Abstract
Long-term food restriction (85 %, 70 % and 50 % of ad libitum energy intake for one month) induced a substantial fall in serum leptin concentration and leptin mRNA levels in epididymal white adipose tissue in rats. Surprisingly, this suppression was not reversed by refeeding ad libitum for 48 h. The reduction in serum leptin concentration and leptin mRNA level did not strictly correlate with reduction in fat or body mass. Unlike serum leptin concentration and epididymal adipose tissue leptin mRNA levels, fatty acid synthase activity, fatty acid synthase protein abundance and fatty acid synthase mRNA levels increased significantly in white adipose tissue after refeeding rats subjected to food restriction. The increase in serum insulin concentration was observed in all groups on different degrees of food restriction and refed ad libitum for 48 h compared to controls. A decrease in serum insulin concentration was found in the rats not refed before sacrifice. Long-term food restriction did not significantly affect serum glucose concentrations in either refed or non-refed rats. The data reported in this paper indicate that there is no rapid rebound in serum leptin concentration or leptin gene expression in contrast to the increase in serum insulin concentration and fatty acid gene expression in white adipose tissue of rats refed ad libitum after one month’s food restriction.
Key words
Leptin - Neuropeptide - Ob gene - Fatty acid synthase - Food restriction - White adipose tissue (rat)
References
-
1
Penicaud L, Ferre P, Assmacopoulos-Jeannet F, Perderau D, Leturque A, Jeanrenaud B, Picon L, Girard J.
Increased gene expression of lipogenic enzyme and glucose tratnsporte in white adipose tissue of suckling and weaned obese Zucker rats.
Biochem J.
1991;
279
303-308
-
2
Guichard C, Dugail I, Le Liepvre X, Lavau M.
Genetic regulation of fatty acid synthase expression in adipose tissue:overtranscription of the gene in genetically obese rats.
J Lipid Res.
1992;
33
679-687
-
3
Phillips M S, Liu Q Y, Hammond H A, Dugan V, Hey P J, Caskey C T, Hess J F.
Leptin receptor missence mutation in the fatty Zucker rats.
Nat Genet.
1996;
13
18-19
-
4
Lee Y, Hirose H, Zhou Y T, Esser V, McGary J D, Unger R H.
Increased lipogenic capacity of the islets of obese rats: a role in the pathogenesis of NIDDM.
Diabetes.
1997;
46
408-413
-
5
Zhang Y, Proenca R, Maffei M, Barone M, Leopold L, Friedman J.
Positional cloning of the mouse obese gene and its human homologue.
Nature.
1994;
372
425-432
-
6
Trayhurn P, Duncan J S, Wood A M, Beattie J H.
Regulation of metallothionein gene expression and secretion in rats adipocytes differentiated from preadipocytes in primary culture.
Horm Metab Res.
2000;
32
542-547
-
7
Meler C A.
Advances in the understanding of the molecular basis of obesity.
Eur J Endocrinol.
1995;
133
761-763
-
8
Campfield L A, Smoth F J, Guisez Y, Devos R, Burn P.
Recombinant mouse ob protein: evidence for a peripheral signal linking adiposity and central neural networks.
Science.
1995;
269
546-549
-
9
Halaas J L, Gaiwala K S, Maffei M, Cohen S L, Chait B T, Rabinowitz D, Lallone R L, Burley S K, Friedman J M.
Weight-reducing effects of the plasma protein encoded by the obese gene.
Science.
1995;
269
543-546
-
10
Pelleymounter M, Cullen M J, Baker M B, Hecht R, Winters D, Boone T, Collins F.
Effects of the obese gene product on body weight regulation in ob/ob mice.
Science.
1995;
269
540-543
-
11
Ahima R S, Flier J S.
Leptin.
Annu Rev Physiol.
2000;
62
413-437
-
12
Trayhurn P, Thomas M E, Duncan J S, Rayner D V.
Effects of fasting and refeeding on ob gene expression in white adipose tissue of lean and obese (ob/ob) mice.
FEBS-Letters.
1995;
368
488-499
-
13
Becker D J, Ongemba L N, Brichard V, Henquin J-C, Brichard S M.
Diet- and diabetes-induced changes of ob gene expression in rat adipose tissue.
FEBS-Letters.
1995;
371
324-328
-
14
Kochan Z, Karbowska J, Swierczynski J.
Unusual increase of lipogenesis in rat white adipose tissue after multiple cycles of starvation-refeeding.
Metabolism.
1997;
46
10-17
-
15
Mizuno T, Bergen H, Kleopoulos S, Bauman W A, Mobbs C V.
Effect of nutritional status and aging on leptin gene expression in mice: Importance of glucose.
Horm Metab Res.
1996;
28
679-684
-
16
Li H, Matheny M, Nicolson M, Tumer N, Scarpace P J.
Leptin gene expression increases with age independent of increasing adiposity in rats.
Diabetes.
1997;
46
2035-2039
-
17
Taylor B A, Philips S J.
Detection of obesity QTLs on mouse chromosomes 1 and 7 by selective DNA pooling.
Genomics.
1996;
34
389-398
-
18
Ma Z, Gingerich R L, Santiago J V, Klein S, Smith C H, Landt M.
Radioimmunoassy of leptin in human plasma.
Clin Chem.
1996;
42
942-946
-
19
Karbowska J, Kochan Z, Zelewski L, Swierczynski J.
Tissue specific effect of clofibrate on rat lipogenic enzyme gene expression.
Eur J Pharmacol.
1999;
370
329-336
-
20
Trayhurn P, Duncan J S, Rayner D V.
Acute cold-induced suppression of ob (obese) gene expression in white adipose tissue of mice: mediation by the sympathetic system.
Biochem J.
1995;
311
729-733
-
21
Chomczynski P, Sacchi N.
Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.
Anal Biochem.
1987;
162
156-159
-
22
Kochan Z, Karbowska J, Swierczynski J.
Effect of clofibrate on malic enzyme and leptin mRNA levels in rat brown and white adipose tissue.
Horm Metab Res.
1999;
31
538-542
-
23
Swierczynski J, Korczynska J, Szolkiewicz M, Karbowska J, Kochan Z, Nieweglowski T, Kusiak E, Rutkowski B.
Low leptin mRNA level in adipose tissue and normoleptinemia in experimental chronic renal failure.
Exp Nephrol.
2001;
9
54-59
-
24
Zelewski M, Swierczynski J.
Comparative studies on lipogenic enzyme activities in brown adipose tissue and liver of rat during starvation-refeeding transition and cold exposure.
Comp Biochem Physiol.
1990;
97B
59-63
-
25
Maffei M, Halaas J, Ravussin E, Pratley R E, Lee G H, Zhang Y, Fei H, Kim S, Lallone R, Ranganathan S.
Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subject.
Nature Med.
1995;
1
1155-1161
-
26
Reul B A, Ongemba L N, Pottier A M, Henquin J C, Brichard S M.
Insulin and insulin-like growth factor 1 antagonize the stimulation of ob gene expression by dexamethasone in cultured rat adipose tissue. Biochem.
J.
1997;
324
n
-
27
Fukuda H, Iritani N, Sugimoto T, Ikeda H.
Transcriptional regulation of fatty acid syntahse gene by insulin/glucose, polyunsaturated fatty acids and leptin in hepatocytes and adipocytes in normal and genetically obese rats.
Eur J Biochem.
1999;
260
505-511
-
28
Iritani N, Sugimoto T, Fukuda H.
Gene expression of leptin, insulin receptors and lipogenic enzymes are co-ordinately regulated by insulin and dietary fat in rats.
J Nutr.
2000;
130
1183-1188
-
29
Muller G, Ertl J, Gerl M, Preibisch G.
Leptin impairs metabolic action of insulin in isolated adipocytes. J.
Biol Chem.
1997;
272
10 585-10 593
-
30
Walder K, Filippis A, Clark S, Zimmet P, Collier G R.
Leptin inhibits insulin binding in isolated rat adipocytes.
J Endocrinol.
1997;
155
R5-R7
-
31
Bai Y, Zhang S, Kim K-S, Lee J, Kim K-H.
Obese gene expression alters the ability of 30A5 preadipocytes to respond to lipogenic hormones.
J Biol Chem.
1996;
271
13 939-13 942
J. Swierczynski
Department of Biochemistry, Medical University of Gdansk
ul. Debinki 1 · 80-211 Gdansk, Poland ·
Fax: + 48 (58) 349 1465
Email: juls@amedec.amg.gda.pl
