INACTIVATION OF CHLORTETRACYCLINE IN MUSCLE TISSUE AND METHOD FOR ITS STABILIZATION

The stability of tetracyclines in muscle tissue at lower temperatures has been studied by WEISER et1), TARR et al2), WALKER and AYRES3), and TOMIYAMA et al 4-6). No concordant results, however, have been reported so far. The present authors studied on factors governing the stability of CTC in mackerel flesh brei, and revealed that two modes of inactivation were involved, namely, one occurred shortly after the addition of CTC, and the other during storage. It was found that the former could be inhibited by the inclusion of chelating agents and the latter by the presence of antioxidants (Tables 2 and 3). These protective substances, however, did not prevent CTC in a buffered solution from deterioration at 100°C (Fig. 1). It was observed that residual CTC after a 3-day icing appeared to become stabilized (Fig. 2). This apparent increase in the stability seems to be due to either antibacterial activity of oxidized CTC or of oxidized oil per se. Data herein reported made it clear that a disagreement among the works above-cited on the stability of CTC in tissues was resulted from a difference among tissues employed by the above cited authors in their ferric iron content and the rate of oxidation of oil in tissues.