Model study of toluene diisocyanate effect on transepithelial ion transport.
BACKGROUND
Toluene diisocyanate (TDI), a low molecular weight compound, is commonly known as a factor causing asthma in chemical industry workers. The present study investigated a possible effect of TDI on ion transport using electrophysiological methods aimed at assessment of ion currents occurring in epithelial tissues.


METHODS
The experiments were carried out on 119 fragments of isolated frog skin, sampled from 59 specimens of hybrid frog Rana esculenta L. The procedures employed involved transepithelial electrical potential (PD in mV) measurement with an Ussing apparatus, modified to enable mechanical stimulation of organs and defined pharmacological actions. Incubation was carried out using Ringer solution and Ringer solution with amiloride and bumetanide. Direct actions of toluene diisocyanate (TDI) were assessed at the time of administering this substance to the Ussing chamber with a peristaltic pump.


RESULTS
Based on the model of frog skin tested with Ussing apparatus, administration of TDI to the fluid stimulating preparations incubated with Ringer solution (RH) and with amiloride (AMI) was demonstrated to cause a hyperpolarization increase after mechanical stimulation. TDI action on isolated frog skin inflicted a change in response to mechanical stimulation, leading to a depolarization. The reaction magnitude of frog skin incubated with bumetanide (BUME) did not change due to TDI.


CONCLUSIONS
TDI influences processes of sodium ion transport in the isolated frog skin model, depending on mechanical stimulation. This indicates that TDI effect on ion transport in epithelial cells depends on C fibres and tachykinins released from their endings.
Kosik-Bogacka
Danuta
D
Department of Biology and Medical Parasitology, Pomeranian Medical University, Szczecin, Poland.
Tyrakowski
Tomasz
T
D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D004594:Electrophysiology; D004847:Epithelial Cells / Q000378:metabolism; D017136:Ion Transport; D007477:Ions; D007552:Isotonic Solutions / Q000494:pharmacology; D011898:Ranidae; D000077331:Ringer's Solution; D012867:Skin / Q000187:drug effects*; D015320:Tachykinins / Q000378:metabolism; D014051:Toluene 2,4-Diisocyanate / Q000494:pharmacology*
D007477:Ions; D007552:Isotonic Solutions; D015320:Tachykinins; D014051:Toluene 2,4-Diisocyanate; D000584:Amiloride; D000077331:Ringer's Solution