Effects of an Environmentally Relevant Organochlorine Mixture and a Metabolized Extract of This Mixture on Porcine Sperm Parameters In Vitro

Organochlorine chemicals are present in the environment worldwide; however, populations living in the Far North are particularly at risk because their traditional diets are mainly composed of contaminated animals (fish, seals, whales, and polar bears). It has been suggested that male fertility is globally declining, possibly because of chronic, low-level exposure to environmental contaminants. This study was designed to assess the effects on fresh sperm fertility parameters using the porcine model of 1) an environmentally relevant mixture of 15 organochlorines and 2) the metabolized extract of this mixture. In the first experiment, the organochlorine mixture (at relative concentrations of 10.5, 14.7, and 21 mu g/mL polychlorinated biphenyls [PCBs]) reduced sperm total motility, progressive motility, and viability, and increased capacitation, spontaneous acrosome reaction rates, and cytosolic calcium levels, suggesting that the mixture alters the sperm membrane and is detrimental to sperm function. In the second experiment, the metabolized extract of this organochlorine mixture (at relative concentrations of 0.9, 1.8, 2.7, 3.6, and 4.5 mu g/L OH-PCBs) tended to decrease only sperm total motility. In an in vitro porcine model, the mixture of organochlorines, as found in the Arctic food chain, was rapidly detrimental to sperm function at concentrations above environmental levels. In contrast, short and physiologically relevant exposure to the metabolized extract of this mixture induced only limited adverse effects on sperm motility.