Apoptosis-Like Cell Death in Experimentally-Induced Cryptorchidism in Adult Mice.

Abstract

ABSTRACT. In order to elucidate the mechanism of germ cell degeneration in experimental cryptorchidism, we examined the testes of adult mice from a morphological standpoint. Adult ICR mice were made cryptorchid either unilaterally or bilaterally. In some mice, testes were surgically replaced back into the scrotum at 2 months after induction of cryptorchidism to observe the regenerative process. Morphological changes of cryptorchid and replaced testes have been studied by light and electron microscopy. Testes were also examined by the TUNEL (TdT-mediated dUTP-biotin nick end labelling) method to evaluate whether the degenerative cells, spermatocytes and spermatids, were dying by apoptosis or by any other process(es). At 8 weeks after the induction of cryptorchidism, the seminiferous epithelium consisted only of Sertoli cells, spermatogonia, and some spermatocytes of early meiotic stages. Soon after the replacement of testes to the scrotum, most of the seminiferous tubules resumed spermatogenic processes. Many degenerating cells, especially the spermatocytes, showed condensation of the nucleus and cytoplasm in cryptorchid testes. Although the cytoplasm was markedly eosinophilic under a light microscope to imply condensation of the cytoplasm, the extent of the condensation was not as pronounced under an electron microscope as reported in previous publications. The cytoplasm showed no expansion. By the TUNEL method, many of the degenerating cells, mainly the spermatocytes, have been shown as undergoing apoptosis. These data provide evidence that at least some of the cells die by apoptosis, or by a process similar to apoptosis. -KEY WORDS: apoptosis, cryptorchidism, germ cell, mouse, TUNEL.

Ceramides and Sphingomyelins with High Proportions of Very Long-chain Polyunsaturated Fatty acids in Mammalian Germ Cells

“…In agreement with previous data (37,38), in few days this resulted in histological evidence of selective loss of the most differentiated cells of the germinal line, sparing spermatogonia and Sertoli cells. A few days after surgery, the cryptorchid testes showed as the most marked change a dramatic decrease in the weight and in the content of total lipid P (Fig.…”

“…Complete loss of the mentioned lipids took just a few days in the case of cryptorchidism (Fig. 7, 8), because the dying elements in this case were mainly preexisting spermatocytes and spermatids (37,38), FIGURE 7. Effects of unilateral cryptorchidism.…”

Expression of a K48R Mutant Ubiquitin Protects Mouse Testis from Cryptorchid Injury and Aging

“…4,[7][8][9][10][11]34,35 The role of heat-shock proteins in cryptorchidism is not clear, since the physiological temperature attained when the testis is elevated into the body cavity is not sufficient to induce many heat-shock proteins. Indeed, testis-specific heat-shock proteins, such as Hsp70 -2, do not increase their activity after experimental cryptorchidism.…”

“…During the course of this germ cell loss, multinucleated giant cells and Sertoli cell vacuolization are observed. 8,9 Although the precise mechanism by which normal body temperature induces germ cell loss is not known, protein and lipid oxidation along with p53 are involved. 4,9 -13 Heat shock is known to cause alterations in protein architecture, and ubiquitin is required for the tagging and subsequent degradation of altered proteins, 14 -16 suggesting a role for ubiquitin in the mechanism of injury following experimental cryptorchidism.…”

Azoospermia of Dogs with Apoptotic Germ Cells and Leydig Cells

“…In mice and rats, apoptosis of germ cells was described with artificial cryptorchidism [9,20], and after long-term treatment with Gn-RH agonist [4], or with chemicals suppressing testosterone (T) secretion [22], as well as after injection of estradiol-17β (E 2 ) [5]. In canine species, the cause of infertility mostly remains unknown [8,17], although spermatogenic dysfunction due to orchitis [3], or poor secretion of the anterior pituitary gland or testis [13] has been observed in some cases.…”