Relative expression of insulin receptor isoforms does not differ in lean, obese, and noninsulin-dependent diabetes mellitus subjects.
The insulin receptor is expressed as two isoforms that differ by a 12-amino acid region at the carboxy-terminus of the alpha-subunit encoded by exon 11. These isoforms are produced by tissue-specific alternate splicing of the insulin receptor mRNA. To determine whether the relative expression of the isoforms is altered in skeletal muscle in two insulin-resistant states, NIDDM and obesity, relative mRNA levels were measured using a polymerase chain reaction technique. There were no differences in the relative amounts of skeletal muscle mRNA encoding the exon 11-containing form compared to the exon 11-lacking form of the insulin receptor among lean normal (30 +/- 2% Ex11-), obese nondiabetic (32 +/- 2%), and NIDDM (31 +/- 1%) subjects. We conclude that altered expression of insulin receptor isoform mRNAs does not account for skeletal muscle insulin resistance in NIDDM and obesity.
Anderson
C M
CM
San Diego Veterans Administration Medical Center, California.
Henry
R R
RR
Knudson
P E
PE
Olefsky
J M
JM
Webster
N J
NJ
D000328:Adult; D000368:Aged; D001483:Base Sequence; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005091:Exons; D006801:Humans; D007536:Isomerism; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D015345:Oligonucleotide Probes / Q000235:genetics; D016133:Polymerase Chain Reaction; D012313:RNA / Q000378:metabolism; D011972:Receptor, Insulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012016:Reference Values; D014158:Transcription, Genetic
D015345:Oligonucleotide Probes; D012313:RNA; D011972:Receptor, Insulin