Lipo-Endomorphin-1 Derivatives with Systemic Activity against Neuropathic Pain without Producing Constipation
A) Lack of inhibitory effect of 3 in doses up to 16 µmol/kg on castor-oil induced diarrhea in rats in contrast to the significant inhibitory effects of morphine at 2 µmol kg/kg. B) Lack of effect of analog 3 (16 µmol/kg) and vehicle in contrast to the inhibitory effect of morphine (2 µmol/kg) on the gastrointestinal transit of a charcoal meal in rats. Data are the mean (± SEM). ***p<0.001, vs. vehicle (n = 8).