Oral Presentation Australian & New Zealand Obesity Society 2014 Annual Scientific Meeting

Postpartum stress during the early postnatal period has long-lasting effects on metabolic profile in rat dams (#51)

Jayanthi Maniam 1 , Christopher Antoniadis 1 , Margaret Morris 1
  1. Pharmacology, UNSW Australia, Sydney, Australia

Stress induced during the postpartum period has been shown to exert a wide range of adverse consequences for behaviour, including depression, but less is known regarding the impact of postpartum stress on subsequent risk for metabolic disorders. Here, we modelled postpartum stress in rats using limited nesting material (LN), and tested the hypothesis that stress during the early postnatal period alters food intake, body weight and glucose and insulin homeostasis. Sprague Dawley rats were mated and dams were subjected to LN from days 2-9 using established protocols1. Stressed (LN) dams were compared to control dams (unlimited bedding material) housed simultaneously in the same facility and maintained on chow diet. Food intake and body weight were measured weekly. A glucose tolerance test was conducted at 35 days, and dams were culled at 40 days postpartum. LN dams showed fragmented maternal care towards their pups with irregular nursing and eating behavior. LN dams had reduced food intake during lactation, and this persisted at 40 days postpartum (p<0.05) when they were 12% lighter compared to control dams (p<0.05). Stressed LN dams were not glucose intolerant but fasting glucose levels at cull tended to be higher compared to control dams (p=0.08) while insulin levels were 50% less than control dams (p<0.05). This finding suggests that postpartum stress induced by LN has long-lasting effects in reducing food intake and body weight. In addition, LN appears to alter glucose and insulin metabolism suggestive of altered insulin signaling.

  1. Ivy, A.S., Brunson, K.L., et al. Dysfunctional nurturing behavior in rat dams with limited access to nesting material: A clinically relevant model for early-life stress. Neuroscience 154, 1132-42 (2008).