Ultrastruktureller und morphometrischer Nachweis einer durch Vitamin-D-Mangel induzierten Störung im oxidativen Stoffwechsel Eine ultrastrukturell-morphometrische Analyse der Ratten-Leberparenchymzelle

Abstract Introduction: Vitamin D deficiency interferes with citrate metabolism. Therefore it was of interest to analyze the influence of vitamin D deficiency on hepatocytic mitochondria. Material and methods: After administration of a rachitogenic diet to juvenile Wistar rats for 3 weeks, liver tissue was prepared for electron microscopy. Random sampling and morphometric procedures used were basically those described by Weibel . Statistical analysis included mean values, standard deviation and “Student's” t-test. Results: Under the influence of vitamin D deficiency, 5 % of liver mitochondria contained non-membrane-bound dense bodies. The mean volumes of single mitochondria and microbodies doubled. Whereas the number of microbodies doubled too, the number of mitochondria per unit cytoplasmic volume dropped to half. The mean surface of membranes of cristae per unit cytoplasmic volume increased. Discussion: The findings provide morphological and morphometric evidence that vitamin D deficiency alters oxidative metabolism in hepatocytes. As a consequence of an adaptive cytoplasmic response, the mitochondria hypertrophy and their cristae proliferate. There is a concomitant proliferation of microbodies. We suggest that the microbodies, acting as peroxisomes, prevent the accumulation of cytotoxic peroxides.