[Regional differences in the sensitivity of the metabolism of coelenterate larvae to external influences]

The regional differences in the sensitivity of protein synthesis and free radical processes to temperature, trypsin, urea and LiCl were studied in Obelia flexuosa by means of autoradiography. The regional differences were also determined with respect to the rate of incorporation and excretion of a labelled aminoacid under the normal conditions. The metabolic reactions of larvae can be divided in primary (the first 30 min following the effect) and subsequent adaptive ones. The primary reactions are characterized by the greater sensitivity of the anterior larval regions to all factors under study. The subsequent reactions are characterized by synchronous and unidirectional metabolic starts in both the anterior and posterior larval regions, the starts being bigger in the anterior regions. The restoration of the normal ratios of metabolic activities of the opposite larval regions does not always correlate with the restoration of the normal absolute level of metabolism. The adaptive reactions are better expressed for protein synthesis, rather than for free radical processes. The anterior larval region has the greatest metabolic non-stability by a series of indices.