Mitochondrial metabolism impairment in muscle fibres of rats chronically intoxicated with Senna occidentalis seeds

The chronic administration of S. occidentalis seeds was found to induce a m itochondrial myopathy in hens. This study was undertaken to determine if th e chronic treatment with S. occidentalis seeds of rats (as a mammalian mode l) would induce a mitochondrial myopathy similar to those described in huma ns and to determine if the histological changes could be correlated with th e amount of ingested seeds. Twenty-one days old rats were fed S. occidental is seeds at different diet concentrations (1, 2, 3%). Rats fed 1% S. occide ntalis seeds had only a few COX-negative muscle fibbers in the pectoralis m ajor muscle. Rats fed 3% Senna occidentalis seeds had a greater number of C OX-negative fibbers. Rats fed 2% had an intermediate number of COX-negative fibbers. Activity of SDH and NADH-rr were decreased in rate, of groups 2% and 3%. Our data indicate that a progressive mitochondrial metabolism impai rment can be produced in rats fed S. occidentalis seeds and that this impai rment can be correlated with the amount of ingested seeds.