Inhibition of insulin secretion from the perfused pancreas of the rat by pizotifen

1 In the perfused rat pancreas the effects of pizotifen on insulin release induced by 20 mM glucose were studied. 2 Pizotifen (10 and 100 muM) significantly reduced the insulin release during a 25 min perfusion period to 49% and 7% of the controls. 3 The same concentrations of the structurally related agents cyproheptadine, doxepin, and chlorpromazine produced a comparable inhibition.