Early changes in enzyme activity during the development of and recovery from vitamin D deficiency in the rat

Abstract

I . Rats were given a rachitogenic diet with or without vitamin D for I , 2, 3 or 4 weeks, and vitamin D was administered to a group of rats which had been deprived of vitamin D for 3 weeks. 2. Changes in enzyme activities of some tissues were followed histochemically. In general, changes in parathyroid preceded those in gut and kidney. Leucine aminopeptidase activity rose in the parathyroid, kidney and jejunum of the vitamin D-deficient rat as did the ribonucleic acid content of the parathyroid and the dehydrogenase activity of the gut. In contrast, the phosphatase activity of the gut and kidney fell in the vitamin D-deficient rat. All these changes were reversed during the I-week recovery period. 3. A slower response of bones to both vitamin D deprivation and vitamin D dosage after deprivation was indicated by the changes in the percentages of ash in the bones and the changes in number and distribution of osteoclasts.In a previous study (Cheesman, Copping & Prebble, 1964) a comparison was made of enzyme activities in the tissues of normal and vitamin D-deficient rats after 4, 5 and 7 weeks of deprivation. Among the differences observed was a consistent rise in leucine aminopeptidase activity in the parathyroids of the deficient rat. Since the parathyroid is so intimately concerned with the distribution of calcium and phosphorus, changes in other tissues could be secondary to those of the parathyroid rather than primary effects of the lack of vitamin D.In the present study some rats were deprived of vitamin D for shorter periods and some deficient rats given a curative dose of vitamin D, to determine whether enzyme activities of other tissues altered before those of the parathyroid during either depletion or recovery. EXPERIMENTAL Animals and procedurePairs or trios of male rats, of the Lister Institute black and white stock maintained at Queen Elizabeth College, were placed on a rachitogenic diet with or without vitamin D (Cheesman et al. 1964) at 28 days of age and maintained on the diet for I , 2 or 3 weeks in experimental series C 35 and for 4 weeks in series C 38. In series C 35 one animal of each pair received vitamin D for the whole experimental period and the other received none. In series C 38 one animal of each trio received vitamin D for the whole experimental period, one animal received vitamin D for the last week of the period only and the third received none.In series C 35 one normal and one deficient animal were killed on each occasion https://www.cambridge.org/core/terms. https://doi

Rhabdomyolysis in a Patient with Hypocalcemia due to Hypoparathyroidism

“…The calcium is the component of the system regulating the characteristics of the cell wall of RBCs [ 18] which con tain LDH 1,2.3 [19], Furthermore, the mucosal cells of the duodenum or jejunum in vitamin-D-deficient rats have been reported to have increased LDH activity [20], It is therefore theoretically possible that the aforemen tioned cells play a role in the increased LDH activity in the hypocalcemic patients. However, the liver tissue is not likely to be a source of elevated LDH activity because it is rich in LDH 5 [ 13], and enzyme not detectable on electro phoretic pattern.…”