[The reaction of acclimated isolated gill epithelium of mollusc to a short-term superoptimal heating].
Thermoresistance (TR) of isolated gill epithelium of molluscs Anodonta anatina L. (n = 20) acclimated for 72 h at 24 degrees C was studied. In 1, 2, 12, 24, 36, 48, 60, and 72 h, the gills were submitted to a provoking action: a 10-minutes heating at 36 degrees C. As a criterion of the tissue TR level served a logarithmic index of the time of survival at 40 degrees C. During 24 h, negative correlation (about 0.50) was revealed between the acclimated epithelium TR level and the value and direction (sign) of its change under the provoking action. In 36 h, this coefficient fell to 0.13. As a result, the range of interorganism variability of the tissue TR level enlarged. Meanwhile, a decrease in the acclimated tissue mean TR level occurred as late as in 60 h of the experiment, being equal to 21%. In 72 h, it reached 30%, which traditionally indicates a deterioration of the functional state of tissue cells and a subsequent death. However, we believe that the deterioration of this state actually had happened earlier, in 36 h, when the range of the interorganism variability of the tissue TR level became enlarged. It was at this moment that the acclimated tissue lost its ability to regulate the shift in stability with the TR level at this period of acclimation.
Mironova
A P
AP
Institute of Cytology RAS, St. Petersburg. apm@mail.cytspb.rssi.ru
D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D049872:Bivalvia / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D004847:Epithelial Cells / Q000502:physiology*; D005880:Gills / Q000166:cytology / Q000502:physiology*; D006358:Hot Temperature; D013997:Time Factors