Extraabdominal fixation of the gubernaculum inhibits testicular descent in newborn rats.
Within 48 hours after birth, newborn rats were anesthetized, and the distal tip of the gubernaculum was exposed extraabdominally, then fixed to the fascia of the groin on the left or the right side under a dissecting microscope (6x). In the sham-operated rats, the distal tip of the gubernaculum was merely exposed. Nonoperated rats were used as controls. In 60- to 90-day-old operated rats (n = 42), all testes were located in the superficial inguinal position, and the incidence of cryptorchidism was 100% on the operated side. In the sham-operated rats (n = 28), 27 of 28 testes descended into the scrotum, and one was located in the perineum; the incidence of cryptorchidism was 3.6% on the operated side. All testes also descended into the scrotum, and the incidence of cryptorchidism was 0% in controls (n = 20). The incidence of cryptorchidism was significantly higher among operated rats than among sham-operated or control rats (P < .001). The testicular weight and the germinal epithelia of the cryptorchid testes were significantly lower than those of the scrotal testes in both sham-operated and control rats. Therefore it is suggested that the extraabdominal fixation of the distal tip of the gubernaculum in newborn rats induces cryptorchidism. The present model is considered to be a simple and useful one to investigate the process of testicular maldescent and inhibited growth of the testis in cryptorchidism.
Shono
T
T
Department of Pediatric Surgery, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
Zakaria
O
O
Imajima
T
T
Suita
S
S
D000818:Animals; D000831:Animals, Newborn; D003456:Cryptorchidism / Q000473:pathology*; D004195:Disease Models, Animal; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012670:Seminiferous Epithelium / Q000473:pathology; D012671:Seminiferous Tubules / Q000473:pathology; D013737:Testis / Q000473:pathology