Vovnianko E K
Ukr Biokhim Zh. 1976 Sep-Oct;48(5):577-80.
Dynamic was studied for nicotinic acid (NA-7-14C) and its total metabolites excretion with area of animals under different physiological states (standard PP-avitaminosis). Various "efficiency" is shown for systems regulating homeostasis of this vitamin. When it is administered both in the amount close to the physiological dose (50 mg per 1 kg of weight) and exceeding the dose (500 mg per 1 kg of weight). The data obtained make it possible to draw a conclusion that the biological halflife period of Na-7-14C administered in excess of a physiological dose depends mainly on the rate of the unchanged vitamin PP excretion with urea and when it is administered in the physiological amount the period depends on the rate of the acid-metabolic transformations in the organism.
研究了烟酸（NA-7-¹⁴C）及其总代谢产物在不同生理状态（标准、维生素PP缺乏症）动物体内的排泄动态。结果表明，该维生素的体内稳态调节系统具有不同的“效率”。分别以接近生理剂量（每千克体重50毫克）和超过该剂量（每千克体重500毫克）给药时，所得数据表明，过量给予Na-7-¹⁴C时，其生物半衰期主要取决于未变化的维生素PP随尿素的排泄速率；而给予生理剂量时，该半衰期则取决于机体中酸代谢转化的速率。
