Cytoplasmic Protein Synthesis in Cells of Various Types and Its Relation to Nuclear Protein Synthesis

Schultze, B.; Citoler, P; Hempel, Klaus; Citoler, Karin; Maurer, W.

doi:10.1016/b978-0-12-395731-3.50012-9

Cited by 12 publications

(3 citation statements)

References 14 publications

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“…1,1986 peptide bonds and thus reflects protein synthesis (Peters and Ashley, 1967). Moreover, Schultze et al (1965) demonstrated that in material that has been processed for embedding in paraffin, the au toradiographic pattern of amino acid incorporation into protein is virtually the same using tyrosine, leu cine, or valine.…”

Section: Discussionmentioning

confidence: 99%

Cerebral Protein Synthesis during Long-Term Recovery from Severe Hypoglycemia

Kiessling

Auer

Kleihues

et al. 1986

J Cereb Blood Flow Metab

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Summary: Regional protein synthesis was investigated in the rat brain during long-term recovery from insulin induced hypoglycemia with 30 min of cerebral electrical silence, At various time intervals up to 14 days after glu cose replenishment, animals received a single dose of L [3,5-3 H]tyrosine and were killed 30 min later. Brains were processed for autoradiography using the stripping film technique, Although hypoglycemia sufficiently severe to cause cessation of EEG activity leads to almost complete inhibition of amino acid incorporation in all "vulnerable" forebrain structures (cerebral cortex, hippocampus, cau doputamen), autoradiographs revealed a very specialized sequence with differential posthypoglycemic restoration of biosynthetic activity in certain neuronal cell types. Three major subpopulations could be distinguished: Neu rons that fully regained their protein synthetic capacity within 6 h following hypoglycemia (cortical neurons of layer III-VI, large neurons in the caudoputamen, CA 3 and CA4 pyramidal neurons, the majority of granule cells Although hypoglycemia is a global insult, its ef fects on the brain are regionally different. This het erogeneity applies to changes in glucose consump tion, blood flow, energy homeostasis, protein syn thesis, and neuronal cell death. Application of the [ 1 4 C]deoxyglucose technique to hypoglycemic "coma" (defined by us as hypoglycemia of suffi cient severity to cause cessation of spontaneous EEG activity) showed a striking heterogeneity in glucose consumption, with low values in the neo cortex, hippocampus, and caudoputamen and high values in the brains tern and cerebellum (Abdul Rahman and Siesjo, 1980 42of the dentate gyrus) seemed to escape neuronal necrosis.Prolonged impairment of protein synthesis with only par tial restoration during the early posthypoglycemic re covery period (CAl neurons, most small-to medium sized neurons of the caudoputamen) carried an increased risk of permanent cell damage. The large majority of these neurons, however, showed full recovery of protein synthesis as late as 7 days after hypoglycemia. Neurons with complete lack of amino acid incorporation after 6 h of recovery (granule cells at the crest of the dentate gyrus, small neurons of the dorsolateral caudoputamen) never resumed protein synthesis, regressed, and died. These studies in conjunction with morphological analysis indicate that the sequential recovery of protein synthesis reflects the extent to which neuronal populations are at risk during severe hypoglycemia. Key Words: Autora diography-Cerebral protein synthesis-Hypogly cemia-Selective vulnerability.zation during severe hypoglycemia, these data dem onstrate interregional differences in glucose avail ability. In addition, the blood flow response to hy poglycemia is regionally different both during hypoglycemia and in the recovery phase (Abdul Rahman et aI. , 1980). While many regions lose vas cular autoregulation during hypoglycemia and be come hypoperfused at very moderate degrees of ar terial hypotension, others...

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Section: Discussionmentioning

confidence: 99%

Cerebral Protein Synthesis during Long-Term Recovery from Severe Hypoglycemia

Kiessling

Auer

Kleihues

et al. 1986

J Cereb Blood Flow Metab

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“…Acid-soluble precursors were removed by repeated changes of the fixation fluid. Under these conditions approximately 96% of the radioactivity in autoradiographs is due to peptide bonds and thus reflects amino acid incorporation (Schultze et al, 1965;Peters and Ashley, 1967). After dehydration and parafin embedding, autoradiographs were prepared from 3-pm sections using Kodak AR-10 stripping film and LKB Ultrofilm.…”

Section: Au Toradiographymentioning

confidence: 99%

Regionally Selective Inhibition of Cerebral Protein Synthesis in the Rat During Hypoglycemia and Recovery

Kiessling

Xie

Kleihues

1984

Journal of Neurochemistry

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Regional cerebral protein synthesis was investigated in anesthetized, mechanically ventilated rats during progressive insulin-induced hypoglycemia and the recovery period following glucose infusion. Polysome profiles from precomatose animals with slow wave/polyspike EEG revealed a slight reduction of polyribosomes and a concurrent increase in monoribosomes, but autoradiographs showed a pattern of L-[3-3H]tyrosine incorporation indistinguishable from that of control rats. During the initial 30 min of insulin-induced isoelectric EEG ("coma"), autoradiographs showed a selective inhibition of protein synthesis in neurons and glial cells of the hippocampus and cerebral cortex, i.e., regions with high susceptibility for the development of hypoglycemic brain damage. Basal ganglia were less affected and areas with low vulnerability (hypothalamus, brainstem, and cerebellum) exhibited a normal pattern of amino acid incorporation. Using a flooding dose of L-[1-14C]valine (7.5 mmol/kg; 15 microCi/mmol), the rate of incorporation in cerebral cortex and cerebellum was found to be reduced to 2% and 80% of control values, respectively. Inhibition of protein synthesis was paralleled by a breakdown of polyribosomes and a concomitant increase in ribosomal subunits, indicating a block in peptide chain initiation. After 90 min of isoelectric EEG all brain structures with the exception of hypothalamus and area postrema showed an almost complete lack of amino acid incorporation. Glucose infusion after a 30-min period of hypoglycemic coma led to a partial restoration of cortical and hippocampal protein synthesis. Within 70-90 min of recovery, L-[1-14C]valine incorporation into neocortical and cerebellar proteins amounted to 47% and 125% of fasted controls.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…During the past decade it has become clear that in cells of higher organisms most protein synthesis is mediated by polysomes occurring free in the cytoplasm or attached to the endoplasmic reticulum . There is ample evidence, however, that synthesis of proteins may also occur at other loci within the cell ; for example, in mitochondria (1-3), in chloroplasts (4)(5)(6), and in the nucleus (7)(8)(9)(10)(11) .…”

Section: Introductionmentioning

confidence: 99%

Effect of Various Inhibitors on Nuclear Protein Synthesis in Rat Liver

Kuehl

1969

The Journal of Cell Biology

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Cytoplasmic Protein Synthesis in Cells of Various Types and Its Relation to Nuclear Protein Synthesis

Cited by 12 publications

References 14 publications

Cerebral Protein Synthesis during Long-Term Recovery from Severe Hypoglycemia

Cerebral Protein Synthesis during Long-Term Recovery from Severe Hypoglycemia

Regionally Selective Inhibition of Cerebral Protein Synthesis in the Rat During Hypoglycemia and Recovery

Effect of Various Inhibitors on Nuclear Protein Synthesis in Rat Liver

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