Effects of maternal administration of alcohol on fetal brain development

The effects of oral administration of alcohol during pregnancy and lactation on fetal and neonatal development were determined. Female Wistar rats were pair-fed nutritionally adequate liquid diets containing either alcohol or isocaloric carbohydrates starting on day 1 of gestation. Blood alcohol levels were determined in the pregnant animals throughout the experiment. On the day of parturition the litters were culled to six. The pups were sacrificed on day 30 and gamma-glutamyl transpeptidase (gamma GTP) activity determined in liver and brain. gamma GTP activity was determined to be elevated in the alcohol treated rats in all areas of brain studied except in the cortex and striatum. Additionally, the alcohol treated animals were smaller than the controls and exhibited higher serum and liver gamma GTP activities. Routine light microscopic plastic sections revealed large vacuolated spaces mainly confined to cortical layer V in the alcoholic rats. Golgi studies also revealed a decreased number of dendritic spines on pyramidal cell dendrites in the alcohol treated animals. These data suggest that exposure to alcohol in utero and in the postnatal period has a dramatic effect on neurons and processes in the cerebral cortex as well as on the membrane bound enzyme, gamma GTP.

Effects of p-chloroamphetamine, a serotonin-depleting drug, on the median eminence and pituitary pars intermedia

p-Chloroamphetamine (PCA), an agent known to cause depletion of levels of brain serotonin in rodents, was administered to rats in three sequential injections (10mg/kg) to study effects on the hypothalamic median eminence and pituitary gland. One week following the initial sequence of injections of PCA, light and electron micrographs revealed degenerate fibers in the outer zone of the median eminence. Lower drug doses or single 10-mg/kg doses did not lead to morphologic changes. Neuronal processes located in the pituitary intermediate lobe appeared normal although there was a significant increase in the numbers of secretory granules contained within intermediate lobe cells drug-treated rats, as compared to controls. Fluorometric analysis of levels of catecholamine and indoleamine showed a decrease in serotonin in median eminence and pons-medulla, but no change in that of the pituitary. Levels of dopamine and norepinephrine remained unchanged after PCA treatment. The data suggest that fibers affected in the median eminence contain serotonin. Processes in the intermediate lobe may be resistant to the serotonin-lowering effects of PCA observed in brain tissue. In addition, PCA may directly affect granule release from pituitary cells, or may alternatively act on hypothalamic regions which affect the release of intermediate lobe cell hormones.

Isolation and purification of multiple forms of gamma-glutamyl transpeptidase from rat brain

Four different forms of the enzyme gamma-glutamyl transpeptidase were isolated from rat brain by chromatography on concanavalin A. An approximate 1500-fold purification was achieved. The four forms were characterized with respect to molecular weight, Km for gamma-glutamyl-p-nitroanilide, mobility on polyacrylamide gels, and inhibitory effects of borate-serine. The multiple forms of the enzyme were found to have molecular weights ranging from 74,000 to 234,000 and Kms of 0.07 to 8.6 mM. It was determined that in brain, the major portion of the enzyme activity is associated with plasma membrane fragments and endoplasmic reticulum.

Rat brain gamma-glutamyl transpeptidase: effects of alcohol

Adult rats were exposed to increasing air ethanol concentrations over a 12-day period without the use of pyrazole. Gamma-glutamyl transpeptidase levels were determined from various regions of rat brain. The enzyme levels in the pons-medulla, mid-brain and the striatum increased significantly during the 12-day exposure to ethanol. Other areas of the brain displayed a slight increase in enzyme activity, but not a significant level.

The lipid composition of muscle cells during development

Developmental changes in the phospholipid, cholesterol, and fatty acid composition of chicken pectoralis muscle cells were analyzed during development in vivo and in tissue culture. The phospholipid composition of muscle cells showed only minor changes during in vivo or in vitro development but there were significant alterations in fatty acid composition. During in vivo development between the 12th and 22nd days the concentration of palmitate and arachidonate decreased with increase in linoleate. In cultured muscle cells the fatty acid composition changes with surprising plasticity depending on the fatty acid supply. Compensatory changes were observed in the chain length and unsaturation of several fatty acids, aimed presumably at maintaining the physical properties of the lipid phase relatively constant.

Metal ion catalyzed oxidation of the antibiotic rifampicin

The metal ions Cu++, Mn++ and Co+++, but not Ca++, Fe+++, K+, La+++, Mg++, Na+, Sr++ or Zn++ catalyzed the oxidation of rifampicin from the naphthohydroquinone to the naphthoquinone form. This reaction was pH dependent, and occurred at neutral or basic pH more rapidly than at acidic pH. Mn++ catalyzed the most rapid oxidation, followed by Cu++ and then Co+++. Rifampicin oxidation was metal ion dependent and complete oxidation occurred at metal ion concentrations below stoichiometric values. Initial rate studies suggest that the oxidation mechanism is complex.

Brain gamma-glutamyl transpeptidase levels in mice genetically selected for sensitivity to ethanol

The present study describes the regional distribution of the enzyme gamma-glutamyl transpeptidase for two lines of mice (long-sleep and short-sleep) selectively bred for differences in sleep-time after the administration of ethanol. The long-sleep animals exhibited higher levels of the enzyme in all areas of brain.

Development of sarcoplasmic reticulum in cultured chicken muscle

The development of sarcoplasmic reticulum membranes was studied in vivo and in tissue culture in chicken pectoralis muscle cells. The concentration of the calcium- and magnesium-activated ATPase measured by selective labeling of the enzyme with [32P]ATP in whole muscle homogenates was found to increase in developing chicken pectoralis muscle in vivo from 0.01 nmol/mg of protein in 12-day embryos to 0.3 to 0.4 nmol/mg of protein in 1-month-old chicks, where it constitutes about 3% of the total protein content of muscle. In cultured muscle cells the concentration of calcium-sensitive phosphoprotein increased from 0.015 nmol/mg of protein at 2 days to 0.04 to 0.05 nmol/mg of protein after 5 days of culture. This amount represents about 0.5% of the protein content of the muscle cells. The accumulation of Ca2+ transport ATPase began during fusion and continued with a linear rate during 8 days of culture. The density of 75 A intramembranous particles seen by freeze-etch electron microscopy on fracture faces of sarcoplasmic reticulum membranes is about 4,000/mum2 in adult chick pectoralis muscle but only 400/mum2 in cultured muscle cells in rough proportion to the concentration of Ca2+-sensitive phosphoprotein. The Ca2+, Na+, and K+ concentration of the medium and addition of ouabain, caffeine, or the calcium ionophores A23187 and X537A sharply influence the concentration of calcium transport ATPase in cultured muscle cells, parallel with their effect upon cell fusion and growth. These observations are consistent with the proposition that the gene expression leading to the accumulation of Ca2+ transport ATPase during development in culture may be regulated by intracellular ion concentrations.

Biochemical localization of gamma-glutamyl transpeptidase within cellular elements of the rat cerebral cortex

The presence of the enzyme gamma-glutamyl transpeptidase was established in cellular elements of the rat cerebral cortex. Lowest enzyme activity was found in the total cerebral homogenate while approximately four-fold increased enzymatic activities were evident in capillary-enriched, glial-enriched and purified neuronal fractions.