The main renal arteries were constricted at two hours, and at 18 hours the renal arterioles were also constricted.
The efferent limb is in resistance arterioles and consists of sympathetically mediated vasoconstriction.
Interestingly, hypotension is also associated with leukoaraiosis,16 consistent with reduced perfusion through narrowed penetrating arterioles in patients with low blood pressure.
Their blood supply is from terminal arterioles with little anastomotic supply, thus a vessel occlusion will usually result in tissue infarction.
It is reasonable to assume that all injected schistosomula will be quickly carried to, and lodge in, the pulmonary arterioles.
However, it is likely that increased tissue pressure also results in compression of the penetrating arterioles, resulting in ischaemia.
Interestingly, we found that the penetrating parenchymal arterioles were also significantly larger during pregnancy and underwent forced dilatation at lower pressures, similar to the posterior cerebral arteries.
No transient intermissions of flow in arterioles or absence of flow were found in any dog, even with the stepped flow decrease to 10 ml/kg/min.
