Isozyme profiles and protein patterns in specific organ damage

Abstract

Serum lactic dehydrogenase isozymes have been utilized as a means of detecting specific organ damage in rats. The serum LDH isozyme patterns seen in response to liver or kidney damage are markedly different, thus these patterns were utilized to identify the damaged organ. Liver damage resulted in increased activity of the serum LDH-5 isozyme while kidney damage produced increased activity of LDH-1 and LDH-2. The ip injection of mercuric chloride (HgCl2) resulted in elevated activity of LDH-1 and LDH-2, characteristic of kidney damage, after doses as low as 2 mg/kg. In a time sequence study following the injection of 4 mg HgCl2/kg body weight, there was an early elevation of LDH-5 suggestive of liver damage. This was followed approximately 12 hours after injection by marked increase of LDH-1 and LDH-2 characteristic of kidney damage. An alteration of the serum protein electrophoretic pattern was also noticed in HgCl2 treated animals. This technique of studying serum isozyme patterns may become a valuable tool in the detection of organ damage produced by toxic compounds.