Modulation of carbachol-stimulated inositol phospholipid hydrolysis in rat cerebral cortex
Cortical slices from rat brain were used to study carbachol-stimulated inositol phospholipid hydrolysis. Omission of calcium during incubation of slices with (/sup 3/H)inositol increased its incorporation into receptor-coupled phospholipids. Carbachol-stimulated hydrolysis of (/sup 3/H)inositol phospholipids in slices was dose-dependent, was affected by the concentrations of calcium and lithium present and resulted in the accumulation of mostly (/sup 3/H)inositol-1-phosphate. Incubation of slices with N-ethylmaleimide or a phorbol ester reduced the response to carbachol. Membranes prepared from cortical slices labeled with (/sup 3/H)inositol retained the receptor-stimulated inositol phospholipid hydrolysis reaction. The basal rate of inositol phospholipid hydrolysis was higher than in slices and addition of carbachol further stimulated the process. Addition of GTP stimulated inositol phospholipid hydrolysis, suggesting the presence of a guanine nucleotide-binding protein coupled to phospholipase C. Carbachol and GTP-stimulated inositol phospholipid hydrolysis in membranes was detectable following a 3 min assay period. In contrast to slices, increased levels of inositol bisphosphate and inositol trisphosphate were detected following incubation of membranes with carbachol. These results demonstrate that agonist-responsive receptors are present in cortical membranes, that the receptors may be coupled to phosphatidylinositol 4, 5-bisphosphate, rather than phosphatidylinositol, hydrolysis and that a guanine nucleotide-binding protein may mediate the coupling of receptor activation to inositol phospholipid hydrolysis in brain.
- Research Organization:
- Univ. of Alabama, Birmingham
- OSTI ID:
- 6087155
- Journal Information:
- Neurochem. Res.; (United States), Vol. 12:8
- Country of Publication:
- United States
- Language:
- English
Similar Records
Guanine nucleotide-dependent, pertussis toxin-insensitive, stimulation of inositol phosphate formation by carbachol in a membrane preparation from astrocytoma cells
Solubilization and functional reconstitution of polymorphonuclear leukocyte formyl-Methionyl-Leucyl-Phenylalanine receptors and guanine nucleotide binding proteins
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
PARASYMPATHOMIMETICS
BIOCHEMICAL REACTION KINETICS
RECEPTORS
PHORBOL ESTERS
BIOLOGICAL EFFECTS
PHOSPHOLIPIDS
METABOLISM
CELL MEMBRANES
CEREBRAL CORTEX
CHLORIDES
DOSE-RESPONSE RELATIONSHIPS
IN VITRO
INOSITOL
LITHIUM
RATS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ALKALI METALS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
BRAIN
CARBOHYDRATES
CARCINOGENS
CELL CONSTITUENTS
CENTRAL NERVOUS SYSTEM
CEREBRUM
CHLORINE COMPOUNDS
DRUGS
ELEMENTS
ESTERS
HALIDES
HALOGEN COMPOUNDS
INOSITOLS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPIDS
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
METALS
MONOSACCHARIDES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PROTEINS
REACTION KINETICS
RODENTS
SACCHARIDES
VERTEBRATES
560300* - Chemicals Metabolism & Toxicology
550501 - Metabolism- Tracer Techniques