Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Rat adipose tissue was homogenized in 0.154 m KCl, and the supernatant fluid, obtained after centrifugation at 15,000 g, was extracted with benzene to remove triglycerides. Most of the lipase activity in the extracted fluid was precipitated with ammonium sulfate between 15 and 40% saturation. The specific activity of the lipase in this fraction was about three times that in the benzene-extracted supernatant fluid. The specific activity of the monoglyceride esterase was increased to a lesser extent. Lipase activity in the benzene-extracted fluid and in the ammonium sulfate fraction was increased 15-45% by incubation with 0.3 mm ATP, 10 mm MgCl(2), and 0.03 mm cyclic AMP for 10 min before assay. None of these compounds alone or in combinations of two was as effective as all three together. The specific activity of the 15-40% ammonium sulfate fraction prepared from fat cells exposed to epinephrine and glucagon was greater than that from portions of the same cell pool not exposed to hormones. In addition, the already elevated lipase activity in preparations from hormone-treated cells was not enhanced by incubation with ATP, MgCl(2), and cyclic AMP. Thus, it seems probable that the lipase activity in the ammonium sulfate fractions represents, at least in part, hormone-sensitive lipase.
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PMID:Activation of hormone-sensitive lipase in extracts of adipose tissue. 432 64

Hormone-sensitive lipase partially purified from adipose tissue of laying hens was markedly activated by cyclic AMP-dependent protein kinase. Activation was approximately 4-fold (ranging up to as great as 10-fold) compared with the much lower degree of activation obtained with analogous preparations from rat and human adipose tissues (59 and 86%, respectively). The partially purified preparations contained adequate endogenous protein kinase activity to effect complete activation with addition of cyclic AMP, ATP, and Mg(2+). Activation was blocked by protein kinase inhibitor (from rabbit skeletal muscle) but could be restored fully by addition of excess exogenous protein kinase (from bovine skeletal muscle). The fully activated lipase was slowly deactivated by dialysis at 4 degrees C and then rapidly and almost fully reactivated by addition of cyclic AMP and ATP-Mg(2+). Reactivation was blocked by protein kinase inhibitor. This deactivation-reactivation cycle was rapid at 23 degrees C with dialysis against charcoal and could be demonstrated repeatedly using a single preparation. The reversible deactivation of protein kinase-activated enzyme is presumed to reflect the action of a lipase phosphatase. Lipase prepared from tissue previously exposed to glucagon yielded a much smaller degree of activation than lipase prepared from tissue not exposed to the lipolytic hormone, indicating that the physiological hormone-induced activation is probably similar to or identical with the protein kinase activation demonstrated in the cell-free preparations. Under the conditions of assay used, the partially purified lipase fraction contained diglyceride, monoglyceride, and lipoprotein lipase activities. However, treatment with cyclic AMP-dependent protein kinase had virtually no effect on these lipase activities.
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PMID:Reversible protein kinase activation of hormone-sensitive lipase from chicken adipose tissue. 437 88

Hypertriglyceridaemia is often observed in patients (1) with chronic renal insufficiency, (2) on haemodialysis and (3) after successful renal transplantation. HDL cholesterol is reduced in all three groups of patients and plasma cholesterol is elevated after renal transplantation. In these three patient groups type IV hyperlipoproteinaemia is found most frequently and after renal transplantation there is a relative increase in the incidence of type II hyperlipoproteinaemia. The role of glucagon resistance and carnitine deficiency in the alteration of fat metabolism seen in patients with chronic renal failure and patients on haemodialysis is discussed. Other factors which may influence fat metabolism in uraemia include calcium and vitamin D status as well as beta adrenergic receptor blocking agents and diuretics. Steroid therapy may be one cause of the hypercholesterolaemia and hypertriglyceridaemia seen after renal transplantation. PHLP lipase activity is reduced in all three groups of patients. In nephrotic syndrome, if hypercholesterolaemia occurs, the HDL cholesterol fraction is increased and thus the cardiovascular risk may be lower than in the three patient group mentioned above.
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PMID:[Alterations of fat metabolism in renal disease - pathogenetic mechanisms (author's transl)]. 612 54

The effects of different adrenergic agents on high density lipoprotein (HDL) cholesterol concentration and on the neutral NaCl-resistant triacylglycerol hydrolase (liver lipase) activity of the liver were studied in rats. Treatment of rats with the beta-blockers metoprolol, atenolol or propranolol led to a lowering of the HDL-cholesterol (esterified and non-esterified) content. The alpha 1-antagonist prazosin had no effect. Administration of norepinephrine for 10 days resulted in an increase of HDL non-esterified cholesterol. This effect of norepinephrine was largely abolished by prazosin, but not by propranolol. In normal rats the liver lipase activity was not influenced by alpha- or beta-blockade. Adrenergic stimulation, either short-term (by diethyl ether stress) or long-term (by norepinephrine treatment), led to a lowered liver lipase activity. The lipase activity was restored by prazosin but not by propranolol. The apparent involvement of the alpha 1-receptor in the regulation of liver lipase activity was further studied in vitro. Blockade of alpha- or beta-receptors with prazosin or propranolol did not affect the secretion of the liver lipase activity by isolated parenchymal liver cells. Stimulation of alpha- or beta-receptors by epinephrine led to a lower secreted lipase activity. Selective stimulation by isoprenaline had no effect. The effect of epinephrine could be abolished by prazosin but not by propranolol. Vasopressin and the calcium ionophore A23187 also lowered the secretion of liver lipase activity in vitro. Glucagon and/or the phosphodiesterase inhibitor Ro 20-1724 had no effect. These results indicate an involvement of the alpha 1-receptor in the regulation of liver lipase activity at the level of synthesis or secretion of the lipase. The effect of the alpha 1-receptor is presumably mediated through changes in the intracellular free calcium concentration. The effect of adrenergic modulation on HDL-cholesterol concentrations can partly be explained through modification of the liver lipase activity.
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PMID:Regulation of liver lipase. II. Involvement of the alpha 1-receptor. 614 7

The effect of salmon calcitonin (SMC) on pancreatic enzymes and hormones was investigated following retrograde choledocho-pancreatography (ERCP). 40 patients were randomly divided in two groups and 2.5 micrograms/h SMC or sodium chloride was infused intravenously for 28 hours. Infusion was started 4 hours before endoscopic procedure and amylase, lipase, glucose, insulin, glucagon and gastrin plasma concentrations were measured before and 2, 12 and 24 hours after the end of the ERCP. According to the radiological findings of pancreatography two additional groups were formed: group 1 with visualization of the main duct and its branches and group 2 with additional visualization of the pancreatic parenchyma. No change in glucose, insulin, glucagon and gastrin was found in any of the groups analyzed. Amylase and lipase showed a significant increase after 2 hours and 24 hours later, values were reached which were not significantly different to baseline levels. The time course of the plasma concentrations was identical in the patients treated by SMC or sodium chloride and showed no significant difference at the various time intervals. Therefore, inhibition of the known increase in pancreatic enzymes following ERCP was not found with SMC treatment.
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PMID:[The effect of salmon calcitonin on pancreatic enzymes and hormones before and after retrograde cholangiopancreatography]. 616 82

Exocrine pancreatic function was evaluated by a Lundh meal test and a secretin-cholecystokinin test in 16 patients with chronic pancreatitis. B cell function was assessed by measuring the concentration of C-peptide after stimulation with oral glucose and intravenous glucagon. The Cc-peptide response to intravenous glucagon and oral glucose was closely correlated (r = 0.88, p less than 0.01). Plasma C-peptide after glucagon was significantly correlated to the post-prandial concentration of lipase (r = 0.72, p less than 0.001), amylase (r = 0.64, p less than 0.05) and to amylase output (r = 0.64, p less than 0.05). Eight out of nine patients treated with insulin had residual B cell function, but it diminished significantly with increasing duration of diabetes. We conclude that B cell function is correlated to pancreatic enzyme secretion and that patients with insulin-treated diabetes secondary to chronic pancreatitis have a residual insulin secretion similar to that of patients with Type 1 (insulin-dependent) diabetes.
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PMID:B cell function in patients with chronic pancreatitis and its relation to exocrine pancreatic function. 618 47

The effects of dietary soybean trypsin inhibitor (SBTI, Kunitz type) or repeated i.p. injections of 95% pure cholecystokinin (CCK-39) on rat pancreas were investigated in a 10-day experiment. SBTI and CKK -39 induced similar increases in pancreatic weight, which led to both cellular hypertrophy and hyperplasia. Trypsin and chymotrypsin activity increased with an increase in pancreatic weight. Amylase activity increased only after CCK-39 injection, whereas lipase activity was not affected by either SBTI or CCK-39 treatment. After both treatments, insulin content showed only a slight tendency to increase, whereas glucagon content was not different from controls. The results indicate that SBTI and CCK-39 mainly exert their effects on the exocrine pancreas in a similar but not identical manner. It is therefore suggested that SBTI is not only a potent stimulator of the secretion of CCK activity but also of other unidentified gastrointestinal factor(s).
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PMID:The effect of feeding soybean trypsin inhibitor and repeated injections of cholecystokinin on rat pancreas. 620 62

Post-heparin lipase activities were measured in normolipemic men with complaints suggestive of symptomatic coronary artery disease. A study group, who showed diffuse atherosclerotic narrowing of the coronary vessels, assessed by a quantitative computer-assisted analysis method, had a lowered hepatic lipase in comparison with a group with normal angiograms. Lipoprotein lipase was lower in the study group but well within the normal range and not statistically different. Some related hormones (cortisol, estradiol, testosterone and glucagon) were different in the two groups while others (insulin, human growth hormone, prolactin, thyroid hormones) were not. The results are discussed in view of the proposed role of hepatic lipase in the uptake of HDL-cholesterol by the liver.
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PMID:Post-heparin lipases, lipids and related hormones in men undergoing coronary arteriography to assess atherosclerosis. 635 16

Rat hearts were perfused for long periods in the presence of 14C-labeled amino acids. From these hearts, postheparin-effluent and a tissue homogenate containing lipoprotein lipase and neutral lipase, respectively, were derived. Lipolytic activity and 14C-labeled protein in both preparations were characterized by affinity chromatography, immunoprecipitation and SDS-polyacrylamide gel electrophoresis. Lipase activity and 14C-labeled protein co-eluted from heparin-Sepharose 4B at 1.2 M NaCl and were inhibited and precipitated by preincubation with anti-lipoprotein lipase gamma-globulins. Gel electrophoresis of both preparations showed the presence of 14C-labeled protein with a molecular weight of 35 000. These data strongly suggest similarity between lipoprotein lipase and neutral lipase and their possible precursor-product relationship and indicate that during perfusion continuous synthesis, secretion and vascular binding of lipase molecules occur. Cycloheximide perfusion induced a dramatic decrease of lipoprotein lipase and neutral lipase activity, indicating a half-life of less than 90 min for both enzymes. Tunicamycin present during perfusion also induced a drop in lipoprotein lipase and tissue neutral lipase activity, indicating that glycosylation is necessary for secretion of lipoprotein lipase. Long-term perfusion of rat hearts in the presence of norepinephrine, glucagon or tyrosine leads to reciprocal alterations in lipoprotein lipase and neutral lipase activities, i.e., lipoprotein lipase activity increased and neutral lipase activity decreased, whereas total lipase activity (lipoprotein lipase + neutral lipase) remained unaltered. During perfusion in the presence of insulin, no net change in lipase activities was observed. Also, insulin did not affect the glucagon-induced inverse effects on either lipase activity. The reciprocal changes in lipase activities occurring during norepinephrine perfusion were hampered by colchicine and propranolol, pointing towards beta-receptor and microtubular mediation of tissue lipase processing and endothelial binding. Our data suggest that the tissue flux and vascular binding of lipase protein may be important sites of hormonal regulation of lipoprotein lipase homeostasis.
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PMID:Effects of hormones, amino acids and specific inhibitors on rat heart heparin-releasable lipoprotein lipase and tissue neutral lipase activities during long-term perfusion. 637 31

The alkaline, heparin-releasable lipoprotein lipase (LPL) activity of isolated, perfused rat hearts was compared with the residual neutral lipase (NL) activity detectable in the post nuclear supernatant (PNS) from a tissue homogenate. Both enzyme activities were increased by serum, heparin and apolipoprotein CII, inhibited by high salt concentrations and by immunotitration with an anti-LPL gamma-globulin fraction. Protamine sulphate from saline liver inhibited LPL activity and the NL activity only in the absence of serum. Incubation of the PNS NL under classic conditions of hormonal stimulation (by phosphorylation) did not alter its activity and upon short-term preperfusion of the hearts with norepinephrine and glucagon also unchanged LPL and NL activities were measured. Our experiments are indicative of a possible similarity between vascular LPL and tissue NL and show that the lipase activities are not sensitive towards hormonal stimulation.
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PMID:Comparison of heparin-releasable lipase and tissue neutral lipase activity of rat heart. 667 39


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