Effects of in vitro hypoxia on depolarization-stimulated accumulation of inositol phosphates in synaptosomes

Journal Article · Sun Jan 01 04:00:00 EST 1989 · Life Sciences; (USA)

DOI:https://doi.org/10.1016/0024-3205(89)90034-9· OSTI ID:5026313

Huang, H M; Gibson, G E ^[1]

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1. Cornell Univ., White Plains, NY (USA)

The effects of potassium and in vitro histotoxic hypoxia on phosphatidylinositol turnover in rat cortical synaptosomes were determined. (2-{sup 3}H) Inositol prelabelled rat synaptosomes were prepared from cerebral cortex slices that had been incubated with (2-{sup 3}H) inositol. Depolarization with 60 mM KCl increased (2-{sup 3}H) inositol phosphates in a time dependent manner. Depolarization with 60 mM KCl increased (2-{sup 3}H)inositol trisphosphate transiently at 5 s. K{sup +} induced rapid formation of (2-{sup 3}H) inositol monophosphate with time. One minute of hypoxia enhance sium-stimulate (2{sup 3}H)inositol bisphosphate and maintained an elevated level for at least 5 min. K{sup +} stimulated gradual formation of (2-{sup 3}H) inositol monophosphate with time. One minute of hypoxia enhanced potassium-stimulated (2-{sup 3}H) inositol bisphosphate formation. However, 30 min of hypoxia impaired potassium-stimulated accumulation of (2-{sup 3}H)inositol phosphates. The effects of histotoxic hypoxia were all dependent upon calcium in the medium and on K{sub +}-depolarization. Thus, hypoxia altered the K{sub +} induced accumulation of inositol phosphates in prelabelled synaptosomes in a time dependent, biphasic manner that was calcium dependent.

• OSTI ID: 5026313
• Journal Information: Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 45:16; ISSN 0024-3205; ISSN LIFSA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ANIMAL CELLS
ANOXIA
BIOLOGICAL ACCUMULATION
BIOLOGICAL EFFECTS
CARBOHYDRATES
ESTERS
HYDROGEN COMPOUNDS
IN VITRO
INOSITOL
INOSITOLS
ISOTOPE APPLICATIONS
LIPIDS
METABOLISM
MONOSACCHARIDES
NERVE CELLS
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHOLIPIDS
POTASSIUM COMPOUNDS
SACCHARIDES
SOMATIC CELLS
TIME DEPENDENCE
TRACER TECHNIQUES
TRITIUM COMPOUNDS