Identification of tissue sites for increased albumin degradation in sarcoma-bearing mice

Journal Article · Fri Feb 01 00:00:00 EST 1991 · Journal of Surgical Research; (USA)

DOI:https://doi.org/10.1016/0022-4804(91)90240-M· OSTI ID:6054509

Andersson, C; Iresjoe, B M.L.; Lundholm, K ^[1]

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1. Univ. of Gothenburg (Sweden)

Plasma albumin concentration declines in both experimental and clinical cancer. Previous investigations have demonstrated that this is partly explained by increased breakdown of albumin. The present study has identified the tissue sites for increased albumin degradation in a nonmetastasizing sarcoma mouse (C57/BL6J) model. Results have been compared to nontumor-bearing animals either freely fed or food restricted (pair-weighed) so that their body composition was similar to tumor-bearing animals. Tumor-bearing mice had increased albumin degradation (0.13 +/- 0.02 mg/hr/g bw) compared to both freely fed (0.09 +/- 0.007) and pair-weighed control animals (0.05 +/- 0.008). Radioactivity from circulating (3H)raffine aldehyde labeled albumin appeared with maximum peak values in lysosomes isolated from both tumor and nontumor tissues at 48 hr following iv injection. The intralysosomal accumulation of radioactivity was two- to threefold higher in tumor tissue compared to liver tissue, although the specific activity of protease(s) for albumin degradation measured in vitro was not higher in tumor tissue (30.4 +/- 3.6 mg/hr/g tissue) compared to normal liver tissue (36.9 +/- 1.7). Accounting for the entire tumor the proteolytic capacity for albumin breakdown was however much larger in the tumor (161.6 +/- 32.6 mg/organ) compared to both normal liver (37.5 +/- 2.3) and tumor-host liver (56.4 +/- 2.8). Pepstatin inhibited 78 +/- 6% of the proteolytic activity in the tumor measured by 125I-labeled undenatured mouse albumin as the substrate. Leupeptin inhibited 49 +/- 6%. There was a significantly decreased breakdown of albumin in both skeletal muscles and the gastrointestinal tract from tumor-bearing animals.

• OSTI ID: 6054509
• Journal Information: Journal of Surgical Research; (USA), Vol. 50:2; ISSN 0022-4804
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ALBUMINS
METABOLISM
SARCOMAS
PATHOGENESIS
EXPERIMENTAL NEOPLASMS
IODINE 125
ISOTOPE DILUTION
MICE
PEPTIDE HYDROLASES
TRITIUM COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
DAYS LIVING RADIOISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
HYDROGEN COMPOUNDS
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
NEOPLASMS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
RODENTS
TRACER TECHNIQUES
VERTEBRATES
550901* - Pathology- Tracer Techniques