Studies of Nitric Oxide Production in Rat Tissues in Postnatal Development by Electron Paramagnetic Resonance Spectroscopy

Paramagnetic complexes containing nitric oxide (NO) have been assayed in rat heart and liver tissues by EPR spectroscopy to investigate the time variation of NO production during postnatal development. Nitric oxide levels have been assessed from the intensity of a characteristic EPR signal belonging to the (DETC)2–Fe2+–NO complex. The results show that the content of NO in liver tissues increases within the age interval from 28 to 56 days but does not change significantly in postadolescence. In heart tissues, the nitric oxide level increases in adulthood compared to puberty. The NO level in the rat liver is significantly higher than in heart tissues in all studied age groups.