Effect of flupenthixol and butaclamol isomers on prolactin secretion in rats.

Cis (alpha)-flupenthixol and (+)-butaclamol are effective anti-psychotic agents but trans (beta)-flupenthixol and (-)-butaclamol are not. alpha-Flupenthixol was found to be 245 times more active in elevating rat plasma prolactin than the beta-isomer. The discrepancy between (+)-butaclamol and (-)-butaclamol was even greater. These results support the hypothesis that the dopamine receptors that mediate the effects of dopamine on prolactin secretion are similar to those that mediate the anti-psychotic effect of neuroleptic drugs.