OBJECTIVETo study contractility of guinea pig ileum in vitro,and analyze the mechanism of anti-emetic effects of Lianqiao.

METHODUsing emesis-relating agonists as drugs, the inhibitory effects of Lianqiao on guinea pig ileum contractility in vitro were observed in organ bath.

RESULTLianqiao could inhibit guinea pig ileum spontaneous contractions, reducing the tone of contractions dose-dependently. Acetylcholine (Ach), histamine (His), 5-hydroxytryptamine (5-HT) stimulated contractions of the guinea pig ileum, enhanced the tone and amplitude. All the three doses (10, 5, 2 g x L(-1)) of Lianqiao could suppress the contractility, significantly reduced the tone and amplitude of ileum contractions stimulated by drugs but not the frequency. Dopamine could inhibit the spontaneous contraction tone and amplitude of ileum; Both the large doses (10, 5 g x L(-1)) of Lianqiao could antagonise the inhibitory effect of DA, enhance the tone and amplitude. Small dose(2 g x L(-1)) had additive effects on tone of ileum contractions with DA,but enhanced the amplitude not the frequency.

CONCLUSIONLianqiao have an inhibitory effect on guinea pig ileum contractions,the mechanism might be blocking M receptor, H1 receptor, 5-HT receptor and D2 receptor or directly suppressed ileum smooth muscle. The mechanisms of anti-emetic effect of Lianqiao needs further study.

Animals ; Antiemetics ; pharmacology ; Dopamine ; pharmacology ; Forsythia ; Guinea Pigs ; Ileum ; drug effects ; physiology ; Male ; Muscle Contraction ; drug effects ; Phytotherapy

PURPOSE: Itopride hydrochloride (itopride) inhibits acetylcholinesterase (AChE) and antagonizes dopamine D(2) receptor, and has been used as a gastroprokinetic agent. However, its prokinetic effect on the small bowel or colon has not yet been thoroughly investigated. The aim of this study was to investigate the effects of itopride on motor functions of the ileum and colon in guinea pigs. MATERIALS AND METHODS: The distal ileum was excised and the activity of peristaltic contraction was determined by measuring the amplitude and propagation velocity of peristaltic contraction. The distal colon was removed and connected to the chamber containing Krebs-Henseleit solution (K-H solution). Artificial fecal matter was inserted into the oral side of the lumen, and moved toward the anal side by intraluminal perfusion via peristaltic pump. Colonic transit times were measured by the time required for the artificial feces to move a total length of 10cm with 2-cm intervals. RESULTS: In the ileum, itopride accelerated peristaltic velocity at higher dosage (10(-10)-10(-6)M) whereas neostigmine accelerated it only with a lower dosage (10(-10)-10(-9)M). Dopamine (10(-8)M) decelerated the velocity that was recovered by itopride infusion. Itopride and neostigmine significantly shortened colonic transit at a higher dosage (10(-10)-10(-6)M). Dopamine (10(-8)M) delayed colonic transit time that was also recovered after infusion of itopride. CONCLUSION: Itopride has prokinetic effects on both the ileum and colon, which are regulated through inhibitory effects on AChE and antagonistic effects on dopamine D(2) receptor.
Animals ; Benzamides/*pharmacology ; Benzyl Compounds/*pharmacology ; Cholinesterase Inhibitors/pharmacology ; Colon/*drug effects/physiology ; Dopamine/pharmacology ; Dose-Response Relationship, Drug ; Gastrointestinal Motility/*drug effects ; Guinea Pigs ; Ileum/*drug effects/physiology ; Neostigmine/pharmacology ; Receptors, Dopamine D1/antagonists & inhibitors/physiology

AIMTo investigate the effects of 323-A and 323-B, two isomers extracted from the metabolites of cultured marine fungus, Halorosellinia oceanicum 323, on the contraction of isolated guinea pig ileum (GPI).

METHODSThe GPI contractions were recorded with a two-channel-physiological recorder with tension transducers. Cumulative dose-response curves of contractions of isolated GPI induced by histamine (Hist), acetylcholine (ACh) and potassium chloride (KCl) were constructed, then the influences of 323-A and 323-B on each curve were observed. Furthermore, possible mechanisms underlying effects of the two compounds were explored by analyzing their influences on the biphasic contractile response to ACh, with comparison of a calcium antagonist, verapamil (Ver).

RESULTSThe data indicated that both 323-A and 323-B inhibited the contractile actions of GPI triggered by Hist, ACh and KCl in a concentration-dependent manner, with pD2' values of 5.13, 4.97, 5.36 and 5.51, 5.56, 5.62, respectively. The initial phase component of the ACh-elicited contractions, in the absence of external Ca2+, was significantly reduced by 323-A, 323-B, as well as Ver, whereas the subsequent sustained tonic contractions induced by adding Ca2+ to the bath solution were almost unaffected.

CONCLUSIONThese results suggest that 323-A and 323-B have calcium antagonistic effects similar to that of Ver in mechanisms, and they might have potential to be developed as calcium antagonists.

Acetylcholine ; antagonists & inhibitors ; Animals ; Calcium ; antagonists & inhibitors ; Calcium Channel Blockers ; isolation & purification ; pharmacology ; Female ; Fungi ; chemistry ; Guinea Pigs ; Histamine Antagonists ; pharmacology ; Ileum ; drug effects ; physiology ; Male ; Muscle Contraction ; drug effects ; Muscle, Smooth ; drug effects ; Potassium Chloride ; antagonists & inhibitors

OBJECTIVETo prepare berberine microemulsion, and to investigate its properities and the absorption character in rat intestine in situ.

METHODThe optimum formulation of the blank microemulsion selected by pseudo tertiary phase diagrams and the berberine microemulsion was prepared based on the blank microemulsion. The viscosity, conductance, refraction rate and particle size of berberine microemulsion were surveyed. An in situ rat perfusion method was used to investigate the intestinal absorption of berberine microemulsion. A UV method for determination of berberine in the intestinal flux was established.

RESULTThe viscosity, conductance, refraction rate and particle size of berberine microemulsion were 2.11 cPas, 125.5 microomega, 1.363 and 24.0 nm, respectively. The absorption rate of berberine at the ileum was the best. The absorption of berberine microemulsion at the ileum was significantly higher than that of raw medicine (P < 0.01).

CONCLUSIONThe microemulsion system might improve the absorption of berberine in the intestinal tract.

Absorption ; Administration, Cutaneous ; Animals ; Berberine ; administration & dosage ; pharmacokinetics ; Drug Delivery Systems ; Drug Stability ; Female ; Ileum ; metabolism ; Intestinal Absorption ; drug effects ; Intestines ; metabolism ; Male ; Particle Size ; Rats ; Rats, Wistar ; Skin ; metabolism ; Skin Absorption ; drug effects ; physiology ; Solubility ; Technology, Pharmaceutical ; methods