Biologically active peptide-containing fractions in schizophrenia and childhood autism.

It is well documented that peptides have a major role in the effective functioning of higher animals at all levels from enzyme stabilization to homeostatic mechanisms governing essential functions such as eating, sexual behavior, and temperature regulation. The effects of exogenously administered peptides on neurotransmitter release, uptake, metabolism and behavioral consequences are also well established. We have attempted to extend these findings by postulating peptidergic neurons as transducers of multisignal inputs, and that development of pathological states may be due to genetically-determined reduced levels of activity of key peptidases, leading to excretion of regulatory peptides into the circulation. We have been able to demonstrate that, in schizophrenia and autism (in well defined clinical cases), the patterns of peptides and associated proteins from urinary samples differ considerably from each other and from normal controls. In addition to this, further purification of the material obtained has led to the discovery of a number of factors capable of modulating the function of major neurotransmitters. Some of these are in the final stages of characterization as peptides, while the remainder are also probably peptides, as purification has been followed by both biological testing and chemical analysis for peptidic material. We have outlined a number of parameters which we consider relevant in any attempt to put psychiatric disorders on a biological foundation. Any new advances in the neurochemical understanding of such disorders must take into consideration the observations of several different disciplines including genetics and psychology. However, at this stage of research it is far too early to speculate on the relevance of the various biological activities to the etiology and symptomatology of schizophrenia and childhood autism.