Single Cell Amperometry Reveals Glycocalyx Hinders the Release of Neurotransmitters During Exocytosis

• The diffusional hindrance of the glycocalyx along the cell surface on exocytotic peaks, observed with single cell amperometry, was investigated. Partial digestion of the glycocalyx with neuraminidase led to the observation of faster peaks, as shown by varied peak parameters. This result indicates that diffusion of small molecules in the partially digested glycocalyx is 2.2 faster than in the intact glycocalyx. Similarly, neutralization of the negative charges present in the cell microenvironment led to faster peak kinetics. The analysis of the vesicular efflux indicates that the diffusion coefficient of dopamine at the cell surface is at most 45% of the diffusion coefficient in free solution. This study shows that the glycocalyx plays an important role in the diffusion kinetics of processes along the cell surface, including exocytotic events.

Subject headings

NATURVETENSKAP  -- Kemi -- Analytisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Analytical Chemistry (hsv//eng)

Keyword

adrenal chromaffin cells

to-substrate contacts

extracellular-matrix

fusion pore

sialic-acid

pc12 cells

electrophoretic mobility

endothelial-cells

chemical-analysis

vesicular volume

fusion pore

Publication and Content Type

ref (subject category)

art (subject category)