Effect of experimental microvascular orchidopexy on testosterone secretion in the dog

This study was undertaken to investigate the endocrine function of the testis that was autotransplanted by microvascular techniques in 10 healthy dogs. After a control period of 4 weeks, hemicastration was carried out, and 4 weeks later the experimental orchidopexy was done. Finally, the transplanted testis was removed after another 4 weeks. Peripheral blood testosterone levels were measured at weekly intervals during the control period, after hemicastration, after autotransplantation and after removal of the transplanted testis. 1 week before each operation, 500 IU human chorionic gonadotrophin (HCG) was given intravenously and the peripheral testosterone levels were determined after 2 and 24 h. During each operation a testicular venous blood sample was taken for testosterone measurements. No differences were found between the basal and HCG-stimulated peripheral plasma levels of testosterone after the hemicastration and the orchidopexy in comparison with the values during the control period. There was a statistically significant positive correlation between the testosterone levels in the testicular venous and peripheral plasma samples. It was concluded that microvascular anastomosis was successful in every case.