Immunohistochemical and immunoblot analyses of collagens in the developing fibrocartilage in the glans penis of the rat.

The distal segment of the os penis of rats is a fibrocartilage whose development is dependent on androgens. Electrophoretic and immunoblot analysis indicated that the fibrocartilage contained both type I and type II collagens. Immunohistochemically, type I collagen was detected in the fibrous matrix of the distal segment in all the stages examined. Type II collagen was detected first at 4 weeks in the extracellular matrix surrounding the mature chondrocytes distributed sparsely as single cells or small clusters among immature chondroblasts. The clusters reactive with anti-type II collagen serum increased in size and number at 6 weeks, and almost all the region of the distal segment became reactive with anti-type II collagen serum at 8 weeks.