The expression of ob gene is not acutely regulated by insulin and fasting in human abdominal subcutaneous adipose tissue.
The regulation of ob gene expression in abdominal subcutaneous adipose tissue was investigated using a reverse transcription-competitive PCR method to quantify the mRNA level of leptin. Leptin mRNA level was highly correlated with the body mass index of 26 subjects (12 lean, 7 non-insulin-dependent diabetic, and 7 obese patients). The effect of fasting on ob gene expression was investigated in 10 subjects maintained on a hypocaloric diet (1045 KJ/d) for 5 d. While their metabolic parameters significantly changed (decrease in insulinemia, glycemia, and resting metabolic rate and increase in plasma ketone bodies), the caloric restriction did not modify the leptin mRNA level in the adipose tissue. To verify whether insulin regulates ob gene expression, six lean subjects underwent a 3-h euglycemic hyperinsulinemic (846 +/- 138 pmol/liter) clamp. Leptin and Glut 4 mRNA levels were quantified in adipose tissue biopsies taken before and at the end of the clamp. Insulin infusion produced a significant threefold increase in Glut 4 mRNA while leptin mRNA was not affected. It is concluded that ob gene expression is not acutely regulated by insulin or by metabolic factors related to fasting in human abdominal subcutaneous adipose tissue.
Vidal
H
H
INSERM U449, Faculté de Médecine Alexis Carrel, Lyon, France.
Auboeuf
D
D
De Vos
P
P
Staels
B
B
Riou
J P
JP
Auwerx
J
J
Laville
M
M
D000005:Abdomen; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000328:Adult; D001483:Base Sequence; D015992:Body Mass Index; D017931:DNA Primers; D005215:Fasting; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D015309:Glucose Clamp Technique; D051275:Glucose Transporter Type 4; D006801:Humans; D007262:Infusions, Intravenous; D007328:Insulin / Q000008:administration & dosage / Q000494:pharmacology*; D020738:Leptin; D008297:Male; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000096:biosynthesis; D009124:Muscle Proteins; D009767:Obesity, Morbid / Q000235:genetics / Q000378:metabolism* / Q000601:surgery; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D012016:Reference Values; D012044:Regression Analysis; D012867:Skin; D014158:Transcription, Genetic / Q000187:drug effects
D017931:DNA Primers; D051275:Glucose Transporter Type 4; D007328:Insulin; D020738:Leptin; D009004:Monosaccharide Transport Proteins; D009124:Muscle Proteins; D011506:Proteins; D012333:RNA, Messenger; C495692:SLC2A4 protein, human