Sleeve gastrectomy-induced endocrine changes in the remnant stomachs of premenopausal and postmenopausal rats: role of the estrogen receptors

Background: Although alterations in the plasma levels of leptin, glucagon-like peptide-1, and gastrin were linkedwith bariatric surgery outcomes, gastric production of these peptides was not elucidated before. Objective: The aim was to evaluate the impact of estrogen depletion and estrogen receptors (ERs) on sleeve gastrectomy (SG)-induced alterations in gastric hormone production, gastric mucosal integrity, and bone mass. Setting: Physiology Research Lab at the University. Methods: Female Sprague-Dawley rats underwent ovariectomy or sham operation (control), and 2 months later SG or sham SG was performed. Rats received either nonselective agonist 17 beta, ER-alpha agonist, ER-beta agonist, or vehicle for 3 weeks. Trunk blood and gastric tissues were collected for biochemicalmeasurements, while histopathologic examination was performed in gastric and femur samples. Results: In the presence of intact ovaries, SG-induced weight loss was accompanied by reductions in the gastric synthesis of leptin and gastrin, while gastric glucagon-like peptide-1 was additionally decreased when SG was performed at the postmenopausal state. SG elevated the depleted serum estradiol levels of menopause, implicating a beneficial effect, but the occurrence of severe gastric mucosal injury was triggered. On the other hand, using ER agonists upregulated gastrinexpressing cells, ameliorated gastric injury, and improved bone loss. Conclusions: SG, either at premenopausal or postmenopausal state, resulted in considerable loss in bone mass, along with reductions in the gastric levels of gastrin and leptin. Functional status of the ovaries needs to be taken into consideration when monitoring the outcomes of SG, and ER agonists could be of value in controlling SG-induced complications. (C) 2020 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.