Using Implantable Radiotelemetry to Assess Energy Balance in Rats Delivered by Cesarean Section

• Rachel Tran, Biomedical Engineering, University of Delaware

• William Kenkel, Psychological & Brain Sciences, University of Delaware

To date, several studies have indicated a relationship between increased weight gain in offspring born via cesarean sections (CS) as opposed to vaginal delivery (VD). Further research links cesarean section with a 34% elevated risk for childhood obesity (Kuhle 2015). We have previously observed that hormone rescue with oxytocin at delivery can prevent excessive weight gain; however, the metabolic mechanism behind both the weight gain and its prevention remains unknown. To characterize this metabolic dysfunction, we implanted both CS and VD animals with radiotelemetry transmitters. The system operates by generating a controlled radiofrequency (RF) field that encompasses the animal’s enclosures, powering continuous wireless Bluetooth communication between the implanted transmitters and their corresponding database. These transmitters subsequently capture mechano-acoustic signals, which correlate with key physiological characteristics, yielding real-time data acquisition of their physical activity, body temperature, and heart/respiratory rates. After data collection, an analytical data-processing system was implemented to visualize both the subject’s baseline biological parameters and any potential metabolic consequences that were revealed as a result of various hormone injections. To probe the autonomic and endocrine control of heart rate, we injected subjects with four different hormone injections that were delivered across multiple days: oxytocin, AVP, atenolol, and atropine. To better understand these metabolic effects, a control of saline was also used, hypothesizing that after the delivery of oxytocin, the metabolic rate of these subjects would normalize. We plan to present results on baseline autonomic parameters in CS and VD offspring, as well as the acute responses to pharmacological challenge. These findings will provide new insights into the impacts of caesarean sections, an obstetric intervention used in 32% of all births.

References

Kuhle, S., Tong, O.S., and Woolcott, C.G. (2015), Caesarean section and childhood obesity. Obes Rev, 16: 295-303. https://doi.org/10.1111/obr.12267