Effect of aging on alpha-1 adrenergic stimulation of phosphoinositide hydrolysis in various regions of rat brain

Journal Article · Sat Dec 01 00:00:00 EST 1990 · Journal of Pharmacology and Experimental Therapeutics; (USA)

OSTI ID:6150341

Burnett, D M; Bowyer, J F; Masserano, J M; Zahniser, N R ^[1]

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1. Univ. of Colorado Health Sciences Center, Denver (USA)

The effects of aging were examined on the ability of alpha-1 adrenergic receptor agonists to stimulate phosphoinositide hydrolysis in three brain regions. Tissue minces of thalamus, cerebral cortex and hippocampus from 3-, 18- and 28-month-old male Fischer 344 rats were prelabeled with ({sup 3}H)myoinositol. Exposure of these prelabeled minces to phenylephrine and (-)-norepinephrine revealed that accumulation of ({sup 3}H)inositol phosphates was selectively reduced by 20 to 30% in the thalamus and cerebral cortex of the oldest age group. Analysis of concentration-response and competition binding curves indicated that this decrease was due to diminished agonist efficacy rather than diminished receptor affinity. The reduction in responsiveness to phenylephrine and (-)-norepinephrine in the cerebral cortex and the lack of any changes in the hippocampus parallel previously reported changes in the density of alpha-1 adrenergic receptors with aging. These data indicate that the ability of alpha-1 adrenergic receptor agonists to stimulate phosphoinositide hydrolysis is reduced in some, but not all, brain regions of aged Fischer 344 rats.

• OSTI ID: 6150341
• Journal Information: Journal of Pharmacology and Experimental Therapeutics; (USA), Vol. 255:3; ISSN 0022-3565
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PHOSPHOLIPIDS
METABOLISM
SYMPATHOLYTICS
BIOCHEMICAL REACTION KINETICS
AFFINITY
AGE DEPENDENCE
CEREBRAL CORTEX
CPB
DOSE-RESPONSE RELATIONSHIPS
HIPPOCAMPUS
INOSITOL
RATS
RECEPTORS
THALAMUS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BODY
BRAIN
CARBOHYDRATES
CENTRAL NERVOUS SYSTEM
CEREBRUM
DRUGS
ESTERS
HYDROGEN COMPOUNDS
INOSITOLS
ISOTOPE APPLICATIONS
KINETICS
LIPIDS
MAMMALS
MEMBRANE PROTEINS
MONOSACCHARIDES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PROTEINS
REACTION KINETICS
RODENTS
SACCHARIDES
VERTEBRATES
550501* - Metabolism- Tracer Techniques