Somatostatin analogue (SMS 201-995) in patients with gastrinomas

We have examined the effects of the somatostatin analogue (SMS 201-995) in 10 patients with gastrinoma syndrome. Four had hepatic metastases, one had a tumor in a peripancreatic lymph node, two had resectable intrahepatic and intraduodenal gastrinomas, and in three the primary tumor was not found. Acutely, SMS 201-995 decreased acid secretion and restored the BAO/MAO ratio to normal in eight of eight patients. Basal and secretin-stimulated gastrin responses were suppressed but not normalized in eight of eight patients. Suppression of endogenous gastrin restored responsiveness to exogenous gastrin. Treatment for up to 12 months with SMS 201-995 controlled symptoms in six of eight patients, suppressed serum gastrin in three of five, and suppressed acid secretion in three of three patients. Treatment with SMS 201-995 in three patients for 5 months decreased tumor secretion of gastrin and diminished basal acid secretion, an effect that persisted in two of three patients 48 hours after withdrawal of SMS. In patients with metastatic disease who had high levels of gastrin, SMS treatment for 5 to 12 months did not inhibit tumor growth or decrease gastrin levels. SMS treatment arrested progression of tumor growth only in patients who had a reduction in gastrin and gastric acid secretion. We conclude that SMS may be useful in the management of gastrinoma patients by decreasing hypersecretion of gastrin and gastric acid and, over a longer term, may even change tumor capacity to release gastrin and gastric acid secretion. SMS may thus be useful as a palliative agent and as an adjunct to conventional treatment of the gastrinoma syndrome. SMS does not appear to shrink tumor mass in patients with very high basal gastrin levels.     

Observations on the effect of a somatostatin analog in the Zollinger-Ellison syndrome: implications for the treatment of apudomas

Somatostatin is known to inhibit hormone release and gastrointestinal secretion and hence may be useful in the treatment of amine precursor uptake, decarboxylase tumors. Clinical application has been limited by the short half-life, potency, and specificity of the natural hormone. Our study evaluated the effect of a synthetic analog of somatostatin, SMS 201-995 (Sandoz, Inc., E. Hanover, N.J.) on basal and stimulated gastrin release and gastric acid secretion in 10 patients with the Zollinger-Ellison syndrome. In experiment 1, H2-receptor antagonists were discontinued for 48 hours; SMS 201-995, 1 microgram/kg, was given subcutaneously; gastrin and SMS levels in plasma were determined by radioimmunoassay; and gastric secretion was measured and titrated at 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, and 18 hours. The mean +/- SEM baseline gastrin level (1526 +/- 733 pg/ml) was significantly inhibited for 16 hours (p less than 0.05, paired t test). Gastric secretion was neutralized for as long as 18 hours (p 0.05). In experiment 2, three patients received either a secretin (2 U/kg) or a calcium stimulation test (2 mg/kg) with or without pretreatment with SMS 201-995, 1 microgram/kg, subcutaneously. The mean +/- SEM interpreted change in gastrin (ng X 60 min/ml) without SMS 201-995, 36.8 +/- 11 (secretin), and 129 +/- 30 (calcium) were reduced with SMS 201-995 to -1.1 +/- 0.76 (secretin) and -29 +/- 28 (calcium) (p less than 0.05). In the Zollinger-Ellison syndrome, SMS 201-995 caused significant and long-lasting inhibition of both tumor gastrin release and gastric acid secretion, probably by direct action on both the gastrinoma and the stomach. SMS 201-995 blocks acid secretion and secretin- and calcium-stimulated gastrin release, indicating that SMS 201-995 inhibits peptide secretion by postreceptor mechanisms. SMS 201-995 will be useful in the palliative treatment of apudomas.     

Effects of tamoxifen and somatostatin analogue on growth of human medullary, follicular, and papillary thyroid carcinoma cell lines: tissue culture and nude mouse xenograft studies

The knowledge that (1) the normal thyroid contains somatostatin, (2) polypeptide growth factors influence thyroid cell function, and (3) thyroid cells contain steroid hormone receptors prompted us to add somatostatin analogue No. 201-995 (SMS) (5 ng/ml) and/or tamoxifen citrate (TAM) (5 mumol/L) to 7-day monolayer cultures (50,000 cells/well) of three separate human thyroid carcinoma cell lines: DR081 (medullary), WR082 (follicular), and NPA'87 (papillary). Results, tabulated as cell numbers/well (X10(5) on day 7, revealed that TAM inhibited growth of medullary and follicular cells and that TAM plus SMS inhibited growth of papillary cells. In vivo studies of subcutaneous tumor cell xenografts in nude mice have documented that TAM (5 mg subcutaneous pellet) significantly inhibits the growth of medullary implants. Flow cytometric DNA studies of medullary cell cultures demonstrated a reduced G2 + M phase with TAM treatment. For papillary cell implants, TAM plus SMS (5 micrograms subcutaneously, twice daily) did not suppress tumor growth. All three cell lines were negative for estrogen receptor; addition of estradiol (5 ng/ml) to medullary cell cultures neither stimulated replication nor reversed the inhibitory effects of TAM in vitro. We conclude that (1) TAM slowed the growth of a cell line of human medullary carcinoma, both in vitro and in vivo; (2) this effect was not reversed by estradiol; (3) TAM plus SMS inhibited replication of a papillary carcinoma cell line in vitro, but not in vivo; and (4) TAM alone and TAM plus SMS inhibited replication of cultures of a human follicular thyroid carcinoma cell line. TAM and SMS may be useful in treatment of some human thyroid carcinomas.     

Effect of long-term treatment with somatostatin analogue (SMS 201-995) on pituitary tumor shrinkage in acromegaly--report of two cases.

The effect of long-term somatostatin analogue (SMS 201-995) treatment in two acromegalic patients is reported. Continuous tumor shrinkage was observed even after 129 and 139 weeks of treatment with 600 micrograms of SMS 201-995 daily. A huge and firm adenoma underwent shrinkage during treatment with SMS 201-995. No serious side effect appeared during 160 weeks of treatment. SMS 201-995 has a longterm tumor shrinkage effect and improves endocrinopathies.     

Perioperative use of long-acting somatostatin analog (SMS 201-995) in patients with endocrine tumors of the gastroenteropancreatic axis

The clinical manifestations of hormone excess caused by functioning neuroendocrine tumors of the gastroenteropancreatic (GEP) axis can be life threatening and frequently prove refractory to conventional antisecretory drugs. Administration of a long-acting somatostatin analog (SMS 201-995) proved effective in three patients with complex management problems related to GEP tumors. A patient with an insulinoma was maintained euglycemic intraoperatively with a single 100 micrograms dose of SMS given before surgery. Gastric suction in two patients with gastrinomas caused hypochlorhydric alkalosis that was preventable with preoperative SMS. Iatrogenic pancreatic fistula occurring after resection of a benign insulinoma healed within 4 days of SMS administration. This drug may be a useful adjunct in the perioperative management of patients with GEP endocrine tumors. Caution is advised regarding potential hazards related to malabsorption and gastric dysmotility.     

Inhibition of growth of two human pancreatic adenocarcinomas in vivo by somatostatin analog SMS 201-995

Somatostatin inhibits hormone secretion from gastrointestinal endocrine tumors. The purpose of this study was to determine whether SMS 201-995, a long-acting analog, would inhibit the growth of pancreatic adenocarcinomas. Two human pancreatic cancers grown in nude mice were studied: SKI, which has cholecystokinin receptors, and CAV, which does not. Tumors were implanted in groups of six mice each. Treatment groups received SMS 201-995 (100 micrograms/kg three times daily) by intraperitoneal injections and control animals received saline solution. Tumor area was measured twice weekly. After 7 weeks, the tumors and mouse pancreases were excised, weighed, and analyzed for protein and RNA and DNA content. In a second set of experiments, treatment was begun 21 days after transplantation. Mean body weights between groups were not different in any experiment. With treatment beginning on the day of transplantation, the tumor areas of SKI and CAV cancers were reduced by the third and fifth weeks of treatment, respectively. Tumor doubling times were prolonged with treatment in both SKI tumors (5 days) and CAV tumors (6 days). In the SKI treatment groups, tumor weight (52 percent), RNA content (72 percent), and DNA content (60 percent) were decreased at sacrifice compared with those of the control groups. In the CAV treatment group, the mean tumor weight (55 percent) and protein (48 percent), RNA (67 percent) and DNA contents (60 percent) were decreased compared with the CAV control group. Tumor growth of SKI and CAV cancers was also inhibited when treatment was delayed 21 days after transplantation. We conclude that these effects are not mediated by inhibition of cholecystokinin, as seen by similar inhibitory effects on both tumors. Treatment with SMS 201-995 may be an effective hormonal therapy in patients with pancreatic cancers.     

Establishment of a human gastrinoma in nude mice

We report the first establishment and characterization of functioning gastrinoma from a human being transplanted into nude mice. Tissue was obtained at operation from a gastrinoma liver metastasis from a patient with the Zollinger-Ellison syndrome. The tumor was implanted subcutaneously in five athymic nude mice. Serum gastrin was measured by means of radioimmunoassay in specimens of mouse blood taken before and 5 minutes after intraperitoneal injection of secretin (100 micrograms/kg). In a second experiment serum gastrin was measured 30 minutes after injection of somatostatin analogue, SMS 201-995 (300 micrograms/kg). Studies were also done in 10 control mice. At passage, the fundus of each tumor-bearing mouse was weighed and examined microscopically. The gastrinoma (tumor line, PT) has been maintained for 34 months through four passages with a tumor doubling time of 37 to 45 days. The histology is similar to the original tumor. Immunocytochemistry showed that PT contained gastrin. In two mice metastasis developed 9 months after implantation. Gastrin levels in mice bearing PT have ranged from 216 to 12,000 pg/ml. Gastrin levels of control mice ranged from 0 to 63 pg/ml. Secretin increased gastrin levels in three of five mice tested and decreased gastrin levels in two mice. Repeat secretin tests showed identical results. SMS 201-995 decreased gastrin levels from basal values. Fundic weight of mice bearing PT (397 +/- 93 mg) was significantly greater than control fundic weight (180 +/- 26 mg). Gastrinomas growing in nude mice produce physiologically active gastrin as shown by elevated serum gastrin levels and by hyperplasia of the stomach. Two distinct subpopulations of gastrinoma cells respond differently to secretin. This model should provide important information on mechanisms of growth control and on gastrin release by gastrinomas in human beings.     

Effects of a somatostatin analogue (SMS 201-995) on the growth and development of hepatic tumour derived by intraportal injection of Walker cells in the rat

Administration of a long active analogue of somatostatin, SMS 201-995 (2 micrograms subcutaneously twice a day) for 3 weeks after intraportal administration of Walker cells significantly inhibited their growth and development in the liver. This was not due to a direct cytotoxic effect of the analogue on Walker cells whose growth was stimulated in vitro. Furthermore, SMS 201-995 had no effect on the growth of Walker cells implanted into the thigh of rats suggesting that the inhibitory action of the analogue could be confined to tumour cells growing in the liver. Further studies suggested that the inhibitory effect of SMS 201-995 on the growth of Walker cells in the liver could be related to a marked stimulation of the hepatic reticuloendothelial system, by a reduction in portal venous flow in the early stages of treatment or by a combination of these effects. Further studies are required to delineate more precisely the mechanism whereby SMS 201-995 inhibits the growth of hepatic tumour derived from intraportal administration of Walker cells.     

Somatostatin analogue SMS 201-995 (octreotide) as a possible solution to the dumping syndrome after gastrectomy or vagotomy

The dumping syndrome, which may follow partial gastrectomy or truncal vagotomy and drainage, may be refractory to treatment. The aim of this study was to determine the effect of the somatostatin analogue, SMS 201-995 (octreotide), on dumping provoked by hypertonic glucose. Ten patients with symptoms and signs of dumping were studied. After a dumping provocation test with placebo, all patients developed severe symptoms: seven patients had early dumping, two had both early and late dumping and one had late dumping alone. With either 50 or 100 micrograms SMS 201-995, the symptoms of early dumping were much reduced in all patients, and those of late dumping were completely abolished. The packed cell volume, pulse and systolic blood pressure changes of early dumping were significantly reduced by SMS 201-995 and the fall in blood glucose in patients with late dumping was abolished. SMS 201-995 may be a useful treatment for early and late dumping.     

Effects of SMS 201-995 on the pharmacokinetic profile and cellular immune and toxic effects of cyclosporine in male Wistar rats

The immunosuppressant cyclosporine and the long-acting somatostatin analog SMS 201-995 (octreotide acetate) may have to be given simultaneously in diseases such as pancreatic transplantation. The aim of the study was to evaluate the effects of SMS 201-995 on the pharmacokinetics of cyclosporine, and to assess whether the addition of SMS 201-995 altered some of the cellular immune and toxic (renal, hepatic, glucose tolerance) effects of cyclosporine. Male Wistar rats were treated with cyclosporine 10 mg/kg/day, SMS 201-995 100 micrograms/kg b.i.d., a combination of the two drugs, or the vehicle alone. The addition of SMS 201-995 delayed the peak plasma levels of cyclosporine without affecting the through levels, and did not alter the effects of cyclosporine on the mononuclear cell subsets. This combination caused significant increases in plasma creatinine and hepatic enzymes, suggesting renal and hepatic toxicity, and severe glucose intolerance. If present in humans, the appearance of severe glucose intolerance with combined administration of SMS 201-995 and cyclosporine for pancreatic transplantation could be misinterpreted as rejection and lead to inappropriate interventions.     

Treatment of the dumping syndrome with the somatostatin analogue SMS 201-995.

In six patients suffering from severe early dumping and six patients with late dumping after peptic ulcer surgery, the effect of the somatostatin analogue SMS 201-995 was compared with placebo. In early dumpers subcutaneous administration of 50 micrograms SMS 201-995 prior to meal ingestion induced a strong improvement of dumping symptoms as reflected by a decrease of the Sigstad dumping score from 12 +/- 2 during placebo to 5 +/- 2 (p less than 0.05). Furthermore, the postprandial increase of pulse rate was abolished; maximum pulse rate decreased from 85 +/- 7 beats/min to 67 +/- 7 beats/min (p less than 0.05). SMS 201-995 did not significantly affect postprandial changes in packed cell volume. In late dumpers 50 micrograms SMS 201-995 reduced peak plasma insulin after oral glucose from 173 +/- 16 mU/L during placebo to 35 +/- 9 mU/L during SMS 201-995 (p less than 0.05) and increased individual plasma glucose nadirs from 1.9 +/- 0.3 mmol/L to 7.5 +/- 3.3 mmol/L (p less than 0.01). Both in early and late dumpers SMS 201-995 improved postprandial expiratory breath hydrogen excretion indicating slowing of gastrointestinal hurry. SMS 201-995 is a powerful therapeutic agent for the management of patients suffering from the dumping syndrome after gastric surgery.     

生长抑素对肝脏转移性结肠腺癌的抑制作用

为探讨生长抑素对肝脏转移性结肠腺癌的抑制作用,采用流式细胞术观察生长抑素衍生物SMS201-995对BALB/C小鼠结肠腺癌(CT26)肝脏转移瘤生长的抑制作用。结果表明:与对照组相比,治疗组小鼠肝转移瘤细胞增殖指数和S期分数明显降低,而GO/Gl期分数却显著增加,同时治疗组小鼠体重降低明显延缓,肝脏转移瘤数目显著减少,生存期明显延长。因此,生长抑素对抑制结肠癌肝转移瘤的生长具有一定的作用。     

The effect of SMS 201-995 on meal and CCK-stimulated peptide YY release

Somatostatin is known to inhibit the postprandial release of most gastrointestinal hormones. The aim of the present study was to evaluate the effect of an analog of somatostatin, SMS 201-995 (120 ng/kg/hr), on both meal-induced and cholecystokinin octapeptide (CCK-8, 500 ng/kg/hr)-induced peptide YY (PYY) release. Six mongrel dogs with distal ileal Thiry-Vella loops were used in this study. PYY was measured in both plasma and ileal luminal effluent. SMS 201-995 did not affect interdigestive plasma or ileal luminal PYY concentrations. CCK-8 and a fat meal both stimulated PYY release into the circulation. SMS 201-995 completely inhibited the CCK-8 and fat-stimulated circulatory release of PYY. Both CCK-8 and a mixed meal increased ileal luminal PYY recovery. SMS 201-995 inhibited CCK-8-induced, but not meal-induced, ileal luminal PYY recovery. These findings support previous studies that describe independent circulatory and ileal luminal PYY release. We conclude that both somatostatin and CCK may have a regulatory role in postprandial circulatory release of PYY.     

生长抑素对小鼠结肠腺癌肝转移瘤的抑制作用

采用流式细胞术观察生长抑素衍生物SMS 201-995对BALB/c小鼠结肠腺癌(CT26)肝脏转移瘤生长的抑制作用。结果表明:与对照组相比,SMS 201-995治疗组小鼠肝脏转移瘤中肿瘤细胞增殖指数和S期细胞百分比明显降低(P<0.01),而GO/G1期细胞百分比则明显增加。同时,治疗组肝脏表面肿瘤结节数量明显减少,体重减轻延缓;生存期延长,因此,SMS 201-995对抑制结肠癌肝脏转移性肿瘤的生长具有一定的作用。     

Inhibition of growth of human breast carcinomas in vivo by somatostatin analog SMS 201-995: treatment of nude mouse xenografts

Minced tumor fragments were xenografted into subcutaneous tissue of the lateral thoracic regions of young adult, virgin female nude mice to study the effects of somatostatin analog SMS 201-995 on growth of estrogen-dependent (MCF-7) and estrogen-independent (BT-20) human breast carcinomas. When tumors became palpable (6 to 10 days), mice were assigned randomly to receive either SMS (4 to 50 micrograms) or acetate buffer (0.2 ml) subcutaneously twice a day. For MCF-7, mean tumor volume was significantly lower on day 20 and days 30 through 50 in SMS-treated mice than in controls (p less than 0.05), and tumor doubling time was increased from 13.2 to 19.0 days. Calculated growth increment was significantly lower with SMS than with buffer treatment (1.1 +/- 0.1 vs 1.9 +/- 0.2) (p less than 0.001). For BT-20, mean tumor volume of SMS-treated mice was slightly, but not significantly, lower than that of controls; however, calculated growth increment was significantly lower for SMS treatment (3.2 +/- 0.3 vs 3.9 +/- 0.4) (p +/- 0.001), and tumor doubling time was increased from 4.0 to 5.8 days. For MCF-7, flow cytometric DNA analysis of tumor biopsy samples demonstrated a reduced G2 + M phase with SMS treatment. We conclude that SMS slows the growth of both MCF-7 and BT-20 human breast cancer xenografts in nude mice and that SMS may be clinically useful in the management of patients with breast carcinoma.     

Novel therapy for the treatment of human carcinoid.

Development of effective treatment for patients with carcinoid tumors has been hampered by lack of an experimental model. The authors have established the only long-term cell line of a functioning human pancreatic carcinoid tumor (BON) that produces tumors in nude mice. In this study the authors examined the effect of three agents, alpha-interferon (IFN), a somatostatin analog, SMS 201-995 (SMS), and an inhibitor of polyamine biosynthesis, alpha-difluoromethylornithine (DFMO), on the growth of BON tumors. BON was implanted bilaterally as 3-mm2 pieces (subcutaneously [sc]) into male BALB/c nude mice. In the first study, 23 mice were randomized to four groups: control, IFN (1 x 10(6) units, sc, four times a day), IFN + SMS (300 micrograms/kg, intraperitoneally, three times a day), and IFN + 3% DFMO in drinking water. Treatments were initiated on day of tumor implantation. In the second study, mice were randomized to six groups: control, IFN, SMS, DFMO, IFN + SMS, IFN + DFMO, and IFN + SMS + DFMO. Treatments were started on day 15 after tumor implantation. Tumor area and body weights were measured weekly. In both studies mice were killed on day 28 after BON implantation and tumors removed, weighed, and analyzed for DNA and RNA content. In the first study, IFN either alone or in combination with SMS or DFMO suppressed BON tumor growth. When treatment was initiated after established tumor growth (study 2), however, the only effective treatments for suppression of growth of BON were IFN + DFMO and IFN + DFMO + SMS.(ABSTRACT TRUNCATED AT 250 WORDS)     

Calcitonin immunoreactivity and hypercalcitoninemia in two patients with sporadic, nonfamilial, gastroenteropancreatic neuroendocrine tumors.

BACKGROUND. Hypercalcitoninemia in gastroenteropancreatic tumors associated with calcitonin immunoreactivity is rare. METHODS. We report here two patients in whom pancreatic neuroendocrine tumors both contained and secreted immunoreactive calcitonin. Both patients experienced elevated basal calcitonin immunoreactivity. RESULTS. The peak responses of immunoreactive calcitonin occurred 5 minutes after pentagastrin administration in these two patients and were 30% and 180% above basal concentrations corresponding to peak increments of 0.39 and 8.78 ng/ml, respectively. The immunoreactive calcitonin response to pentagastrin in these two patients was not significantly different from that seen among five patients with medullary carcinoma of the thyroid gland. CONCLUSION. It does not appear that immunoreactive calcitonin responses to pentagastrin stimulation will discriminate between patients with medullary carcinoma of the thyroid gland and those with nonfamilial, gastroenteropancreatic neuroendocrine tumors that express calcitonin immunoreactivity. In patients with secretory diarrhea and/or flushing, an elevated level of immunoreactive calcitonin, in the absence of a thyroid mass in the neck, may herald the presence of a gastroenteropancreatic neuroendocrine tumor.     

Effects of SMS 201-995, a somatostatin analogue, on the exocrine pancreatic secretion and gut hormone release in dogs

The effect of SMS 201-995, an analogue of somatostatin, on pancreatic exocrine secretion was investigated in both interdigestive and digestive states in dogs. In four dogs with gastric and Thomas duodenal cannulas, the pancreatic juice was collected by direct cannulation of the main pancreatic duct. SMS 201-995 was infused intravenously at doses of 0, 15, 30, 60, and 120 ng/kg/hr for 2 to 3 hours in the following experimental conditions: (1) interdigestive pancreatic secretion, (2) pancreatic secretion stimulated by the intravenous infusion of both secretin, 0.06 CU/kg/hr, and cholecystokinin octapeptide (CCK8), 0.03 microgram/kg/hr, and (3) pancreatic secretion after ingestion of a test meal. Pancreatic juice was analyzed for volume and outputs of bicarbonate and protein. Plasma levels of motilin, pancreatic polypeptide (PP), CCK, and secretin were determined by radioimmunoassay. SMS 201-995 inhibited significantly the pancreatic secretion and release of hormones, including secretin, CCK, PP, and motilin, in all three experimental conditions. The inhibitory action of SMS 201-995 on pancreatic secretion and hormone releases was dose dependent.     

Effect of somatostatin analogue (SMS 201-995) on molecular species of gastrin in gastrinoma

Somatostatin analogue (SMS 201-995) has been shown to decrease total serum gastrin in patients with gastrinoma; however, the gastrin level rarely returns to normal, despite the near-complete inhibition of acid secretion. This implies that SMS may have an inhibitory action on the biologically active molecular species of gastrin and have little effect on biologically inactive species. To test this hypothesis, we determined the effect of SMS on the molecular species of gastrin in eight patients with the Zollinger-Ellison syndrome. Serum obtained before treatment and 6 hours and 18 hours after treatment (SMS 1 microgram/kg, subcutaneously) was sampled and assayed for molecular species of gastrin by means of gel filtration chromatography and fractional quantitation of gastrin species by radioimmunoassay. There was a significant decrease in the amount of G-34 and G-17 species. BBG and G-14 decreased, a change not significant at 6 hours but significant 18 hours after SMS. The distribution of the various molecular species as a percent of total immunoreactive gastrin was analyzed before and after SMS. There was a shift in the distribution of the molecular species, so that 6 hours after SMS treatment nearly 50% of total gastrin activity was accounted for by BBG and component I. SMS seems to have a different potency to inhibit release of the various gastrin molecular species. This observation may explain the failure of total gastrin levels to return to normal after SMS treatment in patients with the Zollinger-Ellison syndrome.     

Long acting somatostatin analogue in dumping syndrome

The effect of long acting somatostatin analogue, SMS 201-995, on postprandial dumping syndrome was studied in eight patients with Billroth II gastric resection. Each patient was subjected to two oral glucose challenges with 75 g glucose. One challenge was premedicated with 50 micrograms SMS 201-995 subcutaneously 15 min before the oral intake of glucose, the other with placebo. With placebo all patients experienced the subjective symptoms of the early dumping syndrome with significant (P less than 0.001) increases (mean (s.d.)) in pulse rate (from 66 (8) to 102 (10) beats/min), in packed cell volume (from 0.36 (0.05) to 0.43 (0.1) l/l) and in the plasma levels of vasoactive intestinal polypeptide (from 3.0 (0.5) to 10.2 (1.8) pmol/l). During the somatostatin study the subjective symptoms and the changes in the various parameters were not detected. In the control study seven patients showed postprandial hypoglycemia. In these patients significant elevations (P less than 0.001) in the insulin level (from 10 (0.9) to 40 (9.1) microE/ml) and gastric inhibitory peptide (GIP) concentration (from 100 (13) to 220 (41) ng/l) were seen, compared with the initial values. During the application of SMS 201-995 hypoglycaemia did not develop and plasma insulin and GIP concentrations remained unchanged. These results indicate that the long acting somatostatin analogue alleviates the symptoms of early and late postprandial dumping syndromes.