ABSTRACT
The mechanisms involved in the weight loss seen after vertical sleeve gastrectomy (VSG) are not clear. The rat stomach has two morphologically and functionally distinct proximal and distal parts. The rat model for VSG involves complete removal of the proximal part and 80% removal of the distal part along the greater curvature. The purpose of this study was to understand the potential independent contributions of removal of these distinct gastric sections to VSG outcomes. We prepared four surgical groups of male Long-Evans rats: VSG, sham surgery (control), selective proximal section removal (PR), and selective distal section removal (DR). Gastric emptying rate (GER) was highest after VSG compared with all other groups. However, PR, in turn, had significantly greater GER compared with both DR and sham groups. The surgery-induced weight loss followed the same pattern with VSG causing the greatest weight loss and PR having greater weight loss compared with DR and sham groups. The results were robust for rats fed regular chow or a high-fat diet. Body mass analysis revealed that the weight loss was due to the loss of fat mass, and there was no change in lean mass after the surgeries. In conclusion, removal of the proximal stomach contributes to most, but not all, of the physiological impact of VSG.
Subject(s)
Gastrectomy , Obesity/physiopathology , Obesity/surgery , Stomach/physiopathology , Stomach/surgery , Weight Loss/physiology , Animals , Gastric Emptying , Male , Obesity/diagnosis , Rats , Rats, Long-Evans , Treatment OutcomeABSTRACT
Lingual lipase generates nonesterified fatty acids (NEFA) from dietary fats during oral processing by lipolysis. Lingual lipase in rodents has strong lipolytic activity and plays a critical role in oral detection of fats. The functional activity of lingual lipase during oral processing of high-fat foods in humans remains poorly characterized. Five commonly consumed high-fat foods varying in physical states and fatty acid composition (almond, almond butter, olive oil, walnut, and coconut) were masticated by 15 healthy human subjects at the rate of one chew per second with and without lipase inhibitor orlistat. Salivary NEFA concentrations were measured. To determine the role of lingual lipase in oral fat detection, sensory ratings were obtained from the same 15 human subjects for almond butter with and without orlistat. Lingual lipase was active during oral processing of almond and coconut. No activity of lingual lipase was detected during processing of almond butter. There was only weak evidence lingual lipase is a determinant of oral fat detection. Lingual lipase may only contribute to NEFA generation and oral fat detection of fatty foods that require stronger oral processing effort.
Subject(s)
Dietary Fats/metabolism , Lipase/metabolism , Sensation/physiology , Taste/physiology , Tongue/drug effects , Tongue/enzymology , Adolescent , Adult , Cocos/metabolism , Enzyme Inhibitors/pharmacology , Fatty Acids, Nonesterified/metabolism , Female , Humans , Lactones/pharmacology , Lipase/antagonists & inhibitors , Lipase/drug effects , Male , Middle Aged , Olive Oil , Orlistat , Plant Oils/metabolism , Prunus/metabolism , Saliva/metabolism , Taste/drug effects , Young AdultABSTRACT
Salivary non-esterified fatty acids (NEFA) are proposed to play a role in oral health, oral fat detection, and they may hold diagnostic and prognostic potential. Yet, little is known about the array and concentrations of NEFA in saliva. The aim of the study was to conduct qualitative and quantitative analyses of salivary NEFA in healthy humans and to present a new, efficient protocol to perform such analyses. Resting saliva samples from fifteen participants were collected. The salivary lipids were extracted using a modified Folch extraction. The NEFA in the extracted lipids were selectively subjected to pentafluorobenzyl bromide (PFB) derivatization and qualitatively and quantitatively analyzed using gas chromatography-mass spectrometry (GC-MS). A total of 16 NEFA were identified in resting saliva. The four major NEFA were palmitic, linoleic, oleic, and stearic acids. Their concentrations ranged from 2 to 9 µM. This is the first study to characterize individual human salivary NEFA and their respective concentrations. The method used in the study is sensitive, precise, and accurate. It is specific to fatty acids in non-esterified form and hence enables analysis of NEFA without their separation from other lipid classes. Thus, it saves time, reagents and prevents loss of sample. These properties make it suitable for large scale analysis of salivary NEFA.
