Relationship of symptomatology of schizophrenia and tardive dyskinesia

Neuroprotective Activity of Proproten in Rats with Experimental Local Photothrombosis of the Prefrontal Cortex

Proproten (ultralow doses of antibodies to S100 protein) exhibited neuroprotective activity in rats with experimental photochemical thrombosis of the prefrontal cortex. Proproten was more potent than standard neuroprotectors piracetam and vinpocetine in alleviating the signs of memory disorders produced by ischemic injury. Pathomorphological study of the damaged area confirmed the neuroprotective effect of Proproten.

Biological significance of the enantiomeric purity of drugs

The knowledge that enantiomers of chiral compounds may differ widely in biological activity, qualitatively as well as quantitatively, is not new. Nevertheless most of the pharmacological data available to date on chiral drugs are obtained from experiments with racemates which assume that the biological activity generally resides in one of the enantiomers. With the advancements made in stereospecific synthesis and stereoselective analysis of drugs pharmacologists are now offered new possibilities to explore the steric aspects of drug action. This survey will discuss pharmacological data obtained with enantiomer pairs of phenylethylamine derivatives which interact with adrenergic mechanisms. The degree of resolution is seldom specified in published work on stereoselectivity of drugs. In a recent study from our laboratory the enantiomers of the beta 2-adrenoceptor agonist formoterol and their diastereomers have been evaluated. We found that the (R;R)-enantiomer was by far the most potent. However, the relative potencies obtained for the (R;S)-, (S;R), and (S;S)-isomers were critically dependent on the degree of enantiomeric purity. It is concluded that the certainty of potency ratios observed for chiral drugs is limited by the enantiomeric purity and by unspecific effects of the least active enantiomer at very high concentrations.