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Updated: Oct 5, 2026

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Published on: April 10, 2026
11Beta-hydroxysteroid dehydrogenase bioactivity is increased in the colon but not kidneys of rats given supplementary
B H Ruszymah1, Z Zaiton, S Aminuddin
1Department of Physiology, Faculty of Medicine, Universiti Kebangsaan Malaysia, Kuala Lumpur. ruszy@medic.ukm.my
Abstract:
The aim of this study was to investigate the effect of altered thyroid status on 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD type 1) and type 2 (11beta-HSD type 2) bioactivity in rat kidney and colon. Male Sprague-Dawley rats (250 g) were treated with either L-thyroxine (T4) or propylthiouracil (PTU) for 4 weeks. Blood were then analysed for serum thyroxine, sodium (Na+) and potassium (K+). The kidneys and colon were assayed for 11beta-HSD type 1 and 11beta-HSD type 2 bioactivity. In T4 treated rats the serum thyroxine was significantly elevated (p<0.05) whilst PTU decreased serum thyroxine significantly (p<0.001) compared to controls. Serum Na+ and K+ were within normal limits. There were no significant changes in 11beta-HSD type 1 bioactivity in both treatment groups compared to controls. However, the 11beta-HSD type 2 bioactivity in rats given thyroxine was significantly higher in the colon (p<0.003) compared to controls. We conclude that altered thyroid status had no effect on 11beta-HSD type 1 bioactivity but 11beta-HSD type 2 bioactivity was elevated in the colon of rats given supplementary thyroxine.
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