Abnormal expression of tyrosine hydroxylase-like immunoreactivity in intraocular transplants of rat caudate nucleus.

The purpose of the present study was to examine tyrosine hydroxylase (TH)-like immunoreactivity in single intraocular grafts of caudate nucleus, and in caudate grafts which were co-grafted with substantia nigra. Grafts of caudate obtained from fetal rats (crown-rump length: 15-17 mm) were placed into the anterior chamber of eye of adult female Sprague-Dawley rats, and were allowed to survive from 6 to 20 months. The host rats were then perfused with fixative and the tissue was prepared for immunocytochemistry for TH. In 7 out of 8 surviving caudate grafts, including those containing no substantia nigra, tyrosine TH-like immunoreactive (THLI) cell bodies were present. The results of our study suggest that TH is inappropriately expressed in caudate grafts placed in the anterior chamber of the eye.