1
|
Morisset J. Life with the pancreas: A personal experience. Adv Med Sci 2020; 65:46-64. [PMID: 31901477 DOI: 10.1016/j.advms.2019.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 09/05/2019] [Accepted: 11/01/2019] [Indexed: 11/30/2022]
Abstract
This review article has primary objective to summarize pancreatic research which has been done in our laboratory since 1965, the first year of the author's registration in the Ph.D. program at the University of Sherbrooke (Canada). It covers the following major topics of pancreatic physiology: controls of pancreatic adaptation to diet, control of pancreatic enzyme secretion, control of pancreatic enzyme synthesis, control of pancreatic growth, intracellular events stimulated during pancreatic growth, pancreas regeneration after pancreatitis and pancreatectomy, the pancreatic cholecystokinin receptor types 1 and 2, growth control and cell signaling in pancreatic cancer cells and finally, cystic fibrosis.
Collapse
Affiliation(s)
- Jean Morisset
- Division of Gastroenterology, Department of Medicine, Faculty of Medicine and Health Sciences, University of Sherbrooke, 3001 12th Avenue North, Sherbrooke, Québec, J1H 5N4, Canada.
| |
Collapse
|
2
|
Abstract
In mammals, secretin is a 27-amino acid peptide that was first studied in 1902 by Bayliss and Starling from the extracts of the jejunal mucosa for its ability to stimulate pancreatic secretion. To date, secretin has only been identified in tetrapods, with the earliest diverged secretin found in frogs. Despite being the first hormone discovered, secretin's evolutionary origin remains enigmatic, it shows moderate sequence identity in nonmammalian tetrapods but is highly conserved in mammals. Current hypotheses suggest that although secretin has already emerged before the divergence of osteichthyans, it was lost in fish and retained only in land vertebrates. Nevertheless, the cognate receptor of secretin has been identified in both actinopterygian fish (zebrafish) and sarcopterygian fish (lungfish). However, the zebrafish secretin receptor was shown to be nonbioactive. Based on the present information that the earliest diverged bioactive secretin receptor was found in lungfish, and its ability to interact with both vasoactive intestinal peptide and pituitary adenylate cyclase-activating polypeptide potently suggested that secretin receptor was descended from a VPAC-like receptor gene before the Actinopterygii-Sarcopterygii split in the vertebrate lineage. Hence, secretin and secretin receptor have gone through independent evolutionary trajectories despite their concurrent emergence post-2R. A functional secretin-secretin receptor axis has probably emerged in the amphibians. Although the pleiotropic actions of secretin are well documented in the literature, only limited information of its physiological functions in nonmammalian tetrapods have been reported. To decipher the structural and functional divergence of secretin and secretin receptor, functional characterization of the ligand-receptor pair in nonmammals would be the next perspective for investigation.
Collapse
Affiliation(s)
- Janice K V Tam
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
| | - Leo T O Lee
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
| | - Jun Jin
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
| | - Billy K C Chow
- School of Biological SciencesThe University of Hong Kong, Pokfulam Road, Hong Kong, Hong Kong
| |
Collapse
|
3
|
Garcia GL, Dong M, Miller LJ. Differential determinants for coupling of distinct G proteins with the class B secretin receptor. Am J Physiol Cell Physiol 2012; 302:C1202-12. [PMID: 22277758 DOI: 10.1152/ajpcell.00273.2011] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The secretin receptor is a prototypic class B G protein-coupled receptor that is activated by binding of its natural peptide ligand. The signaling effects of this receptor are mediated by coupling with Gs, which activates cAMP production, and Gq, which activates intracellular calcium mobilization. We have explored the molecular basis for the coupling of each of these G proteins to this receptor using systematic site-directed mutagenesis of key residues within each of the intracellular loop regions, and studying ligand binding and secretin-stimulated cAMP and calcium responses. Mutation of a conserved histidine in the first intracellular loop (H157A and H157R) markedly reduced cell surface expression, resulting in marked reduction in cAMP and elimination of measurable calcium responses. Mutation of an arginine (R153A) in the first intracellular loop reduced calcium, but not cAMP responses. Mutation of a dibasic motif in the second intracellular loop (R231A/K232A) had no significant effects on any measured responses. Mutations in the third intracellular loop involving adjacent lysine and leucine residues (K302A/L303A) or two arginine residues separated by a leucine and an alanine (R318A/R321A) significantly reduced cAMP responses, while the latter also reduced calcium responses. Additive effects were elicited by combining the effective mutations, while combining all the effective mutations resulted in a construct that continued to bind secretin normally, but that elicited no significant cAMP or calcium responses. These data suggest that, while some receptor determinants are clearly shared, there are also distinct determinants for coupling with each of these G proteins.
Collapse
Affiliation(s)
- Gene L Garcia
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ 85259, USA
| | | | | |
Collapse
|
4
|
Ryberg A, Borch K, Monstein HJ. Expression of multiple forms of 3'-end variant CCK2 receptor mRNAs in human pancreatic adenocarcinomas. BMC Res Notes 2011; 4:131. [PMID: 21504585 PMCID: PMC3094373 DOI: 10.1186/1756-0500-4-131] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Accepted: 04/19/2011] [Indexed: 11/10/2022] Open
Abstract
Background Two main types of receptors for gastrin and cholecystokinin (CCK) have been cloned and identified. CCK1 (CCK-A) receptors are expressed in the pancreas, the gallbladder, and parts of the brain, while CCK2 (CCK-B/gastrin) receptors (CCK2R) are expressed in gastric glands and in most of the brain. A splice variant of the CCK2R designated CCKRi4sv (CCK-C), which is constitutively expressed in human pancreatic cancer cells, has also been described. The purpose of the present investigation was to study CCK2R, CCK2i4svR, and gastrin mRNA expression in human pancreatic adenocarcinoma on the assumption that co-expression of CCK2R and gastrin or constitutive CCK2i4svR mRNA expression plays a pivotal role in the progression of pancreatic cancer. Findings PCR amplification using CCK2R specific primer-pairs, followed by ethidium-bromide stained agarose gel electrophoresis revealed the expression of wild-type CCK2R mRNA in 12 of 17 biopsy specimens. A CCK2R intron 4 specific nested PCR assay revealed that CCK2i4svR mRNA was expressed in only one of the biopsy specimen. The authenticity of PCR amplicons was confirmed by cloning of selected amplicons and DNA sequence analysis. Moreover, we found that hitherto undescribed multiple forms of 3'-end variant CCK2R mRNAs with various deletions in the retained intron 4 and exon 5, tentatively generating truncated proteins, were expressed in the pancreatic adenocarcinomas. Conclusion Cloning and DNA sequencing of selected amplicons revealed that CCK2R and multiple CCK2i4svR-like mRNAs are expressed in human pancreatic adenocarcinoma. The originally described CCK2i4svR mRNA was only expressed in one of 17 tumours and appears to be rarely expressed in pancreatic adenocarcinoma. We report that CCK2R- and gastrin mRNA co-expression may play a role in a portion, but not in all of these tumours, and that aberrant splicing takes places in these tissues generating multiple forms of 3'-end variant CCK2R mRNAs.
Collapse
Affiliation(s)
- Anna Ryberg
- Division of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Clinical Microbiology, County Council of Östergötland, S-581 85 Linköping, Sweden.
| | | | | |
Collapse
|
5
|
Control of somatostatin (SS) secretion by CCK-1 and CCK-2 receptors' occupation in RIN-14B cells, a rat pancreatic islet cell line. Pancreas 2010; 39:127-34. [PMID: 19959964 DOI: 10.1097/mpa.0b013e3181bea475] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
OBJECTIVES This study evaluated the role played by cholecystokinin (CCK) receptors' occupation in the control of somatostatin (SS) secretion in RIN-14B cells. METHODS The presence of the CCK receptors 1 and 2 was confirmed by immunofluorescence, and SS secretion was evaluated by enzyme-linked immunosorbent assay. RESULTS By immunofluorescence, 95% of the cell population was composed of SS cells bearing both CCK-R subtypes with 5% of beta cells (data not shown). Cerulein (Cae), a CCK-1R agonist, and pentagastrin, a CCK-2R agonist, dose-dependently increased SS release, 3-fold at 1 mumol/L Cae, 2.5-fold at 10 mumol/L pentagastrin, with occupation of both CCKRs confirmed by L-364,178 and L-365,260 inhibition of CCK receptors 1 and 2. The occupation of high-affinity CCK-1R by Cae was confirmed on SS release with JMV-180, a high-affinity CCK-1R agonist, and absence of SS release inhibition at high Cae concentration occupying the low-affinity CCK-1R. These cells release more than 60% of their SS content by constitutive secretion, confirmed by cycloheximide and brefeldin inhibiting SS synthesis and intracellular trafficking, respectively. CONCLUSIONS Both CCKR subtypes occupy RIN-14B cells and initiate SS secretion through constitutive secretion controlled at SS synthesis level. Somatostatin secretion via the CCK-1R occupation mobilizes its high-affinity sites.
Collapse
|
6
|
Abstract
This review article has for major objective to summarize the old and latest developments on the hormonal controls of pancreatic growth. The article deals with hormonal controls during the fetal, neonatal and adult periods of pancreas development, growth and regeneration. During the fetal period, comparisons were made between studies performed with pancreatic explants and those designed in vivo. After birth, the effects of glucocorticoids, thyroxine, gastrin, bombesin, secretin, cholecystokinin alone or with secretin are reported. In the adults, similar studies were reported on hormones with addition of the effects of neuropeptides, the cell types targeted by hormones and the hormonal control after pancreatectomy and pancreatitis.
Collapse
|
7
|
Stepan V, Ramamoorthy S, Pausawasdi N, Logsdon CD, Askari FK, Todisco A. Role of small GTP binding proteins in the growth-promoting and antiapoptotic actions of gastrin. Am J Physiol Gastrointest Liver Physiol 2004; 287:G715-25. [PMID: 15331357 DOI: 10.1152/ajpgi.00169.2003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
G17 has growth promoting and antiapoptotic effects on the AR4-2J pancreatic acinar cell line. We previously reported that whereas MAPK regulates G17-stimulation of AR4-2J cell proliferation, Akt mediates the antiapoptotic action of G17. We examined the signal-transduction pathways mediating G17 stimulation of AR4-2J cell growth and survival. G17 activated the small GTP binding proteins Ras, Rac, Rho, and Cdc42. Transduction of the cells with adenoviral vectors expressing dominant negative Akt, Ras, Rho, and Cdc42 but not dominant negative Rac inhibited AR4-2J cell proliferation and survival. Both exoenzyme C3 from Clostridium botulinum (C3), a toxin known to inactivate Rho, and PD98059, a MAPK inhibitor, reversed G17 inhibition of AR4-2J cell apoptosis. G17 induction of Akt activation was reduced by >60% by both dominant negative Ras and Rho and by 30% by dominant negative Cdc42. In contrast, G17-stimulated MAPK activation was blocked by >80% by dominant negative Ras but not by dominant negative Rho and Cdc42. Similar results were observed in the presence of C3. Dominant negative Rac failed to affect G17 induction of both Akt and MAPK, whereas it inhibited sorbitol by almost 50% but not G17-stimulated activation of p38 kinase. Thus G17 promotes AR4-2J cell growth and survival through the activation of multiple GTP binding proteins, which, in turn, regulate different protein kinase cascades. Whereas Ras activates Akt and MAPK, Rho and Cdc42 appear to regulate Akt and possibly other as yet unidentified kinases mediating the growth-stimulatory actions of G17.
Collapse
Affiliation(s)
- Vinzenz Stepan
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0682, USA
| | | | | | | | | | | |
Collapse
|
8
|
Risch HA. Etiology of pancreatic cancer, with a hypothesis concerning the role of N-nitroso compounds and excess gastric acidity. J Natl Cancer Inst 2003; 95:948-60. [PMID: 12837831 DOI: 10.1093/jnci/95.13.948] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In the United States, pancreatic cancer is the fourth most frequent cause of cancer death in males as well as females, after lung, prostate or breast, and colorectal cancer. Each year, approximately 30 000 Americans are diagnosed with pancreatic cancer and about the same number die of it. Germline mutations in a few genes including p16 and BRCA2 have been implicated in a small fraction of cases, as has chronic pancreatitis. The one established risk factor for pancreatic cancer is cigarette smoking: current smokers have two to three times the risk of nonsmokers. Studies of dietary factors have not been entirely consistent but do suggest associations of higher risk with consumption of smoked or processed meats or with animal foods in general and lower risk with consumption of fruits and vegetables. Colonization by Helicobacter pylori appears to increase risk, and a history of diabetes mellitus may also increase risk. The purpose of this epidemiologic review is to consider the possibility that risk of pancreatic cancer is increased by factors associated with pancreatic N-nitrosamine or N-nitrosamide exposures and with chronic excess gastric or duodenal acidity. Host genetic variation in inflammatory cytokine mechanisms may also be involved in this process. Many features of the evidence bearing on the pathophysiology of pancreatic cancer appear to support connections with N-nitroso compounds and with gastric acidity.
Collapse
Affiliation(s)
- Harvey A Risch
- Department of Epidemiology and Public Health, Yale University School of Medicine, 60 College St., P.O. Box 208034, New Haven, CT 06520-8034, USA.
| |
Collapse
|
9
|
Jang JY, Kim SW, Han JK, Park SJ, Park YC, Joon Ahn Y, Park YH. Randomized prospective trial of the effect of induced hypergastrinemia on the prevention of pancreatic atrophy after pancreatoduodenectomy in humans. Ann Surg 2003; 237:522-9. [PMID: 12677149 PMCID: PMC1514462 DOI: 10.1097/01.sla.0000059985.56982.11] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE To investigate whether gastrin has regenerative effect on the pancreas and in particular whether it prevents the atrophy of the distal pancreas after resection of pancreas in humans. SUMMARY BACKGROUND DATA Although pancreatic regeneration after resection is well documented in animals, atrophy rather than regeneration of the distal remnant pancreas commonly occurs following pancreatoduodenectomy in humans. Of the many factors involving pancreatic regeneration, gastrin has been shown to have trophic effect on the pancreas in an animal model. METHODS Between March 1999 and May 2000, a randomized prospective study was performed in 56 patients who underwent pylorus-preserving pancreatoduodenectomy for periampullary neoplasms. Patients were allocated to either a lansoprazole group or a control group. The lansoprazole members were given oral lansoprazole (30 mg/d) over 12 weeks postoperatively to induce hypergastrinemia. During the study period, 19 patients were excluded for different reasons; in the end a total of 37 patients (lansoprazole, n = 18; control, n = 19) were eligible for study. The volume of the distal pancreas as determined using thin-sectioned spiral CT data, nutritional status, and endocrine (insulin level, glucose tolerance test) and exocrine function (stool elastase) of the pancreas and serum gastrin levels were measured before surgery and 3 months after surgery. The two groups were clinically comparable. RESULTS Serum gastrin level was elevated in the lansoprazole group. In this group, the mean volume of the distal pancreas was reduced by 10% after pylorus-preserving pancreatoduodenectomy, whereas severe pancreatic atrophy occurred in the control group. Postoperative insulin and stool elastase levels were higher in the lansoprazole group than in the control group. CONCLUSIONS This study is the first prospective randomized trial of induced hypergastrinemia on the regeneration of the pancreas in humans. It may be possible to use induced hypergastrinemia in the treatment or prevention of pancreatic insufficiency following resection or injury.
Collapse
Affiliation(s)
- Jin-Young Jang
- Department of Surgery, Seoul National University School of Medicine, 28 Yongon-dong, Chongno-gu, Seoul 110-744, Korea
| | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
Gastrin is a peptide hormone that regulates both acid secretion and growth of the gastric oxyntic mucosa. Recent studies suggest that gastrin, in both its amidated, and less processed forms (glycine-extended gastrin and progastrin) may also exert biological activity in other organs in the gastrointestinal tract. This article will review the studies performed to date addressing the physiological role of gastrin outside of the gastric mucosa, with particular emphasis on the information gleaned from gastrin-deficient mice. Most of these studies address the potential role for the less processed forms of gastrin in regulating the proliferation of the colonic mucosa and colon cancers. There is also some data to support a potential role for gastrin in the regulation of the pancreas and the kidney, although the effects of gastrin deficiency on the function of these organs in mice have not yet been rigorously studied.
Collapse
Affiliation(s)
- Theodore J Koh
- University of Massachusetts Memorial Medical Center, Worcester, MA 01605, USA.
| |
Collapse
|
11
|
Yen TWF, Sandgren EP, Liggitt HD, Palmiter RD, Zhou W, Hinds TR, Grippo PJ, McDonald JM, Robinson LM, Bell RH. The gastrin receptor promotes pancreatic growth in transgenic mice. Pancreas 2002; 24:121-9. [PMID: 11854616 DOI: 10.1097/00006676-200203000-00002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION We demonstrated previously, in two different rodent models of pancreatic cancer, that the gastrin receptor is present on malignant pancreatic tumors in spite of the fact that the normal adult rat and mouse pancreas does not express gastrin receptors. AIMS AND METHODOLOGY To determine whether gastrin receptors mediate pancreatic growth or promote carcinogenesis or both, we created a transgenic mouse that constitutively expresses gastrin receptors in the exocrine pancreas. The transgene construct contained the full-length rat gastrin receptor cDNA sequence under the control of the rat elastase promoter. RESULTS Receptor presence and function on exocrine pancreatic tissue of transgenic but not control mice were confirmed by (125)I-gastrin-I binding studies and by gastrin stimulation of intracellular calcium release. Eighteen-month-old transgenic animals had larger pancreas-to-body weight ratios than their nontransgenic littermate controls (p < 0.001 for females; p < 0.01 for males); however, histopathologic examination revealed no neoplasms or other abnormalities. CONCLUSION In both female and male transgenic mice, the expression of the gastrin receptor in the exocrine pancreas is associated with a significant increase in pancreas weight, but it does not appear to promote the development of spontaneous pancreatic tumors.
Collapse
Affiliation(s)
- Tina W F Yen
- Surgical Service, Veterans Administration Puget Sound Health Care System, University of Washington School of Medicine, Seattle, Washington, U.S.A
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Todisco A, Ramamoorthy S, Witham T, Pausawasdi N, Srinivasan S, Dickinson CJ, Askari FK, Krametter D. Molecular mechanisms for the antiapoptotic action of gastrin. Am J Physiol Gastrointest Liver Physiol 2001; 280:G298-307. [PMID: 11208554 DOI: 10.1152/ajpgi.2001.280.2.g298] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Gastrin (G17) has a CCK-B receptor-mediated growth-promoting effect on the AR42J rat acinar cell line. We examined whether G17 inhibits apoptosis induced by serum withdrawal of AR42J cells and CHO-K1 cells stably expressing CCK-B receptors (CHO-K1/CCK-B cells). Cellular apoptosis was measured by flow cytometry and the terminal deoxynucleotidyltransferase-mediated dUTP-FITC nick end-labeling method. Serum withdrawal induced AR42J and CHO-K1/CCK-B cell apoptosis. Addition of 10 nM G17 reversed these effects. We examined the action of G17 (10 nM) on phosphorylation and activation of protein kinase B/Akt, a kinase known to promote cell survival. Akt phosphorylation and activation were measured by kinase assays and Western blots with an anti-phospho-Akt antibody. G17 stimulated Akt phosphorylation and activation. G17 induction of Akt phosphorylation was inhibited by the phosphoinositide 3-kinase (PI 3-kinase) inhibitors LY-294002 (10 microM) and wortmannin (200 nM) but not by the mitogen-activated protein kinase kinase 1 inhibitor PD-98059 (50 microM). To study the role of p38 kinase in G17 signaling to Akt, we examined the effect of G17 on p38 kinase activation and phosphorylation using kinase assays and Western blots with an anti-phospho-p38 kinase antibody. G17 induced p38 kinase activity at doses and with kinetics similar to those observed for Akt induction. The p38 kinase inhibitor SB-203580 inhibited G17 induction of Akt phosphorylation and activation at a concentration (10 microM) 10-fold higher than necessary to block p38 kinase (1 microM), suggesting the possible involvement of kinase activities other than p38 kinase. Transduction of AR42J cells with the adenoviral vector Adeno-dn Akt, which overexpresses an inhibitor of Akt, reversed the antiapoptotic action of G17. In conclusion, G17 promotes AR42J cell survival through the induction of Akt via PI 3-kinase and SB-203580-sensitive kinase activities.
Collapse
Affiliation(s)
- A Todisco
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0682, USA.
| | | | | | | | | | | | | | | |
Collapse
|
13
|
Henriksen JH, de Muckadell OB. Secretin, its discovery, and the introduction of the hormone concept. Scand J Clin Lab Invest 2000; 60:463-71. [PMID: 11129062 DOI: 10.1080/003655100448446] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
The English physician E. H. Starling discovered in collaboration with the physiologist W. M. Bayliss secretin, the first hormone, in 1902. Three years later they introduced the hormone concept with recognition of chemical regulation, early regulatory physiology took a major step forward. The isolation and subsequent synthesis of secretin in the 1960s prepared the way for immunological techniques. Radioimmuno assays in the 1970s enabled demonstration of a direct endocrine role of secretin. Cloning and molecular hybridisation in the 1990s identified production site structure, precursor and evolutionary relation to other gastrointestinal peptides and to the secretin receptor. Although secretin was the first substance to be established as a hormone, even today our understanding is far from complete.
Collapse
Affiliation(s)
- J H Henriksen
- Department of Clinical Physiology 239, Hvidovre Hospital, University of Copenhagen, Denmark.
| | | |
Collapse
|
14
|
Abstract
The peptide hormone gastrin, released from antral G cells, is known to stimulate the synthesis and release of histamine from ECL cells in the oxyntic mucosa via CCK-2 receptors. The mobilized histamine induces acid secretion by binding to the H(2) receptors located on parietal cells. Recent studies suggest that gastrin, in both its fully amidated and less processed forms (progastrin and glycine-extended gastrin), is also a growth factor for the gastrointestinal tract. In this article, we review the recent evidence (including those from the transgenic and knockout mice) for the trophic targets of both the amidated and less processed forms of gastrin in the gastrointestinal tract, pancreas and liver. It has been established that the major trophic effect of amidated gastrin is for the oxyntic mucosa of stomach, where it causes increased proliferation of gastric stem cells and ECL cells, resulting in increased parietal and ECL cell mass. There is insufficient evidence to support that amidated gastrin is a trophic factor for the rest of gastrointestinal tract, exocrine pancreas and liver. On the other hand, the major trophic target of the less processed gastrin (e.g. glycine-extended gastrin) appears to be the colonic mucosa. There is no evidence to suggest that it is trophic for the stomach. It remains to be examined whether the rest of gastrointestinal tract, pancreas and liver are the trophic targets by glycine-extended gastrin and progastrin.
Collapse
Affiliation(s)
- T J Koh
- Gastrointestinal Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | | |
Collapse
|
15
|
Takahashi M, Sasaki I, Naito H, Funayama Y, Shibata C, Ohtani N, Matsuno S. Chronic diversion of bile to the urinary bladder induces pancreatic growth in dogs. J Gastrointest Surg 2000; 4:513-9. [PMID: 11077327 DOI: 10.1016/s1091-255x(00)80094-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The aim of this study was to elucidate the mechanism of chronic biliary diversion and its effect on pancreatic growth. In the first part of the study, nine mongrel dogs underwent diversion of bile from the gastrointestinal tract by ligating the common bile duct and interposing a segment of jejunum between the gallbladder and the urinary bladder (cholecystojejunocystostomy [CJC]). Despite the loss of 7% of their body weight at 12 weeks after bilioenteric diversion, CJC dogs had significantly greater pancreatic wet weight than control dogs (51.2 +/- 2.2 g vs. 37.1 +/- 2.2 g). In the second part of the study, six other dogs underwent CJC. Twelve weeks later, bilioenteric continuity was restored by creating a cholecystojejunoduodenostomy (CJD). The dogs were given butter (3 g/kg) by mouth (prior to surgery, 12 weeks after CJC, and 4 weeks after CJD). Pancreatic excisional biopsy specimens were obtained at each operation and at autopsy. CJC induced more pancreatic RNA per milligram of weight (743 +/- 52, CJC; 579 +/- 44, prior to surgery, P <0.05 vs. CJC; 520 +/- 26 microg/100 mg tissue, CJD, P <0.01 vs. CJC), but not more DNA, and significantly higher basal plasma cholecystokinin levels and butter-stimulated cholecystokinin responses when compared with values prior to surgery or following CJD. We conclude that chronic biliary diversion induces pancreatic growth associated with hypersecretion of cholecystokinin in dogs.
Collapse
Affiliation(s)
- M Takahashi
- First Department of Surgery, Tohoku University School of Medicine, 1-1, Seiryoumachi, Aoba-ku, Sendai 980-8574, Japan
| | | | | | | | | | | | | |
Collapse
|
16
|
Stepan VM, Dickinson CJ, del Valle J, Matsushima M, Todisco A. Cell type-specific requirement of the MAPK pathway for the growth factor action of gastrin. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:G1363-72. [PMID: 10362639 DOI: 10.1152/ajpgi.1999.276.6.g1363] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Gastrin (G17) has a CCKB receptor-mediated growth-promoting effect on the AR42J rat acinar cell line that is linked to induction of both mitogen-activated protein kinase (MAPK) and c-fos gene expression. We investigated the mechanisms that regulate the growth factor action of G17 on the rat pituitary adenoma cell line GH3. Both AR42J and GH3 cells displayed equal levels of CCKB receptor expression and similar binding kinetics of 125I-labeled G17. G17 stimulation of cell proliferation was identical in both cell lines. G17 stimulation of GH3 cell proliferation was completely blocked by the CCKB receptor antagonist D2 but not by the MEK inhibitor PD-98059 or the protein kinase C inhibitor GF-109203X, which completely inhibited G17 induction of AR42J cell proliferation. G17 induced a c-fos SRE-luciferase reporter gene plasmid more than fourfold in the AR42J cells, whereas it had no effect in the GH3 cells. In contrast to what we observed in the AR42J cells, G17 failed to stimulate MAPK activation and Shc tyrosyl phosphorylation and association with the adapter protein Grb2. Epidermal growth factor induced the MAPK pathway in the GH3 cells, demonstrating the integrity of this signaling system. G17 induced Ca2+ mobilization in both the GH3 and AR42J cells. The calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide inhibited AR42J cell proliferation by 20%, whereas it completely blocked G17 induction of GH3 cell growth. The Ca2+ ionophore ionomycin stimulated GH3 cell proliferation to a level similar to that observed in response to G17, but it had no effect on AR42J cell proliferation. Thus there are cell type specific differences in the requirement of the MAPK pathway for the growth factor action of G17. Whereas in the AR42J cells G17 stimulates cell growth through activation of MAPK and c-fos gene expression, in the GH3 cells, G17 fails to activate MAPK, and it induces cell proliferation through Ca2+-dependent signaling pathways. Furthermore, induction of Ca2+ mobilization in the AR42J cells appears not to be sufficient to sustain cell proliferation.
Collapse
Affiliation(s)
- V M Stepan
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA
| | | | | | | | | |
Collapse
|
17
|
Stepan VM, Tatewaki M, Matsushima M, Dickinson CJ, del Valle J, Todisco A. Gastrin induces c-fos gene transcription via multiple signaling pathways. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:G415-24. [PMID: 9950815 DOI: 10.1152/ajpgi.1999.276.2.g415] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We previously observed that the trophic actions of gastrin (G17) on the AR42J rat acinar cell line are mediated by mitogen-activated protein kinase (MAPK)-induced c-fos gene transcription via protein kinase C (PKC)-dependent and -independent pathways. In this study, we further investigated the signaling pathways that target c-fos in response to G17. G17 led to a sixfold induction in luciferase activity in cells transfected with plasmids containing the -356+109 sequence of the murine c-fos promoter, which includes the Sis-inducible element (SIE), serum response element (SRE), and the Ca2+/cAMP response element (CRE) regulatory elements. Addition of either the selective PKC inhibitor GF-109203X or the MAPK/extracellular signal-regulated kinase inhibitor PD-98059 resulted in an 80% reduction in luciferase activity. G17 induced the transcriptional activity of both Elk-1 and Sap-1a, transcription factors that bind to the E26 transformation specific (Ets) DNA sequence of the SRE, and this effect was inhibited by both GF-109203X and PD-98059. Point mutations in the Ets sequence led to a 4-fold induction of c-fos transcription stimulated by G17 and to a 1.3-fold induction in response to epidermal growth factor (EGF). In contrast, mutations in the CA rich G (CArG) sequence of the SRE prevented transcriptional activation by both G17 and EGF. G17 induction of the Ets mutant construct was unaffected by either GF-109203X or PD-98059. Because activation of the SRE involves the small GTP-binding protein Rho A, we examined the role of Rho A in G17 induction of c-fos transcription. Inactivation of Rho A by either the specific inhibitor C3 or by expression of a dominant negative Rho A gene inhibited G17 induction of both the wild-type and the Ets mutant constructs by 60%. C3 also inhibited G17-stimulated AR42J cell proliferation. Thus G17 targets the c-fos promoter CArG sequence via Rho A-dependent pathways, and Rho A appears to play an important role in the regulation of the trophic action of G17.
Collapse
Affiliation(s)
- V M Stepan
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109-0682, USA
| | | | | | | | | | | |
Collapse
|
18
|
Friess H, Kleeff J, Isenmann R, Malfertheiner P, Büchler MW. Adaptation of the human pancreas to inhibition of luminal proteolytic activity. Gastroenterology 1998; 115:388-96. [PMID: 9679044 DOI: 10.1016/s0016-5085(98)70205-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND & AIMS Feedback regulation of pancreatic enzyme secretion is well established in animals, and their pancreases are able to adapt to intraduodenal inhibition of pancreatic enzymes by proteinase inhibitors such as Camostate (FOY-305; Schwarz GmbH, Monheim, Germany). In this study, we addressed whether similar adaptive changes occur in the human pancreas after 4 weeks of 2 g/day Camostate application. METHODS Before, at the end of, and 2 weeks after 4-week Camostate treatment (four times 500 mg daily), pancreatic changes were analyzed with the use of a secretin-cerulein test, a test-meal stimulation, cholecystokinin plasma measurement, and standardized ultrasonographic investigations of the pancreas. RESULTS Duodenal trypsin output after secretion stimulation was significantly increased (+44%; P < 0.01) and duodenal bicarbonate output decreased 22% (P < 0.05) after 4 weeks of Camostate application. The size of the pancreatic head (vertical) increased 8% (P < 0.05) at week 4 and decreased to pretreatment values 2 weeks after treatment (week 6). The other three diameters measured (head oblique, body, and tail) showed a similar pattern. Stimulated cholecystokinin plasma levels 15 minutes after application of a standard test meal increased 62% (P < 0.05). CONCLUSIONS The human pancreas adapts to oral application of the proteinase inhibitor Camostate. These findings support the theory that feedback control of the exocrine pancreas operates in humans.
Collapse
Affiliation(s)
- H Friess
- Department of Visceral and Transplantation Surgery, University of Bern, Bern, Switzerland
| | | | | | | | | |
Collapse
|
19
|
Friess H, Kleeff J, Malfertheiner P, Müller MW, Homuth K, Büchler MW. Influence of high-dose pancreatic enzyme treatment on pancreatic function in healthy volunteers. INTERNATIONAL JOURNAL OF PANCREATOLOGY : OFFICIAL JOURNAL OF THE INTERNATIONAL ASSOCIATION OF PANCREATOLOGY 1998; 23:115-23. [PMID: 9629509 DOI: 10.1385/ijgc:23:2:115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
CONCLUSIONS Adaptive changes in exocrine and endocrine pancreatic function, as well as changes in pancreas size and morphology, were not observed after 4-wk of oral pancreatic enzyme application. These findings suggest that the normal pancreas does not significantly adapt--either morphologically or functionally--to a 4-wk oral application of high-dose pancreatic enzymes. BACKGROUND The control of exocrine pancreatic enzyme secretion is not completely understood. Although it has been established that exocrine pancreatic secretion is mainly regulated in the short-term by the amount of pancreatic enzymes in the proximal small intestine, it is not known whether long-term application of pancreatic enzymes causes changes in exocrine pancreatic secretion in humans. METHODS Twelve healthy male volunteers (median age 27 yr) participated in a prospective, randomized, placebo-controlled, double-blind study. Six were placed in the treatment group and six in the placebo group. Over a 4-wk period, the six subjects in the treatment group took 18 capsules of Panzytrat (20,000 units of lipase, 18,000 units of amylase, and 1000 units of protease per capsule) daily. Before (wk 0), 4 wk following pancreatic enzyme application and 2 wk afterward, a secretin-cerulein test was carried out in all subjects to study exocrine pancreatic function (trypsin, chymotrypsin, bicarbonate content, and total pancreatic fluid secretion in the duodenum). One day following the secretin-cerulein test, a standard test meal was given to all subjects to analyze endocrine pancreatic function. Additionally, before starting the treatment, once per week during treatment and 2 wk afterward, an ultrasound examination of the pancreas was carried out to see whether there was any change in pancreas size and morphology. RESULTS Trypsin content in the duodenal aspirates following simultaneous stimulation with secretin and cerulein after 4 wk of high-dose pancreatic enzyme application was 92% in the treatment group and 82% in the placebo group compared with the wk 0 test results (100%). Two weeks after enzyme application, the secretin/cerulein-stimulated trypsin content was 88% in the treatment group and 107% in the placebo group. None of these changes was statistically significant. The same results were seen for chymotrypsin content, amylase, and bicarbonate content as well as for total pancreatic fluid secretion. Additionally, no change in the endocrine pancreatic function could be observed after 4 wk of pancreatic enzyme treatment. Pancreas ultrasonography revealed no alteration in pancreas size or parenchymal structure during the 4 wk of treatment and the following 2 wk.
Collapse
Affiliation(s)
- H Friess
- Department of Visceral and Transplantation Surgery, University of Bern, Switzerland
| | | | | | | | | | | |
Collapse
|
20
|
Todisco A, Takeuchi Y, Urumov A, Yamada J, Stepan VM, Yamada T. Molecular mechanisms for the growth factor action of gastrin. THE AMERICAN JOURNAL OF PHYSIOLOGY 1997; 273:G891-8. [PMID: 9357832 DOI: 10.1152/ajpgi.1997.273.4.g891] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have previously observed that gastrin has a cholecystokinin B (CCK-B) receptor-mediated growth-promoting effect on the AR42J rat pancreatic acinar cell line and that this effect is paralleled by induction of expression of the early response gene c-fos. We undertook these experiments to elucidate the mechanism for induction of c-fos and the linkage of this action to the trophic effects of gastrin. Gastrin (0.1-10 nM) dose dependently induced luciferase activity in AR42J cells transfected with a construct consisting of a luciferase reporter gene coupled to the serum response element (SRE) of the c-fos promoter. This effect was blocked by the specific CCK-B receptor antagonist D2 but not by the specific CCK-A receptor antagonist L-364,718 or by pertussis toxin, indicating that gastrin targets the SRE via specific CCK-B receptors through a mechanism independent of Gi. Inhibition of protein kinase C (PKC) either by prolonged (24 h) exposure of the cells to the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (100 nM) or by incubation with the selective inhibitor GF-109203X (3.5 microM) resulted in an 80% reduction in luciferase activity. Similar results were observed in the presence of the specific extracellular signal-regulated kinase (ERK) kinase (MEK) inhibitor PD-98059 (50 microM). We measured ERK2 activity in AR42J cells via in-gel kinase assays and observed that gastrin (1 pM-100 nM) induced ERK2 enzyme activity in a dose-dependent manner. Addition of GF-109203X and PD-98059, either alone or in combination, produced, respectively, partial and total inhibition of gastrin-induced ERK2 activity. Gastrin induction of ERK2 activity also resulted in a threefold increase in the transcriptional activity of Elk-1, a factor known to bind to the c-fos SRE and to be phosphorylated and activated by ERK2. PD-98059 blocked the growth-promoting effect of gastrin on the AR42J cells, demonstrating that this effect depends on activation of MEK. Our data lead us to conclude that the trophic actions of gastrin are mediated by ERK2-induced c-fos gene expression via PKC-dependent and -independent pathways.
Collapse
Affiliation(s)
- A Todisco
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109, USA
| | | | | | | | | | | |
Collapse
|
21
|
Xu G, Sumi S, Koike M, Tanigawa K, Nio Y, Tamura K. Role of endogenous hypergastrinemia in regenerating endocrine pancreas after partial pancreatectomy. Dig Dis Sci 1996; 41:2433-9. [PMID: 9011454 DOI: 10.1007/bf02100139] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We studied the possible role of endogenous gastrin in the regenerating pancreas. Male Wistar rats underwent sham operation or 90% partial pancreatectomy (Px). Lansoprazole (30 mg/kg body wt), a proton pump inhibitor (PPI), was given p.o. for 3 weeks after surgery. Plasma glucose levels were higher in Px rats than in shams. Lansoprazole lowered plasma glucose levels in the Px rats. In addition, integrated insulin secretion during an oral glucose tolerance test (2 g/kg body wt) was significantly (p < 0.01) higher in lansoprazole-treated Px rats than in control Px rats, while lansoprazole did not affect insulin secretion in shams. Fasting serum gastrin levels were higher (p < 0.01) in lansoprazole-treated animals than in controls both in sham rats and in Px rats. Furthermore, lansoprazole increased the pancreas weight per body weight and elevated the insulin content of the pancreas in Px rats. These results suggest that endogenous hypergastrinemia has a trophic effect on endocrine pancreas during regenerating processes and that administration of PPI may be clinically beneficial to the remnant pancreas after pancreatectomy if the whole stomach is preserved.
Collapse
Affiliation(s)
- G Xu
- First Department of Surgery, Shimane Medical University, Izumo, Japan
| | | | | | | | | | | |
Collapse
|
22
|
Abstract
BACKGROUND Gastrin is thought to stimulate growth of the pancreas via gastrin/cholecystokinin (CCK)-B-type receptors. The aim of the present study was to examine the trophic response of the pancreas to exogenous gastrin or to hypergastrinemia of endogenous origin and to hypogastrinemia with or without concomitant hyperCCKemia. METHODS Hypergastrinemia was induced in male Sprague-Dawley rats by continuous infusion of human Leu15-gastrin-17 (5 nmol/kg/h, subcutaneously), by removal of the acid-producing part of the stomach (fundectomy), or by treatment with omeprazole (400 mumol/ kg/day, orally). Hypogastrinemia was induced by antrectomy or by gastrectomy. HyperCCKemia was induced by pancreaticobiliary diversion (PBD). The rats were killed 10 days or 8 weeks after the operations or treatments. The concentrations of circulating gastrin and CCK were measured by radioimmunoassay. The pancreatic weight and DNA content were determined. RESULTS Gastrin infusion, omeprazole treatment, and fundectomy greatly increased the serum gastrin concentration. The resulting levels were very similar in the three groups and probably represent the maximum attainable physiologic serum gastrin concentration. Whereas gastrin infusion or omeprazole treatment (hypergastrinemia) and antrectomy (hypogastrinemia) were without effect on the weight and DNA content of the pancreas, gastrectomy (hypogastrinemia) and fundectomy (hypergastrinemia) increased the weight and DNA content. PBD (hyperCCKemia) greatly increased the weight and DNA content of the pancreas. PBD plus fundectomy, PBD plus gastrectomy, PBD plus antrectomy, and PBD plus omeprazole increased the weight and DNA content of the pancreas, as did PBD alone. CONCLUSION CCK is a physiologically important trophic stimulus for the rat pancreas, but gastrin is not. The increase in pancreatic weight and DNA content after fundectomy and gastrectomy cannot be explained by means of either gastrin or CCK.
Collapse
Affiliation(s)
- D Chen
- Dept. of Pharmacology, University of Lund, Sweden
| | | | | | | |
Collapse
|
23
|
Todisco A, Takeuchi Y, Seva C, Dickinson CJ, Yamada T. Gastrin and glycine-extended progastrin processing intermediates induce different programs of early gene activation. J Biol Chem 1995; 270:28337-41. [PMID: 7499334 DOI: 10.1074/jbc.270.47.28337] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
We recently reported that gastrin and glycine-extended progastrin processing intermediates (G-Gly) exert growth-promoting effects on AR4-2J cells (derived from rat pancreas) via interaction with distinct receptors. In this study we sought to investigate the mechanisms by which gastrin and G-Gly stimulate cell proliferation. While gastrin increased [Ca2+]i in AR4-2J cells, G-Gly had no effect. Similarly, G-Gly had no effect either on basal and 10(-7) M vasoactive intestinal polypeptide-stimulated cAMP generation, although gastrin is known to inhibit cAMP generation. Gastrin dose dependently stimulated AR4-2J cell mRNA content of both c-fos and c-jun, two genes known to function in regulating cell proliferation, but G-Gly had no effect. Gastrin also induced the expression of luciferase in AR4-2J cells transfected with a construct consisting of a luciferase reporter gene coupled to the serum response element of the c-fos gene promoter. In similar fashion, gastrin stimulated the activity of mitogen-activated protein kinase, an enzyme known to mediate the induction of the c-fos serum response element in response to growth factor stimulation. Although G-Gly had none of these effects of gastrin in AR4-2J cells, it stimulated activity of c-Jun amino-terminal kinase, an enzyme known to phosphorylate and transcriptionally activate c-Jun. These data support the notion that gastrin stimulates cell proliferation by inducing c-fos and c-jun gene expression, while G-Gly acts by post-translationally regulating early gene transcriptional activation. Our studies represent a novel model in which both the precursor and the product of a key processing reaction, peptide alpha-amidation, act cooperatively to stimulate cell proliferation via distinct receptors linked to different signal transduction pathways.
Collapse
Affiliation(s)
- A Todisco
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109-0368, USA
| | | | | | | | | |
Collapse
|
24
|
Gasslander T, Mukaida H, Herrington MK, Hinder RA, Adrian TE. Profound duodenogastric reflux causes pancreatic growth in rats. Gut 1995; 36:137-41. [PMID: 7890218 PMCID: PMC1382368 DOI: 10.1136/gut.36.1.137] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Although duodenogastric reflux is a physiological event, excessive reflux may be a pathogenetic factor in several diseases of the foregut, including cancer. Long term profound duodenogastric reflux produces pancreatic and gastric tumours in rats. The trophic effect of surgically induced duodenogastric reflux on the pancreas was investigated and the mechanisms involved were examined. Rats with profound reflux from a split gastroenterostomy were compared with sham operated and unoperated controls after two and six weeks. In the six week experiment, one reflux and one sham group were given the cholecystokinin (CCK) receptor antagonist devazepide (25 nmol/kg/h). Duodenogastric reflux caused a significant increase in pancreatic weight, DNA, and plasma CCK and gastrin concentrations at both two and six weeks. Devazepide substantially reduced the pancreatic weight increase after six weeks but did not abolish it completely. CCK and gastrin were not affected by devazepide. These results suggest that CCK is largely responsible for the pancreatic growth induced by reflux but another factor may also be involved. The trophic effect of duodenogastric reflux may contribute to the increased incidence of pancreatic cancer reported after gastric surgery.
Collapse
Affiliation(s)
- T Gasslander
- Department of Biomedical Sciences, Creighton University, Omaha, Nebraska
| | | | | | | | | |
Collapse
|
25
|
Povoski SP, Zhou W, Longnecker DS, Jensen RT, Mantey SA, Bell RH. Stimulation of in vivo pancreatic growth in the rat is mediated specifically by way of cholecystokinin-A receptors. Gastroenterology 1994; 107:1135-46. [PMID: 7523219 DOI: 10.1016/0016-5085(94)90239-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
BACKGROUND/AIMS Cholecystokinin (CCK) and gastrin stimulate growth of rodent pancreas in vivo. However, it remains unclear whether these growth effects are mediated specifically by CCK-A receptors, CCK-B receptors, or both. To clarify this issue, the present study examined the effect of highly selective and biologically active CCK agonists on pancreatic growth. METHODS Rats were subcutaneously injected with either (1) CCK-8, a nonselective CCK agonist (2.50 micrograms/kg body wt); (2) A-71623, a selective CCK-A agonist, tert-butyl-oxycarbonyl-Trp-Lys (epsilon-N-2-methylphenylaminocarbonyl)-Asp-(N-methyl)-Phe-NH2 (1.84 micrograms/kg body wt); (3) SNF-8815; a selective CCK-B agonist, [(2R,3S)-beta-MePhe28, N-MeNle31]CCK26-33 (2.40 micrograms/kg body wt); or (4) saline (control) for 21 days. Rats were killed, and pancreatic weight, protein content, RNA content, DNA content, protein-DNA ratio, RNA-DNA ratio, pancreatic area per nucleus, and number of mitoses per 10,000 acinar cells were determined. RESULTS Nonselective CCK agonist significantly increased pancreatic weight, protein, RNA, and DNA contents, and number of mitoses per 10,000 acinar cells. Likewise, selective CCK-A agonist significantly increased pancreatic weight, protein, RNA, and DNA contents, protein-DNA ratio, RNA-DNA ratio, pancreatic area per nucleus, and number of mitoses per 10,000 acinar cells. In contrast, selective and biologically active CCK-B agonist had no effect. CONCLUSION These findings indicate that pancreatic growth is mediated specifically by CCK-A receptors in the rat in vivo.
Collapse
Affiliation(s)
- S P Povoski
- Department of Surgery, University of Cincinnati College of Medicine, Ohio
| | | | | | | | | | | |
Collapse
|
26
|
Abstract
Peptide alpha amidation is required to produce some hormones, such as gastrin, from their glycine-extended precursors. This terminal posttranslational processing reaction is thought to be essential for the biological activation of many peptide hormones; only amidated gastrin exerts a physiological effect that results in gastric acid secretion. However, both amidated gastrin and glycine-extended gastrin stimulate proliferation of exocrine pancreatic cell line AR4-2J through selective receptors for the substrate and the product, respectively, of peptide alpha amidation. Thus, the amidation reaction may function as a determinant of the specific biological actions of products derived from prohormones.
Collapse
Affiliation(s)
- C Seva
- Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor 48109
| | | | | |
Collapse
|
27
|
Seva C, Scemama JL, Pradayrol L, Sarfati PD, Vaysse N. Coupling of pancreatic gastrin/cholecystokinin-B (G/CCKB) receptors to phospholipase C and protein kinase C in AR4-2J tumoral cells. REGULATORY PEPTIDES 1994; 52:31-8. [PMID: 7972929 DOI: 10.1016/0167-0115(94)90018-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Gastrin and cholecystokinin (CCK) have proven trophic effects on the gut. We have previously demonstrated that these peptides stimulate an early event in cellular proliferation, namely ornithine decarboxylase activity (ODC), in a rat exocrine pancreatic cell line AR4-2J. Furthermore, this effect is mediated through a G/CCKB receptor. Thus, in the present study we sought to examine the signal transduction mechanisms linked to the G/CCKB receptor occupancy. Both gastrin and CCK induced a rapid (maximum at 40 s) increase in inositol triphosphates (InsP3) and diacylglycerol (DAG) formation in a dose-dependent manner (EC50 = 5.6 nM) that quickly returned to baseline. Although InsP3 levels remained at baseline, DAG levels demonstrated a second gradual increase that was maximal at 15 min. CCK/gastrin efficiency to stimulate DAG and InsP3 formation (EC50 = 5.6 nM) could be correlated to the G/CCKB receptor occupancy, suggesting a coupling of this receptor to phospholipase C. To examine the involvement of protein kinase C (PKC) activation in the increase in ODC activity, we stimulated the AR4-2J cells with the phorbol ester TPA and observed an increase in ODC activity with a maximal effect at 100 nM. TPA stimulation of ODC activity was completely abolished by the PKC inhibitor staurosporine (50 nM). However, 50 nM staurosporine inhibited only 65% of the gastrin and CCK induced increase in ODC activity suggesting that a portion of the G/CCKB receptor-mediated increase in ODC activity is PKC independent.
Collapse
Affiliation(s)
- C Seva
- Institute National de la Santé et de la Recherche Médical U.151, CHU Rangueil, Toulouse, France
| | | | | | | | | |
Collapse
|
28
|
Chu M, Rehfeld JF, Borch K. Colonic mucosal proliferation after pancreaticobiliary diversion in the hamster. Dig Dis Sci 1993; 38:1978-84. [PMID: 8223069 DOI: 10.1007/bf01297072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effect of pancreaticobiliary diversion (PBD) on the colonic mucosa was studied in hamsters over 5, 10, and 24 days. Sham-operated animals served as controls. At all three time intervals, experimental animals had increased plasma cholecystokinin concentrations and decreased gastrin concentrations. Five days after PBD, there was an increase in scintigraphically measured [3H]thymidine incorporation into colonic tissue. Correspondingly, there was an increase in the [3H]thymidine DNA labeling index of goblet cells in the colonic mucosa. The total number of cells in the colonic crypt columns were significantly increased on days 5, 10 and 24. Whether this proliferative response in the colon is due to increased release of cholecystokinin, enteroglucagon, other aberrations of hormones or growth factors, or simply an increased bile load on the colonic mucosa remains to be clarified. Such further studies may reveal an alternative animal model for studies on risk factors in colonic carcinogenesis.
Collapse
Affiliation(s)
- M Chu
- Department of Surgery, University Hospital of Linköping, Sweden
| | | | | |
Collapse
|
29
|
Chu M, Franzén L, Sullivan S, Wingren S, Rehfeld JF, Borch K. Pancreatic hypertrophy with acinar cell nodules after longterm fundectomy in the rat. Gut 1993; 34:988-93. [PMID: 8344589 PMCID: PMC1374240 DOI: 10.1136/gut.34.7.988] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of gastric fundectomy with hypergastrinaemia on the pancreas in rats was studied for 14 months. Rats with hypercholecystokininaemia that had had a pancreaticobiliary diversion (PBD) operation and sham operated rats served as controls. Fundectomised rats showed a significant increase in pancreatic weight and total DNA and protein content compared with sham operated rats. DNA flow cytometry showed a significantly higher ratio of tetraploid to diploid nuclei in pancreatic tissue after fundectomy than after sham operation. Mean values of all these variables were significantly lower after fundectomy than after PBD. Acidophilic atypical acinar cell foci of the pancreas were diagnosed in both fundectomised and PBD operated rats, but not in sham operated controls. The volume density and 3H-thymidine labelling index of the acidophilic atypical acinar cell foci were significantly lower after fundectomy than after PBD. Changes consistent with pancreatic adenoma were diagnosed in the PBD group only. In conclusion, fundectomy lasting about half of the life span in rats causes pancreatic hyperplasia and hypertrophy, as well as development of acidophilic atypical acinar cell foci. Although hypergastrinaemia is a prominent feature, it may not be the only factor responsible for this pancreaticotrophical effect of fundectomy.
Collapse
Affiliation(s)
- M Chu
- Department of Surgery, University Hospital of Linköping, Sweden
| | | | | | | | | | | |
Collapse
|
30
|
Affiliation(s)
- J Morisset
- Département de Biologie, Faculté des Sciences, Université de Sherbrooke, PQ, Canada
| |
Collapse
|
31
|
Smith JP, Kramer ST, Demers LM. Effects of gastrin and difluoromethylornithine on growth of human colon cancer. Dig Dis Sci 1993; 38:520-8. [PMID: 8444085 DOI: 10.1007/bf01316509] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The effect of difluoromethylornithine (DFMO), a specific inhibitor of ornithine decarboxylase activity, was evaluated in vivo and in vitro on the growth of a gastrin-sensitive human colon carcinoma (WiDr). In vivo, mice bearing the tumor treated with pentagastrin had larger tumors with higher ornithine decarboxylase activity and polyamine content (P < 0.05) than mice not treated with pentagastrin. Difluoromethylornithine treatment significantly decreased ornithine decarboxylase in both the pentagastrin-treated and the untreated animals; however, DFMO had no effect on tumor volume, weight, protein, or DNA content. In cell culture, gastrin treatment increased WiDr cell number and [3H]thymidine incorporation in the presence or absence of serum. In serum-free conditions, however, gastrin stimulated cell growth without concomitantly increasing ODC activity. DFMO, on the other hand, decreased both ODC activity and growth. These studies suggest that the trophic effect of gastrin on WiDr human colon cancer is independent of ODC activity. Since gastrin treatment increased ODC activity in vivo, gastrin may interact in vitro with other factors present in serum that can alter ODC activity.
Collapse
Affiliation(s)
- J P Smith
- Department of Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
| | | | | |
Collapse
|
32
|
Chu M, Rehfeld JF, Borch K. Effects of gastric fundectomy and antrectomy on the exocrine pancreas in the hamster. INTERNATIONAL JOURNAL OF PANCREATOLOGY : OFFICIAL JOURNAL OF THE INTERNATIONAL ASSOCIATION OF PANCREATOLOGY 1992; 12:139-44. [PMID: 1460328 DOI: 10.1007/bf02924637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The effect of gastric fundectomy and antrectomy on growth of the exocrine pancreas was studied in hamsters over 5 and 25 d. Sham-operated animals served as controls. After 5 d, basal plasma gastrin concentrations were significantly increased in fundectomized animals (80.3 +/- 20.6 pmol/L) and significantly decreased in antrectomized animals (11.6 +/- 1.1 pmol/L) as compared with the controls (20.0 +/- 1.7 pmol/L). Similar differences were present among the 25-d groups, whereas basal plasma cholecystokinin (CCK) concentrations did not differ significantly between any groups at any time. At 5 d after fundectomy, there was a significant increase in pancreatic tissue [3H]-thymidine uptake and total DNA content, both of which were reduced 5 d after antrectomy. Autoradiography showed significantly increased [3H]-thymidine labeling index of acinar, intralobular duct, and centroacinar cells of the pancreas at 5 d after fundectomy. The increased intralobular duct cell labeling index persisted 25 d after fundectomy. Labeling indexes after antrectomy did not differ significantly from those in the controls, although antrectomized animals had the lowest values in all three cell compartments at 25 d. At 25 d, pancreatic wet wt and total DNA and protein content were significantly increased after fundectomy and significantly reduced after antrectomy. These findings indicate that fundectomy in the hamster induces pancreatic exocrine tissue hyperplasia and hypertrophy, whereas antrectomy leads to retardation of pancreatic growth.
Collapse
Affiliation(s)
- M Chu
- Department of Surgery, University Hospital of Linköping, Sweden
| | | | | |
Collapse
|
33
|
Gasslander T, Ihse I, Smeds S. The importance of the centroacinar region in cerulein-induced mouse pancreatic growth. Scand J Gastroenterol 1992; 27:564-70. [PMID: 1641582 DOI: 10.3109/00365529209000120] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Early proliferation events within different exocrine pancreatic cell compartments were studied in mice with or without cerulein administration. A technique with 3H-thymidine labeling of DNA-synthesizing cells was used. Groups of five animals were given either cerulein (20 micrograms/kg/24 h) or saline subcutaneously twice daily. 3H-thymidine was given as a single injection, 300 microCi intraperitoneally, on the 3rd and 8th day of cerulein or saline administration, and the fraction of labeled cells in each cell compartment (3H-thymidine labeling index, TLI) was calculated on the basis of autoradiographic analyses of the tissue. In a second set of experiments the distribution of the tracer between cell compartments, when given on the 3rd day of cerulein (saline) administration, was followed over a 5-day period. The highest proliferative rate was observed in the centroacinar cell compartment (TLI, 6%), and newly formed cells were accumulated during the 5-day 'chase' period. During the same time the relative amount of labeled centroacinar cells increased and comprised 40% of all labeled exocrine cells. The relative size of the compartment did not increase, indicating increased cell turnover with loss of or possibly migration of centroacinar cells into other pancreatic cell compartments. Weak and no trophic effects of cerulein were seen on the acinar and ductal cell populations, respectively. In the control group labeled ductal cells were significantly reduced during the chase period. This was not observed in the cerulein group, indicating addition of labeled cells to this compartment from other sources. A significant non-cerulein-dependent relative increase and decrease of the ductal and acinar cell compartments, respectively, were observed during the chase period.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- T Gasslander
- Dept. of Surgery, University Hospital, Linköping, Sweden
| | | | | |
Collapse
|
34
|
Liehr RM, Reidelberger RD, Rosewicz S, Bussjaeger LJ, Solomon TE. Dose-related involvement of CCK in bombesin-induced pancreatic growth. REGULATORY PEPTIDES 1992; 38:207-19. [PMID: 1375383 DOI: 10.1016/0167-0115(92)90103-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
We examined the role of CCK in bombesin-induced pancreatic growth in rats using the CCK receptor antagonist L-364,718. Rats (155 +/- 1 g, 8-10 per group) received subcutaneous injections every 8 h for 5 days with bombesin (0.6, 1.7 and 5 nmol/kg) or bombesin in combination with L-364,718 (1 mg/kg). After 5 days the pancreas was removed and pancreatic weight, protein content, DNA, amylase and chymotrypsin contents were determined. Bombesin produced a significant increase (48-475%) of pancreatic weight, tissue contents of protein, DNA, amylase and chymotrypsinogen (F = 82, P less than 0.001). When a large dose of bombesin (5 nmol/kg) was combined with L-364,718 a significant inhibition (up to 70%) of all tissue parameters was observed (P less than 0.001). L-364,718 did not affect the growth response to a small dose of bombesin (0.6 nmol/kg). Plasma CCK levels 15 min after a single injection of bombesin (0.6, 1.7 and 5 nmol/kg) were significantly increased in response to the 5 nmol/kg dose (2.0 +/- 0.7 to 3.4 +/- 0.8 pM, F = 6.9, P less than 0.01). No increases of CCK plasma levels were found in response to the 0.6 and 1.7 nmol/kg doses of bombesin, corresponding to the lack of effects of L-364,718 on growth parameters at these doses. Measuring the time-course of CCK plasma levels after a single injection of 5 nmol/kg bombesin revealed an increase from basal values of 1.4 +/- 0.3 pM to maximal levels of 3.5 +/- 0.5 pM after 15 min (F = 7.1, P less than 0.001). Values returned to basal after 60 min. These results suggest that low doses of bombesin act directly at the acinar cell or through release of non-CCK growth factors whereas high doses of bombesin act in part through CCK release.
Collapse
Affiliation(s)
- R M Liehr
- Department of Medicine, Kansas University Medical Center, Kansas City
| | | | | | | | | |
Collapse
|
35
|
Kopin AS, Wheeler MB, Nishitani J, McBride EW, Chang TM, Chey WY, Leiter AB. The secretin gene: evolutionary history, alternative splicing, and developmental regulation. Proc Natl Acad Sci U S A 1991; 88:5335-9. [PMID: 1711228 PMCID: PMC51867 DOI: 10.1073/pnas.88.12.5335] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The gene encoding the hormone secretin has been isolated and structurally characterized. The transcriptional unit is divided into four exons spanning 813 nucleotides. Comparison of the rat secretin gene to the other members of the glucagon-secretin gene family reveals that similarities are restricted to the exons encoding the biologically active peptides. Analysis of RNA from porcine intestine indicates that at least two transcripts are generated from the porcine secretin gene as a result of differential splicing. The longer and more abundant transcript appears to be identical to a previously isolated cDNA, which encodes a precursor that includes a 72-amino acid C-terminal extension peptide. The shorter transcript does not contain the third exon and, as a result, encodes only 44 residues beyond the C terminus of secretin. The amino acid sequence deduced from the shorter transcript is identical to a precursor form of secretin recently isolated from porcine duodenum [Gafvelin, G., Jornvall, H. & Mutt, V. (1990) Proc. Natl. Acad. Sci. USA 87, 6781-6785]. Developmental studies reveal that both secretin mRNA and peptide levels in the intestine are highest just before birth, prior to the onset of gastric acid secretion and feeding. This observation implies that secretin biosynthesis in developing animals is controlled independently of the principal factors known to regulate secretin release in adult animals.
Collapse
Affiliation(s)
- A S Kopin
- Division of Gastroenterology, New England Medical Center, Tufts University School of Medicine, Boston, MA 02111
| | | | | | | | | | | | | |
Collapse
|
36
|
Affiliation(s)
- P J Woll
- CRC Department of Medical Oncology, Christie Hospital, Manchester, UK
| |
Collapse
|
37
|
Gasslander T, Smeds S, Blomqvist L, Ihse I. Proliferative response of different exocrine pancreatic cell types to hormonal stimuli. II. Effects of long-term secretin administration. Scand J Gastroenterol 1990; 25:1111-7. [PMID: 1703319 DOI: 10.3109/00365529008998542] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effect of graded doses of secretin on exocrine pancreatic growth and cell proliferation was studied in a long-term experiment. After 16.5 and 150 micrograms/kg/24 h of secretin, each administered as two subcutaneous injections daily for 14 days, the pancreatic wet weight decreased, whereas the protein and DNA content of the gland was uninfluenced. When administered as described above for 14 days, 16.5, 50, 150, and 450 micrograms/kg/24 h of secretin did not affect the proliferation rate of ductal, acinar, or centroacinar cells as measured by a labeling index after 7 days of continuous 3H-thymidine administration. In the control groups a higher labeling index was found for ductal cells (19.9%) than for acinar cells (11.0%). During the 7 days of 3H-thymidine administration 80-90% of ductal and acinar cells remained in the G0 phase. There was a significantly higher labeling index in interlobular than in intralobular duct cells.
Collapse
Affiliation(s)
- T Gasslander
- Dept. of Surgery, University Hospital, Linköping, Sweden
| | | | | | | |
Collapse
|
38
|
Smith JP, Solomon TE, Bagheri S, Kramer S. Cholecystokinin stimulates growth of human pancreatic adenocarcinoma SW-1990. Dig Dis Sci 1990; 35:1377-84. [PMID: 2226098 DOI: 10.1007/bf01536744] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The effect of a synthetic analogue of CCK (Thr4,Nle7CCK-9) on growth of SW-1990 human pancreatic cancer was examined in two experimental models. Nude mice bearing SW-1990 pancreatic cancer xenografts were injected with CCK (5, 15, or 25 micrograms/kg) or vehicle twice daily for 20 days. Animals were then sacrificed and tumor volume, weight, protein, and deoxyribonucleic acid (DNA) content were evaluated. SW-1990 cells were grown in vitro and the effects of CCK, secretin, vasoactive intestinal peptide (VIP), and proglumide (a CCK-receptor antagonist) on cell number and DNA synthesis were determined. The highest dose of CCK, 25 micrograms/kg, significantly increased tumor weight, protein content, and DNA content (P less than 0.005). In vitro, CCK caused significant increases in cell counts of up to 47% at six days and 66% at 12 days compared to control. Graded concentrations of CCK had a biphasic effect on DNA synthesis with significant increases of up to 65% (P less than 0.005). CCK-induced cell proliferation was inhibited by proglumide. Secretin slightly increased cancer cell growth, although not as potently as CCK, VIP or secretin in combination with CCK did not show potentiation. These results indicate that growth of some human pancreatic cancers may be influenced by gastrointestinal peptides, of which CCK is the most potent.
Collapse
Affiliation(s)
- J P Smith
- Department of Medicine, Milton S. Hershey Medical Center, Pennsylvania State University, Hershey 17033
| | | | | | | |
Collapse
|
39
|
Helton WS, Jacobs DO, Bonner-Weir S, Bueno R, Smith RJ, Wilmore DW. Effects of glutamine-enriched parenteral nutrition on the exocrine pancreas. JPEN J Parenter Enteral Nutr 1990; 14:344-52. [PMID: 2119440 DOI: 10.1177/0148607190014004344] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Total parenteral nutrition (TPN) is associated with intestinal and pancreatic atrophy and pancreatic exocrine insufficiency. Recent investigations have demonstrated that the addition of glutamine to intravenous feedings attenuates TPN-associated intestinal atrophy. However, the effect of glutamine-supplemented intravenous feedings on the pancreas of intact animals is unknown. This study compared the effects of an intravenous infusion of a 2% glutamine-enriched diet (GLN) with an isonitrogenous, isocaloric diet without glutamine (CONT) on the composition and structure of the exocrine pancreas in laboratory rats with and without a 60% small bowel resection. In nonresected, TPN-fed animals, pancreatic weight was significantly increased in the GLN group when compared to CONT (645 +/- 33 g vs 554 +/- 20 g, p less than 0.05). Nonresected GLN animals also had increased pancreatic DNA (3.82 +/- 0.19 mg vs 2.91 +/- 0.49 mg, p less than 0.005) and protein contents (93.0 +/- 5.9 mg vs 76.6 +/- 7.0 mg, p = 0.08) compared to control. Similar significant increases in pancreatic weight, DNA, and protein were observed in intestinally resected animals fed the glutamine diet. When data from CONT and GLN animals were pooled and analyzed together, glutamine significantly increased total pancreatic trypsinogen and lipase contents (p less than 0.05). The increase in trypsinogen in resected GLN animals was significantly greater than in CONT animals (283 +/- 22 vs 139 +/- 23, p less than 0.005). Biochemical and morphometric observations demonstrated that the trophic effects of glutamine on the exocrine pancreas were manifest by acinar hyperplasia and not hypertrophy. Glutamine appears to be an important nutrient for pancreatic exocrine tissue during TPN.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- W S Helton
- Department of Surgery, Brigham and Women's Hospital, Boston, Massachusetts 02115
| | | | | | | | | | | |
Collapse
|
40
|
Pollack PF, Wood JG, Solomon T. Effect of secretin on growth of stomach, small intestine, and pancreas of developing rats. Dig Dis Sci 1990; 35:749-58. [PMID: 2344808 DOI: 10.1007/bf01540179] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Secretin is present in the intestine of a number of developing species, and plasma secretin levels are elevated in newborn pigs and humans. Secretin stimulates the growth and affects the enzymatic composition of the stomach, small intestine, and pancreas in adult rats. This suggests a possible role for secretin in the rapid postnatal growth of these organs. We investigated this hypothesis by injecting rats subcutaneously with secretin (100 micrograms/kg) every 12 hr for seven days beginning on postnatal day 3, 6, 13, or 24. Growth parameters (weight, content of protein, DNA) as well as the composition of organ-specific enzymes of the stomach, small intestine, and pancreas were measured. Secretin increased growth parameters of the stomach and small intestine in a similar pattern, and in a quantitatively different fashion from that observed in the pancreas. Secretin's effects were also dependent on postnatal age for all organs studied. These data demonstrate that secretin can influence organ growth and enzyme composition of the stomach, small intestine, and pancreas of developing rats and may be one factor regulating growth and development of these organs.
Collapse
Affiliation(s)
- P F Pollack
- Department of Pediatrics, University of Texas Health Sciences Center, Houston 77030
| | | | | |
Collapse
|