bluuebunny/crossref_metadata_2025_split huggingface dataset:
HISTOCHEMICAL DEMONSTRATION OF TRYPTAMINE. PROPERTIES OF THE FORMALDEHYDE‐INDUCED FLUOROPHORES OF TRYPTAMINE AND RELATED INDOLE COMPOUNDS IN MODELS
Authors: BJÖRKLUND ANDERS , FALCK BENGT , HÅKANSON ROLF 
Published: December 2008

SummaryA sensitive histochemical fluorescence procedure for the demonstration of tryptamine by a formaldehyde condensation reaction has been devised. This gives a 13–18 fold increase in the fluorescence yield of tryptamine compared with the conventional Falck‐Hillarp method. The conditions of the conventional formaldehyde condensation reaction were modified in the following two ways:1. A gaseous oxidant (ozone) was introduced into the reaction vessel. Up to a certain concentration of ozone, the yield of the formaldehyde‐induced tryptamine fluorescence was markedly increased, probably because of an increased oxidative dehydrogenation of the initial condensation product. None of the other compounds tested showed such an increase in the fluorescence yield upon the combined formaldehyde‐ozone procedure. In fact, the fluorescence yields of catecholamines and 5‐HT were reduced to about 20 % compared with the yields in the conventional formaldehyde treatment. This decrease in the fluorescence intensity was presumably caused by an oxidative break‐down of the amines or of their fluorophores.2. The amine models were acidified by means of HC1‐vapour or glacial acetic acid after the conventional formaldehyde treatment, causing a marked increase in the fluorescence yield of tryptamine.The microspectrofluorimetric characteristics of the fluorophores of different indole compounds (tryptamine, N‐methyl tryptamine, 5‐HT, and tryptophan) where studied at various pH both after conventional formaldehyde treatment and after combined formaldehyde‐ozone treatment. The behaviour of the tryptamine fluorophore under various conditions was characteristic and differed from that of the other indoles and catechols tested, which makes possible the microspectrofluorimetric identification of tissue tryptamine.The combined formaldehyde‐ozone reaction and the acidification after the formaldehyde reaction have been successfully applied to tissues incubated with tryptamine, and they provide sensitive and almost selective methods for the detection of tryptamine at the cellular level.
Stimulation of Gastric Acid Secretion by Irrigation of the Antrum with Some Aliphatic Alcohols1
Authors: Elwin Carl‐Eric 
Published: December 2008

AbstractEthyl alcohol is known to stimulate gastric acid secretion in fundic pouch dogs during irrigation of the antrum. A comparison was made with regard to such an effect of a series of aliphatic alcohols including methyl, ethyl, n‐propyl, isopropyl, n‐butyl, isobutyl, sec‐butyl and tert‐butyl alcohol. Dogs provided with a Heidenhain or a Pavlov pouch and isolated, innervated antral pouch were used. The only alcohol besides ethanol that showed a potent stimulatory effect was n‐propyl alcohol. All other alcohols tested had an effect less than half of that of ethanol. A change from one stimulatory alcohol to the corresponding isocompound caused a marked decrease of the effect. Isopropyl alcohol, one of the “non‐stimulatory” aliphatic alcohols, did neither show a synergistic nor an inhibitory action on the effect of ethyl alcohol or n‐propyl alcohol during simultaneous administration, indicating almost no interference with gastrin release mechanisms. n‐Propyl alcohol together with ethyl alcohol showed a dose‐response related action. Methyl alcohol was almost inactive. The results indicate that the stimulatory effect of alcohols could not be related to water or fat solubility but to the molecular configuration.
The Effect of Nerve Stimulation on Catecholamines Taken up in Adrenergic Nerves after Reserpine Pretreatment
Authors: Häggendal Jan , Malmfors Torbjörn 
Published: December 2008

AbstractThe effect of sympathetic nerve stimulation on the catecholamines (noradrenaline and dopamine) taken up and accumulated after i.v. administration was studied in the adrenergic nerves of rat iris with the fluorescence method and in the salivary glands with biochemical estimations after treatment with reserpine and a monoamine oxidase inhibitor. After administration of noradrenaline (0.1 mg/kg) the stimulation did neither cause a functional response in form of increased pupil diameter or bulb protrusion on the stimulation side, nor any decrease in the amount of noradrenaline accumulated in the examined organs on the same side. However, after administration of dopamine (1.0 mg/kg) there were clearcut functional responses on the stimulated side and a marked decrease of the levels of noradrenaline formed from dopamine. These results imply that exogenous noradrenaline cannot enter the proper sites for release by nerve impulses, 16 hrs after reserpine treatment, but that noradrenaline formed from exogenous dopamine in the doses used and after inhibition of monoamine oxidase can be released by nerve impulses in spite of reserpine pretreatment.
Relation of Afferent Nerve Excitability to Impulse Generation in the Frog Spindle
Authors: Ottoson D. , Shepherd G. M. 
Published: December 2008

AbstractThe excitability properties of the sensory nerve and its finer branches in muscle spindle have been studied in isolated preparations using electrical stimulation of the nerve in conjunction with controlled extension of the spindle. Characteristic differences in recovery cycle were demonstrated between the trunk fibre and the intracapsular branches. The excitability of the afferent nerve was modified by stretch; during stretching there was a rise in excitability and a shortening of the recovery cycle in direct relation to the amount of stretch. These changes were related to the underlying receptor potential and to local currents in the nerve. In the aftermath of stretch the excitability of the nerve as tested with electrical shocks was raised This was in contrast to the depression in mechanical sensitivity as revealed by a test stretch. When an extra impulse was elicited by an electrical shock in the course of sustained stretch the succeeding spike train was shifted, its general pattern being unchanged. It appears that the interjected spike transiently wipes out the currents leading up to the generation of the succeeding spike and resets the impulse generating process. Considerations of the functional properties of the afferent fibre and its branches as found in the present study suggest that the sensory system of the muscle spindle acts in synchrony during stretch.
The Sympathetic Innervation of the Oviduct in the Rat
Authors: Brundin J. , Fredricsson B. , Norberg K.‐A. , Swedin G. 
Published: December 2008

AbstractThe adrenergic innervation of the rat oviduct was studied by fluorescence microscopy. The outer half of the circular muscle layer was penetrated by a thin net of adrenergic nerve terminals throughout the isthmus. Adrenergic nerve terminals were scarcely seen in the muscular wall of the ampulla. In the mesotubarium close to the oviduct a dense net of adrenergic nerve terminals were observed. The functional role of the observations is discussed.
Effects of Reserpine on the Noradrenaline Content of Atrophied Rat Salivary Glands
Authors: Jonason Jan 
Published: December 2008

AbstractThe noradrenaline content was determined in intact and atrophied rat salivary glands at different time intervals after reserpine treatment, both with and without previous monoamine oxidase inhibition. After reserpine administration there was no significant difference between the two glands in the rate of noradrenaline disappearance. The loss of noradrenaline was somewhat accelerated in rats given dry wheat starch (a procedure which has been shown to increase the impulse flow of the adrenergic nerves to the salivary glands), showing that the impulse flow in the adrenergic nerves influences the noradrenaline reduction. After monoamine oxidase inhibition reserpine produced a much slower noradrenaline reduction rate. After this treatment a slower decrease was observed in the atrophied glands than in the intact ones. The data in this study indicate that most of the noradrenaline after reserpine treatment is metabolized by means of intraneuronally localized monoamine oxidase.
Afferent and Efferent Influences on the Activity Pattern of Single Olfactory Neurons
Authors: Døving Kjell B. , Hyvärinen Juhani 
Published: December 2008

AbstractSingle‐unit activity was recorded from secondary olfactory neurons in the burbot (Lota lotaL.) with either microelectrodes from the cell soma in the bulb or from single fibers in the olfactory tract. Stimulation of the olfactory epithelium on the contra‐ or ipsilateral side was made with glutamic acid, morpholin, and taurin, with both the efferent system intact and with the efferent activity to the bulb blocked by cutting or cooling the olfactory tract. Statistical time‐series analyses of the impulse sequences were performed in all experimental conditions. The interval histograms obtained were highly skewed. The histograms of the fiber recordings were often bimodal, whereas in the microelectrode recordings several exponential histograms were found. The intensity functions in two‐thirds of the fiber recordings showed rhythmical time dependent oscillations in the firing probability. These oscillations seemed to be of peripheral origin. The activity from the microelectrode recordings usually revealed renewal processes. Comparisons of the different experimental conditions showed a great variety of influences of peripheral stimuli and efferent activity on the activity patterns of the secondary neurons. Most frequently the differences between different experimental conditions of one cell were smaller than the differences between cells. Therefore, it does not seem likely that differences in external conditions would be coded as variations in the time structure of the impulse sequence.
Studies on the Effect of Adrenergic Blocking Drugs on Catecholamine‐Induced Platelet Aggregation and Uptake of Noradrenaline and 5‐Hydroxytryptamine
Authors: Bygdeman S. , Johnsen Ø. 
Published: December 2008

AbstractAdrenaline (A) and noradrenaline (NA) were both found to induce platelet aggregation in citrated platelet rich human plasma, adrenaline being about 8 times more effective than noradrenaline. No effect was obtained with isoproterenol. The aggregating effect of catecholamines was stereospecific, the l‐form of NA being 30 times as effective as the d‐form. Platelet aggregation induced by A and NA could be blocked by phentolamine, phenoxybenzamine and dibenamine in the concentrations 10‐6M, 10‐4M and 10‐4M respectively, as well as with some β‐receptor blocking agents, pronethalol and propranolol, although only in a 10‐3M concentration. Almost no effect was observed with MJ 1999. High concentrations (10‐3M) of both α‐ and (β‐receptor blocking agents could block adenosine disphosphate induced aggregation indicating an unspecific effect of the blockers at this concentration. Uptake of3H‐NA and14C‐5‐HT in the platelets was inhibited by both α‐ and β‐receptor blocking agents in concentrations from about 10‐5M. There was no obvious correlation between inhibition of uptake by α‐receptor blocking agents and their effect on catecholamine‐induced aggregation indicating that uptake of A or NA was not a necessary step in catecholamine mediated platelet aggregation.
Increased Vascular Permeability Caused by the Trypsin‐like Enzymes Purified from Rat Submandibular Gland
Authors: Ekfors T. O. , Hopus‐Havu V. K. , Malmiharju T. 
Published: December 2008

AbstractThe vascular permeability increasing effect of several trypsin‐like enzymes purified from the rat submandibular gland was studied. The size of the lesion caused by an intradermal injection of small amounts of the enzymes in blued rabbits was used as the measure of the permeability increasing effect. Salivain and four isozymic forms of a kallikrein‐like peptidase caused a very marked increase in the vascular permeability. A clearly weaker response was obtained with glandulain and Depot‐Padutin®, and a very weak response with trypsin. These lesions as well as that caused by bradykinin could not be prevented by prometazine, as was the lesion caused by histamine. The response to the enzymes was lowered to about one half by prior injections of phenylbutazone. It was concluded that the enzymes effect the vascular permeability by liberating vasoactive kinins.
Circulatory and Respiratory Effects of Different Doses of Prostaglandin E1in Man
Authors: Carlson Lars A. , Ekelund Lars‐Göran , Orö Lars 
Published: December 2008

AbstractProstaglandin E1(PGE1) was infused i.v. into 8 healthy male subjects in doses from 0.032 to 0.58 μg/kg/min. With doses from 0.058 to 0.10 μg/kg/min a hyperkinetic circulation was induced, characterized by an increase in heart rate and stroke volume, decrease in peripheral resistance, and a decrease in AVO2difference and simultaneously a less pronounced increase in O2uptake. At the higher dose levels there was a further increase in heart rate and decrease in brachial artery pressure. The stroke volume decreased but the cardiac output remained above resting levels. The high doses also produced an alveolar hyperventilation, a further increase in O2consumption and in three cases a respiratory alkalosis.
Hypothalamic Control of Adrenergic Outflow to the Stomach in the Cat
Authors: Jansson G. , Lisander B. , Martinson J. 
Published: December 2008

AbstractExperiments were performed on chloralosed, adrenalectomized cats with recording of gastric volume, blood pressure and skeletal muscle blood flow. The vagal nerves were cut, but the vagal excitatory fibres to the stomach could be activated by electric stimulation. Topical stimulation of the hypothalamic defence area, or surrounding “pressor” areas, produced not only the characteristic known circulatory responses, but also a prompt and often complete inhibition of a vagally induced increase of gastric motility.‐But when the stomach was not under the influence of continuous vagal excitatory activity, corresponding stimulation of the hypothalamus rarely had any effect on gastric volume, and then only an insignificant and sluggish increase despite considerable “myogenic” tone of the stomach. Stimulation of the adjacent hypothalamic sympatho‐inhibitory area, on the other hand, augmented the vagally induced gastric motility and thereby suggested the presence of a centrally induced suppression of a prevailing sympathetic inhibitory influence on the stomach.‐All the above mentioned effects on gastric volume, produced by central nervous stimulation, could be blocked by guanethidine in these vagotomized cats. It is concluded that the hypothalamus contains neural mechanisms, which can affect stomach motility by changing in both directions the impulse frequency in the inhibitory adrenergic outflow to this organ. Simultaneous activity of vagal excitatory fibres to the stomach was found to be a prerequisite for reducing significantly gastric motility and tone when the adrenergic fibres were excited. This is compatible with the hypothesis that the adrenergic fibres exert their inhibitory effect mainly, or only, by acting on the parasympathetic ganglionic cells, which mediate the vagal excitatory influence to the gastric smooth muscles.
The Effects of L‐Triiodothyronine on the Self‐Selected Circadian Rhythm of Rest and Activity in the Canary
Authors: Wahlström Göran 
Published: December 2008

AbstractCanaries were used as experimental animals. The birds were kept singly. Each cage was separately illuminated. The light could be extinguished by the bird if it used one perch in the cage. As darkness corresponds to rest in adapted birds the self‐selected circadian rhythm of rest and activity could be recorded. The waking‐up times were used as the starting point of the circadian period. L‐triiodothyronine (T3) was given as a single dose at different times during the activity. Oral doses up to 10 mg/kg given early in the activity did not influence the length of the circadian period. There was an uncertain increase in activity. Similar doses given late in the activity increased the length of the circadian period. The duration of activity was increased and the rest was decreased. The changes were maximal in the period after the one in which T3 was given and gradually disappeared during approximately a week. The effects on the circadian period seemed to be related to the amount of T3 given, in the dose interval used (1–10 mg/kg). The increase in activity was less influenced by the amount of T3. Parenteral administration of 1 mg/kg T3 late in the activity caused changes corresponding to those induced by 6–8 mg/kg orally. The magnitude of the maximal increase in duration of circadian period and activity was independent of the pre‐experimental value. Thyrotropic hormone (1–2 IU) in a few birds caused a small increase in the duration of the circadian period in which it was given.
The Evolution of Vascular Smooth Muscle Responses to Histamine and 5‐Hydroxytryptamine
Authors: Reite Ola Bodvar 
Published: December 2008

AbstractIn an attempt to trace the phylogenetical origin of stimulatory (constrictive) and inhibitory (dilatatory) actions of histamine and 5‐hydroxytryptamine on mammalian vascular smooth muscle, the vascular responses to these drugs were studied in jawless vertebrates and fish. Effects were recorded as blood pressure changes in dorsal and ventral aorta after intravascular administration of drugs, and as resistance changes in artificially perfused branchial and systemic blood vessels after administration into the perfusion circuit. The reliability of experimental procedure and recording technique was tested by observing the presence of responses to adrenaline, noradrenaline or acetylcholine. Pharmacological blocking agents were used to dissociate between specific and unspecific actions. In jawless vertebrates, the vascular effects of histamine and 5‐hydroxytryptamine seemed to reflect unspecific actions on adrenergic receptor mechanisms. The effects in cartilaginous fish were slight. Characteristic effects, produced by specific stimulatory actions on vascular smooth muscle, appeared in higher bony fish. Inhibitory actions were not revealed in any species. By comparing the results obtained in intact animals with those from perfused preparations, it may be concluded that stimulatory actions of 5‐hydroxytryptamine appear as a constrictor response in the branchial blood vessels of teleosts, while the stimulatory actions of both histamine and 5‐hydroxytryptamine are fully developed and produce vasoconstriction in all studied sections of the vascular system in lungfish.
Influence of Chloride Ions and ATP‐Mg++ on the Release of Catecholamines from Isolated Adrenal Medullary Granules
Authors: Lishajko F. 
Published: December 2008

Carlsson et al. (1963) and Kirshner (1962) have shown that ATP‐Mg stimulates uptake of amines in isolated adrenal medullary granules. This finding has been confirmed (Lishajko 1968) and in addition it was shown that ATP‐Mg inhibits the “spontaneous” release of amines when phosphate buffer was used as medium. On the other hand Oka et al. (1966), Poisner and Trifaro (1967) have reported that ATP‐Mg in certain incubation media increases the release rate of catecholamines in isolated chromaffin granules.In the present communication it will be shown that the releasing effect of ATP‐Mg is dependent on the presence of chloride ions in the medium.
The Action of Tetrodotoxin on the Frog's Isolated Muscle Spindle
Authors: Albuquerque E. X. , Chung S. H. , Ottoson D. 
Published: December 2008

AbstractTetrodotoxin in concentrations of 0.8–1.0 × 10‐7g/ml completely blocked conducted activity of the afferent nerve of isolated frog muscle spindle without affecting the receptor potential. Development of block was characterized by an increase in threshold of the nerve, a gradual delay of the onset of the impulse response and a reduction and decomposition of the individual action potentials into smaller spikes. The spike decomposition appeared to be due to a de‐synchronization of the conducted activity in the branched afferent terminals. After block by tetrodotoxin for up to 20 min the normal response could be restored by washing the preparation with Ringer's solution. The blocking action of tetrodotoxin was delayed and reduced by increasing calcium; removal of calcium had the opposite effect. Tetrodotoxin (1000 ng/ml) had no significant effect on the receptor potential. With low sodium plus tetrodotoxin the receptor potential was reduced by about 50 %; this reduction was reversed by addition of normal sodium. It is suggested that the sodium carrying system of the generator potential differs from that underlying the regenerative activity.
Ion Movements in Red Cells Treated with Propranolol
Authors: Ekman Aarne , Manninen Vesa , Salminen Simo 
Published: December 2008

AbstractAddition of propranolol to a suspension of human red cells was found to cause outflow of K+ ions and, to a lesser degree, inflow of Na+ ions, until a new stationary state was reached in which their cell/medium concentration ratios did not deviate much from unity. The cell volume decreased. Lactic acid production increased slightly. Against the outflow of bulk K+ ions, tracer K+ and Rb+ ions accumulated very rapidly in the cells and then began to flow out. The ratio of inward to outward rate constant of K+ tracer immediately decreased, while that of Na+ tracer increased, transiently exceeding the medium/cell concentration ratio of Br‐ tracer, in which no abrupt change occurred. In the propranolol‐induced stationary state the cationic tracer rate constants were higher than in the untreated cell, but not so high as just after addition of propranolol. Their order was K.+ > Rb+ > Cs+ > Li+ > Na+. It is suggested that an accelerated “carrier”‐mediated exchange diffusion of cations across the cell membrane, driven by the flow of bulk ions down their gradients, would explain the rapid tracer ion movements.
The Refractory Time in the Visual Cortex of Albino Guinea‐Pigs1
Authors: Simonsen Svend E. 
Published: December 2008

AbstractThe absolutely refractory time of the summed cortical response, tested with paired supramaximal stimuli to the contralateral optic nerve of chloralose‐anesthetized guinea‐pigs, was 86±3 msec. The absolutely unresponsive time tested with paired white flashes to the contralateral eye was 96±6 msec. The difference was thought to be due to the fact that the flashes were not quite supramaximal; in one experiment the absolutely irresponsive time was reached by increasing the intensity of the light and then the recovery time was the same whether the paired stimuli were shocks to the optic nerve or flashes. The colored flashes used –Λmax 450 mμ, 510 mμ and 590 mμ‐evoked responses of equal size and latency and with the same unresponsive time, 125 msec±3 msec. A late response to flashes was variable; when it was large, it could engulf the primary response to the testing flash and make the determination of the unresponsive time impossible.