Activities of Proline-Specific Peptidases in Brain Structures of Rats with Experimental Anxiety-Depressive State Caused by Administration of Dipeptidyl Peptidase IV Inhibitor in the Early Postnatal Period

We studied the dynamics of activity of dipeptidyl peptidase IV (DP-IV) and prolyl endopeptidase (PEP) in the frontal cortex, hypothalamus, striatum, nucleus accumbens, and hippocampus of rats with experimental anxiety-depression state induced by administration of methionyl-2(s)-cyano-pyrrolidine, an inhibitor of DPP-IV, in the early postnatal period. In 1-month-old experimental males, PEP and DP-IV activities increased in the frontal cortex and hypothalamus, while in 1-month-old experimental females PEP activity increased in the hippocampus and DP-IV activity increased in all studied brain structures. At the age of 3 months, increased PEP activity in the hypothalamus and nucleus accumbens was detected in males and decreased DP-IV activity in the nucleus accumbens and decreased PEP activity in the hippocampus were detected in females. At the age of 7 months, PEP activity increased in the frontal cortex and striatum and DP-IV activity increased in all studied brain structures in males; in 7-months-old females, activity of both enzymes increased in the striatum.