Abstract
The effects on Monoamine Oxidase (MAO) in rat brain and liver and production of methemoglobin (Met-Hb) in blood by the administration of NaNO2 and NH2OH have been studied and the following results were obtained : Administration of NaNO2 and NH2OH caused a marked increase in the blood level of Met-Hb. Met-Hb in blood was 6.4 and 4.5 g/dl after i. p. administration of 100mg/kg NaNO2 and NH2OH, respectively. The blood level of Met-Hb reached a maximum at 15 and 30min following i. p. administration of 50mg/kg NaNO2 and NH2OH, respectively and then disappered gradually. Rats were administered NaNO2 i. p. in a dose of 50mg/kg/day for 30 days. The blood level of Met-Hb was increased slightly on the 3rd-4th day. The increasing MAO activity in rat liver was observed immediately and on the 2nd day following i. p. administration of 50mg/kg NaNO2 when tyramine was used as substrate. When benzylamine was used as substrate, MAO activity increased at 2-3 hours and on the 4th day. MAO activity in rat brain markedly increased on the 3 rd-4th day following i. p. administration of NaNO2 with tyramine as substrate. Similar results were obtained when serotonin (5-HT) was used as substrate. Rats were administered NH2OH i. p. in a dose of 50mg/kg/day for 30 days. The blood level of Met-Hb was increased slightly on the 3rd-4 th day. When tyramine was used as substrate, increasing MAO activity was observed on the 5th day of administration. Significant change of MAO activity was not observed when benzylamine was used as substrate. In case of brain, MAO activity increased on the 4th-6th day and decreased 1st-2nd day and 14th-20th day of administration when tyramine was used as substrate. Almost similar results were obtained when 5-HT was used as substrate.
