title: Activation of opioid-containing systems during gestation.
mesh_terms: D000818:Animals; D004723:Endorphins / Q000502:physiology*; D005260:Female; D007743:Labor, Obstetric; D009271:Naltrexone / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology*; D011247:Pregnancy; D011270:Pregnancy, Animal; D051381:Rats; D012684:Sensory Thresholds
chemical_list: D004723:Endorphins; D009271:Naltrexone