摘要:

SUMMARY1. Metoclopramide is a potent antagonist of the inhibitory response to dopamine in two isolated tissues, the electrically stimulated intestine and the spontaneous beating heart, from the molluscTapes watlingi.2. Blockade by metoclopramide of dopamine receptors in the central nervous system of man may account for the relapse of patients with Parkinson's disease which occurs when metoclopramide is given during successful therapy with levodopa.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00568.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. The effect of surgical denervation of the adrenal gland on ACTH‐induced hypertension in the sheep has been examined. ACTH (80 iu/day) was administered for 5 days to eight sheep before and after bilateral surgical denervation of the adrenal.2. In intact sheep, ACTH‐induced hypertension is associated with a significant increase in cardiac output and heart rate. Adrenal denervation obtained by sectioning of the lumbar sympathetic and splanchnic nerves supplying the adrenal gland did not alter the magnitude or time course of the hypertension, or the increase in heart rate.3. Adrenal denervation did not affect the increase in plasma sodium, the fall in plasma potassium, the initial urinary sodium retention, the increase in water turnover or the changes in blood corticosteroids which are seen during ACTH administration to intact sheep. However, in these adrenally denervated sheep ACTH treatment did not significantly change cardiac output.4. This study suggests an important role for a factor or factors from the adrenal cortex in causing ACTH‐induced hyperte

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00569.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. Experiments were conducted in rats to determine the effects of various methods of blood collection upon plasma renin concentration (PRC).2. Either restraint or anaesthesia during blood sampling resulted in PRC levels up to five times higher than in samples collected after decapitation.3. A similar difference was observed in adrenalectomized rats, indicating that the PRC increase did not depend upon liberation of adrenal catecholamines.4. In contrast, administration of propranolol abolished the difference in PRC between decapitated rats, and those sampled during ether anaesthesia, suggesting involvement of a β‐adrenoreceptor mechanism in the stimulation of renin release by anaesthesia.5. Despite high starting levels of PRC in ether‐anaesthetized rats, the PRC response to water deprivation was proportionally the same (a 7‐fold increase), whether sampling was carried out during ether anaesthesia or after decapi

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00570.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. To investigate the hypothesis that some degree of tranquillizer activity is a necessary component of analgesic activity, several narcotic analgesic drugs and narcotic antagonists were tested for their ability to block a conditioned avoidance response in rats, and their actions were compared with those of chlorpromazine and chlordiazepoxide.2. Morphine, oxymorphone, oxycodone and codeine specifically blocked the avoidance response in a dose‐dependent manner, in doses comparable with those having antinociceptive action. Neither nalorphine nor naloxone had any significant effect on the avoidance response, but they caused a parallel shift of the dose‐response curve of morphine to the right.3. Pentazocine specifically blocked avoidance to about 50% in low and intermediate doses, but the highest dose used blocked both avoidance and escape.4. Chlorpromazine was potent in blocking the avoidance response, and nalorphine did not interfere with this action. Chlordiazepoxide had only a slight effect in blocking the avoidance response.5. Interference with 5‐hydroxytryptamine metabolism had no effect on the action of narcotics on conditioned avoidance; this finding is difficult to reconcile with the hypothesis that 5‐hydroxytryptamine is involved in the analgesic action of morphine.6. The results are consistent with the hypothesis that tranquillizer action is a necessary component of analgesia and may provide a basis for more complete screening of potential ana

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00571.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. Intraperitoneal administration of kallikrein (50 u/kg) to rats increased the kinin‐forming activity of the brain but had no effect on behaviour.2. Injection of bradykinin (1 μg) into a cerebral ventricle slightly decreased the behavioural activity of rats.3. The increase in activity produced by pretreatment with nialamide (200 mg/kg) was greatly potentiated by administration of kallikrein or bradykinin in the doses and by the routes mentioned above.4. Injection of noradrenaline (50 μg) into a cerebral ventricle had no effect on activity in normal rats and slightly increased the activity of rats pretreated with reserpine.5. When noradrenaline was given with kallikrein or bradykinin, activity was markedly increased in normal and reserpinized rats.6. The results suggest that kinins may influence central neurotransmiss

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00572.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. Clonidine and three α‐adrenoreceptor blocking agents were injected into the cisterna magna of rats, rabbits and dogs. Clonidine (1 μg. kg−1) induced a fall in blood pressure in the three species.2. Phentolamine, tolazoline and phenoxybenzamine (100 μg. kg−1) induced a fall in blood pressure in rats, but only phentolamine was effective in rabbits, and none of these drugs significantly altered blood pressure in dogs when given intracisternally.3. A subsequent administration of clonidine after recovery of blood pressure no longer decreased blood pressure in rats and rabbits.4. In dogs the effects of clonidine were antagonized by tolazoline and phentolamine, but not by phenoxybenzamine.5. These results indicate that clonidine stimulates central α‐adrenoreceptors to produce a decrease in blood pressure, but the structure of these receptors may vary according to ani

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00573.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. Sodium salicylate has been used as a hypoglycaemic agent in the treatment of diabetic patients and severe hypoglycaemia has been reported in children treated with aspirin. The mechanism of this hypoglycaemic action has never been elucidated.2. In the isolated perfused rat liver, salicylate inhibits gluconeogenesis from lactate, alanine and propionate. The degree of inhibition is related to salicylate concentration and occurs with 2 mM (30 mg/100 ml).3. The inhibitory action probably results from the effect of salicylate on oxidative phosphorylation in that there was little or no inhibition of gluconeogenesis from precursors which do not have a high requirement for ATP in their metabolism to glucose.4. In man, lactate and alanine are the main precursors of glucose, and the liver is the main site of gluconeogenesis. These results demonstrate a mechanism for salicylate induced hypoglycaemia in man, and in addition suggest that accumulation of lactate may account for the acidosis sometimes produced by overdosage with salicylate.

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00574.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. The effect of pretreatment with phenobarbitone on the hepatic transport of sodium14C‐taurocholate was studied in the Sprague Dawley rat. Taurocholate solutions were injected into the portal vein in a volume of 0.2 ml in 2 s.2. Biliary secretion of taurocholate injected into the portal vein in a concentration of 25 μM was not altered by pretreatment with phenobarbitone. This concentration of taurocholate corresponds to that occurring normally in portal venous blood.3. When taurocholate was injected in a much larger concentration (13 mM), biliary secretion of taurocholate was significantly slower in phenobarbitone‐pretreated rats than in control rats.4. Changes in hepatic bile salt transport do not appear to contribute to the choleresis that occurs with phenobarbi

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00575.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY

摘要:

SUMMARY1. Plasma renin concentration (PRC) was measured in eight male rats at intervals during a 6 h period after bilateral nephrectomy.2. PRC fell rapidly, reaching 51% of the mean control level by 10 min, 29% by 30 min, and 2% by 4 h.3. Under the conditions of the experiment, the half‐life of circulating endogenous renin in the rat was about 10 mi

ISSN:0305-1870    

DOI:10.1111/j.1440-1681.1974.tb00576.x

出版商:Blackwell Publishing Ltd    

年代:1974

数据来源: WILEY