| Popis: |
MIF-1, at concentrations of 10−5 and 10−6M, induced stimulations of 53 and 57% respectively in a particulate, crude, brain mitochondrial fraction when guanosine-3′:5′-cyclic monophosphate (cyclic GMP, c-GMP) formation was measured by a radioimmunoassay method. Evidence is presented that these stimulations occurred only after aging the particulate fraction at −20°C for a period of 5 to 7 days. The stimulation of c-GMP formation disappeared if the brain mitochondrial preparation was stored for more than 2 weeks. Reasons for these changes are discussed. Further experiments indicated that the guanylate cyclase system stimulation was not due to an effect of the MIF-1 on GTP-ase or guanylate phosphodiesterase. |
