Gastric Lipase Secretion Research Articles

Gastric Lipase Secretion in Children with Gastritis

Gastric lipase is one of the prepancreatic lipases found in some mammalian species and in humans. Our knowledge of the hormonal regulation of gastric lipase secretion in children and adolescents is still very limited. The aim of this study was to compare the activity of human gastric lipase (HGL) in gastric juice in healthy adolescents and in patients with gastritis. The adolescents were allocated to three groups: the first including patients with Helicobacter pylori gastritis (HPG; n = 10), the second including patients with superficial gastritis caused by pathogens other than H. pylori (non-HPG; n = 14) and the control group including healthy adolescents (n = 14). Activity of HGL was measured in gastric juice collected during endoscopy. Plasma concentrations of cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were measured in all adolescents. Activity of HGL in the non-HPG group was significantly lower than in the HPG group (p < 0.005) and the control group (p < 0.005). Mean plasma GIP levels in the control group were lower than in the non-HPG group (p < 0.003) and the HPG group (p < 0.01). We conclude that the regulation of HGL secretion by GLP-1 and CCK is altered in patients with gastritis. Moreover, GIP is a potent controller of HGL activity, both in healthy subjects and in patients with gastritis.

A Rare Case of GIST with Elevated Lipase and Amylase Levels and Its Effect on Treatment Options

Case Description: A 56-year-old Hispanic male presents with 3/10, nonradiating, diffuse upper abdominal pain of 2 weeks duration. The pain had no prandial or postural associations. He also complained of unintentional 30-pound weight loss in 1 month. Patient had no history of alcohol or drug abuse and was not on any medications. Abdominal exam was unremarkable. Laboratory results showed lipase level of 533 U/L and amylase level of 383U/L with rest of the metabolic profile being normal. Abdominal sonography revealed fatty infiltration of liver with normal gallbladder and intra/extra hepatic biliary system. Computerized tomography abdomen with contrast showed a 2.8 × 2.6 cm focal, hyperdense soft tissue mass abutting the lesser curvature of the stomach with mass effect. Esophagogastroduodenoscopy (EGD) showed a 2-3 cm sub mucosal lesion along the lesser curvature and a small, sliding hiatal hernia. An Endoscopic Ultrasound (EUS) confirmed an exophytic, well-circumscribed lesion 3.36 cm in diameter, arising from the muscularis propria of the gastric wall without an associated lymphadenopathy or invasion. FNAC showed groups of spindle cells negative for CD34 and CD117. Partial gastrectomy was performed and biopsy showed findings consistent with Gastrointestinal Stromal tumor (GIST). Discussion: Serum lipase is mainly derived from pancreatic acinar cells. Typically, higher cut off levels (> 3 times upper limit of normal) has higher specificity for acute pancreatitis. However, asymptomatic lipase and amylase elevation has been associated with diverse gastrointestinal etiologies. To date, GIST has not been reported to be associated with such high levels of lipase or amylase elevation. Gastric lipase has been localized to entire mucosa of the stomach with maximal activity in the fundic area. We propose that the mesenchymal tumor in this case is a direct source of these enzymes or produced a mechanical stimulus for gastric lipase secretion. However, whether or not GIST can be enzymatically active or not would warrant further studies. The normalization of both enzymes within 48 hours of surgery postulates a causative rather than a plausible association. Furthermore, since Imatinib or sunitinib, tyrosine kinase inhibitors are treatment options for metastatic or recurrent GIST tumors, these elevations in lipase and amylase levels may affect further treatment options.

Dietary Counseling Versus Dietary Supplements for Malnutrition in Chronic Pancreatitis: A Randomized Controlled Trial

Up to 50% of patients with chronic pancreatitis (CP) are malnourished. There are limited data on the role of dietary intervention in improving the nutritional status of such patients. The aim was to compare the efficacy of medium chain triglyceride (MCT)-enriched commercial dietary supplements with dietary counseling for homemade food in the management of malnutrition in patients with CP. In a randomized controlled trial, consecutive undernourished patients with CP (body mass index [BMI] <18.5 kg/m(2)) at a tertiary care hospital were randomized to receive either dietary counseling for regular homemade food or commercial MCT-enriched dietary supplements for a period of 3 months to compensate for the dietary calorie deficit. All patients received standard management for CP including pancreatic enzyme supplements. Primary outcome measure was improvement in BMI. Sixty malnourished patients with CP were randomized to counseling group (n = 29; mean age, 32 +/- 10 years; male, 83%) and supplementation group (n = 31; mean age, 28 +/- 10 years; male, 84%). BMI increased in both the counseling group and supplementation group (17.2 +/- 1.7 vs 18.1 +/- 1.8 kg/m(2), P = .001; 16.7 +/- 1.6 vs 18.2 +/- 1.6 kg/m(2), P = .001). There were similar improvements in triceps skinfold thickness, dietary intake, fecal fat, and pain score during a period of 3 months in both groups. There was, however, no significant difference between the counseling and supplementation groups with regard to any of the outcome measures. Dietary counseling for a balanced homemade diet is as good as commercial food supplements in improving malnutrition in patients with CP.

Effects of Lansoprazole on Human Gastric Lipase Secretion and Intragastric Lipolysis in Healthy Human Volunteers

Background: Lansoprazole is a potent proton-pump inhibitor (PPI) of parietal cells, which reduces the secretion of gastric acid. Although human gastric lipase (HGL) is produced only by the chief cells of the stomach, the possibility that interactions may occur between lansoprazole and HGL has never been addressed so far in humans. The aim of this study was therefore to quantify the effects of lansoprazole on HGL secretion and intragastric lipolysis during the ingestion of test meals by healthy human volunteers. Methods: Six healthy volunteers were intubated twice with a gastric and a duodenal tube, before ingesting a standard liquid test meal alone (–PPI experiments) and after 7 days of lansoprazole treatment (+PPI experiments). The HGL concentration was assessed in gastric and duodenal samples by measuring the lipase activity using a pH-stat, and the lipolysis products were quantified by performing thin layer chromatography. The level of intragastric lipolysis was defined as the percentage acyl chains released from the meal triglycerides. The pyloric outputs of HGL and lipolysis products were calculated, based on the use of a non-absorbable marker added to the meal. Results: The pH of the gastric contents was significantly higher in the +PPI experiments than in the –PPI experiments (p < 0.05), since mean values of 4.3 ± 2.5 and 2.2 ± 1.6, respectively, were recorded at the end of the gastric emptying of the meal. The HGL concentrations recorded during the meal were found to be higher in the experiments with lansoprazole (p < 0.05) than in those without lansopra- zole, but the HGL secretion levels (–PPI: 15.4 ± 8.0 mg; +PPI: 19.0 ± 7.4 mg) and the intragastric lipolysis (–PPI: 24.0 ± 8.0%; +PPI: 23.6 ± 6.8%) were not significantly affected by lansoprazole (p > 0.05 in both cases). Conclusion: Lansoprazole affected neither the HGL secretion nor the intragastric lipolysis levels, although an increase was observed in the intragastric pH at the end of the gastric emptying of the meal. The HGL concentration increased, however, due to the decrease in the acid secretion process, resulting in less diluted gastric contents.

Establishment of culture systems of human gastric epithelium for the study of pepsinogen and gastric lipase synthesis and secretion

Establishment of culture systems of human gastric epithelium for the study of pepsinogen and gastric lipase synthesis and secretion

Establishment of culture systems of human gastric epithelium for the study of pepsinogen and gastric lipase synthesis and secretion.

A main purpose of gastric secretion pertains to the digestion of dietary proteins and involves the release of pepsinogens by the fundic and antral mucosa. Over the last decade, data on human gastric physiology has expanded to equally include a significant role in fat digestion. Characteristics of human gastric lipase (HGL) such as optimum acid pH, resistance to proteolysis and non requirement of bile salts or cofactors, are advantageous in gastric lipolysis. Furthermore, the importance of HGL increases in the context of perinatal physiology and pathological situations where secretion of HGL could compensate, to some extent the depressed pancreatic activities. It is therefore important to understand the regulatory mechanisms involved in the synthesis and secretion of human gastric digestive enzymes. The establishment of an organ culture technique as well as a novel primary culture system of human gastric epithelium permitted us to demonstrate that Pg5 and HGL are colocalized in human chief cells and both digestive enzymes are efficiently synthesized and secreted in explants and primary cultures. Pepsin activity rises at the cellular level while its secretion remains constant. In contrast, cellular lipase activity drastically diminishes while being preferentially secreted. This nonparallelism supports the concept that Pg5 and HGL are differently regulated in culture. Furthermore, EGF downregulates HGL expression at the mRNA level via the p42/44(MAPK) pathway without affecting Pg5. Future studies should be designed to fully understand the cellular and molecular mechanisms involved in regulating HGL activity in normal and pathological conditions.

Cephalic Phase of Lipolysis Is Impaired in Pancreatic Insufficiency: Role of Gastric Lipase

Background: Gastric lipase contributes significantly to overall lipolysis and is regulated by interacting neuro-hormonal mechanisms. Patients with alcoholic chronic pancreatitis (ACP) have low, or even absent, activity of pancreatic lipases. In that state the secretion of gastric lipase could be essential and compensate for the pancreatic defect. However, conflicting studies have not resolved the order of magnitude of gastric lipase secretion in these patients. This could be explained by differences in regulatory mechanisms, gastric mucosal changes, and abdominal vagal tone. Methods: Nasogastric intubation with modified sham feeding and upper endoscopy including biopsies for histologic classification and Helicobacter pylori infection status were performed in eight ACP patients, and eight healthy volunteers were studied on separate occasions. Vagal nerve function was assessed by calculation of heart rate variability in ACP patients. Gastric lipase was measured in aspirates by means of enzyme-linked immunosorbent assay and an enzyme kinetic assay. Plasma concentrations of gastrin, secretin, cholecystokinin, and pancreatic polypeptide were measured throughout the study. Results: Sham feeding rapidly and significantly increased gastric lipase secretion in healthy volunteers, whereas ACP patients did not respond to sham feeding. Two of eight patients were infected with H. pylori and had mucosal changes accordingly. The lack of lipase response could not be ascribed to dysfunction of the abdominal vagus. Conclusions: The cephalic phase of gastric lipase secretion is impaired in ACP patients. Although their fundic cells continue to secrete gastric lipase, they are not subject to normal neuro-hormonal regulation.

Inhibition of human gastric lipase by intraduodenal fat involves glucagon-like peptide-1 and cholecystokinin

Seven healthy volunteers were intubated with two double lumen nasogastric tubes, one in the stomach, the other in the duodenum. This system allows simultaneous sampling of gastric juice and separate intraduodenal perfusion with a dietary fat (fish oil, 1269 kJ). Gastrin-17 was infused i.v. at a rate of 40 pmol/kg/h throughout the study. Gastric lipase was measured at 15-min intervals as activity (tributyrin) and as immunoreactivity (ELISA). Infusion of gastrin-17 resulted in a stable increase in the plasma concentration from a basal concentration of 8.3±0.8 pmol/l to 41.4±4.2 pmol/l. Perfusion with fat reduced gastric lipase activity from 24.2±5.3 to 7.2±2.5 kU/l ( P<0.05), and immunoreactivity from 0.7±0.1 to 0.42±0.1 mg/l ( P<0.05). After termination of fat perfusion, gastric lipase secretion increased again, though not reaching preinhibitory concentrations. During the intraduodenal perfusion with fat the plasma concentrations of glucagon-like peptide-1 (GLP-1) and cholecystokinin (CCK) increased from 6.9±0.5 to 15.1±1.5 pmol/l ( P<0.05) and from 1.2±0.4 to 3.8±0.9 pmol/l ( P<0.05). This study reveals a negative effect of fat in the duodenum on gastric lipase secretion. This effect may be mediated by GLP-1 and/or CCK.

Secretin and Gastric Lipase Secretion

Background: Gastric lipase secretion is stimulated by gastrin in plasma, but its regulation by secretin is unknown. Methods: In 7 normal persons we investigated the effect of exogenous secretin on the output of gastric lipase stimulated by intravenous gastrin-17. The gastric content was measured using a nasogastric tube for aspiration. The quantitative lipase secretion was measured by an enzyme-linked immunosorbant assay (ELISA) and the lipolytic activity by a kinetic assay. Plasma concentrations of secretin and gastrin were measured by radioimmunoassay. Results: Gastric lipase secretion (the quantity as well as the lipolytic activity) was significantly stimulated by gastrin. In response to secretin infusion, the lipolytic activity increased as acid secretion decreased. Conclusion: Secretin in postprandial concentrations does not influence the quantitative gastric lipase secretion stimulated by gastrin, but it increases lipolytic activity due to inhibition of acid secretion.

Effect of sham feeding and acute suppression of acid secretion on human gastric lipase secretion.

Gastric lipase and gastric acid are secreted simultaneously. The aim of this study was to investigate whether the acid interferes with the lipase secretion. The secretion of human gastric lipase was studied during blockade of gastric acid secretion and modified sham feeding to estimate the impact of these conditions on both gastric lipase enzyme activity and immunoreactivity. Eight healthy volunteers were intubated with a nasogastric tube. We examined gastric aspirates for the amount and activity of lipase secretion during basal conditions, after blockade of acid secretion with a proton pump inhibitor (omeprazole iv. infusion), and in response to sham feeding (chewing gum) during the blockade. The amount of secreted gastric lipase was unaffected by blockade of acid secretion and increased significantly after sham feeding (169.9+/-35.7 microg/15 min to 348.1+/-79.2 microg/15 min; p < 0.01). Likewise, the output of enzyme activity increased after sham feeding (0.63+/-0.09 kU/15 min to 1.52+/-0.36 kU/15 min; p < 0.03). The concentration of enzyme activity remained unchanged by blockade of acid secretion, whereas the output of enzyme activity was decreased, probably because of reduced volume secretion or denaturation and conformational changes of the enzyme. Plasma concentrations of gastrin increased in response to blockade of acid secretion (basal 9.6+/-1.4 pmol/L to 13.3+/-2.9 pmol/L; p < 0.02). Gastric acid secretion is not a prerequisite for gastric lipase secretion. Lipase enzyme activity, though, is sensitive to anacidic conditions.

Effect of sham feeding and acute suppression of acid secretion on human gastric lipase secretion

Objective: Gastric lipase and gastric acid are secreted simultaneously. The aim of this study was to investigate whether the acid interferes with the lipase secretion. The secretion of human gastric lipase was studied during blockade of gastric acid secretion and modified sham feeding to estimate the impact of these conditions on both gastric lipase enzyme activity and immunoreactivity. Methods: Eight healthy volunteers were intubated with a nasogastric tube. We examined gastric aspirates for the amount and activity of lipase secretion during basal conditions, after blockade of acid secretion with a proton pump inhibitor (omeprazole i.v. infusion), and in response to sham feeding (chewing gum) during the blockade. Results: The amount of secreted gastric lipase was unaffected by blockade of acid secretion and increased significantly after sham feeding (169.9 ± 35.7 μg/15 min to 348.1 ± 79.2 μg/15 min; p < 0.01). Likewise, the output of enzyme activity increased after sham feeding (0.63 ± 0.09 kU/15 min to 1.52 ± 0.36 kU/15 min; p < 0.03). The concentration of enzyme activity remained unchanged by blockade of acid secretion, whereas the output of enzyme activity was decreased, probably because of reduced volume secretion or denaturation and conformational changes of the enzyme. Plasma concentrations of gastrin increased in response to blockade of acid secretion (basal 9.6 ± 1.4 pmol/L to 13.3 ± 2.9 pmol/L; p < 0.02). Conclusions: Gastric acid secretion is not a prerequisite for gastric lipase secretion. Lipase enzyme activity, though, is sensitive to anacidic conditions.

Inhibition of human gastric lipase secretion by glucagon-like peptide-1.

Glucagon-like peptide-1 (GLP-1) may be one of the enterogastrone hormones of the ileal brake mechanism. We therefore studied its effects on gastric lipase secretion in healthy volunteers and vagotomized patients during infusion of pentagastrin. The intestinal incretin hormone GLP-1 (glucagon-like peptide-1, 7-36 amide) was investigated because of its inhibitory effects on gastric acid secretion and motility. GLP-1 infused intravenously in amounts corresponding to the postprandial release significantly inhibited pentagastrin-stimulated gastric lipase secretion and lipolytic activity. The inhibitory effect of GLP-1 persisted in vagotomized patients, suggesting that fundic chief cells, from which gastric lipase is released, or neighboring inhibitory cells could be equipped with GLP-1 receptors. Vagotomized patients had significantly higher plasma concentrations of gastrin and secretin. No significant changes of gastrin, secretin, and CCK secretion were seen during GLP-1 infusion in the vagotomized patients, whereas secretin decreased significantly in the healthy volunteers. GLP-1 seems to be a naturally occurring inhibitor of gastric lipase secretion acting via a nonvagal mechanism. Our results indicate that gastric lipase secretion is subject to hormonal stimulatory as well as inhibitory mechanisms.

Gastric lipase secretion after sham feeding and cholinergic blockade.

Our purpose was to examine gastric lipase secretion after cephalic stimulation (sham feeding) and to examine the effect of cholinergic blockade. Eight healthy volunteers, four women and four men, age 21-58 years, were studied twice on separate days. They were sham fed with and without infusion of atropine. Gastric content was measured and the amount as well as the activity of gastric lipase output were determined. Plasma concentrations of gastrin, secretin, and cholecystokinin (CCK) were measured simultaneously by radioimmunoassays. Cephalic stimuli can evoke human gastric lipase secretion, and this effect was almost ablated by atropine blockade of cholinergic receptors. The concentrations of CCK and secretin in plasma were unaffected by sham feeding with or without atropine blockade, whereas gastrin was stimulated by sham feeding after atropine blockade. Gastric lipase secretion in man is apparently controlled by interacting vagal and hormonal mechanisms.

Deficient Gastric Lipase Secretion in Pancreatic Insufficiency

Background: Gastrin is an important stimulator of gastric lipase secretion in man. In advanced pancreatic insufficiency gastric lipases might compensate for the lack of pancreatic lipases, hut the role of gastrin in such compensation remains to be evaluated. The aim of this study was to examine the effect of gastrin on the gastric lipase secretion in patients with pancreatic insufficiency. Methods: Eight patients with pancreatic insufficiency secondary to alcohol abuse were studied, and six healthy subjects volunteered as controls for the study. All volunteers received identical doses of intravenous gastrin-17 (10, 30, and 60 pmol/kg/h). The gastric content was measured, using a nasogastric tube for aspiration, and the amount and activity of gastric lipase output were determined. Plasma concentrations of gastrin, secretin, and cholecystokinin were measured by radioimmunoassays. Results: The increased plasma levels of gastrin were accompanied by a dose-dependent increase in the amount and activity of gastric lipase in controls, but in the patients the response was almost abolished. Conclusions: Gastrin in postprandial concentrations does not influence the secretion of gastric lipase in patients with pancreatic insufficiency due to chronic pancreatitis.

Deficient gastric lipase secretion in pancreatic insufficiency

Deficient gastric lipase secretion in pancreatic insufficiency

Gastric and pancreatic lipase levels during a test meal in dogs.

The levels of gastric and pancreatic lipases in the duodenum and the jejunum were measured during the digestion of a test meal in dogs. Using both a specific enzymatic titration and an enzyme-linked immunosorbent assay, it is shown for the first time that gastric lipase remains active in the duodenal and jejunal contents. An experimental device was set up for measuring the secretions and the intestinal flows of lipases during the digestion of a liquid test meal. In a dog equipped with gastric and duodenal cannulae, the secretion of gastric lipase was stimulated by food ingestion, reaching 3.0 +/- 0.3 mg/h (three times the basal secretion rate) during the 1st h of digestion. The total secretory outputs of gastric and pancreatic lipases recorded over a 3-h period of digestion were 7.2 +/- 1.2 mg and 18.7 +/- 1.2 mg, respectively.

Post-prandial lipase, pepsin and acid secretion of a Heidenhain pouch in the rabbit

The kinetics of the gastric secretion of lipase, pepsin and acid were studied after a meal in Heidenhain-pouch rabbits. After a 24-h fast, feeding immediately stimulated (< 15 min) lipase (x 4.1) and later on pepsin (x 1.8) output which reached respectively 16 and 47% of the output observed after pentagastrin stimulation (64 micrograms.kg-1.h-1 for 1 h), and which were significantly correlated. Lipase concentration was enhanced earlier and to a greater degree (x 7.3) than pepsin concentration (x 2.5). No stimulation of high basal acid secretion occurred. It was concluded that: 1) gastric lipase secretion is stimulated by feeding in the rabbit; 2) pepsin secretion is stimulated by feeding. The modalities of the secretion of lipase and pepsin are compatible with the existence of distinct secretory cells; 3) acid secretion is not stimulated by feeding. The decrease in acid secretion during the post-prandial phase favors a physiological role for lipase which is altered by low pH. The absence of acid stimulation by feeding in the rabbit, in contrast to other species, requires additional studies on the release of gastrointestinal hormones, namely gastrin, cholecystokinin and somatostatin.

Dog gastric lipase: Stimulation of its secretion in vivo and cytolocalization in mucous pit cells

Dog gastric lipase (DGL) secretion is stimulated in vivo by urecholine, pentagastrin, histamine, 16,16-dimethyl prostaglandin E2, and secretin. Under fasting conditions, DGL is irreversibly inactivated by gastric acid below pH 1.5; consequently, DGL output can be underestimated. This problem has been resolved by buffering the acid or by using an antisecretory drug such as omeprazole during stimulation. There is a clear parallelism between the secretion of DGL and of gastric mucus. This observation led to the present investigation of the cellular localization of DGL using immunofluorescence techniques. Results showed that DGL is cytolocalized in mucous pit cells of gastric glands. Pepsinogen is found in chief cells. To the authors' knowledge, this is the first description of an enzyme (gastric lipase) secreted by mucous-type gastric cells. In contrast to other species, gastric lipase of the dog is located in cardiac, fundic, and antral mucosae.

Fat Absorption in Premature Infants

Fat absorption from two different premature infant formulas and one full‐term formula containing three different fat blends was investigated in two groups of premature infants. The first group of nine infants (gestational age, 29.1 ± 0.88 weeks; postnatal age, 3.13 ± 0.71 weeks) was fed alternately for 1 week each SMA preterm formula containing either high levels (50%) of medium‐chain triglycerides (MCT) (6:0, 8:0, and 10:0) or high levels (86%) of long‐chain triglycerides (LCT) (≥C12). Except for fat blends, the formulas were otherwise identical. The second group of 11 infants (gestational age, 30.5 ± 0.77 weeks, studied at a postnatal age of 4.33 ± 0.91 weeks) was fed for 1 week a full‐term infant formula, S‐26, containing 98% LCT. Fat absorption (studied during a 3‐day fat balance period) was similar irrespective of fat blend: 89.08 ± 2.37% during feeding of preterm SMA, 50% MCT; 87.0 ± 3.81% during feeding of preterm SMA, 86% LCT: and 83.00 ± 2.89% during feeding of S‐26, 98% LCT. Weight gain (grams per day) and increase in length (centimeters per day) were 23.2 ± 1.7, 21.20 ± 1.7, and 14.28 ± 2.9, and 0.17 ± 0.06, 0.16 ± 0.04, and 0.22 ± 0.07 during feeding of the three fat blends, respectively. Lipase activity levels in fasting gastric aspirates were higher during feeding of the LCT than the MCT formula. The possible stimulation of gastric lipase secretion secondary to long‐chain fatty acid stimulation of cholecystokinin secretion might be related to the efficient digestion of formula fat, irrespective of triglyceride‐fatty acid chain length. The study shows that preterm infants are able to digest and absorb efficiently formula fat containing as much as 98% long‐chain fatty acids.

Fat Absorption in Premature Infants

Fat absorption from two different premature infant formulas and one full-term formula containing three different fat blends was investigated in two groups of premature infants. The first group of nine infants (gestational age, 29.1 +/- 0.88 weeks; postnatal age, 3.13 +/- 0.71 weeks) was fed alternately for 1 week each SMA preterm formula containing either high levels (50%) of medium-chain triglycerides (MCT) (6:0, 8:0, and 10:0) or high levels (86%) of long-chain triglycerides (LCT) (greater than or equal to C12). Except for fat blends, the formulas were otherwise identical. The second group of 11 infants (gestational age, 30.5 +/- 0.77 weeks, studied at a postnatal age of 4.33 +/- 0.91 weeks) was fed for 1 week a full-term infant formula, S-26, containing 98% LCT. Fat absorption (studied during a 3-day fat balance period) was similar irrespective of fat blend: 89.08 +/- 2.37% during feeding of preterm SMA, 50% MCT; 87.0 +/- 3.81% during feeding of preterm SMA, 86% LCT; and 83.00 +/- 2.89% during feeding of S-26, 98% LCT. Weight gain (grams per day) and increase in length (centimeters per day) were 23.2 +/- 1.7, 21.20 +/- 1.7, and 14.28 +/- 2.9, and 0.17 +/- 0.06, 0.16 +/- 0.04, and 0.22 +/- 0.07 during feeding of the three fat blends, respectively. Lipase activity levels in fasting gastric aspirates were higher during feeding of the LCT than the MCT formula. The possible stimulation of gastric lipase secretion secondary to long-chain fatty acid stimulation of cholecystokinin secretion might be related to the efficient digestion of formula fat, irrespective of triglyceride-fatty acid chain length.(ABSTRACT TRUNCATED AT 250 WORDS)