Tissue distribution of an endogenous inhibitor of calcium-activated neutral protease and age-related changes in its activity in rats.
1. The distribution of an endogenous inhibitor of calcium-activated neutral protease (CANP) and age-related changes in its activity were studied in male and female rats of different ages by a fluorometric assay on tissue extracts after heat treatment. 2. Ubiquitous distribution of CANP inhibitor in brain, cardiac muscle, lung, spleen, liver, skeletal muscle, kidney and testis and its abundance in spleen, liver and kidney was demonstrated. 3. Comparison in terms of units/ml of crude extracts showed that the level of CANP inhibitor exceeded that of CANP in most tissues and that the relative content of CANP inhibitor to mCANP and microCANP differed greatly among tissues. 4. Sex and species differences in CANP inhibitor activity in each tissue were of little significance. 5. Changes in CANP inhibitor during aging from 6 to 12 months was not obvious but senescent rats showed a tendency toward increased inhibitor activity. This increase was especially evident in the testis.
Nakamura
M
M
Department of Biochemistry, Tokyo Metropolitan Institute of Gerontology, Japan.
Imahori
K
K
Kawashima
S
S
D000375:Aging; D000818:Animals; D002154:Calpain / Q000037:antagonists & inhibitors*; D006023:Glycoproteins / Q000032:analysis*; D006358:Hot Temperature; D051381:Rats; D011919:Rats, Inbred Strains; D012737:Sex Factors; D013045:Species Specificity; D014018:Tissue Distribution
D006023:Glycoproteins; C039304:calpain inhibitors; D002154:Calpain