April 1995 Growth, Development, and Nutrition A735

• EXPRESSION OF TGF-B IN GASTRIC MUCOSAL LESIONS AND ITS

MODIFICATION BY Helicobactor pylori INFECTION. H-- Kutsumi, K. Rokutan 2) , T. Soga, K. Nishimura, S. Fujimoto xl , K. Kawai a) . Gastrointestinal Div., Akashi City Hosp., Hyogo, Jpn~l; Dept. of Nutrition, Tokushima Univ., Tokushima, Jpn2~; Dept. of Preventive Med.,

Kyoto Pref. Univ. of Med., Kyoto, Jpn a) .

Transforming growth factor-~ (TGF-B) has been suggested to involve in healing of gastric ulcer by regulating cell proliferation and differentiation and

by stimulating synthesis of extracellular matrix. We

studied the expresslon of TGF-B in gastric mucosal

lesions and its modification by H. pylori infection. [Materials and Methods] Biopsy specimens were obtained from 70 patients: 40 (20) with gastritis, 20 (10) with

gastric ulcer, and i0 (5) with normal mucosa. Numbers of H. pylori positive cases are shown in each

parenthesis. Specimens were subjected to inununohisto- chemical analysis and Western blotting with an

antibody against TGF-B. H. pylori infection was diagnosed by measurement of serum antibody levels by

EIA, culture of H. pylori in the isolated mucosa, and

H-E staining. [Results and Discussion] InEaunohisto-

chenlical analyses showed that TGF-~ was only weekly detected in the superficial damage associated with gastritis but was strongly expressed in acute stage of

ulcer. Extracellular matrix and some endocrine-like cells were strongly stained with anti-TGF-B, while the

expression in epithelial cells and infiltrating cells were not detected. The strongest expression was observed in freshly granulating regions. These changes

in the expression of TGF-B were also confirmed by

Western blotting. In contrast, both immunohisto- chemical and immunoblot analyses showed that H. pylor$

infection significantly suppressed the expression of

TGF-8- These results suggested that TGF-B may play an important role in ulcer healing by promoting

granulation. H. pylori might disturb the healing

processes by suppressing the expression of TGF-fl.

• EFFECTS OF LANREOTIDE, A SOMATOSTATIN ANALOG, ON POSTPRANDIAL GASTRIC FUNCTION AND BILIOPANCREATIC SECRETION S IN HUMANS.. Lamrani A, Vidon N, Sogni P, Catus F, Lesetbaum A, Chaussade S. Service d'h6pato-gastroent6rologie et IPSEN laboratories, H6pital Cochin, 75014 Paris, France.

Lanreotide (L) is a new stable somatostatin analog. A long-acting formulation of L has been shown to be effective for the treatment of gastroenteropancreatic hormone-producing tumor (Ruszniewski et al, Gastroenterology t994, 106:A319). Its effects on post prandial digestive functions are unknown.

Aim of the study : to determine the effects of continuous perfusion of L on post prandial gastric function and biliopancreatic secretions in man.

Method : 6 healthy male volunteers (mean age : 24 years) were studied twice within a 2 weeks interval, using a perfusion method. L (100/~g/h after a bolus of 100t~g fifteen minutes before the beginning of the study) or Placebo were administered I.V in double blind and random order. A nutrient solution (pH 7, 400 ml, 500 kCal, 55% carbohydrates, 15% proteins, 30% lipids, 10 g/L PEG 4000), was infused into the gastric antrum over a 3 minute period, 15 minutes after I.V L or Placebo bolus injection. A saline solution with PSP (400 mg/L) was simultaneously infused at hnl/min into the second part of the duodenum. 15 minutes interval samples were collected 20 cm below and in stomach over 3 hours.

Results : (mean_sere) P

near the Treitz ligament)

L p

Gastric pH (median) 2,1 6.3 0.001 Gastric meal (volume at 3 h) 35!-_16 73_+12 0.05 Acid secretion (mmol/3h) 36_-+6 4___1 0.01 Lipase output x 103 Ul/3h 175+-20 33_+10 0.01 Bile salt output (mmol/3h) 3.7-+0.7 0.09-+0.04 0.01

Conclus ion : I-L strongly inhibits gastric acid and biliopancreatic secretions, 2-L could be useful in the prevention or in the treatment of pancreatic fistulas, 3-Further studies are necessary to determine the effect of the long-acting formulation upon biliopancreatic function.

• PD153035, AN EGF RECEPTOR (EGFr) TYROSINE-KINASE SPECIFIC 1NH/BITOR, REVERSES THE EFFECT OF EGF ON GASTRIC SECRETION AND TNBS-INDUCED COLITIS IN RATS. C. A. Lesch and A. Gu~lictta. GI Disorders Group, Parke-Davis Pharmaceutical Research Division, Warner- Lambert Company, 2800 Plymouth Road, Ann Arbor, M148105.

PD153035 is a potent and specific inhibitor of the EGFr tyrosine kinase with a 5 pM inhibition constant. In Swiss 3T3 cells, nM Concentrations of PD153035 suppress tyrosine phosphorylation induced with EOF whereas pM or higher concentrations are required to suppress phosphorylation induced by bFGF or PDGF. PD153035 specifically inhibits EGF-induced mitogenesis and reverses the transformed morphology of fibroblasts transfected with human EGFr in the presence of EGF. The aim of this study was to evaluate the in-vivo activity of PD153035 on some well established effects of EGF namely, inhibition of gastric acid secretion and protection against TNBS-induced colitis in rats. Gastric acid secretion was stimulated by pylorus ligation. Animals were then treated with 10 nmol/kg (54 p.g/kg) human EGF (h-EGF) delivered intraperitoneally (IP) with or without concomitant IP administration of 80 mg/kg PD153035. Control animals received an equal volume of IP saline. The volume of gastric secretion, [H +] and gasa-ic acid output were measured 2 hours later. In another set of experiments, colitis was induced in rats by intracolonic administration of 50 mg/kg TNBS dissolved in 50% EtOH. Sixty minutes prior to TNBS administration, rats were treated IP with either saline, 10 nmol/kg h-EGF or l0 nmol/kg h-EGF + 80 mg/kg PD 153035. Animals were sacrificed 24 hours after administration of TNBS and the extent of colonic damage assessed by computerized image analysis. At the dose used, h-EGF was able to both significantly inhibit pylorus- ligated stimulation of gastric acid secretion and to reduce the amount of colonic damage caused by TNBS/EtOH. The volume of gastric secretion and [H ÷] were reduced by 63% and 38.6% respectively, whereas 75% inhibition was observed for gastric acid output. The same dose of h-EGF also caused 80% reduction of the extent of colonic damage induced by TNBS/EtOH. The concomitant administration of PD153035 blocked the effect of h-EGF on all the gastric secretion parameters measured. Similarly, at the dose used, PD 153035 completely reversed the h-EGF-induced reduction of the extent of TNBS colonic damage. This study suggests that inhibition of gastric acid secretion and reduction of the extent of TNBS-induced colonic damage by h-EGF are EGF-r tyrosine kinase mediated events and that PD 153035 is a tyrosine-kinase inhibitor able to inhibit the phosporylation of the enzyme in the whole animal and to block the in-vivo effect of EGF.

• RETINOIC ACID (P.A) UPREGULATES CELLULAR RETINOL BINDING PROTEIN lI (CRBP l]) EXPRESSION AND VITAMIN A UPTAKE IN THE CACO-2 INTESTINAL CELL LINE. M.S. Levin, A.E. Davis, J.L. Wang. Dept. of Medicine, Washington University School of Medicine, St. Louis, MO,

Small intestinal enterocytes are responsible for the assimilation of vitamin Aand Provitamin A carotanoids. Using the human intestinal cell line as a model, we have shown the magnitude of retinol uptake and metabolism are related to CRBP II levels. The importance of CRBP II in vitamin A homeostasis is further underscored by the discovery that the promoter of the rat CRBP II gene contains nuclear retinoic acid RXR response elements. Since RA, which can be synthesized and metabolized in the small intestine, can directly modulate gane expression, the goal of this study was to define the role of RA in regulating intestinal CRBP II levels, vitamin A absorption and intestinal gane expression. Meihods 14 day postconfluent differentiated Caco-2 monolayers were pulsed with RA and changes in expression of CRBP ]I and retinol absorption were determined. Monolayers were switched from complete to serum-free media supplemented with insulin 5 gg/ml, transferrin 5 p.g/ml, selenious acid 5 "qg/ml for 2 h and then to fresh media containing 5 laM RA or vehicle alone for 24 h. To assess retinol absorption, the monolayers were incubated with 5 riM [3H]retinol for the final 4 h. Cells were processed and CRBP IT RNA, CRBP lI protein and [3H]retinol uptake were quantitated by Northern blotting, immunoblotting and liquid scintillation spectrometry, respectively.

Results RA induced expression of CRBP lI mRNA 3.9-fold (Table, all data with p < .05). Modest increases in CRBP 1I protein accumulation were also detected after 24 h incubation with RA. These changes were associated with a significant increase in retinol absorption.

Vehicle RA Fold A I CRBP II mRNA / 7.-actin .91 ~-.12 3.54.1.2 3.9

I CRBP II protein (dens. units) .27 4. .07 .33 4- .05 1.2 retinol uptake (pmol/mg) 123 4- 13 192 + 17 1.6

Conclusions These studies are the first to demonstrate that RA can directly modulate intestinal CRBP 11 expression and indicate intestinal vitamin A absorption may be subjected to autoregulation by dietary and plasma retinoids.