By Matthew Lee ‘21

Arsenic and copper are trace elements that can have deleterious health effects when present in the body in large quantities. Their toxicity in certain body parts such as the liver, nervous system, and lungs is well documented. However, the effects of arsenic and copper on testicular tissues are not as studied. A recent study led by Yizhi Shao of Northeast Forestry University investigatd the inflammatory effects of arsenic and copper on testicular tissue. Their approach measured inflammation by detecting inducible nitric oxide synthase (iNOS) proteins, mRNA levels of inflammatory cytokines, and the mRNA and protein levels of heat shock proteins (Hsps).

Seventy two male Hyline chickens were split into 4 equal groups. One was a control and the others were either given arsenic, copper. or a combination of the two. Every 4 weeks, six chickens from each group would be randomly euthanized for analysis. Compared to the control group, iNOS activity in the treatment groups was consistently higher only after 12 weeks (>0.6 U/mg prot). This is indicative of a proinflammatory response, as iNOS is known to control cytokines. The cytokines iNOS controls are important signaling proteins involved in facilitating the inflammatory response.

Most chickens in the treatment groups saw increased mRNA levels compared to the control group except for IL-10 (about 0.6 times the control mRNA). Of the three heat shock proteins studied, Hsp70 and Hsp90 saw increased mRNA levels and protein levels in all treatment groups, indicating synchronized transcription and translation. These results are in agreement since the role of heat shock proteins is to insure the proper folding of proteins, combatting the inflammatory response.

Poultry are a major component of world agriculture, and  toxic quantities of arsenic, copper, or other trace elements can have a real impact on meat quality and safety. Many countries in Asia and Europe must work to mitigate the presence of harmful trace elements in their livestock. Investigating the mechanisms that occur in the testicular tissue in response to arsenic and copper can lead to a greater understanding of reproductive health and help agribusiness.

References:

1. Y. Shao, et. al., Arsenic and/or copper caused inflammatory response via activation of inducible nitric oxide synthase pathway and triggered heat shock protein responses in testis tissues of chicken. Environmental Science and Pollution Research 24, 1-11 (2017). doi: 10.1007/s11356-017-1042-7
2. Image retrieved from: https://upload.wikimedia.org/wikipedia/commons/thumb/d/d7/82nd_Civil_Support_Team_puts_a_new_twist_on_training_131126-Z-CW157-079.jpg