[Calcification of the arterial wall in the aging process. Electron microscopic and biochemical studies of a model of vitamin D3 overdose].

Abstract

The following mechanisms for inactivating excessive Ca++ are found in the vessel wall (e.g. in old age, arteriosclerosis, hypertension, or overdosage with Vitamin D3): 1. The production of Matrix Vesicles, which reduce biologically active extracellular Ca++ by precipitating it during the initial stage of calcification. 2. An increase in the number of muscle cells changed from the "k" to the "m" form. These also possess a mechanism for reducing the intracellular Ca++ level. If in spite of these mechanisms the extracellular Ca++ concentration remains raised, this can result in calcification of the interzellular substance, particularly the elastic material.