- Email: [email protected]
Management of zollinger-ellison (ZE) patients with pantoprazole
AGAA297
April 2000
HNPT cDNA. Transfection with the reporter construct showed that this DNA fragment could drive luciferase reporter gene expression in CaC02 cells . The studies suggest that this DNA fragment contains the basa l promoter region of HNPT gene . Furthermore, promoter motif analysis reveal s several TATA and CAAT boxe s, Tant , API and Spl protein binding sites. Conclusion: In conclusion, we have cloned the gene encod ing the human , small intestinal type II NPT gene, determined the intronl exon structure and characterized the promoter region. This investigation was supported by NIH grant R37 DK 33209.
1655 CHOLECYSTOKININIB·GASTRIN RECEPTOR EXPRESSION IN HUMAN MEDULLARY THYROID CARCINOMAS. Michael Blaeker, Mareike Tomenen, Martina Schulz, Dorit Arlt, Wolfgang Hoeppner, C. Hoang -Vu, Andreas de Weerth , Tarnmo von Schrenck, Heiner Greten, Universitaets-Krankenhaus Eppendorf, Hamburg , Germany; Institute for Hormone Research, Hamburg, Germany ; UniversitaetsKrankenhaus, Halle, Germany . Background: Pentagastrin is a potent secretagogue for medullary thyroid carcinoma (MTC) cells, leading to calcitonin release . Therefore, before the era of genetic testing, the pentagastrin-test has been a commonly used diagnostic tool in the biochemical screen ing of patients at risk for MTC, e. g. patients with multiple endocrine neopl asia type 2 (MEN2). Given its well established growth promoting actions. gastrin might not only induce secretion but also act as a growth factor in these tumors. Gastrin exerts its functions through stimulation of the cholecystokinin-B/gastrin receptor (CCK-BR). The aim of our study was to analyze CCK-BR expression in MTCs on a molecular level and compare our findings to clinical and patholog ical data. Methods: MTC tissue sample s were obtained from 10 patient s with different tumor stages and underlying diseases (e.g. MEN2). mRNA was extracted and reve rse transcribed into cDNA. PCR was performed using sequence-specific oligonucleotides. Specific ity of PCR products was confirmed by restriction endonuclease dige st. Amplification of cDNA encoding for j3-actin served as an internal contro\. Results: f3-actin expression was comparable in all to investigated tumor samples. CCKBR-specific PeR products were detected in 7 of the 10 MTCs inve stigated. More detailed correlation with clinic al and pathological data indicated that the majority of CCK-BR-positive tumors were small in size (Tl-, TIstages ), wherea s two of the three CCK -BR-negati ve samples were large tumors mith metastases. Only one pre-operative pentagastrin-test result was available : the result was negative and the corre spond ing tumor sample did not show CCK-BR expression. Conclus ion: The aberrant expression of CCK-BRs suggests that human MTCs might be susceptible to the function s of gastrin . Moreover, CCK-BRs might serve as interest ing novel diagno stic and therapeutic targets in these tumors.
1656 EXPRESSION AND FUNCTION OF THE CALCIUM SENSING RECEPTOR (CAR) IN GASTRINOMAS. Stephan U. Goebel, Paolo L. Peghini, Paul Goldsmith, Allen M. Spiegel, Fathia Gibril, Mark Raffeld, Jose Serrano, Robert T. Jensen, NIH, Bethesda , MD. Extracellular calcium levels are able to influence the secretion of gastrin by gastrinomas and possibly affect the growth pattern, however, the cellular basis for these actions is unknown. Recently , a novel calcium sensing receptor (CaR) has been described in parathyroid cells and antral G cells, which is a member of the metabotropic glutamate receptor family. Activation of this receptor can alter growth and secret ion in these cells. The purpose of the present study was to determine whether the CaR is present in gastrinomas and assess its possible role in gastrinoma function . In gastrinomas from 44 patients the amount of CaR mRNA was determined by quantitati ve RT-PeR. Protein expre ssion was analyzed by Western blotting with a CaR monoclonal antibody (ADD) and immunohistochemistry was performed using the same antibod y. CaR mRNA was detected in all gastrinomas. The amount of CaR mRNA varied 1600-fold with a range from 0.OO5-7.89x transcripts per b-actin transcript. The Western blot showed a major immunoreactive band at 250 kD and a minor at 140kD corre sponding to the receptor dimer and monomer, respectivel y. Immunohistochemistry demonstrated variable membrano us staining in all gastrinomas and normal pancreatic islets. No staining was observed in the normal liver, lymph node or exocrine pancreas. The amount of CaR mRNA did not correlate with the fasting serum gastrin level (p= 0.42) or the magnitude of the calcium-evoked gastrin release by the tumors (p = 0.43). However, fasting serum gastrin levels correlated with the magn itude of the calciumevoked gastrin release by the tumors (p = O.OO04) . No significant differences in CaR amounts were found in duodenal, pancreatic or lymph node gastrinomas (p = O.34). Similarly, the size of the tumor «3cm, 3-tocm, > IDem, p=0.66), the extent of the disease (single or multiple sites, liver metastases, p =O.14) or the growth pattem of the tumor were not correlated with the amount of CaR mRNA. We co nclude that the CaR is present in all gastrinomas and the expression is highly variable. Because of the lack of correlation between its expression and growth, Ca + + evoked gastrin release or fasting gastrin levels, the CaR is unlikely to be the primary determinant of the magnitude of any of these functions in gastrinomas. This raises the possibility that the CaR may have additional functions in gastrinomas as seen in other cell types, such as a role in cellular differentiation.
1657 PROXIMAL AND DISTAL GUT HORMONE SECRETION IN SLOW TRANSIT CONSTIPATION. C. Penning, J. B. Delemarre, I. Biemond, C. B. Lamers, A. A. Masclee , Dept of Gastroenterology, LUMC, Leiden , Netherlands; Dept of Surg , LUMC , Leiden , Netherlands; Leiden Univ Med Ctr, Leiden, Netherlands. It has been suggested that slow transit constipation (STC) is part of a more general ized gastrointestinal motility disorder. Recently we have shown that gastric , small intestinal and gallbladder motility are abnormal in STC patients. Aim of the present study was to evaluate whether the secretion of proximal and distal gut hormones, as regulators of motility, is affected in slow tran sit constipation. Twenty-nine STC patients (25 female, 4 male ; age 45 ± 3 yr) and 29 healthy controls (18 female , 11 male; age 42 ± 3 yr) participated in the study . Plasma levels of the proximal gut hormones cholec ystokinin (CCK), pancreatic polypeptide (PP) and gastrin and of the distal gut hormones neurotensin (NT) and peptide YY (PYY) were determined both in the fasting state and for 2 hours postprandially after consumption of a 640 kcal solid meal (26 g fat, 25 g protein and 24 g carbohydrates). In addition we determ ined oro-caecal transit time (OCIT) by means of the lactulose hydrogen breath test. Results : OCTT was significantly (p< 0.05) prolonged in STC patients (108 ± 9 min) versu s controls (78 ± 6 min). Basal and postprandial levels of proximal gut hormones were significantly increased in STC patients. Postprandial secretion in STC versus control s: CCK 228±32 vs 165±22 pM.l20 min (p<0.05); PP 6300± 1280 vs 3l00±560 pM.l20 min (p<0.05); gastrin 9960 ±2050 vs 7150±1600 pM.l20 min (p<0.05); on the other hand postprandial levels of the distal gut hormone PYY were reduced in STC patients: 570±150 versus 121O±350 pM.l20 min (p<0.05) When STC patients were divided in 2 groups based on normal DCTT «120 min) or prolonged DCTT (> 120 min), differences in the postprandial response were observed only in STC patients with delayed intestinal transit. Postprand ial secretion in patients with DCTT >120 min versus ::s120 min: neurotensin 313± 119 vs 645±280 pM.l20 min, (p<0.05), PP 9110±2350 vs 356O±1020 pM.l20 min (p< 0.05). Conclusions: Gut hormone secretion is altered in STC with increased secretion of proximal gut hormones and reduced secretion of distal gut hormones. These alterations are related to intestinal transit with prolonged contact time between nutrients and the proximal intestine and less distal chyme delivery.
1658 MANAGEMENT OF ZOLLINGER·ELLISON (ZE) PATIENTS WITH PANTOPRAZOLE. Pierre Poitras, Hosp Saint-Luc du CHUM, Montreal, PQ, Canada. The management of patients with gastric acid hypersecretion due to gastrinom a, usually recognized as ZE syndrome, was radically changed 10 years ago by the use of proton pomp inhibitors. Surgical treatment now concentrates on tumor excision and, in the very large majority of patients, gastrectomy is no longer required to prevent complications of acid hypersecretion that can now be managed pharmacological1y. AIMS: We verified in 7 patients with documented ZE the capacity of pantoprazole to control acid hypersecretion and the clinical effects of gastric hypersecretion. METHODS: Pantoprazole was administered at an initial dose of 80 mg daily for 7 days before measuring basal acid output (BAO) at 8 AM, i.e. 1 hour before the next dose of pantoprazole is normally ingested. Lower (40 mg) or higher doses (120 mg or more of pantoprazole) could then be used to keep the BAO in the therapeutic range (between 0.1 and 10 mmollhr) and to control clinical symptoms such as acid related pain or diarrhea. RESULTS: Control of BAO and clinical symptoms was achieved with pantoprazole 40 mg daily in I patient, 80 mg daily in 2 patients. 120 mg daily in 3 patients , and 160 mg in I patient . CONCLUSIONS: Pantoprazole was able to control acid hypersecretion in ZE patients when administered in doses between 40 and 160 mg daily . An initial dose of 120 mg daily appears as a reasonable therapeutic attitude before further titration of the drug regimen .
April 2000
HNPT cDNA. Transfection with the reporter construct showed that this DNA fragment could drive luciferase reporter gene expression in CaC02 cells . The studies suggest that this DNA fragment contains the basa l promoter region of HNPT gene . Furthermore, promoter motif analysis reveal s several TATA and CAAT boxe s, Tant , API and Spl protein binding sites. Conclusion: In conclusion, we have cloned the gene encod ing the human , small intestinal type II NPT gene, determined the intronl exon structure and characterized the promoter region. This investigation was supported by NIH grant R37 DK 33209.
1655 CHOLECYSTOKININIB·GASTRIN RECEPTOR EXPRESSION IN HUMAN MEDULLARY THYROID CARCINOMAS. Michael Blaeker, Mareike Tomenen, Martina Schulz, Dorit Arlt, Wolfgang Hoeppner, C. Hoang -Vu, Andreas de Weerth , Tarnmo von Schrenck, Heiner Greten, Universitaets-Krankenhaus Eppendorf, Hamburg , Germany; Institute for Hormone Research, Hamburg, Germany ; UniversitaetsKrankenhaus, Halle, Germany . Background: Pentagastrin is a potent secretagogue for medullary thyroid carcinoma (MTC) cells, leading to calcitonin release . Therefore, before the era of genetic testing, the pentagastrin-test has been a commonly used diagnostic tool in the biochemical screen ing of patients at risk for MTC, e. g. patients with multiple endocrine neopl asia type 2 (MEN2). Given its well established growth promoting actions. gastrin might not only induce secretion but also act as a growth factor in these tumors. Gastrin exerts its functions through stimulation of the cholecystokinin-B/gastrin receptor (CCK-BR). The aim of our study was to analyze CCK-BR expression in MTCs on a molecular level and compare our findings to clinical and patholog ical data. Methods: MTC tissue sample s were obtained from 10 patient s with different tumor stages and underlying diseases (e.g. MEN2). mRNA was extracted and reve rse transcribed into cDNA. PCR was performed using sequence-specific oligonucleotides. Specific ity of PCR products was confirmed by restriction endonuclease dige st. Amplification of cDNA encoding for j3-actin served as an internal contro\. Results: f3-actin expression was comparable in all to investigated tumor samples. CCKBR-specific PeR products were detected in 7 of the 10 MTCs inve stigated. More detailed correlation with clinic al and pathological data indicated that the majority of CCK-BR-positive tumors were small in size (Tl-, TIstages ), wherea s two of the three CCK -BR-negati ve samples were large tumors mith metastases. Only one pre-operative pentagastrin-test result was available : the result was negative and the corre spond ing tumor sample did not show CCK-BR expression. Conclus ion: The aberrant expression of CCK-BRs suggests that human MTCs might be susceptible to the function s of gastrin . Moreover, CCK-BRs might serve as interest ing novel diagno stic and therapeutic targets in these tumors.
1656 EXPRESSION AND FUNCTION OF THE CALCIUM SENSING RECEPTOR (CAR) IN GASTRINOMAS. Stephan U. Goebel, Paolo L. Peghini, Paul Goldsmith, Allen M. Spiegel, Fathia Gibril, Mark Raffeld, Jose Serrano, Robert T. Jensen, NIH, Bethesda , MD. Extracellular calcium levels are able to influence the secretion of gastrin by gastrinomas and possibly affect the growth pattern, however, the cellular basis for these actions is unknown. Recently , a novel calcium sensing receptor (CaR) has been described in parathyroid cells and antral G cells, which is a member of the metabotropic glutamate receptor family. Activation of this receptor can alter growth and secret ion in these cells. The purpose of the present study was to determine whether the CaR is present in gastrinomas and assess its possible role in gastrinoma function . In gastrinomas from 44 patients the amount of CaR mRNA was determined by quantitati ve RT-PeR. Protein expre ssion was analyzed by Western blotting with a CaR monoclonal antibody (ADD) and immunohistochemistry was performed using the same antibod y. CaR mRNA was detected in all gastrinomas. The amount of CaR mRNA varied 1600-fold with a range from 0.OO5-7.89x transcripts per b-actin transcript. The Western blot showed a major immunoreactive band at 250 kD and a minor at 140kD corre sponding to the receptor dimer and monomer, respectivel y. Immunohistochemistry demonstrated variable membrano us staining in all gastrinomas and normal pancreatic islets. No staining was observed in the normal liver, lymph node or exocrine pancreas. The amount of CaR mRNA did not correlate with the fasting serum gastrin level (p= 0.42) or the magnitude of the calcium-evoked gastrin release by the tumors (p = 0.43). However, fasting serum gastrin levels correlated with the magn itude of the calciumevoked gastrin release by the tumors (p = O.OO04) . No significant differences in CaR amounts were found in duodenal, pancreatic or lymph node gastrinomas (p = O.34). Similarly, the size of the tumor «3cm, 3-tocm, > IDem, p=0.66), the extent of the disease (single or multiple sites, liver metastases, p =O.14) or the growth pattem of the tumor were not correlated with the amount of CaR mRNA. We co nclude that the CaR is present in all gastrinomas and the expression is highly variable. Because of the lack of correlation between its expression and growth, Ca + + evoked gastrin release or fasting gastrin levels, the CaR is unlikely to be the primary determinant of the magnitude of any of these functions in gastrinomas. This raises the possibility that the CaR may have additional functions in gastrinomas as seen in other cell types, such as a role in cellular differentiation.
1657 PROXIMAL AND DISTAL GUT HORMONE SECRETION IN SLOW TRANSIT CONSTIPATION. C. Penning, J. B. Delemarre, I. Biemond, C. B. Lamers, A. A. Masclee , Dept of Gastroenterology, LUMC, Leiden , Netherlands; Dept of Surg , LUMC , Leiden , Netherlands; Leiden Univ Med Ctr, Leiden, Netherlands. It has been suggested that slow transit constipation (STC) is part of a more general ized gastrointestinal motility disorder. Recently we have shown that gastric , small intestinal and gallbladder motility are abnormal in STC patients. Aim of the present study was to evaluate whether the secretion of proximal and distal gut hormones, as regulators of motility, is affected in slow tran sit constipation. Twenty-nine STC patients (25 female, 4 male ; age 45 ± 3 yr) and 29 healthy controls (18 female , 11 male; age 42 ± 3 yr) participated in the study . Plasma levels of the proximal gut hormones cholec ystokinin (CCK), pancreatic polypeptide (PP) and gastrin and of the distal gut hormones neurotensin (NT) and peptide YY (PYY) were determined both in the fasting state and for 2 hours postprandially after consumption of a 640 kcal solid meal (26 g fat, 25 g protein and 24 g carbohydrates). In addition we determ ined oro-caecal transit time (OCIT) by means of the lactulose hydrogen breath test. Results : OCTT was significantly (p< 0.05) prolonged in STC patients (108 ± 9 min) versu s controls (78 ± 6 min). Basal and postprandial levels of proximal gut hormones were significantly increased in STC patients. Postprandial secretion in STC versus control s: CCK 228±32 vs 165±22 pM.l20 min (p<0.05); PP 6300± 1280 vs 3l00±560 pM.l20 min (p<0.05); gastrin 9960 ±2050 vs 7150±1600 pM.l20 min (p<0.05); on the other hand postprandial levels of the distal gut hormone PYY were reduced in STC patients: 570±150 versus 121O±350 pM.l20 min (p<0.05) When STC patients were divided in 2 groups based on normal DCTT «120 min) or prolonged DCTT (> 120 min), differences in the postprandial response were observed only in STC patients with delayed intestinal transit. Postprand ial secretion in patients with DCTT >120 min versus ::s120 min: neurotensin 313± 119 vs 645±280 pM.l20 min, (p<0.05), PP 9110±2350 vs 356O±1020 pM.l20 min (p< 0.05). Conclusions: Gut hormone secretion is altered in STC with increased secretion of proximal gut hormones and reduced secretion of distal gut hormones. These alterations are related to intestinal transit with prolonged contact time between nutrients and the proximal intestine and less distal chyme delivery.
1658 MANAGEMENT OF ZOLLINGER·ELLISON (ZE) PATIENTS WITH PANTOPRAZOLE. Pierre Poitras, Hosp Saint-Luc du CHUM, Montreal, PQ, Canada. The management of patients with gastric acid hypersecretion due to gastrinom a, usually recognized as ZE syndrome, was radically changed 10 years ago by the use of proton pomp inhibitors. Surgical treatment now concentrates on tumor excision and, in the very large majority of patients, gastrectomy is no longer required to prevent complications of acid hypersecretion that can now be managed pharmacological1y. AIMS: We verified in 7 patients with documented ZE the capacity of pantoprazole to control acid hypersecretion and the clinical effects of gastric hypersecretion. METHODS: Pantoprazole was administered at an initial dose of 80 mg daily for 7 days before measuring basal acid output (BAO) at 8 AM, i.e. 1 hour before the next dose of pantoprazole is normally ingested. Lower (40 mg) or higher doses (120 mg or more of pantoprazole) could then be used to keep the BAO in the therapeutic range (between 0.1 and 10 mmollhr) and to control clinical symptoms such as acid related pain or diarrhea. RESULTS: Control of BAO and clinical symptoms was achieved with pantoprazole 40 mg daily in I patient, 80 mg daily in 2 patients. 120 mg daily in 3 patients , and 160 mg in I patient . CONCLUSIONS: Pantoprazole was able to control acid hypersecretion in ZE patients when administered in doses between 40 and 160 mg daily . An initial dose of 120 mg daily appears as a reasonable therapeutic attitude before further titration of the drug regimen .