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)

Human umbilical blood vessels have the ability to close spontaneously following delivery at term. It has been suggested that prostaglandins may have a possible physiological role in its closure. This study investigates the effects of 6 naturally occurring prostaglandins (A1, A2, B1, B2, E2, F2a) on the umbilical blood vessels. Umbilical cords were collected from cases of normal spontaneous vaginal deliveries and cesarian section at term. A total of 41 strips of umbilical arteries and 26 strips of umbilical veins from 24 cords were used. A 4-point bioassay method was used to compare the potency of prostaglandins A1, A2, B1 and F2a with PGE2. The effect of Polyphloretin Phosphate (PPP) on prostaglandin-induced contractions was studied on umbilical artery strips from 12 cords. The 6 prostaglandins exerted a stimulant effect on the isolated strips of human umbilical arteries. Prostaglandin B2 was the most potent compound on the umbilical vein, followed by PGA2. PPP in the concentration range of 10 to 40 mcg/ml completely eliminated the responses of PGE2, F2a, A1, A2, and B1. Responses to PGB2 were considerably but not completely abolished. PPP (up to 40 mcg/ml) did not affect contractions induced by 5-hydroxytryptamine, suggesting the presence of discrete receptor sites in the blood vessels for different pharmacologically active compounds. This is the first report of the constrictor effect of PGA and PGB compounds. These naturally occuring prostaglandins with high potencies (compared with other prostaglandins and other vasoactive substances) may play a role in spontaneous closure of umbilical vessels. PGE1, E2, F1 and F2a are found in umbilical blood vessels obtained at term.
Prostaglandins 1974 Dec 10
PMID:Effect of prostaglandins A1, A2, B1, B2, E2 and F2 alpha on human umbilical cord vessels. 445 25

Prostaglandins are analogs of the parent 20 carbon prostanoic acid. They are divided into 4 series: PGE; PGF; PGA; PGB, according to the presence of functionalities in the cyclopentane structure. Biosynthesis of prostaglandins were first independently reported by Bergstrom et.al. and van Dorp et.al. who showed that certain w-6-unsaturated fatty acids were biological precursors of prostaglandins. Later, various investigators reported the biosynthesis of prostaglandins of the different series. The 2 most widely used routes of prostaglandins synthesis are 1) the Corey cyclopentyl-lactone route, and 2) the bicyclohexane route. The synthesis is divided into 1) naturally occuring primary prostaglandins and 2) the prostaglandin analogs and derived prostaglandins. Because of the general instability of natural prostaglandins in the basic and acidic milieu, various preparations of prostaglandins and chemically stable dosage forms have been developed. Various methods used in analyzing prostaglandins include: 1) TLC; 2) GLC; 3) spectral methods; 4) radioimmunoassay; and 5) enzymatic assay. In vitro and in vivo studies on the metabolism and catabolism of various prostaglandins showed that they are rapidly metabolized in various animal systems and humans. The major routes for this metabolic transformation are: 1) oxidation of the secondary C15 hydroxy group; 2) reduction of the C13 double bond; 3) B-oxidation; 4) w-hydroxylation; and 5) w-oxidation. Prostaglandins produce a wide range of biological effects on animal and human systems (the reproductive; gastrointestinal; respiratory; and cardiovascular systems). The biological actions of prostaglandins on animal and human reproductive tissue vary depending on the particular prostaglandin studied and hormonal state of the tissue. Certain prostaglandins can decrease the tonus, frequency, and amplitude of spontaneous contractions of human uterine strips while other prostaglandins can cause contraction of isolated myometrial strips. Prostaglandins are widely used in labor induction; induction of therapeutic abortion; and fertility control. Prostaglandins have also been found to either increase or decrease cyclic AMP; inhibit ADP-induced platelet aggregation; lower blood pressure in animals; affect lipid and carbohydrate metabolism, and prevent adjuvant arthritis.
J Pharm Sci 1972 Dec
PMID:Prostaglandins. 456 72

Gastric secretion in man is inhibited by the presence in the duodenum of hyperosmolar and hypoosmolar solutions. Both acid and pepsin outputs are affected. There is no change in hydrogen, sodium, or potassium ion concentration in the gastric juice. Pepsin concentration, however, is reduced by all inhibitory stimuli. Inhibition is thought to act directly upon parietal and chief cells, and a possible basis for this mechanism is discussed. The response is similar in control subjects and duodenal ulcer patients; there is in particular no evidence of impaired inhibition in the ulcer group. An anomalous feature is the relatively small inhibition of acid output after hypertonic saline in control subjects compared with the duodenal ulcer patients.
Gut 1969 Dec
PMID:Duodenal inhibition of gastric secretion by osmotic agents in normal subjects and patients with duodenal ulcer. 490 22

The purpose of these studies was to characterize the effect of the new anticancer preparation, 5-fluorouracil-polyglycolic acid-composite (F-PGA needle), on experimental tumors and in patients with solid tumors. The formative composite in a F-PGA needle was found to easily dissociate in physiologic saline resulting in the release of 5-fluorouracil (5-FU). The aspect of 5-FU release was observed to be relative to 5-FU content in the needle, but not to the length of the needle. When a F-PGA needle of 10mm in length and 30% in 5-FU content was subcutaneously or intrahepatically implanted in healthy rats, the release of 5-FU was maintained for 9 days in each case. Pathophysiologic examination of the liver following the implantation of a F-PGA needle revealed an increase in severe necrosis and/or degeneration and infiltration of small-round cells with the increase in release of 5-FU. Implantation of F-PGA needles into tumor mass of AH 130-bearing rats resulted in an increased 5-FU level in tumor tissue reaching the maximum level of 16.00 +/- 1.98 micrograms/g after 24 hours, and in a marked inhibition of the tumor growth indicating 2.4% of T/C (tested/controlled) at 10 days after implantation of the needle. A study of the F-PGA needle was made for 10 patients with terminal carcinomas and in 5 of these were verifiable. Of these 5 patients, shrinkage of tumors or improvement of symptoms was observed in 3 cases. From these results, the F-PGA needle is promising in the treatment of unresectable cancer as a long-acting chemotherapy.
Nihon Geka Gakkai Zasshi 1984 Dec
PMID:[Studies on the new anticancer preparation, 5-fluorouracil-polyglycolic acid-composite and its therapeutic evaluation]. 609 6

Human leukocyte interferon (hIFN-alpha) preparations contain immunologically and biologically recognizable endorphin and corticotropin-like (ACTH-like) activities. The ACTH bioactivity was demonstrable only after pepsin or acid treatment. Highly purified hIFN-alpha was composed of two molecular species of interferon (18,500 and 23,000 daltons). Endorphin activity was associated with both of these molecules. Pepsin treatment of the 23,000-dalton but not the 18,500-dalton hIFN-alpha generated ACTH activity. In acid, the 23,000-dalton hIFN-alpha broke down into the 18,500-dalton form and ACTH (4500 daltons). The ACTH derived from hIFN-alpha by pepsin digestion comigrated with a purified ACTH standard in NaDodSO4/polyacrylamide gel electrophoresis. hIFN-alpha-producing lymphocytes showed positive immunofluorescence after staining with highly specific antisera to ACTH alpha-(1-13) and gamma-endorphin. Essentially 100% of the human peripheral lymphocytes were capable of producing both ACTH and gamma-endorphin-related substances, presumably associated with hIFN-alpha. These results strongly suggest a circuit between the immune and neuroendocrine systems which involves neuroendocrine hormone-like substances, some of which are associated with hIFN-alpha
Proc Natl Acad Sci U S A 1981 Dec
PMID:Human lymphocyte production of corticotropin and endorphin-like substances: association with leukocyte interferon. 617 75

Prostaglandins of the A series potently inhibited the production of vaccinia virus in mouse L fibroblasts. With the highest non-toxic dose of PGA1, 4 micrograms/ml, the replication of the virus was inhibited by 95 . 3%. The antiviral activity was dose-dependent and specific for the A series. At the dose used, PGA1 was not toxic to uninfected cells and did not alter cell metabolism as measured by DNA, RNA and protein synthesis. PGA1 did not influence the adsorption of the virus by the host cells and the antiviral activity was not dependent on the presence of PGA1 during the early stages of infection. PGA treatment delayed and partially inhibited virus DNA synthesis and, while it did not produce any change in the pattern of protein synthesis in uninfected cells, it altered both the rate and the pattern of virus protein synthesis. We conclude that PGA1 selectively inhibits one or more steps involved in the replication of vaccinia virus in mouse L fibroblasts.
J Gen Virol 1982 Dec
PMID:Antiviral effect of prostaglandins of the A series: inhibition of vaccinia virus replication in cultured cells. 618 27

The final step in acid secretion is believed to result from the H+-K+-ATPase-mediated exchange of H+ in the parietal cell, with K+ in the lumen. To study the K+ secretion we used Picoprazole and insulin separately and together to inhibit gastric secretion stimulated in gastric fistula dogs with histamine (100 micrograms X kg-1 X h-1). Picoprazole, a substituted benzimidazole (750 mg/kg), reduced gastric H+ concentration and volume with a rise in K+ concentration [( K+]) to 20-25 meq/l. Insulin alone inhibited acid output to the same extent as Picoprazole but with a marked fall in [K+]. Insulin (0.6 U/kg) given with Picoprazole did not alter inhibition of H+ but prevented the large decrease in gastric juice [K+]. An injection of KCl (1 meq/kg) 1 h after Picoprazole did not alter the effects of the inhibitor. Pepsin secretion after insulin was delayed by Picoprazole, whereas during bethanechol chloride infusion (80 micrograms X kg-1 X h-1) pepsin output was reduced for a shorter period and to a lesser extent than acid. We concluded that insulin affects gastric H+ and K+ secretion by a mechanism not related to H+-K+-ATPase and that Picoprazole affects pepsin secretion probably indirectly via its effect on the parietal cell, where its action is quite consistent with an effect limited to inhibition of the H+-K+-ATPase of the parietal cell.
Am J Physiol 1983 Dec
PMID:Effects of KCl and insulin on benzimidazole-inhibited canine gastric secretion. 641 24

Although aflatoxicosis in Coturnix coturnix japonica has been described, the histochemical localization of liver chemicals and the occurrence of ingested aflatoxins within blood, feces, and liver have not been described. Six to 8-week-old quail, which were intubated with a carrier with or without .3 mg mixed aflatoxins (AFB1, AFB2, AFG1, AFG2)/kg body weight were sacrificed within .25 to 5 days of intubation. Deparaffinized sections of livers were stained for lipids, nucleic acids, polysaccharides, and proteins. Other livers and excrement were homogenized and filtered homogenates as well as blood partitioned against chloroform. The aqueous phase was treated with pepsin and then partitioned, but the organic phase was analyzed directly. Organic phases of .25 to 5 day blood, feces, and liver lacked aflatoxins. Pepsin digesta of blood from males and females dosed 6 hr appeared to contain aflatoxicol (disappeared by 24 hr) and an unknown fluorescent compound, respectively. Whereas an unidentified fluorescent compound was observed within excrement of males dosed 6 hr, female excrement contained a fluorescent compound with an AFB1 Rf (disappeared by 24 hr). Although the liver of males dosed 6 hr had three fluorescent compounds (Rfs for AFB1 and AFB2a), only one was seen within dosed females. Ultra violet absorption spectra of presumed AFB2a and aflatoxicol failed to yield their reported absorption maxima. Livers from dosed quail exhibited bile duct proliferation, cellular necrosis, vacuolization, congestion, fatty changes and mild hepatitis. Sinusoidal membranes were thickened and contained abundant periodic acid-Schiff's (PAS)-positive substances. Although livers of nondosed quail abounded with regularly shaped and uniformly distributed, Sudan IV-positive droplets, livers of dosed quail accommodated few, irregularly-shaped and positioned droplets. Hepatocyte nuclei and nucleoli of dosed quail displayed marked affinities for the Feulgen reagent and toluidine blue O, respectively. Lobules of dosed quail possessed concentrations of cells in which their entire cytoplasm was PAS positive. Treatment of sections with alpha-amylase reduced staining suggesting the presence of glycogen. Ninhydrin-positive substances were distributed throughout the liver in both DQ and non DQ with no apparent difference in intensities between the two livers. Generally the DQ showed mild hepatitis due to aflatoxicosis and the toxin altered liver histochemistry for the major classes of cellular chemicals.
Poult Sci 1983 Dec
PMID:Histochemical analysis of liver cells from short term, aflatoxin-dosed and nondosed Coturnix coturnix japonica. 1. Aflatoxin-sensitive quail. 666 1

Single cell protein (SCP) derived from secondary clarifiers of pulp mills is a potential commercial protein supplement in many areas. Samples of SCP were collected from several pulp mills in the Pacific Northwest and evaluated by laboratory procedures. Six in vivo digestion trials were conducted to determine the relative nutritive value of SCP that was dewatered by centrifugation or by the addition of a polyacrylamide polymer before being put through a belt press and dried with a sonic dehydrator. Amino acid analyses showed that SCP was higher in methionine than was cottonseed meal (CSM) and had a similar level of lysine. True protein, based upon amino acids recovered in SCP samples, ranged from 51.6 to 65.9% of the crude protein (CP). Pepsin digestibility of the CP ranged from 16.2 to 36.8%. Pepsin digestibility increased by 6.3 to 11.3 percentage units when SCP were incubated in a buffered rumen fluid for 24 hours. Solubility of the nitrogenous components in 10% Burroughs' buffer solution ranged from 12.4 to 36.5%. The range in mineral composition was : P, .62 to 1.55%; Ca, .14 to .99%; K, .21 to 5.52%; Mg, .07 to .59%. The concentration of trace minerals and heavy metals varied considerably from sample to sample. Digestion trials were conducted with sheep to compare SCP with CSM; 20 to 50% of the total CP was provided by the SCP sources. The CP digestibilities of the centrifuged and the polymer-dewatered SCP were 70.5 to 70.8% and 66.3 to 69.9%, respectively, of that observed for CSM. In all digestion trials, sheep consumed the SCP diets readily, and no digestive disturbances were observed. On the basis of laboratory and in vivo results, pulp mill SCP has the potential to be a viable protein supplement for livestock.
J Anim Sci 1981 Dec
PMID:Evaluation of single cell protein from pulp mills: laboratory analyses and in vivo digestibility. 680 31

The present study was designed to compare collagen synthesized by rabbit lens epithelial cells in culture with rabbit lens capsule collagen. Confluent monolayers of rabbit lens epithelial cells were established. Incorporation of [3H]-proline into glycoproteins secreted into the medium and cell surface components were analyzed in the presence of protease inhibitors. Gel filtration chromatography on sodium dodecyl sulfate--agarose (Bio-gel A-5m) of [3H]-labeled newly synthesized proteins by lens epithelial cells in culture resolved into a single precursor of approximate molecular weight of 160,000 daltons. Neither the medium nor the cell layer showed any evidence of low-molecular weight hydroxyproline-containing material. Limited pepsin digestion of this material cleaved the higher molecular weight chains into smaller components ranging from 25,000 to 110,000 daltons. Pepsin digestion and direct extraction of the collagenous components of the rabbit lens capsule revealed materials of high--molecular weight proteins similar to that synthesized in culture. Low--molecular weight (55,000 daltons) protein was only detected in lens capsules after prolonged pepsin digestion. S-Carboxylation of the lens capsules collagens did not affect their mobilities, but repepsinization gave rise to 110,000 dalton protein, although no significant changes in the amino acid composition were noticed. The absence of synthesis of low--molecular weight protein by cell culture and the presence of low--molecular weight components only after prolonged pepsin digestion of lens capsule could be the result of unusual susceptibility of the basement membrane collagens to pepsin attack.
Invest Ophthalmol Vis Sci 1982 Dec
PMID:Structure and biosynthesis of rabbit lens capsule collagen. 681 26


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