No abstract

The molecular mechanism for copper toxicity on spermatozoa quality in mice is not well understood. In a 4-week experiment, we challenged 24, 6-week-old male CD-1 mice with twice-a-week intraperitoneal copper chloride injections and evaluated spermatozoa quality, copper levels in the testes, serum testosterone, the expression of key antioxidant glutathione peroxidase 5 (GPx5), and the regulated androgen receptor (AR) in the mice testes. We compared these outcomes for four groups of six mice given doses of 0, 1.25, 2.5, 5.0 mg/kg weight copper chloride twice a week for 4 weeks. The mice demonstrated a copper increase spermatozoa head malformation in a dose-response manner. However, we observed no changes in spermatozoa viability and acrosome integrity in the ratio of mouse body weight to testes weight or in the histomorphology of the testes as the average copper level increased. Results of our RT-PCR assays, immunohistochemical tests, ELISA, and histochemistry analyses indicated that testis GPx5 expression was increased, AR expression in the testes was decreased, serum testosterone was decreased, and the activity of 3β-hydroxysteroid dehydrogenase was decreased as the copper dose increased. In conclusion, these data show that sublethal exposure to copper induces spermatozoa head malformation and influences both mRNA and protein levels of GPx5 and AR which is related to copper resides in the testes.

No abstract

Calcium (Ca) and phosphorus (P) are essential mineral elements in pigs, which play an important role in bone development, energy utilization and signal transduction. Inadequate or inappropriate ratio of Ca to P in diets may affect the normal growth and development of pigs (Gonzalo et al., 2018). Vitamin D, as an important nutrient in the body, acts a pivotal part in regulating Ca and P homeostasis, maintaining growth and development of bone (Plum & Deluca, 2010). It is stated that age, sex, dietary vitamin D intake and sunlight exposure were associated with circulating 25(OH)D 3 concentration (Livingstone et al., 2017). Vitamin D is mainly produced in the skin or ingested from the diet (Holick, 2011). At ultraviolet B-type (UVB) exposure, vitamin D synthesis occurs in the skin and is affected by the duration and the intensity of the light (Judistiani et al., 2019). Vitamin D supplementation is more effective than sunlight exposure in increasing circulating