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)

This study examined the acute role of glucagon in sustaining the increased hepatic gluconeogenesis observed in the conscious infected dog. After a basal sampling period, arterial glucagon levels were selectively decreased for 180 min by a peripheral infusion of somatostatin and basal intraportal infusion of insulin (GGN deficient; n = 6). In a separate protocol (GGN replaced; n = 5) glucagon was also infused intraportally to maintain the glucagon level at that seen during sepsis. Tracer and arteriovenous difference techniques were used to assess hepatic glucose metabolism and gluconeogenesis. In the GGN-deficient group the arterial plasma glucagon level fell from 416 +/- 49 to 88 +/- 21 pg/ml, whereas in the GGN-replaced group it remained elevated throughout (321 +/- 48 to 248 +/- 22 pg/ml). When glucagon was reduced, endogenous glucose production decreased by 1.6 +/- 0.3 mg.kg-1.min-1, and an exogenous glucose infusion was required to maintain euglycemia. Glucose metabolism remained unaltered when glucagon was replaced. When glucagon was deleted, net hepatic gluconeogenic precursor uptake was not altered. In contrast, the efficiency of gluconeogenesis was decreased by 33% compared with the GGN-replaced group. Liver biopsies taken at the end of the experiment indicated that a diversion of gluconeogenic carbon to glycogen accounted for 50% of the fall in gluconeogenic efficiency. In summary, the basal hyperglucagonemia seen during an infection helps sustain glucose production both through its effects on hepatic glycogen metabolism and on gluconeogenic efficiency.
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PMID:Effect of acute glucagon removal on metabolic response to infection in conscious dog. 784 Jan 88

To determine the time course of glucagon activation and deactivation of hepatic glucose production (HGP), studies were conducted in 18-hour fasted, conscious dogs. Somatostatin was infused with insulin replaced intraportally at 1.8 pmol x kg(-1) x min(-1) and glucagon replaced peripherally at 1.0 ng x kg(-1) x min(-1). After a 2-hour control period, glucagon infusion was either (1) increased fourfold for 4 hours (GGN 4X), (2) increased fourfold for 30 minutes and returned to a basal rate for 3.5 hours (GGN 4X/1X), or (3) fixed at the basal rate for 4 hours (GGN 1X). In the latter two protocols, glucose was infused peripherally to match glucose concentrations observed during GGN 4X. Glucose turnover was determined by deconvolution with the impulse response of the glucose system described by a two-compartment, time-varying model identified from high-performance liquid chromatography (HPLC)-purified [3-3H]glucose tracer data. In GGN 4X, HGP was stimulated from 15.2 +/- 0.9 micromol x kg(-1) x min(-1) to 52.7 +/- 6.5 micromol x kg(-1) x min(-1) after just 15 minutes, but it decreased over the subsequent 3 hours to a rate 25% above basal. In GGN 4X/1X, the increase in HGP during the first 30 minutes equaled that observed in GGN 4X, but when glucagon infusion was returned to basal, HGP decreased in 15 minutes to rates equal to those observed in GGN 1X. The times for half-maximal activation and deactivation of glucagon action were equal (4.5 +/- 1.0 and 4.0 +/- 1.1 minutes, respectively). The very rapid and sensitive hepatic response to glucagon makes pancreatic glucagon release a key component of minute-to-minute glucose homeostasis.
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PMID:Rates of glucagon activation and deactivation of hepatic glucose production in conscious dogs. 947 59

Puralpha, a single-stranded DNA binding protein, recognizes a PUR element (GGN repeat). We have reported that Puralpha binds to a single-stranded oligonucleotide probe containing the cAMP response element (CRE) of rat somatostatin gene using a gel mobility shift assay. Here, we showed that Puralpha binds to the probe only in the presence of a PUR element by a more detailed characterization. We also examined the effects of Puralpha on the enhancer activity of the somatostatin CRE in PC12 cells using the reporter gene assay. Transfected Puralpha suppressed the CRE enhancer activity stimulated by forskolin (which increases intracellular cAMP), but suppression was not observed when the PUR element was deleted. The neurite extension induced by forskolin was inhibited by the transfection of Puralpha, but that by NGF was not suppressed. The c-fos mRNA induced by forskolin, but not by NGF, was also suppressed by Puralpha transfection. These results indicate that Puralpha suppresses the biological activities induced by forskolin, but not by NGF, in PC12 cells and that Puralpha could interfere with a cAMP-CRE signal pathway.
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PMID:Puralpha, a single-stranded DNA binding protein, suppresses the enhancer activity of cAMP response element (CRE). 1081 31