The Effect of Fa and Lansing Viruses on the Cholinesterase Activity of Brain and Spinal Cord Homogenates

[摘要] Mice were inoculated intracerebrally with FA virus and with Lansing virus. Total brain and spinal cord homogenates and the residue and supernatant fluid from these homogenates obtained by centrifuging were compared with similar preparations from uninfected mice in the following respects: wet weight, total nitrogen content, nitrogen concentration (μg N2/mg wet weight), and the cholinesterase activity expressed both in terms of wet weight and nitrogen content. The results were: 1. 1. There were no significant differences from the controls in mean wet weight and mean total nitrogen content for both brain and spinal cord with both viruses.2. 2. With Lansing virus, there was a significant increase over the control in nitrogen concentration for spinal cord homogenate and the residue and supernatant fluid fractions of this homogenate. With FA virus, the nitrogen concentration of spinal cord residue was significantly increased over the control, while the total homogenate and residue fraction nitrogen concentrations were not significantly different. With neither virus was there any significant difference in the nitrogen concentration of the brain preparations.3. 3. With FA virus, the cholinesterase activity, expressed in terms of tissue wet weight, was significantly decreased in the brain total homogenate and brain residue fraction (8.5% and 10.6% respectively), but not in the supernatant fluid fraction.4. 4. With FA virus the cholinesterase activity of the spinal cord preparations did not differ significantly from the control when the activity was expressed in terms of tissue wet weight, but when the activity was expressed in terms of nitrogen content the spinal cord total homogenate enzyme activity was significantly lower than the control (13.6% decrease).5. 5. With Lansing virus the cholinesterase activity of the three spinal cord preparations, but not of the brain preparations, was significantly lower than the controls, when the activity was expressed in terms of nitrogen content. These changes can be explained by the increased nitrogen concentrations in these preparations, therefore the decrease in enzyme activity probably is not a real one.6. 6. The magnitude of the changes in cholinesterase activity is not sufficient to affect the function of the central nervous system.

[学科分类] 生物科学（综合）