In vivo distribution and behavior of paramagnetic dinitrosyl dithiolato iron complex in the abdomen of mouse

It has been shown that a dinitrosyl dithiolato iron complex is formed under physiological conditions and that it functions as an NO transporter. In th e present study, a diglutathionyl dinitrosyl iron complex [DNIC-(GS)(2)] wa s injected into mice and its abdominal distribution and behavior were exami ned by using electron paramagnetic resonance (EPR) spectroscopy. The X-band EPR signal intensity of the blood, liver, kidney, and spleen decreased wit h time but signals from the liver and kidney were readily detectable even 2 4 h after the injection. The time courses of signal intensity were quite si milar when the agent was administered via intravenous and subcutaneous inje ction routes, suggesting that DNIC-(CS)(2) can penetrate readily and rapidl y through the membranes. Real-time detection of DNIC-(GS)(2) in the upper a bdomen of the living mice was performed by employing an in vivo EPR spectro scopy. These results suggest that DNIC-(GS)(2), an endogenous NO carrier, h as an excellent membrane permeability and has a relatively high affinity fo r the liver and kidney.