Pre- and postnatal blood vessel development of the human spinal cord: association with myelination.

The material comprised spinal cord segments C8 or Th1 of 5 human fetuses aged from 18 up to 34 weeks and 6 infants aged from one day to 3 years. On formalin-fixed paraffin-embedded sections, peroxidase-antiperoxidase Sternberger's et al. (1970) method for visualization of blood vessels endothelium (lectin Ulex europeus and Factor VIII) and myelin basic protein (MBP) was used. A distinct F VIII immunoreactivity of vessels endothelium was recorded since a 1 day old newborn. Lectin immunoreactivity suggested the increased vascularization of the undergoing myelination spinal cord tracts. In the postnatal period, which was characterized morphologically by the nearly completed myelination, the spinal white matter appeared poorly vascularized. A temporary increase of spinal cord tract vascularization during myelination is probably caused by local secretion of angiogenic factors. It is possible that their source might be young developing myelin.