Contrasting actions of intrathecal U50,488H, morphine, or [D-Pen2, D-Pen5] enkephalin or intravenous U50,488H on the visceromotor response to colorectal distension in the rat.

Contrasting actions of intrathecal U50,488H, morphine, or [D-Pen2, D-Pen5] enkephalin or intravenous U50,488H on the visceromotor response to colorectal distension in the rat.