Increased adrenomedullin concentration in cerebrospinal fluid in patients with septic shock

Plasma level of adrenomedullin (AM), a potent vasodilator peptide, is increased in patients with sepsis. AM was also found to be present in cerebrospinal fluid (CSF) of humans, and intracerebroventricular injection of AM resulted in elevated systemic blood pressure in rats. In the present study, we measured AM levels in CSF and plasma of 7 patients with septic shock who had severe hypotension, and compared with those of 10 control patients receiving primary transurethral resection of bladder tumor. CSF samples were obtained through the procedure of lumbar puncture and AM levels were measured by radioimmunoassay. AM concentration in CSF of the septic patients was increased to a level 35 times higher than that of control group (35 +/- 21 vs. 0.9 +/-0 .3 pmol/L, mean +/- S .D., p < 0.01). Similarly, plasma AM concentration was increased by 27 times compared with control group (176 +/- 71 vs. 6.5+/-1.8 pmol/L, p < 0.01). Despite the similar increase in CSF and plasma AM, no significant correlation was found between the AM concentrations in the CSF and plasma (r = 0.01 P = 0.95). Taken together with the central actions of AM, these findings suggest that AM of the central nervous system may be involved in pathophysiology of sepsis of humans.