Research Article| Volume 18, ISSUE 1, P25-45, January 1973

Ultrastructural responses of the astrocytes to portocaval anastomosis in the rat

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      The changes in astrocytes following portocaval anastomosis in rats have been studied by electron microscopy from 1 to 16 weeks after operation.
      Two distinct types of change take place. From 1 week onwards there is a generalised selective swelling of astrocytes without increase in organelles. This is accompanied by folding of the capillary basement lamina and increase in the surface of the astrocyte end-feet. From 4 weeks onwards in some regions there is an increase in organelles within astrocytes and later an increase in astroglial filaments. At the same time degenerative changes occur in myelinated fibres in these regions and there is found the accumulation of granular and fibrillary material in oligodendroglial cytoplasm. These three events may be related to one another.
      The metabolic background to these changes is discussed in relation to the compartmentation of glutamate metabolism as well as in relation to the possible role of ammonium ions acting as anti-metabolites to potassium ions.
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