Ubiquitous presence of calciferin-like and cathepsin D-like activities in the sera (vertebrates) and humoral fluids (invertebrates).
1. Sera (or humoral fluids) from various animals (vertebrates and invertebrates) were assayed for calciferin-like and cathepsin D-like activities, indicating the ubiquitous presence of the latter and the former (with a few exceptions). Animals other than the mammals appeared to contain an organophilic calciferin-like activity in addition to a hydrophilic component (calciferin). 2. A correlation was found between the levels of calciferin and acid protease in most of the mammalian sera. An age-dependent decrease in calciferin (but not acid protease) was found in human sera. The possible presence of an acid protease-inhibitor was suggested.
Terayama
H
H
Kitasato Institute, Tokyo, Japan.
Fukuzumi
R
R
D000818:Animals; D001826:Body Fluids / Q000032:analysis*; D002402:Cathepsin D / Q000097:blood / Q000378:metabolism*; D006801:Humans; D007448:Invertebrates / Q000032:analysis* / Q000201:enzymology; D010281:Parathyroid Hormone / Q000032:analysis* / Q000097:blood; D013045:Species Specificity; D014714:Vertebrates / Q000097:blood*
D010281:Parathyroid Hormone; C040861:calciferin; D002402:Cathepsin D