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Biomedical subjects

C Erlanson-Albertsson

Publications and source records attributed to C Erlanson-Albertsson.

At least 19 recordsLinked to original sources
PubMed1996

Procolipase is produced in the rat stomach--a novel source of enterostatin.

Procolipase was identified in the stomach by in situ hybridisation. A strong autoradiographic labelling of chief cells was seen in the fundus region, declining more distally and being almost absent in antrum. There was no labelling seen in the intestine. Colipase activity was estimated in rat gastric juice following pentagastrin stimulation and was found to average 2 microM. Furthermore, enterostatin, the N-terminal pentapeptide of procolipase, has been identified in the rat gut and pancreas. Extracts from gastric mucosa, intestinal mucosa and pancreas were purified by gel filtration (Sephadex G25), ion-exchange chromatography (CM-Sepharose) and HPLC (C18 reverse phase). Using an ELISA assay with antibodies directed against enterostatin, two forms of the peptide were identified both in the gut and in the pancreas, with the amino-acid sequences APGPR and VPGPR, respectively. APGPR was found to be the predominant form of enterostatin, whereas only a small amount had the structure VPGPR. Enterostatin in the form of APGPR, when injected intracerebroventricularly in female Sprague-Dawley rats, significantly reduced high-fat food intake in a two-choice situation of low-fat (14% fat by energy) and high-fat (38% fat) food. It is concluded that procolipase is produced in the stomach and secreted into the gastric juice. This is also a novel source of enterostatin.

Amino Acid Sequence↗
PubMed1996

Plasma insulin in response to enterostatin and effect of adrenalectomy in rats.

Enterostatin has previously been reported to alter serum insulin and corticosterone levels after central administration of the peptide. The purpose of the present study was to investigate the effect of peripheral administration of enterostatin on insulin and corticosterone levels as well as the response of plasma insulin to enterostatin administration in adrenalectomized rats. Female Sprague-Dawley rats were given a bolus injection intravenously with enterostatin alone or together with glucose. Enterostatin increased basal plasma levels of insulin, but significantly inhibited the increase in plasma insulin stimulated by glucose. Plasma corticosterone levels were not altered after a single intravenous injection of enterostatin. In rats infused chronically with enterostatin, plasma insulin levels were significantly reduced and plasma corticosterone levels were increased. The daily food intake was lower in these rats, but there was no effect on body weight. After adrenalectomy, the responsiveness of plasma insulin to enterostatin infusion was completely abolished. Furthermore, adrenalectomy itself reduced basal plasma levels of insulin and increased plasma levels of endogenous enterostatin. These results suggest that peripheral enterostatin administration produces a similar effect as central infusion of the peptide, and that the glucocorticoid hormones are involved in the regulation of plasma insulin by enterostatin.

Adrenalectomy↗
PubMed1996

Role of intraduodenally administered enterostatin in rats: inhibition of food.

Central and peripheral administration of enterostatin have been reported to reduce fat or high-fat food intake in rats. Enterostatin is formed in the intestinal lumen by tryptic cleavage of pancreatic procolipase during intraluminal fat digestion. The present experiments were designed to test if enterostatin following intraintestinal infusion would affect food intake in a similar way as intracerebraventricularly or intravenously administered enterostatin. Female Sprague-Dawley rats were fitted with a duodenal catheter and adapted to feeding schedule for 6 hours each day. After 10 days enterostatin (5.65 and 11.3 nmol/kg/min) or saline were infused into the duodenum and food intake measured. Enterostatin significantly reduced high-fat food intake during the 6 hours of feeding, but had no inhibitory effect on low-fat food intake. Addition of tetracaine to the enterostatin infusates blocked the satiating potency of intestinal enterostatin. These results support the hypothesis of a preabsorptive site of action for enterostatin.

Anesthetics, Local↗
PubMed1996

Enterostatin in gut endocrine cells--immunocytochemical evidence.

The presence of enterostatin, a pentapeptide acting as a potential satiety signal in rats, was investigated in rat intestine by immunocytochemical methods. Using antibodies directed against the C-terminal part of enterostatin, the peptide was identified in endocrine cells in the antral part of the stomach and in the small intestine of rat. The immunoreactive cells were more frequent in the antrum and duodenum and became gradually fewer towards the distal small intestine. In some of the labeled endocrine cells, a coexistence of enterostatin with serotonin was revealed by immunocytochemical double staining, implying that the cells were enterochromaffin cells. In the pancreas, no enterostatin-immunoreactive cells were detected, indicating enterostatin to be included in its parent molecule, procolipase. In addition, the existence of procolipase in the gastrointestinal tract, including the pancreas, was investigated. Procolipase immunoreactivity was also identified, except in the pancreas, in chief cells in the fundus region of the stomach. The number of labeled cells declined distally in the stomach, finally being absent in the intestine. Immunoreactive enterostatin was measured with a specific ELISA method. Intestinal content and serum were found to average 540 +/- 70 and 50 +/- 4 nM, respectively. Pancreatic duct ligation strongly reduced the levels of enterostatin in intestinal content to 5.4 +/- 1.5 nM (p < 0.001), and also reduced the serum enterostatin level to 35 +/- 5 nM (p < 0.05). It is concluded that the peptide enterostatin in the rat is produced both in the exocrine pancreas, as part of pancreatic procolipase, and in gut endocrine cells, both sources of peptide being important for the circulating enterostatin.

Amino Acid Sequence↗
PubMed1996

Enterostatin efflux in cat intestinal lymph: relation to lymph flow, hyaluronan, and fat absorption.

The question addressed in this study was whether enterostatin, the pancreatic procolipase activation peptide, modulates intestinal hyaluronan turnover via lymph. In anesthetized cats, segments of ileum were surgically isolated from the proximal and distal gut, the draining lymphatic was cannulated, and the segment was autoperfused in situ. In several groups, concentrations of immunoreactive enterostatin in lymph were compared with that in plasma at baseline and elevated lymph flow and in the absence and presence of fat absorption. The baseline ratio of lymph enterostatin to that in plasma (L/P) in the absence of fat absorption was 1.44 +/- 0.29 compared with 4.93 +/- 0.42 after cream feeding (P < 0.05). In a separate group, when the intestinal lumen was perfused for 2 h with a mixture of oleic acid and taurocholate, enterostatin L/P doubled compared with baseline. At high lymph flows, enterostatin concentrations fell in all groups, resulting in an L/P of 0.47 +/- 0.09 (P < 0.05) in the absence of fat absorption, 0.77 +/- 0.35 after oleic acid, and 1.26 +/- 0.13 in the cream-fed group. These changes correlate with the pattern of hyaluronan efflux from the ileum into lymph after fat absorption [R.K. Reed, M.I Townsley, V.H. Pitts, T.C. Laurent, and A.E. Taylor. Am. J. Physiol, 263 (Gastrointest. Liver Physiol. 26): G6-G11, 1992] However, in separate groups when enterostatin was introduced into ileum, either as a close intra-arterial bolus or via the intestinal lumen, there were no resultant changes in efflux of hyaluronan from the intestine into lymph. In conclusion, despite the fact that delivery of pancreatic exocrine secretions to the ileal lumen was blocked in this model, enterostatin concentration in lymph increased after fat absorption. Nonetheless, it seems clear that enterostatin does not modify intestinal hyaluronan turnover.

Animals↗
PubMed1996

Changes in plasma insulin, enterostatin, and lipoprotein levels during an energy-restricted dietary regimen including a new oat-based liquid food.

The changes in plasma insulin, enterostatin, lipid, and glucose levels during weight reduction were studied in 32 subjects having a body mass index of 25-35. The 31 subjects who completed the study followed for 23 weeks an energy-restricted dietary regimen which included a new oat-based soup as the main meal once or twice daily. The intake of energy decreased from 8.9 to 6.2 MJ/day from 0 to 22 weeks, the energy percentage from fat decreased from 35 to 30%, and the intake of dietary fiber increased from 21 to 25 g/10 MJ. The body weight decreased from 83 to 78 kg after 6 weeks and to 77 kg after 23 weeks. Plasma glucose had decreased significantly from 5.4 to 5.2 mmol/l, and plasma insulin from 122 to 98 pmol/l after 23 weeks. In contrast, the plasma enterostatin concentration did not vary significantly over five sampling times, the mean values ranging from 25 to 30 nmol/l. Plasma cholesterol declined from 5.6 to 5.2 mmol/l, low-density lipoprotein cholesterol from 3.8 to 3.3, and plasma triglycerides from 1.5 to 1.3 mmol/l from 0 to 23 weeks. High-density lipoprotein cholesterol increased from 1.1 to 1.3 mmol/l. It is concluded that an energy-restricted regimen leading to lower plasma insulin, triglyceride, and low-density lipoprotein cholesterol levels did not significantly affect the plasma enterostatin concentration in overweight subjects. A new oat-based liquid food as a part of the dietary regimen was well tolerated.

Adult↗
PubMed1995

Metabolism of enterostatin in rat intestine, brain membranes, and serum: differential involvement of proline-specific peptidases.

The degradation of enterostatin (VPDPR), a potent inhibitor of food intake, by intestinal brush-border membranes, brain membranes, and rat serum has been investigated in the presence of specific inhibitors. Hydrolysis by intestinal membranes was found to be 10 and 100 times faster than in serum and brain membranes, respectively. Enterostatin hydrolysis by intestinal and brain membranes involves the removal of C-terminal arginine by carboxypeptidase P, leading to the production of des-Arg-enterostatin, and the splitting of the Pro2-Asp3 bond by dipeptidyl aminopeptidase IV (DPP IV). A small amount of the potent anorectic peptide Pro2-Asp3-Pro4 was released during hydrolysis of des-Arg-enterostatin by brain membranes and rat serum. In rat serum, enterostatin degradation was mainly due to DPP IV.

Amino Acid Sequence↗
PubMed1995

Intravenous enterostatin does not affect single meal food intake in man.

Enterostatin, a pentapeptide released with colipase from pancreatic procolipase in man, affects eating behaviour in animals. We report the first phase II study of intravenous (i.v.) enterostatin (D3800) in obese but otherwise healthy men. Eighteen men (mean age 37 years, mean body mass index 34.9 kg/m2) completed a double-blind, randomized, crossover placebo controlled trial. After in initial session, each man received i.v. 4 mg D3800, 16 mg D3800 or placebo in random order over three sessions, immediately before a test meal served on a universal eating monitor. No statistically significant effect of i.v. enterostatin on any uptake or rating variable was observed. Several factors may explain the lack of effect, e.g. the inability of i.v. enterostatin to reach a site of action, the time between i.v. administration and eating, and the possibility that the only human responders are those who express particular fat preferences.

Adult↗
PubMed1994

The in vitro intestinal absorption of enterostatin is limited by brush-border membrane peptidases.

The intestinal metabolism and absorption of enterostatin was studied using brush-border membrane vesicles and an in vitro model of intestinal segments from rabbit ileum mounted in Sweetana-Grass diffusion chamber. Hydrolysis of enterostatin was observed with both epithelial sheets and brush-border membranes. The main metabolite was found to be des-arginine-enterostatin. Dipeptidylpeptidase IV was found to play a minor role in enterostatin degradation, whereas carboxypeptidase P activity accounted for the initial step of peptide hydrolysis. More than 50% of the amount of enterostatin added to the mucosal compartment of the Sweetana-Grass diffusion chamber was degraded after 30 min. Enterostatin was mainly absorbed as degradation products but a small transepithelial passage of des-arginine-enterostatin and immunoreactive enterostatin was also detected. Although immunoreactive enterostatin exhibits a low apparent permeability coefficient in rabbit ileum, the luminal production of this peptide may be of physiological importance in the control of appetite.

Amino Acid Sequence↗
PubMed1994

Enterostatin inhibits insulin secretion from isolated perifused rat islets.

The effect of enterostatin on glucose-induced insulin secretion was examined in isolated, perifused rat islets. In the presence of 16.67 mM glucose, there was significant inhibition of insulin secretion at concentrations of 200 nM, 2, 20 and 40 microM enterostatin. In particular, the second phase of insulin secretion was inhibited. With a low concentration of glucose (2.78 mM), there was no significant effect on insulin secretion by enterostatin. The inhibition of insulin secretion exerted by enterostatin may be an important effect in the prevention of insulin resistance.

Animals↗
PubMed1994

Reduction of feed intake in sheep by enterostatin, the procolipase activation peptide.

Enterostatin, a peptide formed during the activation of pancreatic procolipase in the duodenum, is likely a mediator of satiety in the rat. The objective of this research was to determine whether administration of enterostatin into the lateral cerebral ventricle of sheep unfed for 2 h resulted in reduced feed intake. Bolus doses of 2 micrograms did reduce (P < .03) feed intake during the hour after injection by one- to two-thirds of control. Doses 20 micrograms or greater were not effective, and .2 microgram also did not have any statistically significant effect. This range of effective doses was similar to that observed in the rat, and the effective dose of 2 micrograms was approximately 10-fold greater on a per-animal basis, but less on a brain-size basis, than the amount needed to achieve a similar response in the rat. Therefore, enterostatin can reduce feed intake and thus may also be involved in satiety in sheep.

Amino Acid Sequence↗
PubMed1993

Enterostatin: a gut-brain peptide regulating fat intake in rat.

The effect of enterostatin on high-fat food intake has been investigated. After 18 h of food deprivation, rats were injected intravenously with enterostatin (VPGPR). A dose of 38 nmol of enterostatin gave a significant inhibition of high-fat food intake, while at a higher dose of 76 nmol the inhibiting effect was lost. During the first hour, after injection of enterostatin, there was even a slight increase in food intake. Binding studies of tritiated enterostatin to crude brain membranes indicated one binding site with high affinity (Kd = 0.5 nM) and one with low affinity (Kd = 170 nM). The two dissociation constants suggest different receptor subtypes and could explain why enterostatin both can inhibit and, at high doses, stimulate fat intake in rats.

Animals↗
PubMed1993

Induction of exocrine pancreas maturation at weaning in young developing pigs.

The influence of weaning, at either 4 or 6 weeks of age, on the maturation of the exocrine pancreas was studied in naturally reared Swedish Landrace pigs that had no access to solid food. The pigs were surgically fitted with chronic catheters at 3 weeks of age, permitting periodic sampling of pancreatic juice and blood in conscious animals < or = 4 weeks after weaning. During the suckling period, pancreatic fluid and enzyme secretion remained low, both before (preprandial) and after (postprandial) milk ingestion. After weaning at 4 or 6 weeks of age, juice secretion, output of total protein, and levels of different hydrolases (amylase, trypsin, lipase, and carboxylester lipase) and the cofactor colipase all increased markedly postprandially. Moreover, after weaning, the plasma insulin level increased postprandially. This did not happen before weaning, although blood glucose levels always rose after feeding. The data showed a relationship between the time of weaning and the induction of exocrine pancreatic maturation in pigs. This finding implies that postnatal development of pancreatic function is triggered by the dietary change from sow milk to dry solid food. In contrast, the age of the pig appears to be of minor importance, since weaning at either 4 or 6 weeks of age gave a similar result.

Animals↗
PubMed1993

Identification of enterostatin, the pancreatic procolipase activation peptide in the intestine of rat: effect of CCK-8 and high-fat feeding.

Enterostatin, the procolipase activation peptide, has been suggested in previous studies to act as a satiety signal for food intake, with a specificity for fat intake. In this study, by use of a competitive enzyme-linked immunosorbent assay with a detection limit of 4.115 nmol/L and within 6% intra- and interassay variation, the immunoreactive and chromatographic characterization of enterostatin in intestinal content was undertaken in Sprague-Dawley rats. Following intravenous infusion of cholecystokinin octapeptide (CCK-8; 200 pmol/kg/h) for 60 min, the concentration of intestinal enterostatin increased from a basal level of 2.0 +/- 0.7 microM to 5.64 +/- 1.1 microM at time point 60 min. The enterostatin level remained at 4.24 +/- 0.54 microM for 120 min after the CCK infusion had ceased. Pancreatic lipase and colipase activities in rat intestinal content also increased during the CCK-8 infusion. The enzyme activities reached the maximal level after 30 min of CCK infusion and thereafter progressively decreased to basal levels, remaining there during the following 2 h. The basal level of intestinal enterostatin in rats fed with standard pellets was found to be increased from 1.42 +/- 0.14 to 3.86 +/- 0.4, 3.17 +/- 0.54, and 5.02 +/- 1.6 microM on days 1, 3, and 7, respectively, after high-fat feeding. Parallel to the increase in intestinal enterostatin, there was a significant increase in pancreatic lipase and colipase activities in the intestine during the ingestion period of high-fat diet as compared with the control group. The estimated molecular mass of enterostatin immunoreactivity of intestinal content was similar to that of the synthetic pentapeptide. These results suggest that immunoreactive enterostatin (Val-Pro-Gly-Pro-Arg) is normally present in rat intestinal content, is significantly increased after stimulation with CCK-8, and is also increased after prolonged high-fat feeding.

Amino Acid Sequence↗
PubMed1993

Human pancreatic proenzymes are activated at different rates in vitro.

The rates of activation of procolipase, prophospholipase (proPLA2), chymotrypsinogen, and trypsinogen were studied after incubation of human pancreatic juice with porcine enterokinase in vitro. Under the conditions chosen procolipase was fully activated within 10 min of incubation. Full activation of phospholipase (PLA2) was seen within 15 min, whereas complete activation of chymotrypsin and trypsin was not seen until after 30 to 60 min, respectively. The different proenzymes probably differ in their suitability as substrates for trypsin. A physiologic consequence of a differentiated activation of the pancreatic proenzymes in vivo could be a delayed proteolytic degradation of the lipolytic enzymes in the intestine.

Animals↗
PubMed1993

Enterostatin--its ability to inhibit insulin secretion and to decrease high-fat food intake.

Enterostatin is a peptide which has been found to decrease food intake with a specificity for the fat contained in the food. In this work we have investigated the effect of enterostatin (Val-Pro-Asp-Pro-Arg) and its proteolytic fragments, des-arg-enterostatin (Val-Pro-Asp-Pro) and the tripeptide Asp-Pro-Arg, on insulin secretion. It was found that enterostatin and desarg-enterostatin inhibited insulin secretion from isolated rat islets by 55.3% (P < 0.05) and 53.6% (P < 0.05) at 1.6 x 10(-4) M concentration, while the tripeptide Asp-Pro-Arg at 1.6 x 10(-4) M concentration had no significant effect and increased insulin secretion by 33.0%. Enterostatin at 200 ng after intraventricular administration was found to inhibit the intake of a high-fat diet by 45.0%, while des-arg-enterostatin (200 ng) had no effect, in agreement with previous findings. The tripeptide Asp-Pro-Arg (200 ng) had no effect on the intake of a high-fat diet compared to saline injection. The ability of enterostatin to inhibit high-fat food intake and decrease insulin secretion may be important for the prevention of obesity and type II diabetes, conditions linked through hyperinsulinemia.

Amino Acid Sequence↗
PubMed1992

Effect of enterostatin given intravenously and intracerebroventricularly on high-fat feeding in rats.

The effect of enterostatin, the amino-terminal pentapeptide of pancreatic procolipase, on high-fat food intake has been investigated after intracerebroventricular as well as after intravenous injection. After an overnight fast enterostatin given i.c.v. at doses of 167 pmol and 333 pmol produced a significant and dose-dependent reduction in high-fat food intake, while a higher dose of 667 pmol had no effect. Following intravenous injection of enterostatin the intake of high-fat food was suppressed at doses of 8.3 nmol and 16.7 nmol, while no effect was observed at higher doses. The inhibition of feeding started 3 h after the initiation of feeding and persisted to the end of the test period (6 h). Enterostatin at a dose of 16.7 nmol gave no sign of aversion in an aversion test comparing the effect of enterostatin, lithium chloride and saline on liquid intake. The data suggest that enterostatin may exert its satiety effect on high-fat feeding by being absorbed into the bloodstream.

Animals↗