Immunologische spezifität von lactatdehydrogenase isozymen dreiner säugetier-organismen

Abstract

• 1.

  1. Lactate dehydrogenase (l-lactate: NAD oxidoreductase, EC 1.1.1.27) isozymes from pig, beef and man have been compared by analyzing their immunological properties. The investigations were carried out mainly by means of agar precipitation techniques—immunoelectrophoretic analysis and double diffusion—in combination with a very sensitive lactate dehydrogenase (both containing mainly isozyme I and some isozyme II and III), isozyme V from pig skeletal muscle and a mixture of the five isozymes from human brain.

• 2.

  2. As we reported previously²² the isozyme I and V from pig possess different antigentic structures, as shown by a clear cut reaction of non identity in double diffusion and by absorption experiments. The failure of anti-isozyme V from pig skeletal muscle to react with isozyme I now confirms this statement.

• 3.

  In addition, a variation of immunoelectrophoretic analysis permitted us to provide evidence for the different antigenic structures of the human isozymes I and V even though we disposed only of mixtures of human isozymes.

• 4.

  The isozymes I and II from beef and from man show in immunoelectrophoretic analysis a reaction of partial identity. The isozymes I, II, and III from pig as well as II, III, and IV from man seem to be in close relation to each other.

• 5.

  All these results are in good agreement with the concept of Markert that mammalian lactate dehydrogenase molecules are composed of 4 sub-units “A” and “B”, isozyme I being the BBBB-, isozyme V the AAAA-form.

• 6.

  3. The cross reactions of lactate dehydrogenase isozymes from pig, beef, and man were studied in detail. It is shown that the cross reactions follow very closely the concept of Markert, “heart-type” cross reacting with “heart-type”, and ‘muscle-type” with “muscle-type”.

• 7.

  Absorption experiments with pure isozymes I or V and subsequent analysis of the remaining cross reactions in the respective supernatants (experiments soon to be published in detail^12,23) confirm this results.

• 8.

  The advantage of the reported cross reactions for clinical research is stressed.