Effects of environmental lead poisoning on the breast muscle of the Canada goose: an ultrastructural study.

Canada geese (Branta canadensis) showing symptoms of lead poisoning were collected from their natural habitat, and their pectoralis muscle was examined for ultrastructural changes. Both the red and white fibre types showed pathological changes. In some red fibres, there were prominent accumulations of glycogen granules, occasionally membrane-bound, at certain spots, and of lipid droplets. Glycogen and lipid were also located within mitochondria. When lipid droplets were sparse in a certain fibre, occurrence of fused mitochondria often with distorted cristae, was observed. Swollen mitochondria with disrupted cristae and dense intramitochondrial inclusions were present. Lysosomes and areas of mitochondrial degeneration were also seen. Dilatation of the terminal cisternae of the sacroplasmic reticulum and of the T-system was also observed in the red fibres. In the white fibres, enormous accumulations of glycogen granules were present and the cristae of mitochondria were often disrupted. In some white fibres the triads and Z-lines were in a state of severe disarray. The nuclei in both the fibre types appeared to be normal and did not contain the typical intranuclear inclusion bodies present in kidney and liver cells of lead poisoned animals and humans. It is suggested that, in the goose, lead has a diabetogenic effect, which in the breast muscle, is manifested in the large accumulations of glycogen and the disruption of glycolytic metabolism. Lead poisoning also affects mitochondrial structure and function leading to adverse effects on oxidative metabolism in the muscle.