Placental CB1 Cannabinoid Receptor Expression in Stillbirths Using a Vervet Animal Model

The purpose of this study was to compare placental CB1 cannabinoid receptor activity in stillbirths to liveborn controls in an African Green Monkey (vervet) colony. We hypothesized that vervet placental CB1 receptor expression would be higher in stillbirths when compared to live-born controls. This was a nested case-control stillbirth study using an animal model. Vervet placentas were collected following vaginal, assisted vaginal and cesarean deliveries. Stillbirths were defined as vervets born in the second half of pregnancy without cardiac activity. Live-born controls were defined as living until day 30 of life or greater. Placental samples were collected from 10 stillbirths and 10 controls. The average gestational age at the time of delivery was 163 days (average vervet gestation 157-165 days). Western blot and real-time quantitative polymerase chain reaction (qPCR) were performed to evaluate CB1 cannabinoid receptor expression. Comparisons between groups were performed using the Mann-Whitney U test. P< 0.05 was considered statistically significant. Of the 20 vervet placentas collected, mRNA was found to be insufficient for quantification in one stillbirth sample, leaving 9 stillbirth samples and 10 live-born controls for a total sample size of 19 for statistical analysis. A statistically significant difference was not found when comparing CB1 protein expression in stillbirths (n=9); 1.03 (+/- 0.09) to controls (n=10); 1.33 (+/- 0.12), p=0.13. A statistically significant difference was not found when comparing CB1 mRNA expression in stillbirths (n=9); 3.11 (+/- 1.22) to controls (n=10); 4.83 (+/- 1.9), p = 0.50. Vervet placental CB1 cannabinoid receptor expression was not found to be statistically significant when comparing stillbirths to liveborn controls.View Large Image Figure ViewerDownload Hi-res image Download (PPT)