Effect of ascorbic acid supplementation on testicular steroidogenesis and germ cell death in cadmium-treated male rats

Stage-dependency of apoptosis and the blood-testis barrier in the dogfish shark (Squalus acanthias): cadmium-induced changes as assessed by vital fluorescence techniques

“…Whereas the mechanism by which cadmium induces cell death in the mammalian testis is still unclear (Chiqouine and Suntzeff 1965;Xu et al 1996;Sinha Hikim et al 1997;Ozawa et al 2002;Gupta et al 2004), the results presented here clearly show that cadmium preferentially increases the apoptotic rate in apoptosis-sensitive germ cell stages in this model. Although our findings provide no direct insight regarding the mechanism of cadmium induction of germ cell apoptosis, Betka and Callard (1999) have found that, although cytosolic cadmium-binding components other than heavy-metal-binding metallothionein can, to some extent, account for the cadmium accumulation gradient in the shark testis, a second nuclear-associated component of cadmium is present in larger amounts in immature than in mature spermatogonial regions in the testis of Squalus.…”

“…The particular sensitivity of the testis to cadmium exposure may be related to the testis being a highly proliferative and acutely hormone-dependent organ. Recent evidence concerning the direct and indirect impairment, at low cadmium doses, of steroidogenic activities, with the subsequent induction of germ cell apoptosis (Ozawa et al 2002;Gupta et al 2004) are consistent with its endocrine disruptive actions in other tissues (Choe et al 2003;Vetillard and Bailhache 2005).…”

“…Interestingly, classic androgen and oestrogen receptors, both zinc-finger proteins, are concentrated in PrM regions of the shark testis (Callard et al 1985;Cuevas and Callard 1992) and cadmium can reduce liver vitellogenin expression through its direct binding to oestrogen receptor-α in the trout (Vetillard and Bailhache 2005). Furthermore, since the Sertoli cell is the sole steroid-producing element in Squalus (Pudney and Callard 1984), cadmium-induced inhibition of steroidogenic activities in mid-stage PrM cysts might result in their increased apoptotic death, as is known for the rat (Ozawa et al 2002;Gupta et al 2004). Taken together, male germ cells and the complex hormonally regulated processes that support their proliferation and development may therefore be especially vulnerable to the effects of cumulative toxicants and chemicals acting as "bio-substitutes" and endocrine disrupters.…”

“…The effects of high doses of cadmium may be so rapid in rodents that the terminal stage of apoptosis, also called secondary necrosis (Majno and Joris 1995), is quickly reached, thus rendering the detection of apoptotic cells by the TUNEL method difficult (Sinha Hikim et al 1997;Gupta et al 2004). These differences further highlight the technical advantages of using a combination of a rapid vital staining technique such as AO, an early detector of apoptosis in living cells (Durrieu et al 1998), and this model for such studies.…”

The effects of ammonium metavanadate on biochemical hormonal, haematological and histopathological parameters of the female wistar rats

“…Furthermore, it also caused hormonal depressions/inhibitions which were positively correlated to the histological damages to uterus, ovaries and oviduct, showing that the histological destruction resulted in the pathophysiological decreases in hormonal production and function which may lead to infertility (Gupta et al 2004, Uche & Obianime 2008and Lafuente 2000. This aspect of positive correlation between structure and function is novel as no other studies had ever undertaken such.…”