganglia (SCG) express mRNA transcripts for IGF-I and its receptor. Moreover, specific membrane protein binding sites for IGF-I within the SCG have also been demonstrated using competition-inhibition and affinity cross-linking techniques. An induction of diabetes with streptozotocin (STZ, 55 mg/kg, i.v.) produced a marked decrease in the SCG levels of mRNA transcripts for IGF-I and its receptor. Concentrations of circulating IGF-I and its receptor protein within the SCG were also reduced in this disease state. Insulin treatment partially prevented diabetes-related alterations in circulating IGF-I and the SCG-IGF-I system. Overall, the data described in this study may be of value in understanding the pathogenetic mechanism(s) responsible for the development of diabetic sympathetic neuropathy.
Bitar
M S
MS
Department of Pharmacology and Toxicology, Faculty of Medicine, Kuwait University, Safat, Kuwait.
Pilcher
C W
CW
Khan
I
I
Waldbillig
R J
RJ
D000818:Animals; D001667:Binding, Competitive; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D006943:Hyperglycemia / Q000139:chemically induced / Q000188:drug therapy; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000378:metabolism; D007457:Iodine Radioisotopes; D008565:Membrane Proteins / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011485:Protein Binding; D012313:RNA / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017526:Receptor, IGF Type 1 / Q000235:genetics* / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate; D017783:Superior Cervical Ganglion / Q000737:chemistry / Q000378:metabolism*
D007004:Hypoglycemic Agents; D007328:Insulin; D007457:Iodine Radioisotopes; D008565:Membrane Proteins; D012333:RNA, Messenger; D012967:Sodium Dodecyl Sulfate; D012313:RNA; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1