Influence of hemorrhage on adrenal secretion, blood glucose and serum insulin in the awake pig.

A study was performed to quantitate the adrenal medullary and cortical response to hemorrhage in awake animals bled at different rates and to relate these responses to simultaneous changes in blood glucose and serum insulin. A series of awake pigs were bled either slowly or rapidly of 30% of their calculated blood volume. Infusions of exogenous epinephrine were performed in an additional series of unbled animals and infusions of epinephrine plus hydrocortisone were similarly performed in an additonal series. Increase in blood glucose and epinephrine secretion rate following hemorrhage were found to be significantly dependent upon the rate of initial hemorrhage. Cortisol secretion was found to rise significantly during and following hemorrhage in both rapidly and slowly bled animals. Serum insulin levels remained at baseline levels during shock, despite the presence of significant hyperglycemia. In unbled animals infused with epinephrine at rates comparable to those measured in shock, elevations in blood glucose were markedly lower, shifting to the right of the dose-response curve during hemorrhage. Simultaneous infusions of cortisol and epinephrine resulted in a dose-response curve which did not differ significantly from that following infusion of epinephrine alone.