Cannabinoids accumulate in mouse breast milk and differentially regulate lipid signaling molecules involved in infant development

Maternal cannabis use during lactation may expose developing infants to cannabinoids (CBs) such as tetrahydrocannabinol (THC) and cannabidiol (CBD). CBs modulate lipid signaling molecules in the central nervous system in age- and cell-dependent ways, but their influence on the lipid composition of breastmilk has yet to be established. This study investigates the effects of THC, CBD, or their combination on milk lipids by analyzing the stomach contents of CD1 mouse pups that have been nursed by dams injected with CBs on postnatal days (PND) 1-10 collected 2 hours after the last injection on PND10. HPLC/MS/MS was used to identify and quantify over 80 endogenous lipid species and cannabinoids in pup stomach contents. We show that CBs differentially accumulate in milk, lead to widespread decreases in free fatty acids, decreases in N-acyl methionine species, increases N-linoleoyl species, as well as modulate levels of endogenous CBs (eCBs) AEA, 2-AG, and their structural congeners. Our data indicate the passage of CBs to pups through breast milk and that maternal CB exposure alters breast milk lipid compositions.