TY - JOUR
T1 - Distribution of mitochondrial enzymes between the perikaryal and synaptic fractions of immature and adult rat brain
AU - Dienel, Gerald
AU - Ryder, Elena
AU - Greengard, Olga
N1 - Funding Information:
Deaconess Hospital. Mr. Dienel is supported by the National Institute of General Medical Sciences Grant GM 00451. The authors would like to thank Ms. Cynthia Peirce and Dr. Y.Z. Huang for carrying out some of the enzyme measurements.
Funding Information:
This investigation was supported by U.S. Public Health Service Grant CA 08676 from the National Cancer Institute and by the U.S. Energy Research and Development Administration Contract E(11-1)-3085 with the New England
PY - 1977/2/28
Y1 - 1977/2/28
N2 - 1. The subcellular distribution of mitochondrial enzymes was studied in cerebral hemispheres of 15-day-old and adult rats. At both ages the synaptosomal fraction contained very little glutamate dehydrogenase (EC 1.4.1.2) but significant amounts of succinate dehydrogenase (EC 1.3.99.1), glutaminase (EC 3.5.1.2), hexokinase (EC 2.7.1.1), malate NADP dehydrogenase (EC 1.1.1.40) and β-hydroxybutyrate dehydrogenase (EC 1.1.1.30). In immature brain, in the fraction enriched with free (perikaryal) mitochondria, the concentrations of these enzymes were 9.5, 1.8, 2.0, 0.92, 1.5. and 2.1 times higher, respectively, than in the synaptosomes. The increase with age in succinate dehydrogenase and glutaminase was restricted to free mitochondria while hexokinase and malate NADP dehydrogenase accumulated and β-hydroxybutyrate dehydrogenase diminished in both fractions. In adult brain, too, where the above ratios became 7.5, 5.2, 3.5, 0.84, 1.4, and 2.0, respectively, the concentrations of enzymes relative to each other distinguished clearly between free and synaptic mitochondria. 2. The results substantiate previously noted signs of mitochondrial heteroeneity in adult brain, and extend them to immature brain. The chemical composition, the quantitative pattern of enzymes, of free and synaptic mitochondria is clearly different, and undergoes separate changes during postnatal differentiation.
AB - 1. The subcellular distribution of mitochondrial enzymes was studied in cerebral hemispheres of 15-day-old and adult rats. At both ages the synaptosomal fraction contained very little glutamate dehydrogenase (EC 1.4.1.2) but significant amounts of succinate dehydrogenase (EC 1.3.99.1), glutaminase (EC 3.5.1.2), hexokinase (EC 2.7.1.1), malate NADP dehydrogenase (EC 1.1.1.40) and β-hydroxybutyrate dehydrogenase (EC 1.1.1.30). In immature brain, in the fraction enriched with free (perikaryal) mitochondria, the concentrations of these enzymes were 9.5, 1.8, 2.0, 0.92, 1.5. and 2.1 times higher, respectively, than in the synaptosomes. The increase with age in succinate dehydrogenase and glutaminase was restricted to free mitochondria while hexokinase and malate NADP dehydrogenase accumulated and β-hydroxybutyrate dehydrogenase diminished in both fractions. In adult brain, too, where the above ratios became 7.5, 5.2, 3.5, 0.84, 1.4, and 2.0, respectively, the concentrations of enzymes relative to each other distinguished clearly between free and synaptic mitochondria. 2. The results substantiate previously noted signs of mitochondrial heteroeneity in adult brain, and extend them to immature brain. The chemical composition, the quantitative pattern of enzymes, of free and synaptic mitochondria is clearly different, and undergoes separate changes during postnatal differentiation.
UR - http://www.scopus.com/inward/record.url?scp=0017348065&partnerID=8YFLogxK
U2 - 10.1016/0304-4165(77)90330-0
DO - 10.1016/0304-4165(77)90330-0
M3 - Article
C2 - 836906
AN - SCOPUS:0017348065
SN - 0304-4165
VL - 496
SP - 484
EP - 494
JO - Biochimica et Biophysica Acta - General Subjects
JF - Biochimica et Biophysica Acta - General Subjects
IS - 2
ER -