Comparative morphometric analysis of rat embryonic and fetal pulmonary structures after general hypothermia

The applied model of morphological assessment of the lung at strictly dated stages of embryonic (gestational day 14) and fetal (gestational day 20) development permitted to specify major planimetric parameters of organ parenchyma, the magnitudes of form-factors of the objects studied. On the basis of morphometric criteria, two main phenotypical variants of rat lung development were established. The factor of hypothermia, by modifying the limits of normal development, "typifies" its variants already in embryonic and perinatal periods with the participation of preacinar regions. This phenomenon is a manifestation of an individual intrauterine preadaptation by the formation of individual variants of "effect of readiness" to the challenge by a similar factor after birth with the object of probable minimal expenditures for the organism.