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)

We examined the hypothesis that the vascular abnormalities of Bartter's syndrome are due to excess production of prostaglandin. Balance studies and vascular reactivity studies were performed before and after indomethacin (200 mg/day) in a patient with well-documented Bartter's syndrome. During indomethacin, potassium balance became positive, serum potassium rose from 2.1--3 mEq/1 in the absence of potassium supplementation, plasma renin activity decreased from 55--3.2 ng/day and peripheral plasma PGA-like activity fell from 1460 +/- 220 to 456 +/- 71 pg/ml. Before indomethacin, forearm vasoconstrictor responses to brachial arterial infusions of angiotensin II, norepinephrine and to neurogenic reflex stimulation elicited by lower body suction were greatly depressed compared to those of normal subjects. During indomethacin these responses were restored to normal. The dose of intravenous angiotensin II required to increase diastolic blood pressure 20 mm Hg decreased from 160--30 ng/kg/min. These data support the hypothesis that the vascular insensitivity to exogenous angiotensin II, norepinephrine and to neurogenic reflex stimulation observed in this patient with Bartter's syndrome is due to excess prostaglandin. Moreover, stimulation of the renin-angiotensin-aldosterone system in this syndrome appears to be a compensatory adaptation to excess prostaglandin production.
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PMID:Effects of indomethacin on the vascular abnormalities of Bartter's syndrome. 67 46

The derivatization of prostaglandins of the A series with 1:1 mixtures of bis-(trimethylsilyl)trifluoroacetamide and nitrogen-containing non-aromatic heterocyclics such as piperidine, pyrrolidine, morpholine and hexamethylenimine (1--4 h at 60--70 degrees C) gives new types of derivatives, designated as 11-heterocycle, 9-enol PGA (TMS)3. These derivatives show very simplified and characteristic mass spectral patterns strikingly dominated by a common [M-173]+ fragment ion and easily detectable by selected ion monitoring. This feature allows the concurrent analytical detection of both prostaglandin A's and 19-hydroxy prostaglandin A's in biological samples. In this case 2 ml samples of human semen were extracted by direct ultrafiltration on a Pellicon membrane with a nominal molecular weight limit of 1000. The prostaglandins in the approximately or equal to 1.6 ml of ultrafiltrate thus obtained were recovered in ethyl acetate, derivatized as indicated above and detected by monitoring of the corresponding [M-173]+ ions.
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PMID:New derivatives of prostaglandin A1 and specific detection of prostaglandin A's and 190hydroxylated prostaglandin A's in human semen. 70 54

The contractile response of the isolated testicular capsule to acetylcholine, norepinephrine and prostaglandins (A-2, E-1 and F-2alpha) was related to the age of the rat. Norepinephrine and PGA-2 caused an increased capsular response between 45 and 60 days of age, the time at which spermiogenesis begins. It is suggested that the activity of the testicular capsule is involved in the transport of non-motile spermatozoa from the testis and into the epididymis.
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PMID:Age-related differences in the response of the isolated testicular capsule of the rat to norepinephrine, acetylcholine and prostaglandins. 72 75

Human volunteers were exposed in an experimental chamber to styrene (4 or 8 hours at 40 to 200 ppm) in order to obtain a quantitative relationship between exposure and urinary elimination of the metabolites mandelic and phenylglyoxylic acids (MA and PGA). For the analysis of PGA a new GC-method was used, based on reductive transformation of the relatively instable PGA into MA, which is stable enough for shipping and handling until final processing. The analysis of the post-exposure elimination shows that spot urine sampled in the morning after exposure and analysed for the sum of MA and PGA is the most reliable index for reflecing a preceding exposure to styrene.
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PMID:Biological monitoring of exposure to styrene by analysis of combined urinary mandelic and phenylglyoxylic acids. 73 98

Since their discovery more than 40 years ago, PGs have been shown to be present in many tissues. The 10 members of this family (PGA-PGI and TxA) that have been identified to date have been noted to have a wide variety of pharmacologic actions. Frequently, the actions of one PG are in direct opposition to those of another. This has led to the theory that PGs play an important role in maintaining homeostasis in many organ systems. Evidence accumulated indicates a major role for PGs in the regulation of blood pressure, the autonomic nervous system, blood flow and platelet aggregation. This is in addition to specific actions on other tissues such as the CNS and reproductive system. A summary of PG actions in humans is contained in Table 1. Unfortunately, the PGs have not been as useful therapeutically as originally hoped. Currently, they are being used to induce labor and to maintain the patency of the PDA. However, they still hold much promise and with the development of synthetic analogues and specific synthesis inhibitors, they should live up to this promise in the future.
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PMID:Prostaglandins: an overview. 74 49

The role of PGA on the release of renin in the anesthetized dog has been studied. The infusion of prostaglandin for 60 minutes at a dose unable to cause pressor modifications (2 microgram/kg/min) was shown to increase the plasma renin activity (PRA); this effect was inhibited by propranolol and strengthened by aminophylline.
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PMID:Effect of prostaglandin A on renin secretion in the dog. 74 59

It may be concluded that the conversion of PGA to DPGA plays a key role in induction and in the regulation of cycle activity. The high concentrations of PGA in actively photosynthesizing chloroplasts reflect this role and the control exerted by adenylate ratios. Thus the cycle can operate at its maximum rate only in the presence of high PGA and low ribulose 5-phosphate concentrations. Once induction is complete, the reductive pentose phosphate pathway will continue to function at its maximum rate if sink activity within the cytoplasm makes available sufficient Pi to support rapid export of triose phosphate. If triose phosphate tends to build up in the straoma, it will favor pentose monophosphate accumulation. A relative excess of ribulose 5-phosphate would, in turn, inhibit PGA reduction (and hence its own formation) by drawing too heavily on the available ATP.
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PMID:Regulation of photosynthetic carbon assimilation. 74 10

1. Electrophoretic separation of proteases from human gastric mucosal extracts of five patients with gastric ulcer, one with duodenal ulcer and three with gastric cancer were investigated by agar-gel electrophoresis at pH 8.3 and pH 5.0. 2. In the fundic mucosal study, there were seven faster moving proteases in all nine cases, but the slowest moving protease showed a slightly different picture in each case. In the antral mucosal study, two of eight cases showed mainly group II pepsinogens, seven of nine cases, however, showed the same results as in the fundic mucosal study. 3. In the cases of the nine mucosal extracts activated at pH 1.5 or pH 4.0, they all showed the same electrophoretic separation at each pH level. At these two pH levels, however, quite different electrophoretic patterns were observed. The presence of pepsin 3 appeared to diminish at the higher levels of pH, although that of pepsin 5 and pepsin 7 appeared to increase at pH 4.0 and above. Pepsin 6 appeared for the first time at pH 4.0 and existed at higher pH levels. 4. We thus conclude that electrophoretic patterns of pepsins in the gastric mucosal extracts are changeable depending on the pH level of the incubating medium, and further that diversity of pepsins in gastric juices may also depend on the pH level of gastric juices.
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PMID:Studies on the pepsinogens of human gastric mucosal extracts. 74 87

Collagen synthesis was studied in monolayer cultures of rabbit corneal endothelial cells by following [14C]proline and [3H]glucosamine or [3H]fucose incorporation into a fraction enriched for collagen and its precursor molecules. Sodium dodecyl sulfate gel electrophoresis of this fraction showed that it consisted of a high-molecular-weight (greater than 300,000 daltons) polypeptide. This component was collagenase sensitive and, in the presence of dithiothreitol, gave rise to two polypeptides of the apparent molecular weights of 200,000 and 160,000 daltons. Pepsin digestion of this material destroyed all the high-molecular-weight material and gave rise to a single collagenase-sensitive component of an apparent molecular weight of 115,000 daltons. This 115,000 dalton material is similar to previously observed basement membrane collagens, and the 160,000 and 200,000 dalton components are probably precursor chains of basement membrane collagen. The very-high-molecular-weight material (greater than 300,000 daltons) may represent a disulfide-linked complex of these precursor chains. DEAE-cellulose column chromatography confirmed the presence of a single procollagen species distinct from the collagen fraction. Amino acid analysis of collagen and procollagen fractions showed a decreased hydroxyproline value as compared with previously reported basement membrane collagens or collagen precursors.
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PMID:Biochemical characterization of procollagen-collagen synthesized by rabbit corneal endothelial cells in culture. 75 87

Four cases of Barrett's esophagus are presented. Three cases presented with significant esophageal bleeding and one case presented with high esophageal stricture. Gastrointestinal panendoscopy was done in each case and multiple biopsies were taken. The biopsies were utilized for histomorphology, pepsinogen agar gel electrophoresis, and tissue gastrin assays. Tissue gastrin levels in esophageal mucosa were elevated in 2 cases when compared to controls with and without hiatus hernia. Pepsin and acid secretory studies were done by isolating the esophagus. Barrett's esophagus was shown to produce pepsin by both chemical studies (2 cases) and agar gel electrophoresis at pH 5.7 (3 cases), and was also shown to produce acid. The mucosa contained either cathepsin or cathepsin and pepsinogens in all cases. Nissen's fundoplication was performed in all of the patients. Of 3 patients who were bleeding, 2 who consented for this operation stopped bleeding after the operation. It is to be noted that the usual clinical treatment of antacids, bedrest, and raising the head end of the bed failed in all of the patients. The follow-up of 9 months to 3 years postoperatively has shown persistence of Barrett's mucosa with no evidence for any reversion to normal esophageal type.
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PMID:Pepsin secretion, pepsinogen, and gastrin in "Barrett's esophagus." Clinical and morphological characteristics. 77 Feb 25


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