Catecholamine-binding brain protein in mice exposed to perinatal malnutrition and neonatal infection.

Abstract

The formation and specific activity of a catecholamine-binding brain protein were studied in mice exposed to perinatal malnutrition and neonatal infection. In the malnourished group, the total norepinephrine (NE)-binding protein was less than in the control group (malnourished 7.1-10.0 mg; control 13.0-14.0 mg), but the dopamine (DM)-binding protein was not significantly affected. In the infected group, the quantity of NE-binding protein was also decreased (infected 6.4-8.0 mg), but the DM-binding protein was higher than in the control group. The specific and total binding activity of [3H]NE to brain protein was greatly reduced in the infected group (infected 22.6 pmol/mg protein; control 88.4 pmol/mg protein), and decreased also in the guanidine-HCl eluate of the malnourished group (56.5 pmol/mg protein). The binding activity of [14C]DM was decreased markedly in the infected group (infected 131 pmol/mg protein; control 330 pmol/mg protein), but its specific binding activity was not as severely affected in the malnourished as in the infected group. The molecular weights of the catecholamine-binding protein were 75,000 in the control, 70,000 in the malnourished and 65,000 in the infected groups. There were no marked differences between the malnourished and control groups with regard to the amino acid composition of the NE-binding protein. The DM-binding protein in these animals had decreased amino acid content. The infected group exhibited remarkable changes in NE- and DM-binding brain protein.