Elevation of cerebrospinal fluid substance P concentrations in spina bifida.

Concentrations of substance P, a peptide believed to have neurotransmitter and possible trophic functions, were determined by radioimmune assay in the cerebrospinal fluids of ten babies and one foetus with spina bifida, and compared to those of five normal babies and ten normal foetuses. The results (mean +/- S.E.M.) were: spina bifida babies (864 +/- 357.6 fmol ml-1), normal babies (141 +/- 14.2 fmol ml-1), spina bifida foetuses (150,000 fmol ml-1), normal foetuses (22,673 +/- 8,340 fmol ml-1). Hence, in spina bifida cerebrospinal fluid substance P concentrations were grossly elevated both pre- and post-natally. The significance of these results can be considered from two aspects: there is the possibility that substance P plays a role in the development of the spinal cord which is disturbed in spina bifida; as substance P has been shown to be involved with sensory perception and autonomic reflexes, abnormal concentration of substance P in cerebrospinal fluid may aggravate the neurological deficit in spina bifida. Possibly, therapeutic manipulation of substance P, when available in the future, may be considered in these patients.