Localization of S-adenosylhomocysteine hydrolase and adenosine deaminase immunoreactivities in rat brain.
Antisera against rat-liver S-adenosylhomocysteine hydrolase (SAH-hydrolase) and calf intestinal mucosal adenosine deaminase (ADA) were raised in rabbits and subsequently used to determine the distribution of the corresponding enzymes in rat-brain using the peroxidase-antiperoxidase immunohistochemical procedure. SAH-hydrolase antigenicity was prominent in the neocortex, hippocampal formation, cerebellum and olfactory tubercle. In the cerebellum, only those cells associated with the Purkinje layer possessed pronounced reactivity with anti-SAH hydrolase. The intense staining present could be correlated mainly with nuclei, the cytosol being stained less intensely. Weak ADA antigenicity was found throughout the brain, but strong antigenic reactivity was associated with neurones in the basal hypothalamus, superior colliculus and in nerve fibres in many regions. Many ADA antigenic neurones and fibres were seen in close proximity to blood vessels. The distribution of ADA antigenicity was also studied in cat and rabbit brain. In cat brain only general staining of tissue occurred with anti-ADA and no intensely stained regions comparable to those seen in rat brain were observed. Rabbit brain showed weak specifically stained neurones only in the superior colliculus. Enzyme assays were also performed to confirm immunohistochemical findings. There appears to be little in common between regions which stained intensely with anti-SAH hydrolase and anti-ADA respectively. The possible implications of these findings are discussed.
D000243:Adenosine Deaminase / Q000378:metabolism*; D043383:Adenosylhomocysteinase; D000818:Animals; D000906:Antibodies; D001921:Brain / Q000201:enzymology*; D002415:Cats; D006651:Histocytochemistry; D006867:Hydrolases / Q000302:isolation & purification / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D009700:Nucleoside Deaminases / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity; D014018:Tissue Distribution
D000906:Antibodies; D006867:Hydrolases; D043383:Adenosylhomocysteinase; D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase