Distribution of Two Urinary Ribonuclease-Like Enzymes in Human Organs and Body Fluids

抄録

1. In order to determine the distribution of two human urinary RNase (RNase Us and RNase U_L)-like enzymes in human tissues and body fluids, enzyme immunoassay systems were established using rabbit anti-RNase sera. The sensitivity of the assay systems was of similar order to that of radioimmunoassay systems previously reported.
2. In the enzyme immunoassay, the cross reactivities of anti-RNase U_L serum towards RNase Us, bovine kidney RNase K₂, bovine RNase A, and bovine seminal RNase V_s were less than 1%. The cross reactivity of anti-RNase Us-serum to-wards RNase U_L was less than 0.5% and cross reactivities were minimal for RNase A, RNase K₂, and RNase V_s.
3. The RNase levels in human organs and body fluids were measured by enzyme immunoassay. In milk, semen and saliva, only RNase U_L-like enzyme was found. Both RNase Us- and RNase U_L-like enzymes were found in kidney, stomach, and pancreas and the RNase Us/RNase U_L ratios were 0.49, 1.35, and 0.34, respectively. In lung, liver, spleen, and leukocytes, most of the RNase activity was accounted for by RNase Us-like enzyme. The activity of RNase Us-like enzyme was especially high in lung, spleen, and leukocytes.
4. The crude extracts of several tissues and body fluids were separated by phosphocellulose column chromatography and the contents of the two urinary RNase-like enzymes were determined by enzyme immunoassay. In stomach, kidney, pancreas, and serum, both enzymes were present in multiple forms. In spleen and lung, both the major RNase (RNase Us) and minor RNase (RNase U_L) existed in two forms. A single peak of RNase was found in liver and in leukocytes.
5. The activity staining of liver, leukocytes, spleen, and lung RNases indicated that RNase Us-like enzyme in these tissues is also present in multiple forms.