Proposed sex-dependent relationships between exogenous phenylephrine (Phe), endogenous adrenomedullin (ADM), and ERK MAPK, in the setting of fluid percussion brain injury (FPI), in determining the ability of Katp- and Kca-channel agonists to elicit cerebrovasodilation, thereby contributing to autoregulation during hypotension. Arrow thickness reflects the relative degree to which this action occurs (ERK, extracellular signal-related kinase; MAPK, mitogen-activated protein kinase).