Regional Distribution of Adenosine Deaminase in the Human Neuraxis

Abstract

Adenosine deaminase was determined in 28 different areas of the human neuraxis in 5 adult male cadavers, with no known disease of the nervous system, using a very sensitive colorimetric method. The enzyme was highest in the frontal lobe white matter, and lowest in the medulla and all levels of the spinal cord. Enzyme content was about twice as great in the white matter of the frontal and temporal lobes and cerebellum as it was in the cortical gray matter of these areas, but only slightly higher in the white matter of the parietal and occipital lobes as compared to gray. Average values of the enzyme were found in the remaining areas of the brain, with the exception of the pons and cerebellar white matter, where a higher than average value was noted.

Anatomical Distribution of Nucleoside System in the Human Brain and Implications for Therapy

“…The distribution of 5 ¢ NTs, ADA, ADK, PNP, and GDA ( Fig. 29.1 ) activities in the human brain have been previously described (Dawson 1971 ;Nagata et al 1984 ;Norstrand et al 1984 ;Norstrand and Glantz 1980 ) (Table 29.1 ).…”

“…Nucleosides and nucleoside metabolic enzymes are found in brain areas involved in movement disorders (Dawson 1971 ;Kovács et al 2010a ;Nagata et al 1984 ;Norstrand et al 1984 ;Norstrand and Glantz 1980 ) (Table 29.1 ). Nucleoside transporters are present in the caudate nucleus, putamen, globus pallidus, and substantia nigra (Barnes et al 2006 ;Jennings et al 2001 ;Ritzel et al 2001 ) .…”

“…In the human hippocampus, ADA and GDA have intermediate activity (Dawson 1971 ;Norstrand et al 1984 ) (Table 29.1 ). Adenosine and Ino levels are low, but intermediate concentrations of Guo and Urd are present (Kovács et al 2010a ) .…”

“…Nucleoside levels, metabolic enzymes, transporters, and receptors are unevenly distributed in the human brain ; Barnes et al 2006 ;Dawson 1971 ;Fredholm et al 2001 ;Jennings et al 2001 ;Kovács et al 1998Kovács et al , 2010aNagata et al 1984 ;Norstrand et al 1984 ;Norstrand and Glantz 1980 ;Pennycooke et al 2001 ;Phillips and Newsholme 1979 ;Ritzel et al 2001 ) . In addition, nucleoside concentrations are dependent on age and gender (Kovács et al 2010b ) .…”

The Antiepileptic Potential of Nucleosides

“…In addition, uneven distributions of ADA activity and ADK activity, which may regulate Ado levels in the brain tissue, were revealed in the different brain areas. For example, the activity of ADA was intermediate to low in the hippocampus and intermediate to high in the cortical areas [31,[127][128][129], and intermediate/low and very low levels of ADK activity were demonstrated in the cortex and hippocampus, respectively [31,93,130]. ADA activity decreased with age in the cortex and hippocampus [131], which may induce an increase in Ado levels in elderly people.…”