Exposure to PCB126 during the nursing period reversibly impacts early-life glucose tolerance

Area of Science:

• Environmental Toxicology
• Developmental Toxicology
• Endocrinology

Background:

• Polychlorinated biphenyls (PCBs) are persistent environmental pollutants with known adverse health effects.
• Previous studies showed PCB126 exposure during gestation and perinatal periods impacts offspring glucose tolerance and body composition.
• The effects of PCB exposure solely during the nursing period on offspring metabolic health remain less understood.

Purpose of the Study:

• To investigate the impact of PCB126 exposure during the nursing period on offspring glucose tolerance and body composition.
• To determine if maternal exposure to PCB126 via milk affects offspring metabolic profiles.

Main Methods:

• Female ICR mice were exposed to PCB126 (1 µmole/kg) or vehicle via oral gavage on postnatal days 3, 10, and 17.
• Offspring body weight, lean and fat mass, and glucose tolerance were assessed every three weeks.
• Statistical analyses were performed to compare outcomes between PCB126-exposed and control groups.

Main Results:

• PCB126 exposure did not significantly alter dam or offspring body weight or body composition.
• Offspring exposed to PCB126 during nursing exhibited significantly impaired glucose tolerance at 3 and 9 weeks of age.
• Glucose tolerance returned to normal levels by 6 and 12 weeks of age, indicating a short-term effect.

Conclusions:

• Maternal exposure to PCB126 during the nursing period does not affect offspring body composition.
• Short-term glucose intolerance is a consequence of PCB126 exposure via maternal milk.
• These findings highlight the critical window of the nursing period for PCB-induced metabolic disruption.