ABSTRACT
Relative and total amounts of plasma protein fractions are affected by infections, inflammation, and nutritional and physiological status, and are therefore important health indicators in free-living animals. Our objectives were: (1) to examine intercolony differences in plasma protein fractions in prefledgling gulls and terns; (2) to investigate relationships between plasma proteins and other physiological measures such as weight loss, growth, and immune function; and (3) to examine potential associations between organochlorine exposure and plasma proteins. During 1992, blood was collected from 3-week-old herring gull (Larus argentatus) chicks from six sites on Lakes Superior, Huron, Michigan, Erie, and Winnipeg and from 3-week-old Caspian tern (Sterna caspia) chicks from five sites on Lakes Huron, Michigan, and Ontario. These sites provided a wide gradient of organochlorine contamination. Plasma proteins were separated by high-resolution agarose gel electrophoresis and stained with Coomassie brilliant blue dye. Six major fractions were quantified: prealbumin, albumin, alpha-globulins, beta(1)-globulins, beta(2)-globulins, and gamma-globulins. Total protein, prealbumin, albumin, and gamma-globulin concentrations and the albumin/globulin ratio did not differ among sites. Total protein, albumin, and the albumin/globulin ratio were not decreased in birds experiencing food stress or weight loss. Intersite differences were found in alpha- and beta-globulins. In gulls, beta(2)-globulins were positively associated with polychlorinated biphenyls (PCBs) and 1,1-dichloro-2,2-bis(p-chlorophenyl)ether (DDE). In terns, PCBs were negatively associated with alpha-globulins and positively associated with beta(1)-globulins. Additional research is needed to identify individual proteins and elucidate causal relationships between the particular protein concentrations and factors such as contaminants, growth, and condition.
