Abstract
The effects of sodium nitroprusside (SNP) and acidified sodium nitrite (ASN) solutions, nitric oxide (NO)-donating compounds, and N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO synthesis, were studied on the spontaneous contractile activity of the isolated rabbit jejunum. The addition of SNP (10-5 to 10-3 mol/l) or ASN (10-5 to 10-3 mol/l) to the organ bath inhibited the amplitude of the spontaneous contractions in rabbit isolated jejunum in a concentration-dependent fashion, while L-NAME (3 x 10-5 to 3 x 10-4 mol/l) was without effect. Methylene blue (3 x 10-7 to 3 x 10-6 mol/l), which inhibits soluble guanylate cyclase, and oxyhemoglobin (10-5 mol/l), an NO scavenger, counteracted the effects of both SNP (3 x 10-4 mol/l) and ASN (10-4 mol/l). The spontaneous motility of rabbit jejunum was also inhibited in a concentration-dependent manner by 8-Br-cyclic GMP (10-5 to 10-3 mol/l), a permeable analogue of cyclic GMP. These results provide evidence that exogenous NO may inhibit spontaneous contractility and that this effect might be mediated, in part, by cyclic GMP, whereas endogenous NO does not seem to play a role in the regulation of the spontaneous motility of rabbit jejunum in vitro.
| Original language | English |
|---|---|
| Pages (from-to) | 109-113 |
| Number of pages | 5 |
| Journal | Pharmacology |
| Volume | 53 |
| Issue number | 2 |
| Publication status | Published - Aug 1996 |
Keywords
- Cyclic GMP
- Intestinal motility
- Jejunum
- Methylene blue
- Nitric oxide
ASJC Scopus subject areas
- Pharmacology