Uridine diphosphoglucose dehydrogenase in the intervertebral disc

Intervertebral discs of an old sheep and a young pig were examined for the presence of cells containing the enzyme uridine diphosphoglucose dehydrogenase. In the sheep, the inner anulus had a higher proportion of active cells than the outer anulus; in the pig, there was no difference. From a consideration of cell numbers, it is suggested that there is an accumulation of glycosaminoglycans in the centre of the disc rather than an increased production rate. Notochordal cells in the pig disc contain uridine diphosphoglucose dehydrogenase and are capable of producing glycosaminoglycans.