Age-dependent changes in the total protein concentrations in the brain regions and hypophyses of the pig

Abstract

88 crossbred Large White male day-old piglets were used to investigate age-related changes in total protein concentrations in ten regions of the pig brain and hypophyses from birth to 36 months of age. Age-related changes in protein concentrations in all the brain regions except the pons and cerebral cortex were not significant (P>0.05). However, the linear and quadratic curves and coefficients revealed substantial increase in total protein content in all the brain regions from day-old to between 12 and 20 months, thereafter declining rapidly and, in certain regions, gradually to much lower levels. In the pons, a rise in total protein of 1,091% was observed from day-old to 12 months, declining thereafter by 88% to 36 months. In the cerebellum, values rose by 642% from day-old to 10 months progressively falling by 75% in subsequent months to 36 months. Similar trends were observed in the amygdala and hippocampus. In the hypothalamus, midbrain and medulla oblongata, total protein levels rose progressively by 212%, 229% and 316% respectively from day-old to 36 months with a few non-specific fluctuations in- between. Significant falls in total protein levels with advancing age were observed in the adenohypophysis (P<0.01) and neurohypophysis (P<0.05). The decline in protein concentrations in several brain regions with advancing age may be due to a combination of decreased synthesis and rapid breakdown and are evidence of degenerative changes. The increases in protein in the midbrain, cerebral cortex and hypothalamus are parabolic and support the initial postnatal growth “spurt” hypothesis. This study has shed more light on the interplay between age and protein synthesis in the brain and suggests a closer investigation of the metabolic changes the brain undergoes during aging for a clearer understanding of their implications for nutrition and management.

Keywords: brain, protein, brain regions, age, development, senility

International Journal of Agricultural and Rural Development Vol. 5 2004: 19-26