Abstract
In vitro and in vivo experiments were undertaken to evaluate enzyme-replacement therapy with an acid stable lipase preparation in pancreatic lipase insufficiency. Utilizing an emulsion of [1-14C] trioleylglycerol, partially purified rabbit gastric lipase exhibited a maximal specific activity of 6.45 μmoles FFA/h, a Km of 80 mM, an optimal peak activities at pH 4.86 and 5.48, and stability in acidic medium. Although preferential lipolysis of medium chain fatty acid ester bonds was evidenced by experiments with a commercial formula (SimilacR) containing 28% MCT (C6-C8-C10-C12), the gastric lipase preparation also displayed ability to split the long chain fatty acid ester bonds in a fine emulsion of triglycerides for IV use (IntralipidR). Triacylglycerol hydrolysis was enhanced either by 4 mM Na-taurocholate or 4 mM Na-glycocholate, and remained unchanged following the addition of these bile salts at 8 mM. These in vitro findings suggested that the gastric lipase preparation was biologically active under the conditions prevailing in the stomach and in the upper small intestine. To investigate its in vivo lipolytic activity exogenous rabbit gastric lipase was added to the stomach of rats with ligated pylorus and oesophagus. With long-chain triacylglycerols as substrate, a 40% increase of ester bond cleavage occurred during 1 h of intragastric incubation, relative to rats from which exogenous enzymes were excluded. Similarly, a level of 40% hydrolysis was reached into the intestine of rats with a diversion of pancreatobiliary secretions. Our studies clearly indicate that hydrolysis of dietary fat may be initiated into the stomach by exogenous gastric lipase preparation and may continue in the upper small intestine. On the basis of these findings, studies in humans with this enzyme preparation appear warranted to define its role in the management of patients with exocrine pancreatic insufficiency who do not respond satisfactorily to currently available enzyme preparations.
| Original language | English |
|---|---|
| Pages (from-to) | 607-619 |
| Number of pages | 13 |
| Journal | Nutrition Research |
| Volume | 11 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jan 1 1991 |
| Externally published | Yes |
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Keywords
- diversion of pancreatobiliary secretions
- Gastric lipase
- Intralipid
- Na-glycocholate
- Na-taurocholate
- Similac
ASJC Scopus subject areas
- Endocrinology
- Endocrinology, Diabetes and Metabolism
- Nutrition and Dietetics
Cite this
Partially purified rabbit gastric lipase : in vitro and in vivo experiments to assess its potential contribution to gastric and intestinal lipolysis. / Levy, Emile; Rouleau, Thérèse; Lepage, Guy; Smith, Lesley J; Junien, Jean Louis; Roy, Clauce C.
In: Nutrition Research, Vol. 11, No. 6, 01.01.1991, p. 607-619.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Partially purified rabbit gastric lipase
T2 - in vitro and in vivo experiments to assess its potential contribution to gastric and intestinal lipolysis
AU - Levy, Emile
AU - Rouleau, Thérèse
AU - Lepage, Guy
AU - Smith, Lesley J
AU - Junien, Jean Louis
AU - Roy, Clauce C.
PY - 1991/1/1
Y1 - 1991/1/1
N2 - In vitro and in vivo experiments were undertaken to evaluate enzyme-replacement therapy with an acid stable lipase preparation in pancreatic lipase insufficiency. Utilizing an emulsion of [1-14C] trioleylglycerol, partially purified rabbit gastric lipase exhibited a maximal specific activity of 6.45 μmoles FFA/h, a Km of 80 mM, an optimal peak activities at pH 4.86 and 5.48, and stability in acidic medium. Although preferential lipolysis of medium chain fatty acid ester bonds was evidenced by experiments with a commercial formula (SimilacR) containing 28% MCT (C6-C8-C10-C12), the gastric lipase preparation also displayed ability to split the long chain fatty acid ester bonds in a fine emulsion of triglycerides for IV use (IntralipidR). Triacylglycerol hydrolysis was enhanced either by 4 mM Na-taurocholate or 4 mM Na-glycocholate, and remained unchanged following the addition of these bile salts at 8 mM. These in vitro findings suggested that the gastric lipase preparation was biologically active under the conditions prevailing in the stomach and in the upper small intestine. To investigate its in vivo lipolytic activity exogenous rabbit gastric lipase was added to the stomach of rats with ligated pylorus and oesophagus. With long-chain triacylglycerols as substrate, a 40% increase of ester bond cleavage occurred during 1 h of intragastric incubation, relative to rats from which exogenous enzymes were excluded. Similarly, a level of 40% hydrolysis was reached into the intestine of rats with a diversion of pancreatobiliary secretions. Our studies clearly indicate that hydrolysis of dietary fat may be initiated into the stomach by exogenous gastric lipase preparation and may continue in the upper small intestine. On the basis of these findings, studies in humans with this enzyme preparation appear warranted to define its role in the management of patients with exocrine pancreatic insufficiency who do not respond satisfactorily to currently available enzyme preparations.
AB - In vitro and in vivo experiments were undertaken to evaluate enzyme-replacement therapy with an acid stable lipase preparation in pancreatic lipase insufficiency. Utilizing an emulsion of [1-14C] trioleylglycerol, partially purified rabbit gastric lipase exhibited a maximal specific activity of 6.45 μmoles FFA/h, a Km of 80 mM, an optimal peak activities at pH 4.86 and 5.48, and stability in acidic medium. Although preferential lipolysis of medium chain fatty acid ester bonds was evidenced by experiments with a commercial formula (SimilacR) containing 28% MCT (C6-C8-C10-C12), the gastric lipase preparation also displayed ability to split the long chain fatty acid ester bonds in a fine emulsion of triglycerides for IV use (IntralipidR). Triacylglycerol hydrolysis was enhanced either by 4 mM Na-taurocholate or 4 mM Na-glycocholate, and remained unchanged following the addition of these bile salts at 8 mM. These in vitro findings suggested that the gastric lipase preparation was biologically active under the conditions prevailing in the stomach and in the upper small intestine. To investigate its in vivo lipolytic activity exogenous rabbit gastric lipase was added to the stomach of rats with ligated pylorus and oesophagus. With long-chain triacylglycerols as substrate, a 40% increase of ester bond cleavage occurred during 1 h of intragastric incubation, relative to rats from which exogenous enzymes were excluded. Similarly, a level of 40% hydrolysis was reached into the intestine of rats with a diversion of pancreatobiliary secretions. Our studies clearly indicate that hydrolysis of dietary fat may be initiated into the stomach by exogenous gastric lipase preparation and may continue in the upper small intestine. On the basis of these findings, studies in humans with this enzyme preparation appear warranted to define its role in the management of patients with exocrine pancreatic insufficiency who do not respond satisfactorily to currently available enzyme preparations.
KW - diversion of pancreatobiliary secretions
KW - Gastric lipase
KW - Intralipid
KW - Na-glycocholate
KW - Na-taurocholate
KW - Similac
UR - http://www.scopus.com/inward/record.url?scp=0025834290&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025834290&partnerID=8YFLogxK
U2 - 10.1016/S0271-5317(05)80351-3
DO - 10.1016/S0271-5317(05)80351-3
M3 - Article
AN - SCOPUS:0025834290
VL - 11
SP - 607
EP - 619
JO - Nutrition Research
JF - Nutrition Research
SN - 0271-5317
IS - 6
ER -