Table 1.
Comparison of BBB permeability values obtained in brains of young and aged mice by use of intravital two-photon microscopy with data from the literature
| Molecular Mass of Tracers, kDa | Volume Imaging (Current study) |
Single Microvessel (Current study) |
Single Microvessel(Kutuzov et al. 2018) |
Single Microvessel(Shi et al. 2014) |
||
|---|---|---|---|---|---|---|
| Young | Aged | Young | Aged | Young | ||
| 500 | 0.54 ± 0.09 | 0.95 ± 0.28 | ||||
| 40 | 1.85 ± 0.52 | 12.67 ± 4.89 | 1.01 ± 0.21 | 2.91 ± 1.57 | 1.40 ± 0.15 | 1.15 ± 0.23 |
| 3 | 2.32 ± 0.41 | 30.68 ± 5.56 | 1.85 ± 0.18 | 12.91 ± 6.13 | ||
| 0.3 | 9.51 ± 0.94 | 70.01 ± 5.19* | 5.54 ± 3.71 | 32.12 ± 4.4* | 3.91 ± 0.41 | 12.92 ± 3.59 |
Values are means ± SE Measured blood-brain barrier (BBB) permeability by two-photon microscopy, P (10−7 cm/s). Calculated permeability values for fluorescent tracers with different molecular masses in brains of young and aged mice are shown. Data obtained by using both volume imaging and single-microvessel imaging are shown. data obtained in young mice from the literature are shown for comparison. Note that the absolute permeability data for 40-kDa tracer obtained both by volume imaging and by single-microvessel imaging in young mice are virtually identical to the literature data. The permeability data for the 0.3-kDa sodium fluorescein tracer obtained using volume imaging and single-microvessel imaging are comparable to the data of Shi et al. (24) (obtained by analyzing postcapillary venules, 20-40 μm in diameter) and the data of Kutuzov et al. (21) (obtained by analyzing capillaries), respectively. *Note that in case of sodium fluorescein the intensity in aged animals was often over the dynamic range; therefore, precise measurement was not always possible.