Effects Of Gastric Surgery Research Articles

The effects of gastric surgery on systemic ghrelin levels in the morbidly obese.

Circulating ghrelin, produced primarily in the stomach, is a powerful orexigen. Ghrelin levels are elevated in states of hunger, but rapidly decline postprandially. Early alterations in ghrelin levels in morbidly obese patients undergoing weight reduction surgery may be attributed to gastric partitioning. Thirty-four patients underwent Roux-en-Y gastric bypass with a completely divided gastroplasty to create a 15-mL vertically oriented gastric pouch. Eight other patients underwent other gastric procedures that did not involve complete division of the stomach, including 4 vertical banded gastroplasties and 4 antireflux surgical procedures. Six additional patients undergoing antireflux surgery served as lean control subjects. Plasma samples were obtained before surgery and immediately after surgery. In a substudy, plasma was collected after Roux-en-Y limb formation and after dividing the stomach to identify any changes in plasma ghrelin levels. Tertiary university medical center. Ghrelin levels at different stages of surgical intervention. Mean +/- SEM preoperative and postoperative ghrelin levels in the gastric bypass group were 355 +/- 20 and 246 +/- 13 pg/mL, respectively (P<.001). In the vertical banded gastroplasty group and in all patients undergoing antireflux surgery, ghrelin levels were not significantly changed. Compared with morbidly obese humans, lean controls had significantly higher plasma ghrelin levels at baseline. A divided gastroplasty creating a small proximal gastric pouch results in significant early declines in circulating ghrelin levels that are not observed with other gastric procedures. This may explain, in part, the loss of hunger sensation and rapid weight loss observed following gastric bypass surgery.

Pharmacokinetics of Ranitidine after Partial Gastrectomy in Dogs

The effect of gastric surgery on the pharmacokinetics of ranitidine was studied in six dogs, all serving as their own controls. Prior to and after surgery, each dog received a single oral dose (5 mg/kg of body weight) of a ranitidine solution. The surgery consisted of partial gastrectomy (antrectomy) and truncal vagotomy. Ranitidine plasma and urine concentrations were measured by reversed-phase ion-pair liquid chromatography with UV detection. Pharmacokinetic parameters were estimated by noncompartmental data analysis techniques. Gastric surgery tended to slow the absorption of ranitidine as reflected by a slight increase of the time necessary to reach the peak plasma concentration. The maximum observed plasma concentration was slightly lowered. The amount of drug absorbed remained unchanged as reflected by no change in the AUCs. Other parameters such as mean residence time, elimination half-life, apparent oral clearance, and fraction excreted unchanged in the urine remained unchanged. However, due to the small number of animals and the considerable intersubject variability, none of these trends reached statistical significance.

Effects of Gastrointestinal Surgery on Ingestive Behavior in Animals

Surgical manipulations of the gastrointestinal system can have a major impact on the ingestive behavior of animals. Particularly well-documented are the feeding and drinking effects of JIB and vagotomy. These two surgical procedures are similar in that they reduce the food intake and body weight of obese animals more than that of lean animals, and of hypothalamic obese rats more than that of genetically obese rats. Intermediate effects are obtained with other obesity models. Given the multiple etiologies of human obesity, it is not surprising that gastrointestinal surgery has variable effects in obese humans. The effects of gastric surgery on the ingestive behavior of animals have received relatively little attention. This is unfortunate because gastric bypass is now one of the most widely used methods for surgical treatment of human obesity. In light of recent developments in gastric surgical techniques and new findings concerning the gastric modulation of food intake, the effects of gastric surgery on the feeding behavior of animals should be further investigated. Much remains to be learned about the physiologic and behavioral mechanisms by which gastrointestinal surgery influences ingestive behavior and body weight. Surgical manipulations of the gastrointestinal system may affect ingestive behavior by directly altering the neural and hormonal feedback signals to the brain from the stomach, intestines, and other organs (liver, pancreas), or they may indirectly alter these feedback signals by modifying the preabsorptive and/or postabsorptive flow of nutrients. Seen from a functional perspective, the gut sends to the brain different types of messages that modulate ingestive behavior. Most attention has focused on gut satiety signals, but the gut can also be the source of painful sensations that suppress ingestive behavior. The distinction between satiety and discomfort is not always clear-cut. For example, gut distention may be satiating when it is moderate, but painful when it is extreme. Nevertheless, the distinction is an important one, and the nature of the feeding-inhibitory effects obtained in animal studies must be carefully evaluated. Ideally, obesity surgery should produce minimal aversive consequences, although whether it is possible to reduce food intake and body weight without producing any discomfort remains to be established. In addition to being a source of feeding-inhibitory cues, the gastrointestinal system may also provide excitatory cues that stimulate feeding and modify food preferences. For example, intestinal infusions of carbohydrates increase subsequent food intake under certain conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

The effect of gastric surgery on intact neurotensin (NT) response to a fatty meal

The effect of gastric surgery on intact neurotensin (NT) response to a fatty meal

Effect of Gastric Surgery on the Gastrointestinal Drug Absorption in Man

The effect of gastric surgery on the absorption of quinidine, ethambutol, and sulphafurazole was studied in 14 male patients, all serving as their own controls. Antrectomy with gastroduodenostomy (ABI) and selective vagotomy lowered the serum levels of all drugs significantly during the 6-hour test period. Excretion of drugs in 6-hour urine also decreased. Three patients showed practically no absorption up to 2 hours, and even therafter the absorption was lowered. Over one year after operation the urinary excretion of ethambutol, but not of the other drugs, was improved. ABI alone did not modify absorption. Preoperative gastric retention seemed to delay absorption.

Effects of gastric surgery upon gastric emptying in cases of peptic ulceration.

Effects of gastric surgery upon gastric emptying in cases of peptic ulceration.