Characterization of rat monoamine oxidase and the alteration of their activities in iron deficiency

Abstract

In order to clarify the interrelationship between the monoamine oxidase (MAO) and iron deficiency anemia, the author has performed the following experiments. Sixty Wistar rats, weighing 50g were divided into sixteen groups. Seven groups were fed on an iron deficient diet (ID). The remaining eight groups were fed on normal diet (C). The last one group was sacrified at the onset of the experiment and the following biochemical studies were carried out. (1) MAO-A and MAO-B activity of the liver mitochondria. (2) Concentrations of liver ferritin and DNA. (3) Hb concentration and Ht value. (4) Body weight and liver weight. The studies were performed at the initiation, 2, 4, 6, 7, 8, 10 and 15 weeks. Moreover, the MAO-B was purified from the control group and the molecular weight and iron atoms per molecule were determined. The results obtained were as follows: (1) There was no significant difference in body weight, liver weight, and DNA density concentration during the entire course of the experiment in ID and C groups. (2) The significant lowered concentrations of liver ferritin and Hb, and Ht value were encountered at 2, 4, 7 weeks in ID group (p<0.05) in comparison with C group. (3) The alteration of the MAO activity was similar in ID and C groups. Moreover, MAO-A activity pattern was similar to that of the MAO-B activity pattern as well. The elevation of activity was encountered at 4 week and the lowest value was seen at 6 week and again the reelevation of value was seen at 8 week. (4) To clarify the further detailed interrelationship between MAO activity and iron deficiency, determination of the MAO activity (activity value of iron deficiency/ respective control) has been performed in MAO-A and MAO-B in respective week. The MAO-A activity disclosed concaved pattern, while, the MAO-B activity disclosed convexed pattern. (5) The molecular weight of the MAO-B which was obtained from the gel filtration with Sepharose 6 B was 75, 000 and that from SDS electrophoresis was 72, 000 respectively. The iron content was determined 3 atoms per one molecule. Based on the observations, the MAO activity was influenced by iron deficiency of the rats. Moreover, the activity ratio pattern may be influenced by the inhibitory metabolic factors which compensate the effect of the iron deficiency.