Are genetically hypertensive rats deficient in nerve growth factor?

We have shown previously that sympathetic ganglia from genetically hypertensive Otago Wistar (GH) rats contain fewer neurons than those of normotensive animals and are heavily innervated by substance P-containing axons. In adult GH rats treated over days 1-7 of postnatal life with 10 micrograms/rat/day of nerve growth factor (NGF) s.c., ganglion cell numbers were similar to those of normotensive rats. By contrast, NGF treatment of neonatal normotensive animals did not affect ganglion cell numbers. In NGF-treated GH animals, the numbers of substance P-positive axons were substantially reduced relative to age-matched controls. We conclude that the abnormalities seen in ganglia of GH rats may involve a perinatal deficiency of a nerve growth factor.