Effects of perifornical hypothalamic microinjections of phenylpropanolamine and amphetamine on latency to feed and mash intake in rats.

To determine whether phenylpropanolamine (PPA) and amphetamine act on a common satiety mechanism, the present experiment compared the effect of unilateral microinjections (40, 80, and 160 nmol) of phenylpropanolamine hydrochloride (PPA: d,1-norephedrine) and of d-amphetamine sulfate within the perifornical hypothalamus (PFH) on consumption of a palatable sweetened-mash diet in adult male rats. Microinjection of d-amphetamine (40-160 nmol) within the PFH induced dose-dependent anorexia, whereas PPA microinjections were without effect on feeding. These results document that amphetamine and PPA do not act at a common CNS site, such as the PFH, to induce anorexia.