Tissue distribution and elimination of radiolabelled methyltestosterone fed to adult blue tilapia

C. A. Goudie; W. L. Shelton; N. C. Parker

doi:10.1016/0044-8486(86)90088-8

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Tissue distribution and elimination of radiolabelled methyltestosterone fed to adult blue tilapia

C. A. Goudie·W. L. Shelton·N. C. Parker

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Abstract

Radioactivity levels in 10 tissues were monitored for 21 days after adult (1-year-old) blue tilapia, Oreochromis aureus , were fed a single meal of a diet containing 30 μg unlabelled methyltestosterone (MT) per gram of feed and radiolabelled MT ( 3 H-labelled steroid nucleus and 14 C-labelled 17α-methyl group). Radioactivity was highest in all tissues 6–12 h after the feeding; about 90% of the radioactivity was in the digestive tract, liver, gall bladder, and kidney. Radioactivity declined nearly 90% by 4 days and only 0.5% of original radioactivity (67 ng/g of fish) remained after 21 days. Half of the remaining exogenous hormone was in digestive and excretory tissues; concentrations in muscle were less than 1 ng/g of tissue. Ratios of 3 H: 14 C in tissues were similar to those incorporated in the diet and suggested that the 17α-methyl group was not removed during metabolism.

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C. A. Goudie, W. L. Shelton, N. C. Parker. 1986. Tissue distribution and elimination of radiolabelled methyltestosterone fed to adult blue tilapia. https://doi.org/10.1016/0044-8486(86)90088-8

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