M-Rna Translatability in the Liver, Brain and Kidney of Rats: Effect of Protein Calorie Malnutrition in Early Life

The m-RNA level and its translational capacity were
determined in the liver, brain and kidney of rats which
had been exposed to undernutrition early in life. To
achieve this objective, lactating females were divided
into 2 groups i week after they gave birth to offspring.
These control and experimental groups were made to suckle
8-11 and 13-16 pups, respectively, for a period of 2
weeks. The young of both groups were then killed and
their livers, brains and kidneys were isolated.
Polyadenylated RNA (poly A + RNA) was fractionated by
affinity chromatography on an oligo-dT-cellulose column.
Poly A + RNA content as well as the percentage of poly A +
RNA in relation to total RNA were both lower in the
malnourished pups in comparison to the controls.
Analysis of the in vitro translation product primed by
poly A + RNA of the liver, brain and kidney revealed a
decrease of 35S-methionine-ineorporation in the liver and
brain of the dietary-insulted offspring, the reduction
being greater in the liver than in the brain. No
significant variation was noted in the kidney of the
control and PCM groups. Sodium dodecyl sulfatepolyacrylamide
gel electrophoresis, autoradiography and
densitometric autoradiographie tracings confirmed these
findings and demonstrated that proteins were synthesized
at a lower rate in the livers and brains of the
malnourished rats than in the controls. These data
indicate that malnutrition early in life modulates the
metabolism of m-RNA and, consequently, protein synthesis
in the liver, brain and kidney of rats.