Absorption & metabolic disposition of azo dye metanil yellow in rats
Raza, H.; Khanna, S.K.; Singh, G.B.; Murti, C.R.
Indian Journal of Experimental Biology 20(1): 48-51
Metabolic disposition of metanil yellow, m-(p-anilino phenyl)azo benzene sulfonic acid after feeding to male albino rats was studied. The absorption through gastrointestinal tract was slow. A peak concentration in blood plasma was obtained at 6 h post-feeding. The total dye excreted unchanged in the urine was .apprx. 2% of the initial dose. The remaining portion was reduced at its azo linkage leading to the formation of 2 amines which are excreted in urine and feces and identified as metanilic acid and p-aminodiphenylamine (p-ADPA). Under in vitro conditions the absorption of the dye and its metabolites through everted gut sacs was in the following order: p-ADPA > metanilic acid > metanil yellow. The metanil yellow absorption was concentration independent, presumably carrier mediated and a nonactive process. The absorption of metanilic acid and p-ADPA, was by passive diffusion.