Effects of brovincamine on stereological capillary parameters in adult and old Fischer-344 rats.

The intercapillary distance in the parietal cortex (area 39) and hippocampus (CA1 region) was greater in senescent Fischer-344 rats (27 1/2 months old) than in adult Fischer-344 rats (18 months old). Furthermore, an improvement was found in stereological parameter after a 42-day period of treatment with brovincamine (Sabromin) at dosages of 2.5, 5.0, and 10.0 mg/kg. Treated senescent rats showed a dose-dependent decrease in intercapillary distance and an increase in the number of capillary segments per measurement field compared with untreated controls. The values approximated those found in the adult control animals. In the adult rats the administration of the drug induced similar but far less marked changes in the stereology of the capillary network. The findings suggest that brovincamine affects the interactions between nerve cells, astroglia, and capillary blood flow (changes of the intercapillary microenvironment). The results show that a 42-day treatment with brovincamine decreases pericapillary resistance, thus supporting capillary microcirculation.