The improved survival following high-dose
corticosteroid (HDC) treatment of
septic shock conditions has been suggested to be partly due to the metabolic effects of HDC.
Endotoxins are known to deplete
glycogen stores,
hexose phosphates and phosphoenol-
pyruvate. Elevated levels of
fructose diphosphate and phosphoglycerates are seen and there is an accumulation of
lactate.
Endotoxemia also seems to inhibit the utilization of non-
carbohydrate precursors for
glucose production and
hypoglycemia is characteristically seen with time in septic states. In severe
shock mitochondrial oxidative metabolism and ion transport capacity are defective and tissue energy store will be depleted. The underlying metabolic pathology in
shock states is still not known in detail but
endotoxins seem to have direct antiglucocorticoid effects. HDC counteracts the acceleration of glycolysis by the Embden- Meyerhof pathway seen in septic states and prevents the
endotoxin-mediated stimulation of
enzymes in the hexose monophosphate shunt. The levels of Krebs cycle intermediates and
pyruvate in the liver are raised
after treatment indicating enhanced gluconeogenesis. The conversion of
lactate to
glucose is increased and the
lactate/
pyruvate ratio decreased.
Protein catabolism is stimulated by HDC elevating the plasma levels of
amino acids and thereby further enhancing the potential for gluconeogenesis. The
endotoxin-induced
mitochondrial dysfunction is reversed and cellular energy production is improved. The beneficial metabolic effects of HDC may to some extent be indirect. A depressed febrile response will decrease tissue
oxygen needs. The vasodilatory effects will improve tissue
oxygen availability and thereby reduce tissue
hypoxia. Stabilization of cellular membranes may also prevent systemic metabolic effects caused by lysosomal
enzymes released from damaged cells.