Ultrastructural organization of the liver of rat pups in early postnatal ontogenesis when pregnant and lactating rats are kept on a low-protein diet.

Abstract

Protein deficiency in the diet during pregnancy and lactation has a serious impact on the offspring by programming a predisposition to such serious diseases as hypertension and type 2 diabetes mellitus. In our study, we examined liver ultrastructure of rat pups at ages 2, 21, and 40 days with maternal protein deficiency. Body weight of the pups progressively lagged behind the control throughout the experiment, and the timing of eye opening indicated a slowdown of development. In the liver of 2-day-old animals, the proportion of hematopoietic cells at early stages of differentiation was higher as compared to the control. At the ultrastructural level, no obvious pathological changes were revealed, but a decrease in the amount of organelles was observed simultaneously with accumulation of lipids and glycogen. In the course of the experiment, a progressive decrease in the amount of the rough endoplasmic reticulum and ribosomes and increasing accumulation of glycogen in the cytoplasm of hepatocytes were noted. The most pronounced difference in ultrastructure between periportal and pericentral hepatocytes of control rat pups was detected on the 40th day of development, whereas in the low-protein diet group, the difference was weakly pronounced throughout the experiment. Thus, we showed that with prenatal and early postnatal protein deficiency, the growth and development of rat pups slows down, and glycogen accumulates excessively in the liver concurrently with a decrease in the amount of organelles.