ISSN:0031-7012    

DOI:10.1159/000139209

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Senna consists of the dried leaflets or fruits of Cassia senna (C. acutifolia) known in commerce as Alexandrian senna and of Cassia angustifolia commonly known as Tinnevelly senna. The senna plants are small shrubs of Leguminosae cultivated either in Somalia, the Arabian peninsula and near the Nile river. Tinnevelly senna is obtained from cultivated plants mainly in South India and Pakistan. Owing to the careful way in which the plant is harvested, the leaflets of the drug are usually little broken. Damaged leaves and lower quality products are often used for making galenicals. The senna pods (fruits) are collected during the same period as the leaves, then dried and separated into various qualities. The active principle of Senna was first isolated and characterized by Stoll in 1941. The first two glycosides were identified and attributed to the anthraquinone family. These were found to be dimeric products of aloe emodin and/or rhein which were named sennoside A and sennoside B. They both hydrolyze to give the aglycones sennidin A and B and two molecules of glucose. Later work confirmed these findings and further demonstrated the presence of sennosides C and D. Small quantities of monomeric glycosides and free anthraquinones seem to be present as well. The active constituents of the pods are similar to those of the leaves but present in larger quantities. Two naphthalene glycosides isolated from senna leaves and pods are 6-hydroxymusicin glucoside and tinnevellin glucoside. Both compounds can be utilized to distinguish between the Alexandrian senna and the India senna, since tinnevellin glucoside is only found in the latter and the first only in the C senna. Finally, a series of other compounds has been isolated from senna such as the yellow flavanol kaempferol, its glucoside kaempferin, isorhamnetin, further sterol glucosides, mucilage polysaccharides, resin and calcium oxalate. Detailed studies on the water-soluble polysaccharides reported the presence of several distinct hydrocolloids.

ISSN:0031-7012    

DOI:10.1159/000139654

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Neuroimmunophysiology involves direct communication between the mucosal immune system and the minibrain in the colon. Communication is chemical in nature (paracrine) and involves specialized sensing functions of the immune cells for specific antigens together with intelligent interpretation of the signals by the enteric nervous system. Immunoneural integration progresses sequentially starting with immune detection followed by signal transfer to enteric microcircuits followed by neural interpretation and then selection of a specific neural program of coordinated mucosal secretion and motor propulsion that acts to clear the antigenic threat from the colonic lumen. Histamine and serotonin are important chemical messages released from mucosal mast cells to act at specific receptor subtypes on neural elements of the enteric minibrain.

ISSN:0031-7012    

DOI:10.1159/000139836

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Omeprazole, a proton pump inhibitor, is used in the treatment of gastrointestinal diseases associated with hyperacidity. It binds to, and inhibits, some of the activities of hepatic cytochrome P450 resulting in increased half-lives of certain pharmacologic and endogenous compounds. It may also increase the activity of cytochrome P450 under certain conditions. Oxidative metabolism of endogenous estrogens, particularly the 2-hydroxylation pathway, is P450-dependent, and is highly sensitive to a variety of dietary and pharmacologic agents. We therefore studied the extent of estradiol 2-hydroxylation in 7 normal male volunteers before and during oral treatment with omeprazole 20 mg twice daily. Using a specific in vivo radiometric assay, the mean extent (±SEM) of estradiol 2-hydroxylation was found to be unchanged before and after omeprazole treatment (27.3 ± 3.0 vs. 27.5 ± 3.4%, respectively). The excretion of the endogenous urinary estrogen metabolites, 2-hydroxyestrone, estriol, and estrone was also unaltered by omeprazole. These results show that omeprazole, in contradistinction to other medications used in the treatment of peptic ulcer disease, is without effect on estradiol metabolism in m

ISSN:0031-7012    

DOI:10.1159/000139072

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

Previously it was demonstrated that intravenously administered morphine produced greater analgesic but lower hyperthermic responses to morphine in 24-week-old rats in comparison to 8-week-old rats. The differential pharmacological responses to morphine could not solely be attributed to the pharmacokinetic parameters, namely area under the serum morphine concentration-time curve, serum levels of morphine extrapolated to zero time, half-life, mean residence time, apparent volume of distribution at the steady state, terminal rate constant and total body clearance of morphine in serum. In order to determine whether the differences in pharmacological responses to morphine in rats from two age groups are related to differential distribution of morphine in the central nervous system, in the present study, the time course of the distribution of morphine in brain regions (hypothalamus, hippocampus, cortex, pons and medulla, amygdala, midbrain and corpus striatum), spinal cord and serum following intravenous injection of 10 mg/kg dose to 8- and 24-week-old male Sprague-Dawley rats was determined. Morphine injected intravenously produced a greater analgesic but less intense hyperthermic effect in 24-week-old rats in comparison to 8-week-old rats. In most of the brain regions and spinal cord, with few exceptions, the concentration of morphine was found to be greater in 24-week-old rats than in 8-week-old rats. Similarly, the ratio of the concehtration of morphine in brain region or spinal cord to serum was significantly higher in rats from the older age group. The studies demonstrate that the altered pharmacological responses to intravenously administered morphine to rats of differing ages may be related to the higher concentration of morphine in the central nervous system of older rats, which in turn may be related to the differences in the blood-brain barrier to morphine in the two age groups.

ISSN:0031-7012    

DOI:10.1159/000139073

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effect of oral treatment with sennosides (50 mg/kg) on the time-course of net H2O and electrolyte transport rates was studied in 1-hour incubation experiments in the rat colon in vivo. Net H20, Na+ and Cl- absorption rates did not change during the first 4 h after treatment, but were reversed to net secretion after 6 h and partly recovered during the next 18 h. K+ and Ca2+ were secreted in controls, and net secretion increased from 6 to 24 h after treatment. Paracellular permeability of [14C]erythritol was 3-fold 6 h after treatment but unchanged at other times after treatment (2, 4, 12 or 24 h). LDH leakage into the lumen was not enhanced by treatment. Neither mucosal Na+, K+-ATPase activity nor cAMP or phosphodiesterase activity was affected by sennosides. As stool consistency and acceleration of transit by sennosides has entirely normalized 24 h after treatment but not net absorption of H20 and electrolytes, it is concluded that there may be regional differences in the absorptive behavior of the colon induced by sennosides. Slow transit and increased absorption in some parts of the colon may overcome secretion in other parts.

ISSN:0031-7012    

DOI:10.1159/000139838

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The involvement of Ca2+ in the mechanism of the purgative action of rhein anthrone was studied. Among individual or combination pretreatments with calcium channel blockers, calmodulin antagonists and prostaglandin biosynthesis inhibitors, the combination of indometacin and nifedipine completely blocked the diarrhoea induced by rhein anthrone and also inhibited its effects on colonic fluid and electrolyte transport, and large intestinal motility. Calmodulin antagonists were less active regarding suppression of the effects of rhein anthrone. We concluded that, in addition to prostaglandins, diarrhoea induced by rhein anthrone must also involve the calcium channel which can be blocked by nifedipine, but not verapamil.

ISSN:0031-7012    

DOI:10.1159/000139839

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

In the first of two experiments, acetaminophen (paracetamol) was measured in the saliva of healthy male and female Sudanese, Libyan and Senegalese volunteers. Saliva was collected 1 h after ingesting 1 g of the drug. In the second experiment, acetaminophen (1 g) was given orally to male Sudanese and Libyan volunteers, and saliva was collected 0.5, 1, 2, 3, 4, 5 and 6 h thereafter. The drug concentration in both experiments was measured by a modified spectrophotometric method with a detection limit of 1 μg/ml. The results indicated that the salivary acetaminophen concentration in Sudanese was significantly (p 0.05). There were no statistically significant differences in salivary acetaminophen concentrations between Sudanese, Libyans and Senegalese volunteers, although male Senegalese had higher levels than the Sudanese and Libyans by 11.4 and 15.8%, respectively. Acetaminophen salivary concentrations in Sudanese were slightly but significantly (p 0.1). The results of both experiments do not support the suggestion of inter-ethnic differences in acetaminophen clearance, but indicate that males may clear more of the drug through saliva than females

ISSN:0031-7012    

DOI:10.1159/000139074

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effects of quinine, quinidine, cinchonine, cinchonidine and chloroquine on phospolipid synthesis in the Jurkat T cell line have been compared. It was found that the two potassium channel blockers, quinine and quinidine, markedly enhanced phosphatidylserine synthesis and strongly decreased both phosphatidylchohne and phosphatidylethanolamine synthesis. The inhibition of phosphatidylchohne and phosphatidylethanolamine synthesis was due to the inhibition of the uptake of [3H]choline or [3H]ethanolamine, respectively, by the cells. This effect was also observed when using either cinchonine, cinchonidine and chloroquine. In contrast, these three drugs were unable to modify phosphatidylserine synthesis, indicating that the K+ channel blockers, quinine and quinidine, specifically interfere with the synthesis of this phospholipid.

ISSN:0031-7012    

DOI:10.1159/000139075

出版商:S. Karger AG    

年代:1993

数据来源: Karger

摘要:

The effect of sodium rhein on contractile activity and fluid flow in the rat complete large intestine was studied in vitro. Contractile activity was recorded using serosal strain gauges and volume transducers recorded distal fluid flow from the segment. Luminal sodium rhein (1 mM) produced a protracted increase in caecal activity yet increased colonic contractility transiently. Fluid flow from the preparation was increased and the number of propagated complexes was elevated after the initial 10 min of exposure. The effect did not appear to be related directly to dose. Sodium rhein (0.1 mM) did not significantly stimulate contractility and a higher dose (5 mM) only produced a transient effect on propagated contractions. However, this dose had the effect of significantly reducing activity when the rhein was replaced by normal buffer. The data suggest that the action of sodium rhein is subtle; after an initial excitation, the glycoside shifts the pattern of motor activity in favour of propulsion at the expense of segmentation. The large intestine is more able, therefore, to expel luminal contents in a caudal direction following the addition of this anthraquinone laxative.

ISSN:0031-7012    

DOI:10.1159/000139840

出版商:S. Karger AG    

年代:1993

数据来源: Karger