Fig. 4.

Receptors and enzymes potentially involved in diprophylline-induced bidirectional modulation. Effects of diprophylline on the jejunal contractility pretreated with (A) 10 µM atropine and (B) 10 µM diphenhydramine respectively in normal contractile state (NC) and in representative low contractile state (RLCS). Effects of diprophylline on jejunal contractility, pretreated with (C) 10 µM phentolamine, (D) 5 µM propranolol, and (E) 10 µM L-NG-nitroargenine (L-NNA) respectively in NC and representative high contractile state (RHCS).