Effect of Glucose Deprivation on Sulfatide Synthesis and Oligodendrocytes in Cultured Brain Cells of Newborn Mice

Abstract

Summaryuted exclusively to hypoglycemia could not be defined. Hypoglycemia in the newborn is usually accompanied by secondary pheThe present work was designed to a mode' for studying nomena, such as hypoxia, circulatory failure, or toxic influences the effect of substrates on brain cell metabolism. The synthesis of due to infections, all of which may lead to brain damage per se, sulfatide, a myelin lipid, which takes place predominantly in oliBrain changes in animals induced by expenmental hypoglycegodendrocytes was measured in vitro in dissociated cell cultures of mia showed a decrease of brain weight with decreased total protein newborn mouse brains a t 13 days in culture. This corresponds to and DNA in young rats (8), swelling of neurones and oligodenan active stage of in vivo myelination. The effect of increasing droglia with only mild swelling of astrocytes in rat brains durations glucose (below in the and cortical changes in rhesus monkeys (19,30). Metabolic conwas assessed 0' ""'r~ho'og~~ ce'"lar protein, DNA, sequences hypoglycemia in animals comprise alterations in sulfatide synthesis, cerebroside sulfotransferase activity, and mu-brain aminoacids (25. 41). glucose and glycogen (8, 25) and copolysaccharide synthesis.glycolytic as well as citric acid cycle intermediates (25). The brain was by the "Itured above a high-energy phosphates were depleted only at marked hypoglyconcentration of 0.4 mM in the medium. At high and intermed~ate cemia (26). The membrane lipids cholesterol and phospholipid glucose concentrations. between 43.8 and 63.6% of the glucose we_ diminished (*), Brain cerebroside as well as sulfate incorpoconsumed was accumulated a s Iactate on a molar ratio, indicating ration into the myelin lipid sulfatide was also reduced, whereas that the pyruvate deh~drobenaw com~lex was rate limitin& In lipid N-acelyl-neuraminic acid as a measure of gangliosides losevere glucose deprivation. Iactate consumption of the cultures cated in neurones was not by hypoglycemia (*).exceeded accumulation. The purpose of the present work was to characterize the effect With increasing duration of severe glucose deprivation (below of glucose deprivation on a specific step in structural brain metabmM)* the fOllowing major changes wereThe number olism during early development. Sulfatide synthesis (SFS) was of phase dark cells identified by immunofluorescence a s oligoden-chosen as a specific function of oligodendrocytes which plays a drocytes progressively decreased. Immunologically identified as-central role in myelination, A of cultured trocytes were unaffected glucose Sul-brain cells from newborn mice was utilized which shows an ageIatide 'ynthesis ~~~b~~~~~~~ to 3*8% * and dependenl SFS to the ; , , ,,jvo developmenl ( 4 2 ) This cerebroside sulfotransferase dropped to 10.3% of control with system makes it possible to study directly the effects of glucose prolonged glucose Thus, Oligodendroc~tes and One on brain cell metabolism, avoiding changes at the blood their specific functions were damaged by glucose deprivati...

Age-Dependent Utilization of d-β-OH-Butyrate and Oleic Acid as Glucose Substitutes by Neonatal Mouse Brain Cell Cultures

“…One possible explanation for this is the increasing activity with age of the pyruvate dehydrogenase complex, as has been documented between these developmental stages in rat brain homogenates and mitochondria1 preparations (5,12,20,23). In our cell culture system, indirect evidence for the rate limiting role of the pyruvate dehydrogenase complex was found: on a molar basis approximately half the glucose consumed by 13-day-old cells accumulated as lactate (25). The necessity to switch from glucose to D-P-OH-butyrate or oleic acid as an energy source either would not occur at all or would only occur at lower glucose availability in the older cells, because glucose utilization through the more active PDH-complex is facilitated as this stage.…”

“…The developmental pattern of enzymic activities in these cultures parallels that of the developing mouse brain in vivo (22). The system has proved useful in the study of the effect of low glucose levels on sulfatide synthesis (25), in that hypoglycemia was found to have a similar effect on sulfatide synthesis in vivo (4). Thus, the relevance of this culture system to the in vivo situation has been demonstrated.…”

Utilization of Galactose in Cultured Brain Cells of Neonatal Mice

“…Oligodendrocytes as small, glowing, round cells began to appear around the 6th DIC and increased in numbers until the 10th DIC. They were present on the upper layer of the bilayered cell culture (33).…”

“…Dissociated brain cells were prepared according to Wiesmann et al (31) with some modifications (33). Newborn mice from term-pregnancy Swiss albino dams (Hoffmann-La Roche, Fiillinsdorf, Switzerland) were decapitated within 12 h after birth.…”

“…It has been used before to study utilization of glucose (33), ketones, and oleate (4). In the present work, experiments were performed when the cultures were at a developmental stage characterized by a high number of oligodendrocytes (3) and active synthesis of sulfatide, a major galactolipid of myelin (27).…”