Relaxation of @entity35 gastrointestinal smooth muscle by XXXX .

@entity2701 @entity35 @entity4727 @entity5402 @entity934
In this study we investigated whether @entity4727 ( @entity4727 ) can produce relaxation of gastrointestinal (GI) smooth muscle as it has been reported to do for vascular and uterine smooth muscle. Muscle tissue preparations from @entity35 stomach, duodenum, ileum, or colon were mounted in a 37 degrees C tissue bath and perfused with oxygenated medium. Changes in isometric @entity2701 were recorded with a force-displacement transducer connected to a polygraph. Decreases in either resting @entity2701 or agonist-induced @entity2701 (0.5-1.0 microM @entity934 or @entity5402 ) were observed within 1-2 min of @entity4727 addition and were reversible upon removal of the peptide. All GI regions tested were responsive to @entity4727 . Synthetic rPTH-(1-34) (0.1-100 nM) produced a dose-dependent relaxation of both fundic (ED50 = 5.2 nM) and colonic (ED50 = 2.5 nM) muscle strips. At 100 nM, a 90% decrease in fundic @entity2701 and a 70% decrease in colonic @entity2701 were seen. At 100 nM, bPTH-(1-34), but not bPTH-(7-34) or @entity35 calcitonin gene-related peptide, also was effective in relaxing fundic or colonic muscle. Similarly, in the fundic muscle, 500 nM bPTH-(3-34) alone was ineffective, but it inhibited the effect of 5 nM rPTH-(1-34) when both peptides were tested in combination. Likewise, 100 nM bPTH-(3-34) also inhibited the relaxation induced by 5, 10, or 100 nM bPTH-(1-34). The results show @entity4727 to be highly effective in nanomolar concentrations in causing relaxation of GI smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)
