DISTRIBUTION OF AND AGE-RELATED-CHANGES IN CILIARY NEUROTROPHIC FACTOR PROTEIN IN RAT-TISSUES

We developed a sensitive enzyme-linked immunosolvent assay for measuri ng ciliary neurotrophic factor (CNTF) and examined age-related changes in the CNTF contents of a variety of rat tissues during postnatal dev elopment. CNTF contents were substantially higher in the sciatic nerve and spinal cord than in the other tissues tested, the kidney coming t hird. In all the tissues except the sciatic nerve (90 ng/g), the CNTF content was less than 1 ng/g at 1 week of age, then gradually increase d. It was highest at 5 weeks of age in the sciatic nerve (3171 ng/g), spinal cord (118 ng/g), and kidney (36.8 ng/g), after which it slowly decreased. In contrast, the maximum in the brain stem (9 ng/g) and cer ebellum (3.6 ng/g) was at 8 weeks of age, whereas in skeletal muscle i t was at 2 weeks of age (14.6 ng/g). These findings indicate that CNTF functions in the postnatal development of the rat.