Tandospirone (SM-3997) is a selective and potent 5-HT1A receptor partial agonist with anxiolytic and antidepressant activity that potentiates the anticardiac fibrotic effect of valsartan in spontaneously hypertensive rats, and can be used in the study of central nervous system disorders.

brain hippocampal membranes (rat):9.4 nM (Kd), brain hippocampal membranes (rat):213 fmol/mg (Bmax), 5-HT1A receptor:27 nM (Ki)

Tandospirone has negligible effects at 5-HT1B receptors, 5-HT uptake sites, β-adrenergic receptors, muscarinic cholinergic receptors, and benzodiazepine receptors. [1]3H-Tandospirone rapidly binds to rat brain hippocampal membranes and achieves binding in a high-affinity, reversible, and saturating fashion (Kd: 9.4 nM, Bmax: 213 fmol/mg protein). [2]

Chronic administration of Tandospirone (0.2 and 1.0 mg/kg/day, but not 2.0 mg/kg/day) was effective in alleviating elevated levels of eLAC in the anterior cingulate cortex (mPFC) due to foot shock stress. [3] After acute administration of Tandospirone (0, 0.1 and 1 mg/kg, intraperitoneally) to rats, a significant reduction in the number of premature responses in a dose-dependent manner was observed, an index used to assess impulsive behavior. [4]