Browsing by keyword "Choline"
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Basal ganglia choline levels in depression and response to fluoxetine treatment: an in vivo proton magnetic resonance spectroscopy studyWe have investigated proton magnetic resonance spectra of the basal ganglia in 41 medication-free outpatients with major depression, prior to starting an 8-week standardized trial of open-label fluoxetine, and 22 matched comparison subjects. Upon completing the trial, depressed subjects were classified as treatment responders (n = 18) or nonresponders (n = 23), based on changes in the Hamilton Depression Rating Scale. Depressed subjects had a lower area ratio of the choline resonance to the creatine resonance (Cho/Cr) than comparison subjects. This statistically significant difference between the depressed subjects and comparison subjects was more pronounced in the treatment responders than in the nonresponders. There were no differences in the relative volumes of gray matter or white matter in the voxel used for proton spectroscopy in depressed subjects relative to comparison subjects. These results are consistent with an alteration in the metabolism of cytosolic choline compounds in the basal ganglia of depressed subjects and, in particular, those who are responsive to fluoxetine.
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Ultrastructural localization of glycerolipid synthesis in rod cells of the isolated frog retinaThe incorporation of two glycerolipid precursors, 3H-glycerol and 3H-choline, into rod cells of the isolated frog retina has been studied using quantitative electron microscope autoradiography. The results indicate that the endoplasmic reticulum (ER) is the major site of early incorporation of these precursors suggesting that the ER is the primary site of lipid synthesis. Of the different types of ER present in rod cells, the rough ER (RER) and nuclear envelope predominate in this activity. The organized region of smooth ER (SER) in the subellipsoid region does not appear to be of major quantitative importance, although SER closely intermingled with RER in the myoid region may be involved to some extent. We also compared the pattern of labelling observed at various incubation times in 3H-glycerol and 3H-choline with that observed with 3H-leucine. Differences were observed between the pattern of lipid and protein labelling, particularly in the labelling of the Golgi apparatus, mitochondria, plasma membrane, presynaptic terminals and outer segments. This suggests that lipids and proteins may differ in some aspects of the routes and mechanisms by which they are transported from their sites of synthesis to the membrane delimited compartments for which they are destined.