G I Gorodeski1, U Hopfer. 1. Department of Reproductive Biology, Case Western Reserve School of Medicine, Cleveland, Ohio, USA.
Abstract
OBJECTIVE: We sought to determine what type of regulation of transepithelial transport in leaky epithelium can occur at the level of paracellular permeability. METHODS: The epithelial permeability to the polar acid pyranine (Ppyr) and the transepithelial electrical resistance (R) were determined in cultured human cervical epithelium. RESULTS: Extracellular adenosine triphosphate (ATP) acutely and reversibly decreased the paracellular permeability, as evidenced by an increase of R from 10 +/- 3 to 16 +/- 2 omega/cm2 and a decrease in Ppyr from 13 +/- 3 to 9 +/- 3 x 10(-6) cm/sec and (P < .01 for both). The ATP effect was dose related (average median effective concentration 2 +/- 1 microM), saturable at 50 microM, and desensitized with repeated administration; it was mimicked by uridine triphosphate and ATP-gamma-S but not by adenosine monophosphate, adenine, adenosine, or adenosine diphosphate. The ATP effect on resistance remained intact even when the intercellular resistance was decreased with a basal-to-apical pressure gradient, but was abolished by lowering extracellular calcium. CONCLUSIONS: These results indicate the following: 1) Paracellular permeability in the cervical epithelial cell line is regulated by a nucleotide receptor; and 2) the tight junctions are effectors of nucleotide-receptor stimulation. We suggest that extracellular ATP may regulate mucus production in the cervix in vivo by acting on a surface receptor and by increasing the resistance of the tight junctions.
OBJECTIVE: We sought to determine what type of regulation of transepithelial transport in leaky epithelium can occur at the level of paracellular permeability. METHODS: The epithelial permeability to the polar acid pyranine (Ppyr) and the transepithelial electrical resistance (R) were determined in cultured human cervical epithelium. RESULTS: Extracellular adenosine triphosphate (ATP) acutely and reversibly decreased the paracellular permeability, as evidenced by an increase of R from 10 +/- 3 to 16 +/- 2 omega/cm2 and a decrease in Ppyr from 13 +/- 3 to 9 +/- 3 x 10(-6) cm/sec and (P < .01 for both). The ATP effect was dose related (average median effective concentration 2 +/- 1 microM), saturable at 50 microM, and desensitized with repeated administration; it was mimicked by uridine triphosphate and ATP-gamma-S but not by adenosine monophosphate, adenine, adenosine, or adenosine diphosphate. The ATP effect on resistance remained intact even when the intercellular resistance was decreased with a basal-to-apical pressure gradient, but was abolished by lowering extracellular calcium. CONCLUSIONS: These results indicate the following: 1) Paracellular permeability in the cervical epithelial cell line is regulated by a nucleotide receptor; and 2) the tight junctions are effectors of nucleotide-receptor stimulation. We suggest that extracellular ATP may regulate mucus production in the cervix in vivo by acting on a surface receptor and by increasing the resistance of the tight junctions.
Authors: Elisabet Aliagas; August Vidal; Benjamín Torrejón-Escribano; Maria del Rosario Taco; Jordi Ponce; Inmaculada Gómez de Aranda; Jean Sévigny; Enric Condom; Mireia Martín-Satué Journal: Purinergic Signal Date: 2012-12-06 Impact factor: 3.765