Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1 The report of the depression by indomethacin of vasoconstrictor responses to noradrenaline and their partial restoration by prostaglandin E(2) (PGE(2)) and PGE(1) in rat isolated perfused mesenteric blood vessels was investigated. The further suggestion that prostaglandins may be necessary for the combination of noradrenaline with the alpha-adrenoceptor in this tissue was also studied.2 The reported depression by indomethacin was confirmed and was further shown to be in the form of a concentration-dependent flattening of the noradrenaline concentration-effect curve.3 A concentration-dependent restorative effect was observed for all prostaglandins studied. The decreasing order of potency for the restoration towards normal of the indomethacin-depressed responses to noradrenaline was: PGE(2), PGE(1), PGA(1), PGF(2alpha), PGA(2).4 The prostaglandins studied were not uniform in their restorative actions and could be separated into two groups. PGE(2) and PGE(1) restored responses towards the control level whereas PGA(1), PGA(2) and PGF(2alpha) increased responses to an above control level and did so over a smaller concentration range. The possibility of several prostaglandin receptors is discussed.5 At concentrations equi-effective in restoring depressed responses to control levels PGA(1) but not PGE(2), caused a parallel shift of the noradrenaline concentration-effect curve to the left and a small, gradual rise in the basal perfusion pressure.6 The reason for the differing effects remains obscure but does not seem to involve a change in the alpha-adrenoceptor as indicated by the pA(2) of phentolamine. Furthermore, the restorative and potentiating effect of PGA(1) is not mediated by blockade of neuronal uptake of noradrenaline.7 It appears that prostaglandins are required for the vasoconstrictor action of noradrenaline in rat mesenteric blood vessels and that this effect is distal to the drug-receptor interaction. The possible involvement of prostaglandins with intracellular calcium ions is discussed.
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PMID:The influence of prostaglandins on noradrenaline-induced vasoconstriction isolated perfused mesenteric blood vessels of the rat. 20 65

The NAD+-linked 15-hydroxyprostaglandin dehydrogenase (PGDH) of swine lung was purified to a high specific activity by affinity chromatographies on prostaglandin (PG)-and NAD+-Sepharose. The affinities of the enzyme for various synthetic analogues of PGA, E, F, and I and their inhibitory effects on the enzymatic reaction were examined. The modification of the alkyl side chain of PG, particularly at C-15 or C-16, reduced the affinity of the enzyme for these PG analogues. Furthermore, 14-methyl-13,14-dihydro-PGE1 and 16-cyclopentyl-omega-trinor-15-epi-PGE2 were potent inhibitors of PGDH.
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PMID:Studies on 15-hydroxyprostaglandin dehydrogenase with various prostaglandin analogues. 21 66

Prostaglandins (PG) have been shown to raise the level of cyclic AMP (cAMP) in various tissues, and to increase permeability. Whether both events are linked, is at present a matter of speculation. We have investigated the effects of PGE1, E2, A1, A2, F1alpha and F2alpha on an isolated rat mesentery placed in a diffusion cell (surface area : 2 sq.cm). The PGs (5 microgram/ml) increased the passage of (I 125) - Albumin across the mesentery. In other experiments, diks of rat mesentery (surface area : 2 sq.cm) have been incubated in assay tubes, and cAMP levels measured by a binding protein assay. We have observed an excellent correlation between increases in permeability and cAMP levels (r=0.961). In order of increasing potency on both parameters, the PGs may be classified as follows : PGF, PGA and PGE. In the rat mesentery, under the influence of prostaglandins, increases in permeability and in cAMP levels are apparently connected.
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PMID:The role of various prostaglandins on the correlation between permeability to albumin and cAMP levels in the isolated mesentery. 21 45

Sera from 84 patients with chronic liver disease [CLD] (74 chronic active) and from 53 blood donors were tested immunochemically for anti-liver cell membrane antibody (LMAb). LMAb to rat liver tested by an indirect immunofluorescent technique was positive in 53.3% of CLD patients with positive HB surface antibody (HBsAb) and 40.0% of HBsAb positive blood donors. Pepsin digestion of the sera indicated that the binding between liver cell membrane and IgG was at the Fc site on the immunoglobulin. The sera with positive LMAb from HBsAb positive blood donors had elevated Clq-binding activity (Clq-BA). The LMAb to rat liver was a macro-molecular IgG (19-22S IgG) when assayed by Sephadex G-200 column chromatography and 5-40% sucrose density gradient ultracentrifugation. The results suggest that the LMAb in serum from a patient with chronic active liver disease may be an immune complex which consists of various antigens such as HB virus and its antibodies in serum.
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PMID:Detection and characterization of antibody to liver cell membrane in sera from patients with chronic active liver diseases. 22 Aug 48

1. The serum gastrin level, gastric mucosal blood flow and acid secretion from the canine Heidenhain pouch have been measured in response to the introduction of bovine serum albumin, pepsin-digested albumin, an amino acid mixture, liver extract and mannitol used as control. 2. Distention of the Heidenhain pouch with mannitol or albumnin at pH 5-0 produced a similar pressure-related increase of acid secretion reaching a peak of only 10 percent of the maximal response to histamine. Pepsin-digested albumin was capable of producing larger acid outputs than undigested albumin. The highest acid output, attaining about 80 percent of the maximal response to histamine, was obtained with liver extract both before and after exhaustive dialysis to remove all the amino acids and short peptide fragments. An amino acid mixture containing all essential amino acids was also found to stimulate acid secretion but a lesser degree than liver extract. 3. This concluded that it is not the intact protein but the products of its digestion, the polypeptides and free amino acids, which are potent chemical stimulants of acid secretion from the oxyntic gland area. Since the serum gastrin level was not changed during acid secretion induced by peptic digests bathing the oxyntic gland area, the mechanism of chemical stimulation appears to be gastrin-independent. 4. The response to chemical stimulation by peptic digests can be greatly potentiated by combining this with distention of the oxyntic gland area. Topical application of xylocaine or atropine causes a marked decrease of Heidenhain pouch response to peptic digests, suggesting a possible neural reflex component in the mechanism of chemical stimulation of the oxyntic gland area. 5. When the pH of the liver extract in the Heidenhain pouch was gradually decreased in sequential order from 5-0 to 1-0, this resulted in a pH-related decrease in acid secretion and in the mucosal blood flow falling to the basal level at pH 1-0. Exogenous secretion given in graded doses from 0-5 to 8-0 u./kg. hr caused a small but dose-related inhibition of acid response to liver extract accompanied by a decrease of mucosal blood flow but without any significant change in the serum gastrin level. 6. The results indicate that the chemical stimulation of the oxyntic gland area by peptic digests is capable of inducing acid secretion by a local, gastrin-independent, partially neural reflex mechanism; sensitive to pH, pressure and secretin.
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PMID:Chemical stimulatory mechanism in gastric secretion. 23 20

Ribulose-diphosphate carboxylase from Thiobacillus novellus has been purified to hemogeneity as observed by polyacrylamide gel electrophoresis and U.V. light observation during sedimentation velocity analysis. The optimum pH for the enzyme with Tris-HCl buffers was about 8.2. Concentrations of this buffer in excess of 80 mM were inhibitory. The apparent Km for RuDP was about 14.8 muM with a Hill value of 1.5, for HCO3- the apparent Km was about 11.7 mM with an n value of 1.18 and for Mg2+ about 0.61 mM. The enzyme was specific for this cation. Relatively high concentrations of either Hg2+ or pCMB were required before significant inhibition was observed. Activity declined slowly during a 4-hr incubation period in either 3.0 M or 8.0 M urea. Incubation for 12 hrs resulted in complete loss of activity which was not prevented by 10 mM Mg2+ and was not reversed by dialysis and subsequent addition of 10 mM cysteine. Polyacrylamide gel electrophoresis revealed a loss of the major band and the appearance of 2 new bands. SDS polyacrylamide gel electrophoresis gave an average M.W. of 73500 +/- 2500 for the slower moving band and 12250 +/- 2500 for the faster moving. However, incubation in urea for up to 40 hrs revealed a decrease in the M.W. of the slower moving band to about 60000. The Ea for the enzyme was calculated to be about 18.85 kcal mole-1, with the possibility of a "break" between 40 and 50 degrees C. The Q10 was 3.07 between 20 and 30 degrees C whereas between 30 to 40 degrees C it was 3.31. Only phosphorylated compounds caused significant inhibition of enzyme activity. They included ADP, FDP, F6P, G6P, PEP, 6PG, 2-PGA, R1P, R5P, and Ru5p.
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PMID:Properties and regulation of ribulose diphosphate carboxylase from Thiobacillus novellus. 24 94

Metabolic degradation of prelabeled collagen in whole body skin and whole intestine was compared to that of types I and III collagens from skin in young, rapidly growing rats. Pregnant rats were given [3H]proline during the last week of gestation; and after birth, littermates were compared. Between the second and sixth weeks of age, there was a 43% loss of radioactivity from dermal collagen but no significant loss of radioactivity from intestinal collagen. Pepsin treatment solubilized 90% of the dermal collagen but only 12% of intestinal collagen. Skin from 2- and 6-week-old rats yielded the same proportions of type I and type III collagens (type I, 82%; type III, 18%). The relative losses of total radioactivity from types I and III were similar to each other (50 and 44%, respectively) and to the loss from whole skin. Because types I and III collagens are known to be present in both skin and intestine, the marked degradation of both collagen types in skin but not in the intestine may be related to the amount and kind of intermolecular crosslinks present.
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PMID:Collagen degradation in rat skin but not in intestine during rapid growth: effect on collagen types I and III from skin. 26 84

This study compared the osteogenic potential and tissue compatibility of biodegradable copolymers--PLA/PGA--and a biodegradable ceramic--Ca3(PO4)2. These compounds were placed in experimentally created defects in rat tibias, both in combination and singly, and evaluated at 14, 28, and 42 days. The ceramic served as a format to result in uniform osteogenesis throughout the defect. The copolymer implants resulted in a more gradual bone formation, progressing slowly from the would peripheries. The ceramic and copolymer combination behaved little differently from the copolymer alone. All experimental materials were extremely tissue tolerant, with minimal inflammation and no foreign-body reactions.
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PMID:Evaluation and comparisons of biodegradable substances as osteogenic agents. 26 77

Antiserum raised in rabbits against the FBP obtained from CML cells, and the purified binder labeled with 125I, have been used for an RIA which can measure an immunologically similar protein in human serum. The concentration of the binding protein in normal serums ranged from 1.2 to 9.3 ng/ml, with a mean +/- S.E.M. of 3.8 +/- 0.4 ng/ml. Elevated values of the binder protein were measured in the serums from patients with folate deficiency, vitamin B12 deficiency, liver disease, uremia, myeloproliferative disease, chronic lymphocytic leukemia, and various types of cancer and in the serum from pregnant women. The concentration of the binder protein and the capacity of the serum to specifically bind isotopically labeled PGA correlated poorly, indicating that the binding protein concentration and degree of saturation by endogenous serum folate vary independently in many instances.
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PMID:The identification and measurement of a folate-binding protein in human serum by radioimmunoassay. 27 99

Gastric H+ and pepsin studies before and at intervals for 4o months after fundic vagotomy (HSV) in 3 fistula dogs were done with the vagal stimulant 2-deoxyglucose (2-DG), and blocked the secretory response to 2-DG, but secretion began to recover by 5-6 months, and from 16 months on stabilized at 60% H+ and 13-17% pepsin (preoperative = 100%). After HSV the stomach showed hypersensitivity to urecholine with a lower threshold and lower Km, but unchanged Vm, while with histamine the curves were shifted to the right, with Vm unchanged and Km increased. With pentagastrin there was also a small decrease in Vm. Pepsin responses to urecholine recovered and exceeded control by 16 months, but remained relatively unresponsive to histamine or pentagastrin. A cholinergic background provided by urecholine at subthreshold doses (less than 10 mug/kg-hr) restored both pentagastrin and histamine responses to prevagotomy levels. Gastrin release from the innervated antrum by 2-DG was several times greater than in controls and was atropine sensitive. The results indicate that denervation of the secretory mucosa, especially of the peptic cells, is never more than partially reversed even after 3 years. Even though the response to vagal stimulation is partial, the mucosa remains capable of normal response, ie, there is no atrophy, and therefore, the vagus is not directly trophic to the gastric fundus. Moreover, vagotomy was followed by some hypersensitivity to urecholine, indicating changes in cholinergic receptors like those seen in denervated muscle cells.
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PMID:Long-term effects of highly selective vagotomy (HSV) in dogs on acid and pepsin secretion. 31 58


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