IMMUNOHISTOCHEMICAL DEMONSTRATION OF NERVE GROWTH-FACTOR RECEPTOR IN BOVINE TESTIS

Nerve growth factor receptor (low-affinity form) was demonstrated immu nohistochemically in bovine testis by using a monoclonal mouse anti-hu man antibody. In the 7-month-old fetus and in the early postnatal test is, the peritubular and intertubular fibroblast-like mesenchymal cells showed a strong reaction. Following differentiation of these cells in to Leydig and myoid peritubular cells, the nerve growth factor recepto r was no longer expressed. However, peritubular and intertubular testi cular fibroblasts/fibrocytes, which are also derived from mesenchymal precursors, remained positive. Additionally, the nerve growth factor r eceptor was demonstrated in postnatal prespermatogonia, A-spermatogoni a, I-spermatogonia and members of the spermatogonia precursor cell lin e; B-spermatogonia remained negative. In A-spermatogonia and I-spermat ogonia, the expression of the nerve growth factor receptor was cell-cy cle-dependent and was mostly observed during G(1)-phase. Pre-embedding ultrahistochemistry with gold-conjugated antibody followed by silver- enhancement revealed that the nerve growth factor receptor was localiz ed at the outer cell surface. The metal granules showed a regular dist ribution in positive spermatogonia. In testicular fibroblasts/fibrocyt es the long narrow processes were preferentially decorated.