Optically active amines. XV. Action of (S)- and (R)-para-substituted amphetamine hydrochlorides and (.alpha.S)- and (.alpha.R)-p-chloronorephedrine and (.alpha.S)- and (.alpha.R)-p-chloronorpseudoephedrine hydrochlorides on the level of 5-hydroxytryptamine and the activity of tryptophan hydroxylase in rat brain