Guinea intestine

The action of anabasine is similar to that of nicotine. When the piperidine ring of anabasine is opened to produce 8-amino-8-3-pyridyl-n-valeric acid the activity is reduced, and this is also true of the corresponding lactam and the benzoyl derivative. According to De Eds myosmine is less toxic than nicotine but more active on isolated guinea-pig intestine. ... 

Pharmacological Action. As already pointed out, cularine shows some resemblance to papaverine and hydrastine in action (p. 196). The M.L.D. (mgm./kilo.) for mice by intravenous injection of ochotensine is 10-6 i 0-54 so that it seems to be the most toxic of the fifteen corydalis alkaloids examined by Anderson and Chen, who also state that it stimulates isolated guinea-pig or rabbit uterus, inhibits isolated rabbit-intestine and induces a fall in blood pressure on intravenous injection in etherised cats. 

Chen et al. state that dendrobine produces moderate hyperglycemia, diminishes cardiac activity in large doses, lowers blood pressure, depresses respiration, inhibits isolated rabbit intestine and contracts isolated guinea-pig uterus. It has a weak analgesic, antipyretic action. Chen and Rose found that the convulsions induced by injection of dendrobine can be controlled by use of sodium isoamylethylbarbiturate they appear to be central in origin due to action on the cord and medulla. 

Burgen, A. S. V., and Spero, L. (1968). The action of acetylcholine and other drugs on the efflux of potassium and rubidium from smooth muscle of the guinea-pig intestine. Br. J. Pharmacol., 34 99—115. 

Paton, W. D. M., and Rang, H. P. (1965). The uptake of atropine and related drags by intestinal smooth muscle of the guinea pig in relation to acetylcholine receptors. Proc. R. Soc. Lond. [Biot.] 163 1-44. 

Pertwee RGS, L. A. Elrick DB, Mechoulam R, Corbett AD. Inhibitory effects of certain enantiomeric cannabinoids in the mouse vas deferens and the myenteric plexus preparation of guinea-pig small intestine. Br J Pharmacol 1992 105 980-984. 

Madara JL. (1983). Increases in guinea pig small intestinal transepithelial resistance induced by osomotic loads are accompanied by rapid alterations in absorptive-cell tight-junction structure. J Cell Biol 97 125-136. 

Lauterbach, F., Intestinal permeation of nonquatemary amines a study with telenzepine and pirenzepine in the isolated mucosa of guinea pig jejunum and colon, J. Pharmacol. Exp. Ther. 1987, 243, 1121-1130. 

Nixon Several years ago a study showed there were 10 times more InsP3 receptors than RyRs in the guinea-pig intestinal smooth muscle (Wibo Godfraind 1994). We have found in most smooth muscles that there are fewer RyRs. 

There were no histopathological changes in the stomach, small intestines, or large intestines for rats, guinea pigs, dogs, or quail that were exposed to concentrations of 0, 260, or 5,900 ppm hexachloroethane for 8 hours or to 0, 15, 48, or 260 ppm hexachloroethane 6 hours/day, 5 days/week for 6 weeks (Weeks et al. 1979). 

Unlike the previously discussed compounds, which inhibit MTP in both liver and intestine, an intestine-selective orally-active MTP inhibitor JTT-130 (structure not yet disclosed) has been reported to decrease plasma cholesterol and TG in guinea pigs with no hepatic lipid accumulation [16]. Although further studies in human are needed, inhibitors that selectively target intestinal MTP might be a safer alternative as a treatment for hyperlipidemia than the liver-targeting MTP inhibitors. 

The activities of the indole carbazimidamide derivatives 5 at the 5-HT4 receptor were measured in vitro using the field-stimulated LMMP-GPI preparation (Table 1) followed by in vivo investigations applying the gastric emptying and intestinal transit models in the guinea-pig and rat. 

The intracellular localization of carboxylesterases is predominantly microsomal, the esterases being localized in the endoplasmic reticulum [73] [79] [93], They are either free in the lumen or loosely bound to the inner aspect of the membrane. The carboxylesterases in liver mitochondria are essentially identical to those of the microsomal fraction. In contrast, carboxylesterases of liver lysosomes are different, their isoelectric point being in the acidic range. Carboxylesterase activity is also found in the cytosolic fraction of liver and kidney. It has been suggested that cytosolic carboxylesterases are mere contaminants of the microsomal enzymes, but there is evidence that soluble esterases do not necessarily originate from the endoplasmic reticulum [94], In guinea pig liver, a specific cytosolic esterase has been identified that is capable of hydrolyzing acetylsalicylate and that differs from the microsomal enzyme. Also, microsomal and cytosolic enzymes have different electrophoretic properties [77]. Cytosolic and microsomal esterases in rat small intestinal mucosa are clearly different enzymes, since they hydrolyze rac-oxazepam acetate with opposite enantioselectivity [95], Consequently, studies of hydrolysis in hepatocytes reflect more closely the in vivo hepatic hydrolysis than subcellular fractions, since cytosolic and microsomal esterases can act in parallel. 

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