Uneven distribution of nucleoside transporters and intracellular enzymatic degradation prevent transport of intact [14C] adenosine across the sheep choroid plexus epithelium as a monolayer in primary culture

Table 1 The permeability values (Pe - x 10^-3cm/min) of laminin-coated inserts without cells (w/o cells), laminin coated inserts with 8d-old CPEC monolayer (with cells control) and laminin coated inserts with 8d-old CPEC monolayers which were pre-treated to reduce adenosine metabolism (with cells inhibition). [¹⁴C] adenosine was used as a test molecule and [³H] mannitol as an inert reference of the paracellular diffusion. From these values the permeability of CPEC monolayers (P_cells) was calculated and then permeability for mannitol subtracted from the permeability for adenosine to estimate permeability of cellular monolayers for [¹⁴C] adenosine. All values are mean+/- SEM from 3–4 different inserts, which were produced from at least two animals.

	Upper chamber as the donor		Lower chamber as the donor
	Adenosine	Mannitol	Adenosine	Mannitol
W/o cells	3.26 ± 0.76	3.40 ± 0.068	3.09 ± 0.41	3.32 ± 0.22
With cells control	0.64 ± 0.17	0.35 ± 0.11	0.73 ± 0.21	0.55 ± 0.08
With cells inhibition	1.50 ± 0.15	0.39 ± 0.10	1.35 ± 0.16	0.44 ± 0.08
Pe_cells control	0.79 ± 0.05	0.39 ± 0.06	0.95 ± 0.11	0.64 ± 0.07
Pe _ado -Pe _mannitol control	0.40 ± 0.03		0.31 ± 0.04
Pe_cells inhibition	2.78 ± 0.14	0.44 ± 0.11	2.39 ± 0.17	0.67 ± 0.09
Pe _ado -Pe _mannitol inhibition	2.34 ± 0.17		1.72 ± 0.14

ISSN: 2045-8118