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.

Diurnal variation in circulating levels of free fatty acids and growth hormone during crop gland activity in the pigeon (Columba livia).

1. Circulating levels of free fatty acids (FFA) and growth hormone (GH) were measured over a 24 hr period during the crop gland cycle of domestic pigeons (Columba livia). 2. Plasma FFA levels showed a marked circadian rhythm (p less than 0.004) with the peak level (considerably higher than that previously reported in nonbreeding pigeons) occurring at approximately 2400 hr. 3. It is suggested that these elevated levels reflect the increased demands for energy during incubation and crop "curd" production. 4. Diurnal fluctuations of plasma GH synchronizing with those of plasma FFA were not significant though peak concentrations were noted 4 hr previous to those of FFA. 5. Pigeons studied 12 days after hatching of young had the lowest levels of both plasma GH (p less than 0.06) and FFA (p less than 0.02) indicating their interacting relationship. 6. A consistently higher FFA level (p less than 0.02) was observed in the crop glands of male pigeons.

Diurnal variations in plasma calcium, parathormone and calcitonin levels and crop gland activity in pigeon.

Circulating levels of plasma calcitonin and parathormone were measured in the pigeon by radio immunoassay in relation to plasma concentrations of calcium. Adult birds undergoing 3 particular phases of crop gland activity (Group 1.--4 days prior to hatching, Group 2.--2 days following hatching, Group 3.--12 days following hatching), were used as experimental animals. Calcium showed a marked circadian rhythm and the levels of plasma calcitonin and parathormone fluctuate similarly with calcium changes. Significant differences between treatment groups were noted for calcium, calcitonin and parathormone, indicating the interacting control of calcium mobilization and utilization by these two hormones during crop gland activity.

The effects of lead poisoning on various plasma constituents in the Canada goose.

Plasma glucose, free fatty acid and uric acid levels were measured in lead-poisoned Canada geese (Branta canadensis). Although plasma glucose levels were only slightly elevated, uric acid was significantly higher and free fatty acids were significantly lower. Altered plasma levels were attributed to increased protein catabolism and perhaps renal disfunction. Plasma level of growth hormone and prolactin was assessed by radioimmunoassay. Growth hormone remained unchanged while prolactin was unusually high. The increased prolactin levels may reflect an effort to stabilize free fatty acids.