Effect of platelet-activating factor on the electrophysiology of the human Fallopian tube: early mediation of embryo-maternal dialogue?
Platelet-activating factor (PAF) is produced by preimplantation embryos and may be involved in the earliest stages of embryo-maternal dialogue. This study explored the potential effects of PAF acting as a signalling agent on human Fallopian tubal epithelial cells grown as a polarized layer in primary culture. The response of the tubal epithelium was assessed in terms of the transepithelial potential difference and short-circuit current (I(scc)), which were recorded using a modified Ussing chamber. Resistance was calculated from the measurements of potential difference and I(scc). PAF (1.9 nmol to 1.9 micromol l(-1)) administered to the apical surface of the cells produced a marked, transient increase in both potential difference and I(scc) in a dose-dependent manner. The mode of action of PAF on the electrophysiological responses of human tubal epithelial cells was investigated. Blockers of Na(+), K(+) and voltage-operated Ca(2+) channels had little effect on PAF action. However, incubation of the epithelial cells in Cl(-)free medium or with a blocker of the Na(+)-K(+)-2Cl(-) cotransporter (Furosemide) reduced the effect of PAF. Blockade of chloride-bicarbonate channels with 4-acetamido-4'-iso-thiocyanostilbene-2.2'-disulphonic acid (SITS) reduced the effect of low doses of PAF only. These results indicate that PAF influences the movement of chloride ions across the tubal epithelial cell and is a candidate molecule for initial embryo-maternal dialogue.
D000328:Adult; D018929:Cell Culture Techniques; D002712:Chlorides / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity; D004594:Electrophysiology; D004847:Epithelial Cells / Q000187:drug effects / Q000502:physiology; D005187:Fallopian Tubes / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D005260:Female; D006801:Humans; D015640:Ion Channel Gating / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D008875:Middle Aged; D010972:Platelet Activating Factor / Q000494:pharmacology*
D002712:Chlorides; D010972:Platelet Activating Factor