ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01544.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Summary.1. Responses were evoked in the hippocampal pyramidal and granule cells by stimulation of the dorsal fornix.2. Current flow at different instants after the shock and from different positions within the hippocampal laminae is described.3. Evidence is presented to show that the evoked potential is not propagated in the apical dendrites of the pyramidal cells.4. After repetitive stimulation, or after injury, signs of inward current may be detected in the layer of apical dendrites.5. This inward current is associated in some way with seizure discharges.6. Seizure discharges may propagate by routes which do not correspond to normally conducting pathways.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01545.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Summary.1. In lightly anaesthetized cats and rabbits the threshold temperatures for several temperature regulating reactions,i. e., onset and cessation of shivering and cutaneous vasoconstriction, were repeatedly determined when stimulating the animals in different ways2. It was found that various stimuli, such as nociceptive stimulation, pinna reflex, and electrical stimulation of the midbrain tegmentum which all activated the electroencephalogram and the gamma motor system, tended to raise the temperatures at which both heat‐producing and heat‐dissipating reflexes are brought into action with a rise in body temperature as a consequence.3. Similar shifts of the temperature for thermo‐balance were obtained by systemic infusion of adrenaline and noradrenaline. Changing the composition of the inspired gas was also found to influence thermoregulation.4. Stimuli which inhibited the activity of the gamma motor system and evoked a synchronized cortical activity,e. g.stroking the back of the animal, lowered the threshold temperatures with as light fall in body temperature as a result.5. The results support the view that the body temperature is set at different levels in different states of act

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01546.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Summary.1. The cortical blood flow was recorded in lightly anesthetized or unanesthetized (encéphale isolé) cat preparations in which different EEG effects were elicited by electrical stimulation of the brain stem.2. The regular EEG ‘arousal reaction’ (‘cortical activation’) was followed by a marked increase of the cortical blood flow which was due to a reduction of the cortical vascular resistance (Ingvar1955b, Ingvarand Söderberg1956b).3. From this was distinguished another type of EEG response, the ‘flattening reaction’, characterized by reduction of amplitude with only occasional slow waves, differing significantly from the other by the fact that no cortical vasomotor changes were found to accompany it. Respiratory and systemic circulatory changes, as well as effects upon the muscle tone concomitant to the brain stem stimulation were not related to this response. It also seems unlikely that local vasoconstrictions could explain it. For these reasons it is set off as a specific reaction.4. It was confirmed that ‘sleep spindles’ could be elicited by electrical stimulation of the brain stem. No cortical vasomotor changes could be recorded during such responses. Physiological sleep was not studied.5. A fourth type of response was characterized by generalized high voltage slow waves. It often occurred during systemic circulatory failure and possibly had some relation to a defective cortical circulatory homeostasis and to the development of brain edema,

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01547.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Summary.1. The ATP that is stored in large amounts, together with the sympathomimetic amines, in the specific granules of the adrenal medulla is rapidly broken down to AMP when the granules are ruptured in hypotonic media. This breakdown is brought forth by a true ATP‐ase, removing only the terminal phosphate group of ATP, and by an adenylate kinase.2. There is good evidence that the ATPase activity is localized to the specific granules. The adenylate kinase activity probably belongs to these granules but the evidence is not conclusive.3. The ATPase activity is exclusively localized to the water insoluble residue obtained at lysis of the granules and probably to a main part consisting of granule membranes. This residue also shows an ADP transphosphorylase activity which is not removed by repeated washings and is heat‐stable in acid. A soluble adenylate kinase is released from the granules at lysis in water or in dilute salt solutions. There is no further evidence, however, that there really are two different ADP transphosphorylases in the granules.4. The adenylate kinase activity is activated by Mg++and inhibited by NaF. The ATPase activity is inhibited by p‐chloromercuribenzoate and salyrgan but not by stibophen and it is relatively insensitive to NaF at pH 6 where maximal activity is found. Under other conditions NaF may give appreciable inhibition.5. ATP and ADP seem readily to penetrate to the sites of enzyme activity from the outside of intact granules. No transphosphorylation between the intragranular ATP and AMP penetrating from the outside could be demonstrated, however, and the stored ATP is in some way protected from the ATPase under “resting” conditions. It may thus be that the ATPase and the ADP transphosphorylase are present in an outer zone separated from the ATP stored within an inner part of the granules.6. The intimate connections between the catechol amines and the ATP stored in the granules and a possible role of the ATPase in the amine release are

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01548.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Summary.1. The pH of the urine appears to have no influence upon the tubular excretion of histamine.2. Tm for histamine is shown to be comparatively high.3. The excretion of histamine is not influenced by brom cresol green.4. The excretion of histamine is depressed by priscoline and, at east partly, by cyanine.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01549.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Summary.1. Determinations of total hemoglobin according to Sjöstrand'smodification of the CO method were carried out in three groups of experiments: A. On smokers on consecutive days, when the subjects had stopped smoking before the first test. B. On smokers, with additional O2breathing immediately before the test. C. On non‐smokers with two determinations separated by some 10 minutes. In a part of this group venous blood samples were drawn during the procedure and analyzed for CO.2. It was observed that the effect of smoking upon results of total hemoglobin determinations can be eliminated by a 20 minute period of O2breathing from an open system, and that increased initial COHb, as obtained in repeated determinations, does not substantially influence the results.3. The results are discussed and interpreted with regard to the influence of the distribution of the ventilation/perfusion ratios of the alveo

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01550.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

Summary.1. The effects of variations in heart rate on ventricular function, myocardial oxygen consumption, and coronary blood flow were studied in anesthetized, open‐chest dogs. The heart rate was held at desired rates by electrical stimulation.2. The following changes occurred when the rate was increased in steps from 33—80 per min. to 200—280 per min.: cardiac output increased 0 to 73 per cent and reached a maximum at rates varying from 90 to 180 per min.; above these rates there was usually a decrease. Stroke volume decreased progressively. Mean aortic pressure rose slightly, and the pulse pressure was diminished. Myocardial oxygen consumption and left coronary flow increased, even at the high rates when ventricular work was constant or decreasing; there was a marked fall in coronary resistance.3. Ventricular function curves,i. e.ventricular stroke work plotted against the respective mean atrial pressure, were obtained at the various rates. The curves were always lower at higher than at lower rates.4. Myocardial oxygen consumption per unit of mechanical work was greater at higher rates, probably because of the larger amount of “isometric work” per min. Coronary blood flow per unit of work increased similarly with rate. Coronary vascular resistance was always much lower at high heart rates than at low, indicating coronary vasodilation.5. It is concluded that during normal circumstances myocardial oxygen consumption is a major determinant of coronary blood flow.6. Effects of heart rate during abnormal circulatory conditions were illustrated and

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1958.tb01551.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY