DIETARY NUCLEOSIDE-NUCLEOTIDE MIXTURE AGGRAVATES NASAL ALLERGIC RESPONSES INDUCED BY TOLUENE DIISOCYANATE IN MICE

In this study we evaluated the effect of a dietary nucleoside-nucleoti de mixture (NNM) on nasal allergy induced by toluene diisocyanate(TDI) in mice. Female ddY mice were randomized into two groups and fed a nu cleic-acid free 20% casein (control) or this diet supplemented with NN M for 4 weeks. On the 4th week, mice were divided into 2 sub-groups NN M sensitized, NNM-nonsensitized, control-sensitized and control-nonsen sitized. The sensitized groups of mice were treated with two courses o f intranasal application of 5% TDI in diethyl acetate for 5 consecutiv e days each time, separated by one week rest. Nonsensitized group of m ice were similarly treated with vehicle. A week after the second sensi tization all the treatment groups were provoked by applying 2.5% of TD I in vehicle. Nasal responses of sneezing, rhinorrhea, itching and sno rt at provocation, were scored for ten minutes. Degree of hair loss fr om the snout of mice was also scored for the length of the experiment. Lung and serum IgE were measured by ELISA. Results show that the sens itized groups of mice from each dietary group sneezed more frequently than the nonsensitized groups (p<0.05). The NNM sensitized group sneez ed more frequently that was different (p<0.05) compared to the rest of the groups. Nasal responses for the sensitized groups were higher rel ative to the nonsensitized groups, with the NNM sensitized group havin g an overall higher nasal response than the rest of the groups. Both s ensitized group of mice showed a higher concentration of lung and seru m IgE compared to the non-sensitized groups (p<0.05, with the NNM sens itized group having an overall higher IgE concentrations in both tissu es compared to the rest of the groups (p<0.05). We conclude that dieta ry NNM may aggravate nasal allergic responses in the predisposed. (C) 1997 Elsevier Science Inc.