title: Histophotometrical measurements concerning the distribution of myofibrillar ATPase activity within the tissue block after aldehyde fixation.
abstract: The inhibition of myofibrillar ATPase activity by aldehyde fixation in tissue pieces of myocardium of the rat was measured by scanning histophotometry. The relative amount of the final reaction product of the histochemical method for ATPase (Padykula and Herman 1955) was taken as a measure for the enzyme activity. Along scanning lines in slides from the surface to the centre of tissue block, a higher activity was found in the centre in contrast to the marginal zone. Compared with the centre of the block (approximately equal to 100%), in the marginal region a loss of about 40% (in paraformaldehyde PFA) and of 75% (in glutaraldehyde GA) was found, the latter with a sharp decline between the marginal zone and the central part. For quantitative enzyme histochemistry by histophotometry unfixed material is recommended.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D006321:Heart / Q000033:anatomy & histology; D006651:Histocytochemistry; D009206:Myocardium / Q000166:cytology / Q000201:enzymology*; D009210:Myofibrils / Q000201:enzymology* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D000251:Adenosine Triphosphatases