Endogenous ammonia

Endogenous ammonia Byproduct of metabolism and bacterial catabolism... 

Lim CB et al Reduction in the rates of protein and amino acid catabolism to slow down the accumulation of endogenous ammonia a strategy potentially adopted by mudskippers during aerial exposure in constant darkness. J Exp Biol 2001 ... 

Endogenous ammonia is converted to a nonresponsive product creatinine does not react with glutamate dehydrogenase (GlDH) and is converted to ammonia when it reaches the immobilized creatinine deiminase. 

Following exposure to 500 ppm ammonia for 10-27 minutes, healthy male subjects eliminated 70-80% of the inspired ammonia by this route (Silverman et al. 1949). Analysis of endogenous ammonia levels in the expired air of rats showed concentrations ranging from 10-353 ppb (mean=78 ppb) in nose-breathing animals (Barrow and Steinhagen 1980). 

EPA. 1979. Effects of endogenous ammonia on neutralization of inhaled sulfuric acid aerosols. Cininnatti, OH U S. Enviromnental Protection Agency, Health Effects Research Lab. EPA-600/1-79-045PB 80 147 978. 

Utell MJ, Mariglio JA, Morrow PE, et al. 1989. Effects of inhaled acid aerosols on respiratory function The role of endogenous ammonia. J Aerosol Med 2 141-147. 

Creatinine The microbial enzyme creatinine deimi-nase (EC 3.5.4.21) works well in the enzyme thermistor giving a linear range from 0.01 to at least 10 mmol 1 This could be a very powerful assay for clinical use since it requires only one enzyme and is independent of endogenous ammonia. Unfortunately, the determination of creatinine in human serum requires a higher order of magnitude increase in sensitivity than is available with the present instrumentation. 

The ability to predict responses to current ambient acid levels requires further understanding of the role of endogenous ammonia and the extent to which it may offer some protection from breathing acids. Also, exercise will complicate the neutralization process, by changing the breathing mode and the residence times of particles. 

Utell, M.J., J.A. Mariglio, P.E. Morrow, F.R. Gibb, and D.M. Speers (1989), Effects of Inhaled Acid Aerosols on Respiratory Function The Role of Endogenous Ammonia, /. Aerosol Med. 2 141-147. 

Fig. 7 Conceptual scheme of the BioET to determine urea in presence of endogenous ammonia and alkaline ions, as interferents in the multidetermination application in clinical samples...

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