Effects of cadmium exposure on Iberian ribbed newt (<i>Pleurodeles waltl</i>) testes

Abstract

To characterize the histomorphologic effects of cadmium on adult newt testes, male Iberian ribbed newts (6 months post-hatching) were intraperitoneally exposed to a single dose of 50 mg/kg of cadmium, with histologic analysis of the testes at 24, 48, 72, and 96 h. Beginning 24 h after cadmium exposure, apoptosis of spermatogonia and spermatocytes was observed, and congestion was observed in the interstitial vessels of the testes. Throughout the experimental period, the rates of pyknotic cells and TUNEL and cleaved caspase-3 positivity were significantly higher in the spermatogonia and spermatocytes of cadmium-treated newts compared with control newts. There were no significant differences between cadmium-treated and control newts in phospho-histone H3 positivity in the spermatogonia and spermatocytes. These results suggest that spermatogonia and spermatocytes in adult Iberian ribbed newts are highly sensitive to cadmium. This is the first report of the histomorphologic characteristics of cadmium-induced testicular dysfunction in newts.

Mechanisms of Cadmium-Induced Testicular Injury: A Risk to Male Fertility

“…Cadmium-induced testis showed increased activity of caspase 3 and 9, which increases the number of morphological signs of apoptosis, including chromatin decondensation and marginalization in primary spermatocytes, loss of the nuclear envelope in the spermatogonium, disruption of mitochondrial membrane potential (MMP), degradation of cytoplasmic organelles, and DNA distribution [ 102 ]. The testicles of rats [ 103 ], fish [ 104 ], and lizard [ 105 ] all showed evidence of cadmium-induced spermatogonia and spermatocyte apoptosis. The concentration-dependent effect of cadmium on human embryonic germ cell apoptosis was revealed by immune signaling detection of caspase 3 in testicular tissue [ 106 ].…”

Cadmium as a testicular toxicant: A Review

“…Various morphological characteristics of apoptosis, eg, chromatin condensation and marginalization in primary spermatocytes, degeneration of cytoplasmic organelles, disappeared nuclear envelope in spermatogonium, and fragmentation of DNA were observed in Cd‐intoxicated testes of freshwater crab ( Sinopotamon henanense ), along with increased activities of caspase‐3 and ‐9 in a concentration‐dependent manner (Wang et al, 2011). Other morphological and ultrastructural studies have also reported Cd‐induced apoptosis of spermatogonia and spermatocytes in rodents (Boujelben, Abdennabi, Guermazi, & Elfeki, 2018; Niknafs et al, 2015), fish (Hirako, Takeoka, Furukawa, & Sugiyama, 2017) and newt (Hirako et al, 2017) testis, respectively. A concentration‐dependent effect of Cd on apoptosis of human fetal germ cells was illustrated by immunohistochemical detection of caspase‐3 in testicular tissue under in vitro conditions (Angenard et al, 2010).…”

Male Reproductive Hazards Associated with Cadmium Exposure

“…This includes chromatin decondensation and marginalization in primary spermatocytes, loss of the nuclear envelope in spermatogonia, alterations in DNA distribution, degradation of cytoplasmic organelles, and disruption of mitochondrial membrane potential [35]. Apoptosis induced by cadmium has been observed in the testes of various mammalian species [36][37][38]. In humans, the concentration-dependent impact of cadmium on the death of embryonic germ cells has been demonstrated through the detection of caspase 3 enzyme activity in testicular tissue [39].…”