Nerve fibers showing immunoreactivities for thyrosine hydroxylase and dopamine-beta-hydroxylase re-appear in the guinea pig uvea after sympathectomy.

After sympathectomy we have studied the re-appearance of nerve fibers showing catecholaminergic characteristics in the uvea of the guinea pig. Immunoreactivities for two catecholamine symthetizing enzymes, tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH), were used as markers. Both TH-like and DBH-like immunoreactive nerve fibers disappeared after the extirpation of ipsilateral superior cervical ganglion. In the choroid the TH-like and DBH-like immunoreactive nerve fibers re-appeared within 2 weeks. In the iris and the ciliary body both of these types of immunoreactive nerve fibers re-appeared 10 weeks after the denervation. The morphological appearance of these re-appearing nerve fibers was not similar to those in the non-denervated uvea.