Studies on nutrient digestibilities (pre‐caecal and total) in pancreatic duct‐ligated pigs and the effects of enzyme substitution

Abstract

Introduction Exocrine pancreatic insufficiency causes digestive disturbances in humans and animals. However, although clinical symptoms of pancreatic insufficiency, e.g. steatorrhoea, only occurs after loss of 80–90% normal pancreatic secretory capacity (D iM agno et al. 1973), pancreatic enzyme supplementation does not always result in normalization of digestion (especially of fat), even with high doses of enzymes (L& ouml; ser and F& ouml; lsch 1995). In order to better understand the physiological and the pathological consequences of exocrine pancreatic insufficiency in humans as well as its therapy with enzyme substitution, studies have been made using an animal model of induced pancreatic exocrine insufficiency. Hither to, studies concerning pancreatic duct ligation and/or the influence of enzyme substitution have mainly been focused on estimation of enzyme activities in chyme (e.g. A bello et al. 1989) and/or on faecal analyses of total digestibility (e.g. I mmondi et al. 1972). To get more information on effects of enzymes (natural or substituted) it seems necessary to investigate the site and extent of digestion more intensively (S udendey 1995). Therefore a pig model of induced pancreatic exocrine insufficiency, via pancreatic duct ligation, was chosen and pre‐caecal digestibility was measured by means of an ileo‐caecal re‐entrant fistula. Studies on the digestibility of a high fat diet were made, since cystic fibrosis patients with exocrine pancreatic insufficiency are recommended to take in high amounts of energy to avoid catabolic metabolism and nowadays these high energy diets comprise increasing proportions of fat (D urie and P encharz 1989; S hepherd et al. 1991). The following aspects were investigated in controls and pancreatic duct‐ligated pigs that were fed a high fat diet: changes in the composition of ileal chyme and faeces; effects on nutrient digestibility (pre‐caecal and total); efficacy of enzyme substitution in total exocrine pancreatic insufficiency.

Human Pancreatic Digestive Enzymes

“…It is likely that intestinal peptidases are not capable of digesting enough proteins to meet metabolic needs of children (e.g., pancreatic insufficiency owing to cystic fibrosis), and probably not adults (e.g., alcoholic chronic pancreatitis). Indeed, in a minipig model of complete pancreatic exocrine insufficiency it was shown that when animals were fed meals containing approximately 80 g protein per day, approximately 70% protein remains unabsorbed in the small intestine, whereas only 20% is unabsorbed in the small intestine in control animals [4,5]. Surprisingly, residual protein in feces dropped to only 40% in pancreatic insufficiency and 10% in control pigs, suggesting a possible role for hindgut digestion or fermentation in pigs.…”

“…Available studies on animals confirm that preduodenal lipases, gastric or lingual, contribute to dietary fat digestion [101][102][103][104]. No animal model of gastric lipase deficiency exists.…”

The Pancreatic Duct Ligated Pig as a Model for Patients Suffering from Exocrine Pancreatic Insufficiency—Studies of Vitamin A and E Status

“…The pancreatic duct ligated (PL) (mini)pig is an established model for studying EPI in humans [25][26][27][28], and it also is used for in vivo testing of the efficacy of pancreatic enzymes [26,29,30]. Ligation of the ductus pancreaticus accessorius results in a complete loss of exocrine pancreatic function without affecting endocrine function [31,32].…”

Oral Supplementation with a Special Additive of Retinyl Palmitate and Alpha Tocopherol Reduces Growth Retardation in Young Pancreatic Duct Ligated Pigs Used as a Model for Children Suffering from Exocrine Pancreatic Insufficiency

“…As exocrine pancreatic function is essential for digestion and absorption of nutrients the complete loss of pancreatic secretion causes maldigestion and malabsorption of various macro- and micronutrients [24,25,26,27]. The juvenile PL pig was used in several studies to test the effects of PEI on growth and different parameters in juveniles [23,28,29,30,31].…”