Gonadotrophin-like substance in the testis. Immunocytochemical localization in the guinea pig

A gonadotrophin-like material (GLM) was observed by immunocytochemical methods in prepuberal guinea pig testes, not only on Sertoli and interstitial cells, but also on spermatogonia and spermatocytes. The intracellular cytoplasmic localization of GLM is discussed in relation to the receptor internalization theory. Variations between young and adult animals allowed us to approach the physiological significance of testicular GLM.