[Histochemical and electron microscopical changes in the kidney of pregnant rats at the time of partus (author's transl)].

In the convoluted proximal tubules of the kidney of pregnant rats alkaline phosphatase activity decreases from 21 days gestation till the 2nd day after birth. During the same time the reaction product of the histochemical succinate dehydrogenase assay exhibits an atypical granular character in some of the proximal tubules, which sometimes additionally contain sudanophilic structures. Electron microscopy reveals dilated mitochondria, an increased number of autophagosomes and big lipid vacuoles of low density.