Acrylamide inhibits dopamine uptake in rat striatal synaptic vesicles

Area of Science:

• Neuroscience
• Toxicology
• Biochemistry

Background:

• Acrylamide (ACR) neurotoxicity is linked to reduced presynaptic neurotransmitter release.
• Defective neurotransmitter release may stem from impaired storage within synaptic vesicles.

Purpose of the Study:

• To investigate the effects of ACR exposure on dopamine (DA) transport into rat striatal synaptic vesicles.
• To determine if ACR disrupts neurotransmitter storage mechanisms.

Main Methods:

• In vivo and in vitro exposure of rat striatal synaptosomes and isolated vesicles to ACR.
• Measurement of 3H-dopamine uptake and KCl-evoked DA release.
• Analysis of synaptic vesicle protein content and synaptosomal glutathione levels.
• Kinetic analysis of DA uptake and assessment of neurotransmitter retention.

Main Results:

• Vesicular DA uptake was significantly reduced in rats exposed to ACR.
• ACR exposure decreased KCl-evoked synaptosomal DA release.
• In vitro ACR exposure concentration-dependently inhibited 3H-DA uptake into vesicles, affecting Vmax and Km.
• ACR did not alter neurotransmitter retention in loaded vesicles.

Conclusions:

• Acrylamide impairs dopamine uptake into synaptic vesicles, likely via interaction with sulfhydryl groups on proteins.
• This disruption of neurotransmitter storage may underlie defective presynaptic release and ACR-induced neurotoxicity.