Radioimmunoassay of vasotocin, vasopressin, and oxytocin in human neonatal cerebrospinal and amniotic fluid.

Arginine vasotocin (AVT) has been measured in neonatal cerebrospinal fluid (CSF) and human amniotic fluid using a newly developed specific radioimmunoassay system. There were significant amounts of AVT in all samples. Vasopressin and oxytocin also were measured in the samples and could not account for the levels of vasotocin found. The source and function of these neurohypophyseal peptides in CSF and amniotic fluid remains speculative.