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)

In order to obtain plasma membrane-rich fractions two methods were tried. Approach A was based on differential pelleting followed by discontinous gradient centrifugation in a B-XIV zonal rotor. In approach B homogeneization was performed in buffered water (NaHCO3, pH 7.4). The 73 300 X g pellet from this homogenate was subjected to buoyant density equilibrium in a HS zonal rotor (continuous sucrose gradient). Using approach A, the highest relative specific activity for plasma membrane markers was found at the 30-37% sucrose interphase. However, an increase for glucose 6-phosphatase (endoplasmic reticulum marker) was also found at that interphase. Using approach B marker profiles different from approach A were found. Approach B results in a subdivision of membrane material in four distinct regions. These regions do not contain completely pure membrane species, although region I seems to be essentially derived from plasma membranes. It is also concluded from approach A that plasma membranes from bovine thyroid tissue are heterogeneous.
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PMID:Subcellular structure of bovine thyroid gland. VII. A study on the distribution of bovine thyroid plasma membranes by density gradient centrifugation in zonal rotors. 8 Jan 97

The distribution of labeled neurons in the paraventricular nucleus of the hypothalamus (PVN) was studied following injections of horseradish peroxidase (HRP) into the spinal cord (C8 to T1) or the hypophysis in the rat. Injections were also made in the spinal cord in another group of animals, which were subjected to water deprivation for a period of 3 days, and the PVN of these animals was examined with the electron microscope. Spinal projection neurons (paraventriculospinal tract, PVST, neurons) formed two groups; the dorsal and the ventral groups. They were located within the parvocellular part of the PVN and fused into one at the caudal level. The neurons of the dorsal group were well assembled whereas those of the ventral group were intermingled with paraventriculohypophyseal tract (PVHT) neurons, which were concentrated in the magnocellular part. Electron microscopic observations revealed that HRP-labeled neurons after spinal injections did not contain neurosecretory granules and that they were not affected by water deprivation. On the other hand, neurons containing a number of neurosecretory granules displayed a significant degree of dilatation of the endoplasmic reticulum as the result of water deprivation. These neurons contained no HRP granules. The present findings suggest that the PVST neurons are distinct from the PVHT neurons and that the neuronal groups of both systems form different cell columns within the nucleus.
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PMID:Identification and distribution of the spinal and hypophyseal projection neurons in the paraventricular nucleus of the rat. A light and electron microscopic study with the horseradish peroxidase method. 8 56

Papillary component ultrastructure and acid mucopolysaccharide distribution have been investigated in the kidney of the water vole A. terrestris. Structural differences between the descending and ascending parts of the Henle's loop are rather small, cell cytoplasm of these segments being poor in organells. Unusual ultrastructure of the collecting duct epithelium with high level of cytoplasmic organization (elongated thin mitochondria, fairly developed Golgi complex, numerous phagosomes and pinocytotic vesicles, long branching microvilli) was described. Apical membrane of the epithelium is covered by rich glycocalix layer. Heil-positive substrances are located intracellularly inside phagosomes and on vesicle membranes, as well as on the membranes of cisternae of endoplasmic reticulum. Interstitium is abundant, but no close contacts between papillary components were found. Acid mucopolysaccharide content of the interstitium is low, "gel" filter being not formed. The described peculiarities are discussed in relation to water and salt metabolism of the rodents investigated.
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PMID:[Ultrastructural organization of the inner medullary zone of the kidney of the water vole Arvicola terrestris]. 15 94

Liver neoplasms were induced in medakas (Oryzias latipes) by the addition of diethylnitrosamine (DENA) to their aquarium water at levels of 15-135 ppm for 8 weeks. After 13 weeks, 21 to 32 fish had developed hepatomas. Medakas are useful for further studies because they are highly susceptible to the carcinogenic effect of DENA, and the time for tumor induction is relatively short. Histologic type differed in the lesions of different fish and also within individual tumors. Some were typical trabecular hepatomas, others were anaplastic hepatomas or cholangiomas, or mixtures of these. Electron microscopy revealed an extensive rough-surfaced endoplasmic reticulum in a lamellar pattern, many mitochondria, and several round lysosomes in tumor cells. A few fat droplets with occasional crystalline ghosts were sometimes in the cytoplasm. The Golgi apparatus was not conspicuous. Some cells had highly developed microvilli that showed differentiation toward structures resembling bile capillaries.
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PMID:Histologic and electron microscopy observations on diethylnitrosamine-induced hepatomas in small aquarium fish (Oryzias latipes). 17 29

Male albino rats were deprived of water for 6 days, then they were allowed to drink tap water ad libitim. The structure of the liver was examined by light and electron microscopy, and the protein and dry matter contents, oxygen consumption and glucose-6-phosphatase activity of the liver were determined after rehydration. At 10 minutes, the mitochondria showed signs of division and a peculiar transformation of the cristae. At 60 minutes, the membranes of the rough endoplasmic reticulum were found to have proliferated. At 12 hours, the smooth-surfaced membranes showed hypertrophy and the bile canaliculi were distended. At 24 hours all rehydration induced organelle alterations were declining. The biochemical findings agreed well with the fine structural changes and both were indicative of an enchanced functional capacity of liver cells during rehydration.
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PMID:Effect of rehydration of rat liver tissue after water deprivation. 18 Jul 60

A quantitative ultrastructural investigation was undertaken to compare the nucleus circularis (NC) and supraoptic nucleus (SON) of the rat both under normal and water-deprived conditions. NC was found to have dramatically more of its cells and membrane surface involved in direct soma-somatic contact than the SON. Water deprivation, even for one day, brought about a significant increase in both percentage of cells and membrane surface in contact in both nuclei, apparently by the retraction of fine glial processes from between the somata. The normal NC was made up of only one ultrastructurally identifiable cell type. The normal NC had no cells showing expanded endoplasmic reticulum, although these were seen following 5 days (but not 1 day) of water deprivation. The normal SON did have 4.4% of its cells showing expanded endoplasmic reticulum. This percentage significantly increased following water deprivation. The vesicle population per area of cytoplasm was very similar between the two normal nuclei. One day of water deprivation brought about a significant increase in less than 800 A vesicles in NC but not the SON. Five days of water deprivation resulted in a significant decrease in the lysosomal population per unit area in both nuclei. Vesicle changes have been discussed in relation to the volume changes in the cells.
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PMID:Ultrastructural comparisons of neurons of supraoptic and circularis nuclei in normal and dehydrated rats. 18 83

Daily sc injections of 8 mg N6, O2'-dibutyryl 3',5'-cyclic AMP (DBcAMP) beginning 1 day after tumor implantation significantly increased the growth rate of R32230AC rat mammary adenocarcinomas, which nearly doubled in in situ volume by day 40 compared to similarly implanted tumors in saline-injected controls. Weights of excised tumors, intact, drained, and dried all increased approximately 80%, which suggested that the increase in tumor size was not due to accumulation of secreted fluid or tissue water. Injections of 17beta-estradiol valerate (0.1 mg/wk) from day 1 or of DBcAMP from day 22 resulted in insignificant changes in growth--28% and 35% increases in tumor volume and a 5% decrease and an 18% increase, respectively, in drained wet weight. Electron microscopic examination revealed that estrogen and DBcAMP caused differentiation of the tumor cells into two different states: Estrogen-treated tumors resembled lactating mammary glands; they contained large lipid droplets, organized rough endoplasmic reticulum, and vesicles containing electron dense granules resembling protein. DBcAMP-treated tumor cells were marked by a proliferation of the Golgi complex and numerous vesicles containing fine granular material.
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PMID:Enhancement of R3230AC rat mammary tumor growth and cellular differentiation by dibutyryl cyclic adenosine monophosphate. 19 Apr 20

The sequential pattern of lipid accumulation and associated biochemical changes were studied in two commonly used experimental models of nutritional fatty liver in rats. Female rats were maintained for 8 weeks on high fat, low protein diets containing adequate methionine and choline, and drinking water ad libitum (Diet 1), or deficient in methionine and choline and containing 20% ethanol as a substitute for drinking water (Diet 2). Histologically, there was a progressive increase in liver lipids, mainly in the periportal areas. Occasional foci of liver cell necrosis with lipogranuloma formation occurred in areas of severe fatty change. These changes appeared earlier and were more marked in rats maintained on Diet 2. Electron micrographs revealed large lipid droplets in the liver cells, which sometimes contained myelin figures. The mitochondria were enlarged, distorted and appeared as amorphous structures with disorientated cristae in rats on Diet 1, whereas they had a condensed conformation in rats maintained on Diet 2. Rough endoplasmic reticulum was fragmented and degranulated particularly in rats on Diet 1, and smooth endoplasmic reticulum showed hyperplasia and vesiculation in rats on Diet 2. There was a progressive increase in the total liver lipids and triglycerides in both the groups of rats. This fatty change was accompanied by a significant increase in hepatic 3-hydroxybutyrate, acetoacetate, malate, 2-oxoglutarate, citrate, lactate, ammonia, glutamate, alanine and aspartate, and a significant decrease in oxaloacetate, urea and glucose concentrations. The mass action ratios for alanine aminotransferase, aspartate amino transferase, and glutamate dehydrogenase, generally moved in a parallel direction. Hepatic ATP content was considerably reduced accompanied by a decrease in [ATP]/[ADP] ratios and a significant increased in [lactate]/[pyruvate] and [3-hydroxybutyrate]/[acetoacetate] ratios. There was a corresponding decrease in the [NAD+]/[NADH] ratios both in the cytoplasmic and mitochondrial compartments. These biochemical changes were particularly severe in rats maintained on Diet 1 and Diet 2 for 8 weeks. There was a very good relationship between impaired mitochondrial and endoplasmic reticulum functions, redox and phosphorylation states, and the relevance of their changes to the fate of fatty liver cells.
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PMID:Lipid accumulation in the rat liver: a histological and biochemical study. 23

The toxicology of water soluble chemical compounds may be investigated in tissue culture systems. The toxicology of triethyllead chloride, methylmercury chloride and cadmium acetate was studied in chick embryo brain cell cutlures. Tetraethyllead is added to petrol as an anti-knock agent. When tetraethyllead is absorbed by the organism, it is converted to triethyllead which cause the symptoms of tetraethyllead poisoning. Chick embryo brain cell cultures derived from cerebrum of 11-day-old chick embryos developed both neurons and glial cells. The neurons formed nerve processes and synapsis in the cultures. The effect of triethyllead chloride was investigated by addition of triethyllead chloride to the nutrient medium. The median tissue culture lethal dose, TCLD50 = 1.9 mg/l, was determined as the concentration of triethyllead chloride at which the confluent layer of glial cells was destroyed in 50% of the cultures. The neurons lost their processes at even lower concentration, TCED50 = 0.57 mg/l. Electron microscopy revealed cells with swollen Golgi apparatus and dilated endoplasmic reticulum in chick embryo brain cell cultures which were treated with triethyllead chloride, 1.0 mg/l. Studies with radioactive labelled precursors revealed that triethyllead chloride inhibited the synthesis of DNA, sulfatides and cerebrosides without hydroxyfatty acids.
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PMID:Toxicology of triethyllead, methylmercury and cadmium, determined in chick embryo brain cell cultures. 27 23

Male and female dogs, aged 17--21 months, were administered orall M 73101 (0, 60, 120 and 240 mg/kg/day), a new analgesic and antiinflammatory drug, for 27 weeks, and following recovery test was carried out for 5 weeks. Dead animals were not found throughout the experimental period. Body weight gain, and food and water consumption were not affected due to M 73101 administration. Except for a slight increase of vomitting in the highest dose, there were no abnormal symptoms. Biochemical examination showed the slight increase in serum alkaline phosphatase activity and free cholesterol level. Pathological examination revealed a dose-dependent increase of liver weight and hypertrophy of hepatocytes due to proliferation of smooth endoplasmic reticulum. In addition, mitochondria became irregularly large in the highest dose. There were no abnormal findings in the gastro-intestinal tracts except for an erosion of gastric mucosa, which was noted in a female dog treated 240 mg/kg/day of M 73101. From these results, it was suggested that the maximum non-toxic dose was 60 mg/kg/day or less, and the greatest safety dose was 120 mg/kg/day in beagle dogs.
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PMID:[Chronic toxicity test of 4-ethoxy-2-methyl-5-morpholino-3(2H)-pyridazinone (M73101) in beagle dogs (author's transl)]. 31 11


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