Enhanced expression of leptin following acute gastric injury in rat

Citation
Pc. Konturek et al., Enhanced expression of leptin following acute gastric injury in rat, J PHYSL PH, 50(4), 1999, pp. 587-595
Citations number
16
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physiology
Journal title
JOURNAL OF PHYSIOLOGY AND PHARMACOLOGY
ISSN journal
0867-5910 → ACNP
Volume
50
Issue
4
Year of publication
1999
Pages
587 - 595
Database
ISI
SICI code
0867-5910(199912)50:4<587:EEOLFA>2.0.ZU;2-6
Abstract
Leptin, a product of ob-gene plays an important role in the regulation of f ood intake. Recently, leptin expression has been detected in gastric epithe lium, but the physiologic role of gastric leptin remains unknown. The purpo se of this study was: 1) to determine the effect of gastric injury by ethan ol and aspirin on the expression of leptin in gastric mucosa and 2) to inve stigate whether exogenous leptin affects the integrity of gastric mucosa ex posed to noxious agents such as ethanol or aspirin. In Wistar rats the acut e gastric lesions were induced by intragastric application of 1.5 mi of 75% ethanol or acidified aspirin (100 mg/kg in 0.2N HCl). Rats were divided in to two groups and pretreated either with leptin (1-10 mu g/kg i.p,) or vehi cle (saline). Rats were anesthetized 1 h after i.g. induction of acute gast ric lesions and the gastric blood flow (GBF) was measured by H-2 gas cleara nce method. Then the rats were sacrificed, the stomach was excised and the mean lesions area was assessed by planimetry. In addition, mRNA and protein expression for leptin was analyzed in the gastric mucosa by reverse transc ription polymerase chain reaction (RT-PCR) and Western blot, respectively. Both ethanol and acidified aspirin induced acute gastric lesions and led to significant reduction in GBF.:In the intact gastric mucose, the mRNA and p rotein expression for leptin was small but detectable. The exposure of gast ric mucosa to noxious agents such as ethanol and aspirin was associated wit h markedly increased expression for gastric leptin at mRNA and protein leve l. Application of 75% ethanol or acidified aspirin caused wide-spread mucos al lesions. The pretreatment with exogenous leptin reduced dose-dependently these ethanol or aspirin-induced gastric lesions. The protective effects: of exogenous leptin were accompanied by a significant attenuation of the fa ll of GBF. We conclude that: 1) Exogenous leptin exerts potent gastroprotec tive and hyperemic actions on gastric mucosa, and 2) Acute injury of gastri c mucosa is:associated with increased expression of leptin suggesting a pos sible role of this peptide in-mediating of repair process in injured gastri c mucosa.