Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of octreotide in vivo and in vitro on hormone release, in vivo [123I]Tyr3-octreotide scanning, and in vitro [125I]Tyr3-octreotide autoradiography were compared in five patients with endocrine pancreatic tumors. [123I]Tyr3-octreotide scanning localized the primary tumor and/or previously unknown metastases in four of the five patients. The patient with a negative scan had an insulinoma that did not respond to octreotide in vivo. No Tyr3-octreotide-binding sites were subsequently found at autoradiography of the tumor, whereas somatostatin-14 receptors were present at a high density. In parallel, culture studies with the cells prepared from this adenoma showed that insulin release was not affected by octreotide, while both somatostatin-14 and -28 significantly suppressed hormone release. Culture studies of the tumor cells from two gastrinomas showed a dose-dependent inhibition of gastrin release by octreotide. Octreotide exerted direct antiproliferative effects in one of these gastrinomas, which had been shown to be rapidly growing in vivo. Both gastrinomas had specific somatostatin receptors, as measured by in vitro receptor autoradiography. Somatostatin release by the cultured somatostatinoma cells from one of these patients was suppressed by octreotide. In conclusion, 1) the [123I]Tyr3-octreotide scanning procedure is valuable in the localization of primary endocrine pancreatic tumors as well their often clinically not yet recognized metastases; 2) the in vitro detection of somatostatin receptors in those tumors that were also visualized in vivo after injection of [123I] Tyr3-octreotide indicates that the ligand binding to the tumor in vivo indeed represents binding to specific somatostatin receptors; and 3) the parallel between the presence of somatostatin receptors on tumors and in in vivo and in vitro effects of octreotide on hormonal release from these tumors indicate that a positive scan predicts a good suppressive effect of octreotide on hormonal hypersecretion by these tumors.
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PMID:Parallel in vivo and in vitro detection of functional somatostatin receptors in human endocrine pancreatic tumors: consequences with regard to diagnosis, localization, and therapy. 216 29

The effect of an octapeptide analogue of somatostatin, octreotide, on tumor blood flow was evaluated with angiography in eight patients with hepatic endocrine tumors; one patient had primary intrahepatic gastrinoma, two patients had hepatic metastases from gastrinomas, two patients had VIPomas (vasoactive intestinal polypeptide-secreting tumor), and three patients had carcinoid tumors. Octreotide caused a marked decrease in tumor blood flow in two patients with gastrinomas and two with VIPomas. One patient could not be evaluated due to the lack of a tumor blush on a control angiogram. In patients with carcinoid tumors, octreotide caused a slight reduction in blood flow through the tumors in two patients, while there was no change in one patient. Octreotide markedly decreased gastrin and gastric acid secretion in two of three patients with gastrinomas, lowered VIP and stopped the diarrhea in patients with VIPomas, and controlled symptoms in two of three patients with carcinoid tumors. The vasoactive effect of octreotide on hepatic endocrine tumors may be a direct action on tumor blood supply or secondary to inhibition of the endocrine tumor cell secretion and consequent decreased blood flow.
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PMID:Effect of somatostatin analogue (octreotide) on blood flow to endocrine tumors metastatic to the liver: angiographic evaluation. 217 Oct 15

Growth hormone is assumed to be involved in the development of diabetic retinopathy. In a randomized study we evaluated the possible effects of one year treatment with a somatostatin (SRIH) analogue, octreotide, on early retinopathy and on metabolism in Type I (insulin-dependent) diabetes mellitus. Eleven patients were allocated to treatment with a continuous sc infusion of 400 micrograms octreotide per day and 9 served as controls. Only 7 patients from each group completed the study. Three octreotide-treated patients left the study owing to severe diarrhea. The subjects were evaluated at entry, after 2, 6 and 12 months treatment, and 2 months after withdrawal. Octreotide induced a decrease in GH secretion, expressed as the area under the 24 h serum GH profiles (p less than 0.05), and of the serum levels of IGF-I (p less than 0.05). The entire decline in GH levels occurred during the daytime, whereas the nocturnal levels were unaffected. Retinopathy, as assessed by determination of the blood retina barrier permeability, by colour fundus photography, and flurescein angiography was unchanged in both groups. Apart from a decline in insulin requirements, octreotide had no major effect on glycemic control, but induced a mild transient pituitary hypothyroidism, not clinically relevant. We conclude that treatment with octreotide for one year has modest effects on GH, IGF-I, and glucose metabolism, but has no significant effect on early retinopathy in Type I (insulin-dependent) diabetes.
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PMID:Effect of one year continuous subcutaneous infusion of a somatostatin analogue, octreotide, on early retinopathy, metabolic control and thyroid function in Type I (insulin-dependent) diabetes mellitus. 219 45

To determine the specific alteration in B-cell function caused by a somatostatin analog in man and to determine the effect of the induced insulin deficiency on insulin action, we administered octreotide (SMS 201-995; 50 micrograms twice daily) to nine healthy male subjects, aged 24-35 yr. B-Cell function was assessed by measuring the acute insulin response (AIR) to glucose (AIRglucose) at fasting glucose and to arginine (AIRarg) at glucose concentrations of fasting, approximately 14 and more than 28 mM after 2 (n = 7) and 8 days (n = 9) of octreotide. The AIRarg at more than 28 mM glucose (AIR500) is an estimate of B-cell secretory capacity, while the glucose level at which 50% of AIR500 occurs is termed PG50 and can provide an estimate of B-cell glucose sensitivity. Insulin sensitivity and the parameters describing glucose disposal were measured using Bergman's minimal model. Octreotide administration resulted in the development of mild fasting hyperglycemia, marked fasting hypoinsulinemia, as well as a marked reduction in AIRglucose [mean +/- SE; pretreatment, 260 +/- 48 pM; 1 day, 62 +/- 14 pM (P less than 0.005 vs. pretreatment); 8 days, 62 +/- 7 pM (P less than 0.005 vs. pretreatment)]. In addition, there was an associated marked reduction in iv glucose tolerance. While the AIRarg at fasting glucose (pretreatment, 233 +/- 27 pM; 2 days, 144 +/- 27 pM; 8 days 281 +/- 55 pM) and AIR500 (pretreatment 1000 +/- 178 pM; 2 days, 651 +/- 82 pM; 8 days, 1041 +/- 219 pM) remained unchanged, the AIRarg at 14 mM decreased significantly during octreotide [pretreatment 986 +/- 178 pM; 2 days, 363 +/- 62 pM (P less than 0.001 vs. pretreatment); 8 days, 623 +/- 130 pM (P less than 0.005 vs. pretreatment)], resulting in a rightward shift of the dose-response curve such that the estimated PG50 increased from 8.8 +/- 0.6 to 12.9 +/- 1.3 mM (P less than 0.05) after 2 days and was maintained for 8 days (11.2 +/- 0.8 mM; P less than 0.05 vs. pretreatment). Despite the development of marked insulin deficiency, the insulin sensitivity index (SI) did not change significantly (pretreatment, 11.34 +/- 1.59 x 10(-5); 1 day, 10.01 +/- 2.28 x 10(-5); 7 days, 9.65 +/- 1.69 x 10(-5) min-1/pM).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Treatment with a somatostatin analog decreases pancreatic B-cell and whole body sensitivity to glucose. 220 30

Somatostatin is widely distributed within the nervous system and the gastrointestinal tract. Gastrointestinal actions of somatostatin include inhibition of hormone release, reduction of pancreatic secretion, inhibition of motility, and reduction of blood flow. The purpose of this study was to investigate the role of somatostatin and its analogue octreotide on water and electrolyte transport in the small intestine. Rabbit ileal segments (n = 17) were harvested and arterially perfused ex vivo with a nonrecirculating oxygenated sanguineous solution. The lumen was perfused with an isotonic solution containing carbon 14-labeled polyethylene glycol. Net fluxes of water, Na+, and Cl- were calculated for three 20-minute periods designated basal, drug infusion, and recovery. Three groups were studied: somatostatin at 10(-6) mol/L (n = 5), somatostatin at 10(-5) mol/L (n = 5), and octreotide at 10(-5) mol/L (n = 7). Somatostatin at 10(-5) mol/L yielded a proabsorptive effect on the flux of water and electrolytes. Octreotide at 10(-5) mol/L caused a significant (p less than 0.05) proabsorptive response in the fluxes of water, sodium, and chloride during the period of drug infusion, which returned to basal secretory levels during the recovery period. This proabsorptive effect occurred without alterations in vascular resistance and necessarily was independent of systemic hormone interaction, supporting a direct effect of octreotide on intestinal ionic transport.
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PMID:Direct proabsorptive effect of octreotide on ionic transport in the small intestine. 224 38

One of the exciting recent developments in endocrinology research has been the introduction of the somatostatin analog, octreotide into clinical practice. Octreotide provides a new therapeutic tool for diseases in which somatostatin or somatostatin-like products are secreted abnormally. Unfortunately, early experience was obtained largely with uncontrolled, compassionate drug use. When clinical information regarding octreotide is critically reviewed, evaluation is hampered by the lack of long-term studies with adequate numbers of patients and controls. Nevertheless, the information available does indicate that octreotide is promising in the acute treatment of some of the manifestations of the carcinoid syndrome, including carcinoid crisis. Similarly, octreotide ameliorates symptoms of other gut neuroendocrine tumors, particularly vasoactive intestinal peptide (VIP)-secreting tumors. Octreotide also has potential in the management of growth-hormone-secreting tumors. Long-term treatment with octreotide for these diseases requires more information regarding alterations in disease progression and development of adverse effects including variable effects on blood sugar regulation and steatorrhoea. Octreotide also has been used in nonmalignant gastrointestinal disorders, but larger studies are necessary before recommendations regarding these applications can be made. The cost of octreotide, as may be expected, is high but is justified for patients with the specific indications outlined in this review. These indications may change as understanding of the drug increases. Octreotide offers promise, particularly as acute treatment for the troublesome symptoms of several neuroendocrine disorders.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Octreotide: a long-acting somatostatin analog. 224 80

Octreotide, an analog of somatostatin, is a valid tool for the cure of acromegalic disease. This compound has a prolonged half-life and is more selective than native somatostatin in suppressing growth hormone (GH) secretion. Octreotide, 100 micrograms tid sc, decreases GH levels and improves clinical symptoms in about 85% of acromegalic patients, lowering GH to below 5 ng/ml in 45% and to below 2 ng/ml in 17-21%. Octreotide normalizes somatomedin-C (IGF-I) levels in 36-50% of patients. The increase of dosage up to 1500 micrograms/day does not appear useful in poor responsive patients. No adverse effects on other endocrine functions submitted to hypothalamus-pituitary control have been observed. A slight shrinkage of the pituitary tumor is observed in 30-50% of cases. Octreotide therapy is well tolerated and side effects are usually mild. However the possibility of colelithiasis, liver damage and diabetes mellitus in patients with glucose intolerance must be taken into account. In conclusion octreotide is a useful complement to therapeutic means now used for the treatment of acromegaly.
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PMID:[Treatment of acromegaly with octreotide, a synthetic analog of somatostatin with extended action]. 227 11

A 27-year-old woman with multiple bilobal liver metastases of a carcinoid tumour and carcinoid syndrome was treated with the somatostatin analogue Octreotide, 450-600 micrograms daily subcutaneously. This improved previous attacks of marked epigastric pain, while endocrine activity and tumour mass remained unchanged. Shortly after treatment had begun, soft fatty stools and oxaluria were noted. After six months severe renal colics were found to be due to non-opaque caliceal calculi, and a contracted non-functioning gallbladder was discovered. The calculi consisted of oxalate. The enteric hyperoxalosis, oxaluria and urolithiasis were presumably side effects of the Octreotide treatment.
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PMID:[Enteral hyperoxalosis due to therapy with a somatostatin analog]. 229 34

The experience of St Bartholomew's Hospital in the treatment of acromegaly with octreotide is presented. When administered intravenously and subcutaneously, octreotide had a longer circulating half-life than natural somatostatin. Subcutaneous octreotide in a range of doses (50-400 micrograms) caused a very similar degree of growth hormone (GH) suppression, but the duration of suppression increased with size of dose. A dose of 100 micrograms octreotide 8-hourly provided very good suppression of GH in acromegalic patients; occasional nocturnal escapes may be a problem of inadequate dosage. Long-term octreotide treatment in 14 patients reduced GH to below 20 mU/l and only 1 case was apparently unresponsive. No serious side effects have so far been seen. Octreotide antibodies have been detected in 1 patient unresponsive to octreotide infusion. Gallstones have been found in 6 of 14 patients.
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PMID:Octreotide treatment of acromegaly. 235 94

Octreotide, a long-acting somatostatin analogue, was used 22 patients with carcinoid syndrome. Administered at doses of 100 to 1,000 micrograms per day according to the clinical status, octreotide resulted in a definite reduction, sometimes complete, of diarrhoea and flushes in about 60% of the cases, and in a significant decrease of urinary output of 5 hydroxy-indol acetic acid from initial values, in 18 patients that could be tested before and during the initial phase of therapy (- 37.6 +/- 7.9%, p less than 0.02). The symptomatic improvement was maintained in 13 patients treated for 3-36 months, even when no anti-tumoral complementary procedure was performed. In 2 patients, treatment discontinuation was followed by symptomatic relapse, rapidly controlled when therapy was reintroduced. These results suggest that octreotide allows for short term and prolonged control of carcinoid syndrome in the majority of patients presenting with this condition.
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PMID:[A prolonged-action somatostatin analog and carcinoid syndrome]. 247 66


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