bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects on cardiac muscle and nerve of a fluorinated decahydroquinoline derivative, L7810, rapidly absorbed after oral administration
Authors: BAGWELL E. E. , POLSTER P. , WILLIAMS E. M. VAUGHAN 
Published: July 2012

Summary
. L7810 (4‐carbamoyloxy‐1‐(4‐(4‐fluorophenyl)‐4‐oxobutyl) decahydroquinoline, has a local anaesthetic action on frog nerve 1·75 times that of procaine.
. L7810 protected anaesthetized guinea‐pigs against ouabain‐induced ventricular fibrillation and increased the lethal dose of ouabain.
. L7810 reduced the rate of rise of intracellularly recorded action potentials in rabbit isolated atria; the resting potential was not affected, but the duration of the action potential was prolonged.
. Unlike most drugs with local anaesthetic properties L7810 did not depress contractions in isolated atria but increased them.
. L7810 reduced the spontaneous frequency, maximum follow frequency and conduction velocity of rabbit isolated atria.
. L7810 had no blocking action on the chronotropic or positive inotropic actions of isoprenaline on isolated atrial muscle.
. In anaesthetized dogs L7810 caused a small dose‐related bradycardia, and a large dose‐related decrease in peripheral vascular resistance. There was no blockade of the effects of isoprenaline on heart rate or peripheral blood flow.
Interaction between picrotoxin and 5‐hydroxytryptamine in the superior cervical ganglion of the cat
Authors: de GROAT W. C. , LALLEY P. M. 
Published: July 2012

Summary
. Electrophysiological techniques were utilized to study the actions of 5‐hydroxytryptamine (5‐HT) and picrotoxin on the superior cervical ganglion of the cat.
. The intra‐arterial administration of 5‐HT to the ganglion elicited both depressant and excitatory actions. In low doses (0·01–0·5 μg) the amine produced a depression of ganglionic transmission. In larger doses (2–50 μg) it produced an excitation of ganglion cells (early discharge) and an initial enhancement of transmission, which was followed by depression. Picrotoxin (25–500 μg, i.a.) blocked the initial excitatory effects of 5‐HT but did not block the depression. Picrotoxin did not antagonize the excitatory actions of injected cholinomimetic agents or potassium chloride.
. In ganglia conditioned by repetitive stimulation of the preganglionic nerve (30 Hz for 30 s) 5‐HT also elicited a late‐occurring and very prolonged discharge on certain postganglionic nerves (‘spinal’) but not on others (external carotid). The late discharge was only partially depressed by picrotoxin.
. Recordings from the surface of the superior cervical ganglion revealed that 5‐HT produced three types of ganglionic potentials: (1) an initial transient depolarization which coincided with the early discharge, (2) a late‐occurring, prolonged depolarization which coincided with the late discharge, and (3) a hyperpolarization which in some experiments accompanied the depression of transmission. The late depolarization and hyperpolarization were not observed in every experiment. Picrotoxin (25–500 μg) blocked the initial depolarization, but did not block the late depolarization or the hyperpolarization.
. It is concluded the 5‐HT can produce three distinct responses in the superior cervical ganglion: a depressant effect and two types of excitation. It seems likely that depression and excitation occur via the activation of different receptors, since picrotoxin selectively blocks the latter. The finding that picrotoxin is a 5‐HT antagonist in peripheral ganglia raises the possibility that picrotoxin might also influence tryptaminergic mechanisms in the central nervous system.
The distribution of vasopressin and oxytocin in the hypothalamoneurohypophysial system of the guinea‐pig
Authors: BISSET G. W. , ERRINGTON M. L. , RICHARDS C. D. 
Published: July 2012

Summary
. The ratio of the content of vasopressin to that of oxytocin (V/O ratio) was estimated in the supraoptic nucleus (SON), paraventricular nucleus (PVN) and posterior pituitary gland (PIT) of guinea‐pigs.
. Extracts were assayed for antidiuretic activity to estimate vasopressin and for milk‐ejecting activity to estimate oxytocin. In assays for milk‐ejecting activity, trypsin was used to inactivate vasopressin in the extracts.
. The mean V/O ratios in the SON, PVN and PIT were 28, 85 and 70 respectively in male guinea‐pigs, 6·8, 7·4 and 6·9 in non‐lactating females, and 5·1, 3·3 and 6·6 in lactating females.
. The distribution of the hormones within the hypothalamus is discussed in relation to their independent release in response to electrical stimulation of the SON and PVN.
Cyclopentolate in treatment of sarin miosis
Authors: MOYLAN‐JONES R. J. , THOMAS D. PRICE 
Published: July 2012

Summary
. Six young male volunteers were exposed to sarin vapour (isopropyl methyl phosphonofluoridate) at a concentration of 0·5 mg/m3 for 30 min (concentration time (Ct) 15 (mg min)/m3).
. The resulting clinical syndrome was treated by instilling 0·06 ml of a 1% solution of cyclopentolate into the conjunctival sac.
. Visual acuity, retinoscopy, objective and subjective refraction and pupil sizes were noted before the trial, after exposure to sarin and after treatment with cyclopentolate.
. No appreciable difference was demonstrated between the control objective retinoscopy values and those obtained after cyclopentolate treatment of the clinical syndrome induced by sarin. Reduced near visual acuity was observed in some subjects treated with cyclopentolate as compared with acuity after exposure to sarin alone, considered to be due to the partial cycloplegia produced by treatment. Visual acuity after exposure to sarin alone was improved in some instances by the miosis produced.
. It is suggested that unless full dark adaptation is a consideration, treatment of the ophthalmic condition resulting from exposure to this dosage of sarin should be reserved for those experiencing distressing ocular symptoms.
Actions of morphine on the segmental reflex of the decerebrate‐spinal cat
Authors: KRIVOY W. , KROEGER D. , ZIMMERMANN E. 
Published: July 2012

Summary
The actions of morphine were studied on the segmental reflex of the decerebrate‐spinal cat. Morphine decreased arterial blood pressure.
Morphine inhibited mono‐ and polysynaptic reflexes. The influence of morphine on monosynaptic reflexes was more obvious at stimulation of the dorsal root at a frequency of 12·5 Hz than at 05 or 2·5 Hz.
The total amount of activity recorded from the ventral root after morphine depended on whether or not the evoked reflex was maximal or submaximal.
These actions of morphine were antagonized by naloxone.
Some initial animal and human pharmacological studies with benapryzine (BRL 1288)
Authors: BROWN D. M. , HUGHES B. O. , MARSDEN C. D. , MEADOWS J. C. , SPICER B. 
Published: July 2012

Summary
The pA2 anti‐acetylcholine activity in vitro for benapryzine was 6·55 compared with 902 for benzhexol.
In vivo, the anti‐acetylcholine activity of benapryzine relative to benzhexol was 0·038 as assessed by the mydriatic response of mice after subcutaneous administration. The relative activity assessed by the inhibition of pilocarpine‐induced salivation was 0·13 after oral administration and 0056 following subcutaneous administration of the drugs.
Benapryzine had the same order of activity as benzhexol in inhibiting oxotremorine‐induced tremors in mice.
Benapryzine had anticonvulsant properties but no analgesic activity, whilst in high doses it antagonized the extrapyramidal symptoms induced by perphenazine in rats.
In patients benapryzine was effective in reducing the symptoms of Parkinson's disease without overt anti‐cholinergic effects or central hallucinogenic actions.
Benapryzine abolished the excess tremor and reduced the rigidity and akinesia induced by physostigmine in Parkinsonian subjects.
Acute systemic anaphylaxis in the calf
Authors: EYRE P. , LEWIS A. J. , WELLS P. W. 
Published: July 2012

Summary
Acute systemic anaphylaxis in calves was characterized by marked systemic hypotension hypertension in the pulmonary arteries and abdominal vena cava, and transient apnoea. Calves responded with a second reaction to antigen, but a third anaphylactic response could not be evoked.
Suppression of systemic anaphylaxis could not be effected with mepyramine, whereas methysergide or diethylcarbamazine each suppressed anaphylaxis by 50%. Disodium cromoglycate alone did not inhibit anaphylaxis: however, when disodium cromoglycate was combined with diethylcarbamazine almost total suppression (85%) was achieved. Sodium meclofenamate also was a powerful inhibitor of anaphylaxis (80%). It is tentatively suggested that slow reacting substance (SRS‐A) may be an important mediator of bovine anaphylaxis.
Bilateral vagotomy did not modify the circulatory responses to injected histamine, 5‐hydroxytryptamine (5‐HT) or antigen, whereas the effects of these agents on ventilation (apnoea) were abolished by vagotomy.
Plasma histamine concentration was increased during anaphylaxis, whereas plasma 5‐HT was not. Whole blood histamine concentration fell sharply and remained depressed during 20 min of anaphylactic shock. Reduced whole blood histamine levels probably reflect the severe leucopoenia in the calves.
Histamine concentrations in six tissues taken from calves subjected to anaphylaxis were not different from those in control calves mast cells were of similar numbers to controls, but showed some swelling, granular spilling and metachromasia.
Histamine, 5‐HT, bradykinin and antigen caused increased pulmonary artery perfusion pressure and ventilation resistance in isolated lungs from sensitized calves. However, there was no difference in histamine and 5‐HT concentration in perfusates obtained during antigen infusion of sensitized and control lungs.
Systemic anaphylaxis of calves may result from the interaction of histamine, 5‐HT and SRS‐A. The present data implicate (by indirect measurement) SRS‐A as an important mediator of anaphylaxis in this species.
Attenuation of amphetamine‐induced motor stimulation and stereotypy by 6‐hydroxydopamine in the rat
Authors: FIBIGER H. C. , FIBIGER H. P. , ZIS A. P. 
Published: July 2012

Summary
In accord with previous reports, intraventricular administration of 6‐hydroxydopamine (250 μg) to rats did not influence spontaneous locomotor activity. Neither was the stereotyped behaviour seen after high doses of (+)‐amphetamine (5 mg/kg) changed by this treatment. Increases in motor activity induced by (+)‐amphetamine (0·5 and 1·0 mg/kg) were significantly reduced after 6‐hydroxydopamine.
When 6‐hydroxydopamine (250 μg) was administered to tranylcypromine (5 mg/kg) pretreated animals, spontaneous activity was significantly reduced. The stimulant effects of (+)‐amphetamine (0·5 and 10 mg/kg) were completely abolished and amphetamine stereotypy (5·0 mg/kg) was absent or reduced after this treatment.
Bilateral injections of 6‐hydroxydopamine (10 μg) into the substantia nigra abolished the more pronounced features of amphetamine stereotypy. However, although significantly reduced, amphetamine‐induced locomotor stimulation was observed in these animals. Spontaneous activity was also reduced.
These observations suggest that dopaminergic nigro‐striatal neurones mediate some of the stimulant effects of amphetamine as well as being of critical importance in amphetamine‐induced stereotypy. However, other catechol‐aminergic neurones also appear to be involved in amphetamine motor stimulation. The results are consistent with the view that amphetamine exerts its behavioural effects indirectly through its action on brain catecholamines.
Passage of intravenously administered tubocurarine into the liquor space in man and dog
Authors: DEVASANKARAIAH G. , HARANATH P. S. R. K. , KRISHNAMURTY A. 
Published: July 2012

Summary
In anaesthetized patients under controlled respiration, samples of lumbar cerebrospinal fluid were withdrawn 15 and 60 min after an intravenous injection of 30 mg tubocurarine. When tested on the frog rectus muscle preparation contracted by acetylcholine, they exerted curare‐like activity which corresponded to between 0·05 and 0·33 μg/ml tubocurarine.
In dogs anaesthetized with pentobarbitone sodium and artificially ventilated, two procedures were adopted to find out if tubocurarine passes into the liquor space after an intravenous injection of 0·3 or 3 mg/kg and during its intravenous infusion at a rate of 10 (μg/kg)/minute. Either samples of cisternal cerebrospinal fluid (c.s.f.) were collected, or different regions of the liquor space were perfused with artificial c.s.f. and the effluent was collected. The samples of c.s.f. and the effluent were assayed for curare‐like activity on the frog rectus muscle.
After the intravenous injection of tubocurarine samples of cisternal effluent collected during perfusion from lateral ventricle to cisterna exerted curare‐like activity. It corresponded to 20 ng/min tubocurarine in the sample collected during the first 15 min after the injection of 0·3 mg/kg and to 40–60 ng/min in the samples collected up to 2 h after the injection of 3 mg/kg.
During intravenous infusion of tubocurarine the cisternal c.s.f. as well as the effluent from the perfused regions of the liquor space exhibited curare‐like activity. Expressed in equivalents of tubocurarine, the activity in the cisternal c.s.f. ranged from between 0·1 and 0·75 μg/ml. On perfusion from lateral ventricle to aqueduct or cisterna, the activity ranged from between 3 and 25 ng/min in the aqueductal and from between 4 and 40 ng/min in the cisternal effluent. On perfusion from the lumbar‐spinal subarachnoid space to cisterna it ranged from between 6 and 55 ng/min in the cisternal effluent.
Effect of long‐term treatment with high doses of guanethidine on sperm transport and fertility of rats
Authors: HEPP R. , KREYE V. A. W. 
Published: July 2012

Summary
Male rats treated with guanethidine 25 mg/kg daily for eight weeks had no demonstrable ejaculatory function immediately after cessation of treatment. Four weeks later, ejaculatory function had returned in two‐thirds of the males, and after eight weeks, all males were able to deposit sperm in the vagina. However, fertility had returned at that time in only two of the nine males. On the basis of these findings it might be expected that fertility would return in the other males after a more prolonged observation period.
At autopsy, 66 days after cessation of treatment, the vasa deferentia were congested and filled with viscous material, and along their course dilated regions and pseudocysts containing sperm debris and spermatozoa were found.
The isolated ducts of the guanethidine‐treated males showed a markedly increased response to noradrenaline if compared with ducts from control rats. Response to tyramine was similar in both treated and untreated rats. In view of the increased response to noradrenaline it may be concluded that the noradrenaline stores, which are sensitive to tyramine, were still reduced 66 days after guanethidine treatment had been stopped.
Myogenic peristalsis in isolated preparations of chicken oesophagus
Authors: BARTLET A. L. 
Published: July 2012

Summary
Nicotine, 20 μg/ml, briefly and partially blocked the longitudinal contractions of a chick vagus nerve‐oesophagus preparation to nerve stimulation, but potentiated them in the presence of hyoscine, 10 μg/ml.
Strychnine, 20 μg/ml, antagonized the longitudinal contractions of the chick oesophagus to nerve stimulation, though not to acetylcholine or 5‐hydroxytryptamine. Hyoscine, 10 μg/ml, enhanced the nerve‐blocking action of strychnine.
These observations suggest that in the vagus nerve of the chicken, hyoscine either blocks certain types of fibre selectively or interacts with pharmacological receptors for strychnine and nicotine.
Tetrodotoxin, 1 μg/ml, propranolol, 40 μg/ml, cocaine, 200 μg/ml, or strychnine, 100 μg/ml, which render autonomic nerves inexcitable, potentiated the spontaneous movements of isolated preparations of chicken oesophagus at normal intra‐luminal pressure; they also potentiated peristaltic response to increased intra‐luminal pressure.
These observations suggest that the preparations contain intramural nerves that inhibit the musculature.
Peristalsis in the chicken oesophagus was unaffected by nicotine, 20 μg/ml, tubocurarine, 20 μg/ml, hyoscine, 10 μg/ml, phentolamine, 1 μg/ml, propranolol, 0·5 μg/ml, mepyramine, 1 μg/ml, methysergide, 0·1 μg/ml, and morphine, 20 μg/ml. It was produced in preparations of chicken oesophagus after removal of the mucous membrane. Papaverine, 20 μg/ml, inhibited the peristalsis and had a spasmolytic action in the musculature.
These observations suggest that the peristalsis in isolated preparations of chicken oesophagus is dependent solely upon myogenic contractility.
Barbiturate‐induced transmitter release at a frog neuromuscular junction
Authors: THOMSON T. D. , TURKANIS S. A. 
Published: July 2012

Summary
The influence of barbiturates on neuromuscular transmission at end‐plates of frog sartorius muscles was investigated electrophysiologically on preparations bathed in Ringer solution containing a low concentration of calcium and a high concentration of magnesium.
Effects of a convulsant barbiturate, 5‐(2‐cyclohexylideneëthyl)‐5‐ethyl barbituric acid (CHEB), were compared with those of phenobarbitone.
CHEB and phenobarbitone increased the mean quantum content of the end‐plate potentials and decreased the mean amplitude of the miniature end‐plate potentials.
Both barbiturates enhanced the duration of the nerve‐terminal action potential and had little or no effect on the effective resistance of the skeletal muscle membrane.
Characterization of α‐adrenoceptors in the myocardium
Authors: BENFEY B. G. 
Published: July 2012

Summary
In the driven rabbit left atrium α‐adrenoceptors mediate the inotropic effect of phenylephrine and the prolongation of functional refractory period by sympathomimetic amines.
These receptors are highly sensitive to blockade by phentolamine and phenoxybenzamine.
Prolongation of functional refractory period is greater with the secondary amines, phenylephrine, adrenaline and epinine, than with the primary amines, norphenylephrine, noradrenaline and dopamine.
Effect of cocaine on the affinity of α‐adrenoceptors for noradrenaline
Authors: INNES I. R. , MAILHOT R. 
Published: July 2012

Summary
Doses of cocaine which cause specific or unspecific supersensitivity in cat spleen did not alter the blocking effect of phenoxybenzamine on the responses of isolated cat spleen strips to noradrenaline.
The same doses of cocaine did not increase the protection of α‐adrenoceptors given by noradrenaline during a standard exposure to phenoxybenzamine.
It is concluded that cocaine does not change the affinity of the α‐adrenoceptor for noradrenaline, and therefore changes in affinity are not responsible for the potentiating action of cocaine.
The role of the substantia nigra in the locomotor stimulant action of amphetamine
Authors: COSTALL B. , NAYLOR R. J. 
Published: July 2012

Summary
The electrolytic brain lesion technique was used to evaluate the role of the substantia nigra in the mediation of the locomotor stimulant effect of (+)‐amphetamine in the rat The effect upon the results of variations in strain and basal activity levels of the rats was assessed.
In the immediate postoperative phase the lesioned animals developed spontaneous stereotyped behaviour patterns which were more intense in rats of initially high basal activity. Activity was depressed at this stage and only that of the low activity animals was stimulated by amphetamine.
After the 2nd postoperative day rats with lesions of the substantia nigra developed hyperactivity, but this was only maintained in rats initially of low basal activity. During this stage the locomotor stimulant effect of amphetamine (1·0 mg/kg) was apparent and after the 9th postoperative day animals generally displayed an increased sensitivity to the drug effect.
The involvement of the substantia nigra with the control of locomotor activity is indicated but its integrity would not appear essential for the mediation of the locomotor stimulant effects of amphetamine.
Anti‐inflammatory and some other pharmacological effects of 3,4‐trans‐2,2‐dimethyl‐3‐phenyl‐4‐[p‐(β‐pyrrolidinoethoxy)‐phenyl]‐7‐methoxy‐chroman (Centchroman)
Authors: DHAWAN B. N. , SRIMAL R. C. 
Published: July 2012

Summary
Anti‐inflammatory, analgesic, antipyretic and other pharmacological activities of a new chroman derivative, Centchroman, have been described.
Centchroman was found to possess significant anti‐inflammatory action in the carrageenin‐induced oedema test in mice and rats. It inhibited granuloma formation in the cotton pellet test. The anti‐arthritic activity was also evident in formaldehyde‐induced arthritis and adjuvant‐induced arthritis in rats.
Centchroman had a lower ulcerogenic index than phenylbutazone.
The mechanism of the anti‐inflammatory action of Centchroman seemed to be independent of endogenous adrenocortical hormones or of its weak oestrogenic activity.
Centchroman antagonized phenylquinone writhing and bradykinin‐induced bronchospasm but was devoid of any antipyretic activity.
The metabolic effects, and the composition of the tissue lost, in weight reduction by obese patients on treatment with fenfluramine
Authors: DURNIN J. V. G. A. , WOMERSLEY J. 
Published: July 2012

Summary
Three groups of obese patients were treated for periods of up to 6 months. One group of 52 individuals received 80–120 mg fenfluramine daily. The second group of 20 people had placebo tablets. The third group of 28 patients were on a dietary restricted régime.
Only the fenfluramine and dietary treated groups lost weight but there was no evidence of an increased metabolic rate after fenfluramine, either at rest or in standardized exercise. During the first month of treatment the mean weight loss in the group treated with fenfluramine was greater than that in the group treated by diet alone, but the difference was not significant (P<0·05). By the third month of treatment the mean weight loss was smaller in both groups, particularly in the women.
The composition of the tissue lost in the weight reduction had a mean fat content of 75% and did not differ significantly between the fenfluramine group and the diet‐restricted group, except in women.
Localization of the central cardiovascular action of clonidine
Authors: BOUSQUET P. , GUERTZENSTEIN P. G. 
Published: July 2012

Summary
The fall in arterial blood pressure with bradycardia that occurs on injection of clonidine into the cerebral ventricles and into the cisterna magna is attributed to an action on ‘chemosensitive zones’ situated at the ventral surface of the brain stem. This conclusion is based on the following results obtained in cats anaesthetized with pentobarbitone sodium.
The fall in blood pressure no longer occurs on injection of clonidine (10 to 100 μg) into the cerebral ventricles when the passage of clonidine into the subarachnoid space is prevented by cannulation of the aqueduct. In this condition, the injections produce instead a rise in blood pressure.
Applied bilaterally, by means of perspex rings, to the ventral surface of the brain stem, clonidine (10 μl of a 50 to 1,000 μg/ml solution placed in each ring) produces a fall in blood pressure with bradycardia, but only when the perspex rings cover the ‘chemosensitive zones’ from which changes in blood pressure and heart rate are obtained with various drugs.