title: Distribution of alpha 2-macroglobulin in normal, inflammatory, and tumor tissues in rats.
abstract: Distribution of uptake and catabolism of intravenously administered 125I-labeled rat alpha 2-macroglobulin(125I-alpha 2MG) were examined in normal, inflammatory, and tumor tissues of rats. Clearance of intravenously administered [125I]alpha 2MG from the circulation was rapid. Accumulation of this compound into inflammatory tissue was 2-3 times more extensive than in normal tissues. The accumulation into sarcoma tissue was much less. Radioactivity in TCA-PTA precipitates remained fairly constant for the first 12 h in inflammatory tissue and for the first 24 h in sarcoma. These patterns of accumulation were never observed in the normal tissues. As the kidney preferentially accumulated large amounts of [125I]alpha 2MG in the nondegraded form and its degradation products, the tissue may play a special role in the metabolism of alpha 2MG. Rapid clearance from the circulation and relatively small amounts of accumulation in tissues suggest that alpha 2MG may function as a protease inhibitor, mainly in the circulation rather than in the tissues.
mesh_terms: D000818:Animals; D007249:Inflammation / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012513:Sarcoma, Experimental / Q000378:metabolism*; D014018:Tissue Distribution; D000511:alpha-Macroglobulins / Q000378:metabolism*
chemical_list: D000511:alpha-Macroglobulins