The use of the frog palate preparation to assess the effects of oxidants on ciliated epithelium.
This work was designed to develop a simple method based on the frog palate preparation to study the effects of hydrogen peroxide (H2O2) on ciliated epithelium. For this purpose, five sets (n = 10 per set) of frog palate preparations (Rana catesbeiana) were studied during 35 min after immersion in increasing concentrations of H2O2: 1, 8, 16, 32, and 64 microM. The effects of H2O2 on ciliated epithelium were assessed by measuring transepithelial potential difference (PD) and mucociliary transport (MT). Measurements were performed at 5-min intervals. In addition, the palates submitted to the 64 microM dose were immersed in Ringer's solution and followed by another 30 min to assess the possible recovery after maximal injury. Transepithelial potential difference (PD) was measured by means of agar-filled microelectrodes connected to the high input of a grounded electrometer. Mucociliary transport (MT) was determined by directly monitoring the movement of autologous mucus along the palate surface. Significant decrease in MT was observed in 16 microM and beyond and significant change in PD was observed in 32 microM and 64 microM. Palates submitted to 64 microM of H2O2 returned to their baseline levels of PD and MT within 30 min of recovery in Ringer's solution. In conclusion, the frog palate preparation was shown to be an efficient experimental tool to assess the deleterious effects of H2O2 on the ciliated epithelium.
Macchione
M
M
Laboratório de Poluição Atmosférica Experimental, Faculdade de Medicina da USP and Instituto do Coração, HC-FMUSP, São Paulo, Brazil.
Lorenzi-Filho
G
G
Guimarães
E T
ET
Junqueira
V B
VB
Saldiva
P H
PH
D000704:Analysis of Variance; D000818:Animals; D002923:Cilia / Q000187:drug effects; D003363:Cost Control; D004563:Electrochemistry; D004848:Epithelium / Q000187:drug effects / Q000648:ultrastructure; D005069:Evaluation Studies as Topic; D005240:Feasibility Studies; D005609:Free Radicals; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D066298:In Vitro Techniques; D018384:Oxidative Stress / Q000187:drug effects*; D010159:Palate / Q000187:drug effects*; D011892:Rana catesbeiana
D005609:Free Radicals; D006861:Hydrogen Peroxide