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)

Somatostatin is an ubiqutary neuropeptide and hormone which has been reported to exert hemodynamic effects and to bind to receptors on the red cell membrane. We investigated its effects on red cell deformability by three filtration methods: (a) filtration of red cells resuspended at hematocrit 8% in Tris-Albumin-Glucose buffer under atmospheric pressure; (b) filtration of red cells resuspended at hematocrit on native plasma at 8% hematocrit under a negative pressure of 5 cm of water; (c) filtrability of whole blood under a negative pressure of 20 cm of water. Aprotinin (Antagosan*) was added to the different suspensions in order to avoid rapid destruction of somatostatin. Increased quantities of somatostatin (from 1 pg/ml to 1 microgram/ml) were obtained by adding natural somatostatin (Modustatin*) to the media, before they were incubated at 37 C for 30 minutes. In 11 samples from healthy subjects, somatostatin was shown to increase red cell flow rate in technique (c) (+ 118%, p less than 0.05) and to reduce red cell rigidity index in technique (b) (- 71%, p less than 0.025) whereas a nonsignificant similar tendency (- 56%) was observed with technique (a). Similar results (p less than 0.05) are observed when adding somatostatin to blood of diabetics. These in vitro data suggest that somatostatin, like other previously studied hormones, may modify red cell deformability.
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PMID:In vitro effects of somatostatin on red cell filterability measured by three methods. 167 5

Studies were performed on previously nephrectomized dogs to examine roles of hormonal factors in plasma potassium alterations in acute alkalosis. Respiratory and metabolic alkalosis were induced by hyperventilation and intravenous NaHCO3 or tris(hydroxymethyl)aminomethane (Tris) infusion, respectively. Respiratory and NaHCO3-induced alkalosis provoked decreases in plasma potassium from the control value of 5.12 +/- 0.68 (SE) to 4.21 +/- 0.55 meq/l (P less than 0.01) and from 4.65 +/- 0.26 to 3.91 +/- 0.16 meq/l (P less than 0.01) within 180 min, respectively. In contrast, Tris-induced alkalosis elicited an increase in plasma potassium from the control value of 4.56 +/- 0.30 to 5.31 +/- 0.30 meq/l (P less than 0.01). Hypokalemia in respiratory alkalosis was associated with a decrease in the plasma norepinephrine concentration from the control level of 377 +/- 104 to 155 +/- 41 pg/ml (P less than 0.05) but not with changes in plasma levels of epinephrine, insulin, glucagon, cortisol, and aldosterone. However, this hypokalemia was not affected by phentolamine. Also, somatostatin did not modify the hypokalemic response. NaHCO3-induced hypokalemia was associated with a decline in the plasma aldosterone and norepinephrine concentrations. The decline in plasma norepinephrine in NaHCO3-induced alkalosis followed the decrease in plasma potassium. In Tris-induced alkalosis, plasma insulin increased but norepinephrine decreased. The findings do not suggest fundamental roles of the hormonal factors in the plasma potassium alterations in bilaterally nephrectomized dogs with acute alkalosis.
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PMID:Role of hormonal factors in plasma K alterations in acute respiratory and metabolic alkalosis in dogs. 215 37

Tris(hydroxymethyl)aminomethane (Tris) has been shown to inhibit selectively the Golgi apparatus and Golgi-endoplasmic reticulum-lysosomal system (GERL system) of several kinds of cells including pancreatic B cells. This study was designed to assess the effect of Tris on insulin, glucagon and somatostatin release and insulin synthesis in pancreatic B cells by using isolated rat pancreatic islets. Tris suppressed glucose-induced insulin release, whereas it did not affect the glucagon and somatostatin release. Furthermore, the incorporation of [3H]leucine into the insulin fraction was suppressed by 10 mM Tris, but the sum of the radioactivity of both proinsulin and insulin fraction were not influenced. The present study suggests that the Golgi apparatus and GERL system may play a role in insulin secretion and biosynthesis in pancreatic B cells.
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PMID:Effects of tris(hydroxymethyl)aminomethane on biosynthesis and release of insulin in the pancreatic Langerhans islets. 287 7

Peptide sequence analysis and cDNA cloning indicate that a previously described mouse arginine-specific dibasic cleaving enzyme (dynorphin converting enzyme) [Csuhai et al. (1995) Biochemistry 34, 12411] is the homologue of N-arginine dibasic convertase (NRDc) isolated from rat testis [Chesneau et al. (1994) J. Biol. Chem. 269, 2056]. A mouse NRDc cDNA exhibited 98% amino acid identity with the rat cDNA. However, within a 74 residue acidic stretch, this identity drops to 82%. Likewise, the corresponding acidic stretch of human NRDc is only 73% identical with that of rat NRDc. To reconcile previously observed kinetic differences between rat and mouse NRDc, the hydrolysis of peptide substrates by the rat, human, and mouse enzymes was compared using phosphate and Tris as buffers. Although the three NRDc's behaved similarly, Tris had a pronounced effect on the kinetics of peptide hydrolysis. With BAM-8, alpha-neoendorphin, and dynorphin B as substrates, Tris increased KM up to 40-fold with little change in Vmax, while with dynorphin A or somatostatin 28 as substrate, Tris caused a decrease in KM of up to 100 fold, again with only a modest change in Vmax. Other amines, including the polyamines putrescine, spermidine, and spermine, all affected NRD convertase activity. It is proposed that amines bind to the acidic stretch found in NRDc, and that quantitative differences in the sensitivity to amines between the rat, mouse, and human enzymes can be at least partially accounted for by differences in their acidic stretch. The role of polyamines as physiological modulators of N-arginine dibasic convertase is considered.
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PMID:Regulation of N-arginine dibasic convertase activity by amines: putative role of a novel acidic domain as an amine binding site. 952 98

More efficient and faster separation conditions for qualitative as well as quantitative analysis of neuropeptides in human plasma using capillary zone electrophoresis (CZE) have been developed. The analysis method for neuropeptides has been improved specifically to study thyroid hormone related neuropetides for the regulation of thyroid disease. In this study, we investigated the pretreatment methods, composition of the running buffer and rinsing procedures between runs in order to obtain more sensitive and faster separation of trace neuropeptides in plasma by CZE. The tested neuropeptides were somatostatin (SOMA), vasopressin (VP), neurotensin (NT), and thyrotropin-releasing hormone (TRH). Plasma samples were pretreated by deproteinization and solid-phase extraction method. The fraction of neuropeptides was reconstituted in 40% acetonitrile followed by ultrafiltration, and then analyzed by CZE. Resolution and sensitivity was improved using the separation buffer composition with 100 mM Tris-phosphate buffer (pH 2.0) while the sensitivity was further improved via a stacking method using the sample buffer of 40% acetonitrile. These sample pretreatment methods and buffer condition permit quantitative analysis on tested neuropeptides at the 20 ng/mL level. The rinsing procedures between runs using 90% ethanol dramatically shortened the rinsing time to 30 min.
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PMID:Influence of buffer composition and sample pretreatment on efficiency separation for monitoring neuropeptides in plasma using capillary electrophoresis. 1150 49