Genetic, Environmental And Stochastic Factors Contribute To Variation In The Posterior Communicating Collaterals Of The Circle Of Willis

Variation in blood flow mediated by the posterior communicating collateral arteries (PComs) contributes to variation in severity of tissue injury in obstructive disease. The “extent” of PCom collaterals (lumen diameter u0026/or number—ie, presence bilaterally, unilaterally or absent) varies widely in humans and other species due in part to developmental differences, since well-known patterns of variation are present at birth. However, mechanisms underlying this variation have not been examined. Herein we used angiography to probe involvement of genetic, environmental and stochastic factors. PCom extent varied widely among 7 mouse strains with different genetic backgrounds that was unrelated to differences in PCA diameter or brain weight. The pattern differed strongly from that previously reported by us for differences in extent of pial collateral arterioles. Like pial collaterals, PCom diameter was reduced by advanced aging (-28±3%, n=11-16, pu003c0.01; opposite seen for PCA diameter) and hypertension (-14±8%, n=...