The developmental pattern of rabbit brain insulin and insulin-like growth factor receptor expression.
To examine the effect of development on rabbit brain insulin and insulin-like growth factor (IGF) receptor expression, we characterized and quantitated receptor mRNAs by Northern blot analysis and affinity-labeled ligand bound receptors by SDS-PAGE and autoradiography. At various stages of development ranging from 23 to 30 day gestational (term approximately 31 days), 1 to 10 day postnatal ages and the adult, no change in the whole brain insulin receptor mRNA (7.0, 6.0 and 5.5 kb) and affinity-labeled receptor protein (approximately 125 kDa) levels was observed. The IGF-I receptor mRNA (11.5, 6.5 and 4.5 kb) and affinity-labeled receptor (approximately 125 kDa) protein levels declined during the neonatal stages of development. In the case of the IGF-II receptor, while the mRNA levels (9.0 and 4.5 kb) remained constant, the corresponding affinity-labeled receptor protein (approximately 230 kDa) declined with maturation. We conclude that a differential regulation of brain insulin, IGF-I and IGF-II receptor expression occurs during development.
Devaskar
S U
SU
Department of Pediatrics, St. Louis University School of Medicine, MO.
Sadiq
H F
HF
Holtzclaw
L
L
George
M
M
D000818:Animals; D001345:Autoradiography; D015152:Blotting, Northern; D001921:Brain / Q000196:embryology / Q000254:growth & development*; D001923:Brain Chemistry / Q000502:physiology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000378:metabolism; D007335:Insulin-Like Growth Factor II / Q000378:metabolism; D007457:Iodine Radioisotopes; D008565:Membrane Proteins / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D017527:Receptor, IGF Type 2 / Q000096:biosynthesis*; D011972:Receptor, Insulin / Q000096:biosynthesis*
D007457:Iodine Radioisotopes; D008565:Membrane Proteins; D012333:RNA, Messenger; D017527:Receptor, IGF Type 2; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D011972:Receptor, Insulin