Effect of castration on the epiphyseal cartilage of young male rats
Tarsoly, E.; Zeher, M.; Lukács, P.
Zeitschrift für Mikroskopisch-Anatomische Forschung 99(6): 897-910
1985
ISSN/ISBN: 0044-3107 PMID: 4096096 Document Number: 254137
The effect of castration on the epiphyseal cartilage of young male rats was investigated by histological and enzyme histochemical methods. The duration of the experiment was 12 weeks. The animals were killed 4, 6, 8, 10, and 12 weeks after castration. In the 4 and 6 weeks stage, the castrated animals exceeded in body length and weight the controls. In the later stages, however, a decrease in growth rate was observed. By the 12th week, the castrated rats were smaller than the controls. Histological study revealed that the epiphyseal cartilage in castrated animals has thickened displaying an irregular distribution of large hypertrophoid cells. Beginning from the 8th week, a marked decrease in the number of bone trabeculae could be noted in the metaphysis. Of the enzymes studied, only lactate dehydrogenase activity remained unchanged in the epiphyseal cells of castrated animals, while dehydrogenases of the pentose-phosphate cycle, and those of the citrate cycle showed marked reduction in activity. In these animals, hardly any chondroclasts were observed on the bone-cartilage border. In the case of castration, the absence of testosterone exerts a marked effect on the activity of the epiphyseal cartilage. It is not the growth rate which is primarily affected by testosterone, but the proportion of the stages and the normal course of ossification. When testosterone is lacking, as early as after 4 to 6 weeks, a notable decrease of cartilage formation, cartilage resorption, and bone formation can be observed. The epiphyseal cartilage remains thick, but it displays an irregular structure, its cells indicating severe metabolic disturbances. Such epiphyseal cartilages cannot ensure the normal longitudinal growth of the bones.