DEVELOPMENT OF AN IN VITRO RAT NASAL EPITHELIAL MODEL FOR PREDICTING UPPER RESPIRATORY TRACT TOXICITY

Nasal toxicology is an important, expanding area of research, which has, in the past, centered on in vivo studies. There is now a need for in vitro methodology to study this target organ, and the aim of this work was to develop such a model using isolated rat nasal turbinates. Initially, optimal culture conditions for olfactory epithelium (OE)and respiratory epithelium (RE) were determined using lactate dehydrogenase (LDH) release as an indicator of viability. The optimal culture conditions were found to be incubation at 31 C under an atmosphere of 95%O:5%CO2, in six-well plates containing 2 mL of William's E medium supplemented with glutamine (2 mM) and gentamycin (100 mug/mL), with shaking at 60 strokes/min (amplitude 3.5 cm). Under these conditions, LDH release from both tissues was 30-40% by 24 h. The model was further characterized in terms of a rangeof viability parameters reflecting different aspects of cellular function. Initial values for intracellular potassium, ATP, and nonprotein sulfhydryl le...