Certain flavonoids inhibit antigen-induced release of histamine from mast cells and basophils and also inhibit contraction of guinea pig ileum induced by histamine, acetylcholine, and PGE2. We examined the effect of one flavonoid, quercetin, on anaphylactic smooth muscle contraction of ileum from guinea pigs sensitized to egg albumin. Quercetin inhibited both the phasic and tonic components of ...

1 Experiments were performed on a variety of tissues from different species to establish whether or not the properties of p-chlorophenylalanine methyl ester (PCPA) included a 5-hydroxytryptamine (5HT)-like action which might explain the soporific action of PCPA in chicks. 2 PCPA, like 5-HT, contracted the rat fundal preparation (as did PCPA base), and in cats enhanced twitch tension of a lower ...

Isolated perfused segments of pig ileum and sigmoid colon were used as an extrinsically denervated model of intestinal fluid propulsion to compare the effects of intraluminal (IL) with intraarterial (IA) administration of cisapride and mebeverine. The ileal segments had a spontaneous mean activity of 0.008 (SEM 0.003) ml Krebs propelled aborally min-1, with propulsive waves at a mean frequency ...

The present study was designed to further evaluate a possible spasmolytic activity of synthetic lapachol derivatives, norlapachol, alpha-norlapachone, beta-norlapachone and hydro-hydroxy-norlapachol (HH-norlapachol), on guinea-pig ileum. In guinea-pig ileum, except for norlapachol, all naphthoquinones inhibited the phasic contractions induced by carbachol or histamine. Even when the ileum was p...

Antagonistic activity of cyproheptadine against common spasmogens, like acetylcholine, histamine, serotonin, bradykinin and angiotensin, was studied on isolated guinea-pig ileum. Cyproheptadine produced a reversible antagonism of non-competitive type and was most effective against serotonin. It was less potent against histamine, bradykinin and angiotensin and least potent against acetylcholine.

In this work, we investigated the spasmolytic effect of caulerpine, a bisindole alkaloid isolated from marine algae of the Caulerpa genus, on guinea pig ileum. Our findings indicated that caulerpine inhibited phasic contractions induced by carbachol (IC₅₀ = 7.0 ± 1.9 × 10⁻⁵ M), histamine (IC₅₀ = 1.3 ± 0.3 × 10⁻⁴ M) and serotonin (IC₅₀ = 8.0 ± 1.4 × 10⁻⁵ M) in a non-selective manner. Furthermore...

Watary extract of ALLIUM SATIVUM when administered Intravenously (I.V.) to NORMOTENSIVE dogs, produced a significant fall in their mean blood pressure. This effect was not antagonized by atropine or antihistamines. The extract increased the activity of Isolated Guinea Pig Ileum preparation. This effect of A Sativum was blocked by Diamentane (JPMA 31:12, 1981).

The effects of Mono sodium glutamate on smooth muscles were studied using the guinea-pig isolated ileum. Mono sodium glutamate produced spasmogenic effect. Atropine blocked the contractile response elicited by Mono sodium glutamate whereas mepyramine and hexamethonium failed to do so. These findings suggest a cholinergic involvement at post ganglionic site of action.

Sodium ascorbate, an antioxidant, has been reported to have a complex stimulating action on guinea pig ileal longitudinal smooth muscle (3.5-7). Acetylcholine-induced contractions are augmented (3,6) in small concentrations. Larger concentrations inhibit spasmogenic responses induced by acetylcholine, histamine and 5-hydroxytryptamine (2,3,5), potentiate the effect of DMPP on guinea pig ileum b...

We have assessed the potential of several mu-opioid receptor antagonists to elicit a response in the guinea-pig isolated ileum in the presence of, and following overnight exposure to, morphine. Naloxone, D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH(2) (CTOP), (-)-5, 9alpha-diethyl-2-(3-furyl-methyl)-2'-hydroxy-6,7-benzomorphan (MR2266), but not D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH(2) (CTAP), produc...