Influence of the salt moiety on the effectiveness of corticosteroid therapy in cardiogenic shock.

Using closed chest coronary artery microsphere embolization, myocardial infarction and subsequent shock were produced in healthy adult mongrel dogs. Following infarction animals were distributed among the following groups: (1) control; (2) methylprednisolone sodium succinate (MPSS); (3) methylprednisolone sodium phosphate (MPSP); (4) sodium phosphate (SP); and (5) sodium succinate (SS). Drug doses of equivalent anti-inflammatory activity were administered i.v. 15 min after infarction. Compared to control animals, only dogs treated with MPSS exhibited significant improvements in hemodynamic parameters and permanent survival. Survival in MPSS dogs was significantly (P = 0.02) better than that of either group treated with SP or SS and substantially (P = 0.02) better than that of either group treated with SP or SS and substantially (P = 0.065) better than the survival rate of dogs receiving MPSP. It appears that succinate is permissive, while phosphate is restrictive, with respect to efficacy of methylprednisolone in experimental cardiogenic shock. Possible explanations for these observations are discussed.