Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: HUMANGGP:036206 (endoplasmic reticulum)
 63,868 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. The morphology of the juxtaglomerular apparatus, plasma renin activity, plasma renin substrate and renal renin have been studied in rats after maximal stimulation by bilateral adrenalectomy and salt depletion, and also after blocking this stimulation by deoxycorticosterone and salt load. 2. After stimulation the juxtaglomerular apparatus showed a well-developed granular endoplasmic reticulum and a low secretory granule content. Plasma renin activity was markedly elevated and plasma renin substrate was low. After blockade numerous specific granules with crystalline structures were seen and the granular endoplasmic reticulum was less developed. Plasma renin activity was now low and plasma renin substrate elevated. 3. After prior acidification of the kidney extract a significant increase of renal renin was observed in both conditions but was greater in the second group at the time when large numbers of young granules containing crystalline material were seen. 4. Kidney slices from the adrenalectomized salt-depleted rats released more renin than control slices. Vincristine did not affect this release, but inhibited release from slices stimulated by isoprenaline.
Clin Sci Mol Med Suppl 1976 Dec
PMID:Control of renin secretion in vivo and in vitro in rats: arguments in favour of a precursor form of renin and of a role of a microtubular system. 1 63

Nine young, healthy male volunteers were given ethanol (75 g/day) for 5 weeks. The ethanol was divided into five daily doses and taken so that blood ethanol levels never exceeded 0.04% (w/v). During the latter part of the ethanol intake period, there was a significant, transient increase of plasma triglyceride (TG) concentrations followed by reduction to normal levels. A three-fold increase of lipoprotein lipase activity (LLA) occurred in biopsy specimens of adipose tissue. An increase of alpha-lipoprotein concentrations, which correlated significantly with the decrease in plasma TG levels and the increase in adipose LLA, was also observed during the ethanol intake period. No changes were observed in plasma cholesterol and beta-lipoprotein levels. A transient, three-fold increase of TG concentrations occurred in liver biopsy specimens. Ultrastructural and cytochemical examinations of the biopsy specimens showed hyperplasia of the smooth endoplasmic reticulum, and increased canallicular activity of gamma-glutamyl transferase (gamma-GT) activity in most subjects towards the end of and after the ethanol intake period. Serum gamma-GT levels also increased significantly.
Eur J Clin Invest 1977 Apr
PMID:Alterations of lipid metabolism in healthy volunteers during long-term ethanol intake. 1 44

Modification in the enzymatic complement and lipogenic functions of rat liver endoplasmic reticulum (ER) were shown to occur during pneumococcal sepsis. Glucose-6-phosphatase, 5'nucleotidase, esterase, and NADPH cytochrome C reductase decreased in activity by as much as 50% with respect to controls. Hydroxymethylglutaryl-CoA and NADH cytochrome C reductases were increased 6-and 2-fold, respectively. Alkaline phosphatase and inosine-5'-diphosphatase did not differ with respect to fasted controls. The lipogenic capacity of the ER was shown to be enhanced. In vitro [14C]acetate incorporation into cholesterol and other lipids by hepatocytes isolated from infected rats was increased 2-to 10-fold. It is concluded that the flow of acetyl-CoA in liver cell of Streptococcus pneumoniae-infected rats is toward lipogenesis rather than ketogenesis.
Am J Clin Nutr 1977 Aug
PMID:Effects of pneumococcal infection on rat liver microsomal enzymes and lipogenesis by isolated hepatocytes. 1 31

Acute and chronic ethanol ingestion can alter both the pharmacodynamics and pharmacokinetics of other drugs. For psychotherapeutic drugs, modification of drug action by alcohol is much more important than kinetic interaction, such as ethanol induced drug metabolism. In contrast, the importance of the effects of alcohol on the kinetics of other classes of drug is incomplete. The probability and mechanism of alcohol kinetic interactions with other drugs can nevertheless be anticipated, in part, on the basis of the extent of binding of the drug to plasma proteins, the capacity of the liver for extracting the drug from blood passing through the liver and the true distribution space of the drug. Highly bound drugs with low intrinsic hepatic clearance are among the most commonly reported to have their kinetics altered by ethanol (e.g. benzodiazepines, phenytoin, tolbutamide and warfarin). Less highly bound drugs are less consistently affected (e.g. meprobamate, glutethimide, pentobarbitone and phenobarbitone). Acute administration of ethanol to laboratory animals or incubation of microsomal preparations with ethanol inhibits the mixed function oxidase activity. In the human, the elimination half-life of meprobamate, pentobarbitone and tolbutamide is increased by acute ethanol administration. Chronic administration of ethanol to rats and humans causes proliferation of the smooth endoplasmic reticulum, increase in microsomal protein content and cytochrome P450 and results in an augmentation in drug metabolising ability of the microsomes in vitro. Even though the plasma half-life of some drugs is decreased by chronic ethanol ingestion, the clinical determination of the mechanism is incomplete because few studies have measured drug metabolite levels. In addition, alcohol effects on drug distribution have not been studied very extensively. The effects of chronic alcohol ingestion on drugs with low and high hepatic extraction, high and low binding, important tissue localisation and microsomal and non-microsomal metabolism will be quite different. Systematic studies of the mechanism of alcohol kinetic interactions are needed. Such kinetic studies should be combined with pharmacodynamic measures in order to establish the clinical importance of changes in drug kinetics.
Clin Pharmacokinet
PMID:Drug kinetics and alcohol ingestion. 3 Dec 57

The localization of gamma-glutamyltransferase activity in guinea pig liver was studied after subcellular fractionation. The enzyme activity was essentially connected with plasma membranes whereas only low activity was found in the endoplasmic reticulum. A similar activity distribution was demonstrated for 5'-nucleotidase. Highest specific activity of gamma-glutamyltransferase was found in plasma membranes enriched in bile canaliculi. In this fraction the specific activity was 35 times greater than the specific activity of the total homogenate, a value similar to the relative specific activity of (Na+,K+)-ATPase. More than 90% of the total gamma-glutamyltransferase activity in guinea pig liver was connected with parenchymal cells and the enzyme seemed to have an outside orientation. Animals treated with phenobarbital showed moderate increased in gamma-glutamyltransferase activity in serum and liver, whereas high activities were found in most bile samples. No particular liver subfraction showed substantial accumulation of gamma-glutamyltransferase activity. The present findings do not support the suggested use of serum gamma-glutamyltransferase measurements as a direct index of "microsomal enzyme induction".
Clin Chim Acta 1979 Jun 01
PMID:Subcellular localization of gamma-glutamyltransferase activity in guinea pig liver. Effect of phenobarbital on the enzyme activity levels. 3 6

Asynchronously dividing mouse fibroblasts (L-cells) treated with the antitumour antibiotic Bleomycin show various rather specific morphological alterations. Many of the cells exposed to bleomycin assume a more or less epitheloid cell shape and are larger than untreated cells; in addition to an increase in nuclear size these cells often contain multiple nuclei. In most of the cells nuclei show an almost complete loss of peripheral condensed chromatin. The nucleolar hypertrophy initially observed is followed by a shrinkage and segregation of the nucleolar components. The cytoplasmic alterations include dilatation of the cisternae of the rough endoplasmic reticulum as well as an increase of free, non membrane attached ribosomes, often arranged in spiral- and rosette-shaped polysomes; they are not specific for bleomycin.
Z Krebsforsch Klin Onkol Cancer Res Clin Oncol 1976 Jan 02
PMID:Effect of bleomycin on the fine structure of mouse fibroblasts. 5 93

The therapeutic effectiveness of bromocriptine as well as the post-operative ultrastructural aspects of treated pituitary adenomas were investigated in five acromegalic patients. Although concentrations of GH basal decreased and the glucose tolerance test and the TSH responses were significantly improved, the release of GH induced by TRH was not prevented by the dopaminergic agonist. Adenomatous cells were densely granulated and contained a dilated endoplasmic reticulum. Misplaced exocytosis was frequently observed. These findings clearly indicate that bromocriptine inhibits the spontaneous release of GH but does not interfere with the abnormal GH response to TRH. This suggests a separate site of action. The drug seems not to block the synthesizing activity of the adenomatous cell, a finding in accordance with clinical observations that warns against its use as a single therapeutic agent.
Clin Endocrinol (Oxf) 1978 Oct
PMID:Serum growth hormone and ultrastructural studies of adenohypophysial tissue in bromocriptine treated acromegalic patients. 10 68

Three lysosomal glycosidases, beta-glucuronidase (EC 3.2.1.31), beta-galactosidase (EC 3.2.1.23), and N-acetyl-beta-glucosaminidase (EC 3.2.1.30) have been investigated in bile that was freshly collected from rats through a complete bile fistula. Assay conditions have been established on the basis of appropriate kinetic studies. The biliary excretion patterns for these enzymes were found to vary considerably from rat to rat during the 24-h collection period. In a given animal, however, the three hydrolases were excreted in parallel and showed a gradual increase in activity with time, most marked after 10- 12 h of collection. 24-h biliary outputs of the three hydrolases averaged congruent with3% of their respective contents in total liver, and bile diversion had no effect on hepatic glycosidase activity or total protein content. Other enzymes known to be associated primarily with mitochondria, endoplasmic reticulum, and cell sap were also detected in bile, generally in smaller amounts. The biliary excretion of the plasma membrane markers, alkaline phosphodiesterase I and 5'-nucleotidase, however, was comparable to that of the lysosomal hydrolases. Biliary excretion of total protein was relatively constant and corresponded to 3.0% of the total hepatic protein content per day, whereas biliary bile acid secretion decreased during the first 12 h and then remained constant. Exocytic bulk discharge of hepatocyte lysosomes is proposed as the most likely mechanism for the biliary excretion of lysosomal enzymes. These results call attention to the possible pathophysiologic significance of biliary excretion of hepatic lysosomal contents as a means of residue disposal.
J Clin Invest 1979 Oct
PMID:Coordinate secretion of acid hydrolases in rat bile. 11 27

Stem cells of these tumors formed nests consisting of undifferentiated embryonic cells in the center with more differentiated cells towards the periphery. A type viral particles were seen in the cisternae of rough endoplasmic reticulum. Ultrastructurally the stem cells of ovarian teratomas did not differ from stem cells of testicular or embryo-derived teratomas. They were however distinct from the cleavage stage embryonic cells and/or the unfertilized ovum, they stemmed from. They correspond both cytologically and developmentally to ectodermal embryonic cells from the egg-cylinder, the most advanced developmental stage of parthenotes observed previously in the ovary of LT mice.
Z Krebsforsch Klin Onkol Cancer Res Clin Oncol 1975 Aug 08
PMID:Ultrastructure of ovarian teratomas in LT mice. 12 56

85 surgically removed pituitary adenomas were studied by light and electron microscopical and in part immunohistochemical methods. The tumors were histogically classified and reexamined by the ultrastructure. Histochemically the adenomas could be differentiated in acidophil adenomas (1. group, 41%), mucoid cell adenomas (2. group, 6%), and chromophobe adenomas (3. group, 37%) whereas oncocytic adenomas (4. group, 16%) could be identified only in plastic-embedded sections. About half of the acidophil adenomas were highly differentiated and showed structures which correspond to those of normal STH cells (subgroup 1.1). 1 adenoma consisted of cells of prolactin type (subgroup 1.2). The other acidophil adenomas were differentiated to a lower degree and showed no resemblance to the structures of normal acidophil cells. The 5 mucoid cell adenomas were proved to be with all methods highly differentiated adenomas of ACTH-cell type (subgroup 2.1). TSH-cell adenomas (subgroup 2.2) and lower differentiated mucoid cell adenomas (subgroup 2.0) were lacking in our collection. More than one third of the chromophobe adenomas showed well developed endoplasmic reticulum and Golgi complexes. The other had little and small organellas that resemblances to immature stem cells were evident. The oncocytic adenomas were identified in plastic-embedded sections by their fine-granular structures which were based ultrastructurally not on small secretory granules but on closely arranged mitochondrias.
Z Krebsforsch Klin Onkol Cancer Res Clin Oncol 1975 Oct 27
PMID:[Light and electron microscopic studies for classification of pituitary adenomas (author's transl)]. 12 39


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