Dextro- and L-amphetamine are equipotent in releasing human growth hormone

(1) Peak plasma human growth hormone (HGH) response to a single intravenous administration of d- and l-amphetamine sulfate 0.1 mg/kg was evaluated in ten healthy subjects each being his own control. (2) No statistical difference was found between the mean HGH responses of the subjects to either amphetamine isomer. Also, the number of deficient HGH responses to d- and l-amphetamine was equal. (3) By analogy with similar data from studies in monkeys, the involvement of noradrenergic rather than dopaminergic mechanisms in mediating amphetamine-induced HGH release in man is tentatively suggested and possible implications for recent neuroendocrinological findings in endogenous depressives are discussed.