摘要:

AbstractChanges in arterial gas levels in response to constant‐load, dynamic exercise (400 and 700 kpm/min for 6 min) were studied in 8 healthy male subjects by continuous analyses of arterial pH and O2saturation. During pre‐exercise rest, spontaneous time‐variations in these variables occurred in all individuals at half‐minute intervals or longer. These cyclic fluctuations, which were quite marked in some individuals, probably in part explain differences reported as to the magnitude and direction of changes occurring in response to exercise. To eliminate most of such influences on the observed deviations following the onset of exercise, the time‐averages over the preceding 3 min were chosen as reference levels. Both pH and O2saturation, when referred to the blood passing through the left heart, remained essentially constant during the first 20–30 sec following the transitions from rest to exercise and from exercise to rest at both work loads. The arterial [H+] rose to reach a plateau during the 3rd and 4th min (average decrease in pH = 0.022 at 400 kpm/min and 0.036 at 700 kpm/min). Calculated arterial PO2, after a transient drop during early exercise, was increased by about 5 mm Hg during the last 3 min of exercise at both loads. About 30 sec after cessation of work, arterial [H+] fell rapidly towards pre‐exercise level, whereas arterial PO2rose markedly to reach its maximal deviation after about 1.5 min. The shift towards acidosis during exercise was roughly proportional to the relative intensity of work, whereas no such relationship was observed on the part of the concomitant increment in

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02864.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractRed cells labelled with Cr51and albumin labelled with I131were given i. v. to unanesthetized rabbits. Additional doses of I131‐albumin kept the plasma concentration of labelled albumin at a steady value. At different times after the first injection the animals were killed and the eyes dissected. The red cell contents of the choroid, the anterior uvea and the retina were the same at all time intervals, while the apparent volume of the plasma equivalent albumin space in the tissues increased with time. The results were analyzed in terms of intravascular and extravascular albumin compartments having the same concentration of I131‐albumin as plasma. The apparent volumes of the extravascular plasma albumin compartments were: in the choroid 112μl per g tissue, in the anterior uvea 94μl per g tissue and in the retina 4.8μl per g tissue. The apparent turnover rates for the albumin solution in the extravascular albumin compartments were: in the choroid 0.0847μl per min, in the anterior uvea 0.234μl per min and in the retina 0.0075μl per min. It was calculated that the albumin concentration in the tissue fluid of the choroid and in that of the anterior uvea as a whole is more than tenfold the albumin concentration in the aqueous humour and that the albumin drainage with the aqueous humour can account for less than 10 per cent of the albumin drainage fro

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02865.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractSeveral local anesthetic agents have been tested for their ability to counteract adrenaline‐and noradrenaline‐induced contractions of the spirally cut strip of rabbit aorta. The method used includes a calibrated spiral spring arrangement attached to a conventional strain gauge transducer. This device which is very useful also for several other isolated organs, is described in detail. All the local anesthetics tested possess anti‐adrenaline activity in appropropiate concentrations (1–3 mM), but procaine, mepivacaine and o‐methyl‐α‐propylamino‐propionanilide (L 67) are about 5 times more active than lidocaine and cocaine in this respect. The antagonism is non‐specific in nature and contractions induced by histamine are counteracted in a similar manner. The results are discussed in relation to the known anesthetic properties of the agents. The conclusion is drawn that the non‐specific anti‐adrenaline action varies independently of the local anesthetic effect as measuredin vitroon the isol

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02866.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractNoradrenaline levels in skeletal muscle extracts purified by cation exchange chromatography were analyzed fluorimetrically by the THI procedure. The average amount of nor‐adrenaline found in muscles from different species varied between 0.031 and 0.119μg/g. Adrenaline was found only in minute amounts, never constituting more than 11% of the sum of noradrenaline and adrenaline. In the cat, a constant relation was found between the noradrenaline values in different muscles. Preganglionic sympathetic denervation caused a slight increase in muscle noradrenaline during the first days. Noradrenaline levels in the muscles tended to rise during the first two days after postganglionic sympathetic denervation, only to decline abruptly after about 48 hours. Forteen days after postganglionic denervation the muscles were practically devoid of noradrenaline, indicating that skeletal muscle noradrenaline is stored almost exclusively in postganglionic sympathetic nerv

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02867.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractVagal denervation of the HCl glands by transforming Pavlov pouches into Heidenhain pouches markedly reduced the submaximal acid secretory response to exogenous gastrin in four fasting dogs but reduced the submaximal acid secretory response to histamine in only one of four dogs, three dogs being common to the gastrin and histamine studies. The results suggest that a continuous vagal discharge on the HCl glands is necessary to maintain the sensitivity of the glands to gastrin. An interpretation is presented for the different effects of vagal denervation on the sensitivity of the HCl glands to gastrin and histamine.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02868.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractDaily intramuscular injections of reserpine for 3 days or more elevate basal gastric secretion of acid and increase the acid secretory responses of nonanesthetized gastric fistula cats to intravenous histamine and gastrin. The possibility that the gastric hypersecretion of the reserpine treated cats might be due to the reduction or loss of adrenergic nerve influences on the stomach was investigated. Neither preganglionic nor pre‐and postganglionic sympathetic denervation of the stomach altered basal acid secretion. Nor did such denervations alter gastric secretory responses to histamine and gastrin except in one of three cats, in which the responses to histamine increased after pre‐and postganglionic denervation. Reserpine treatment produced hypersecretion to the same degree in sympathectomized as in ordinary gastric fistula cats. Daily subcutaneous injections of guanethidine produced no reserpine‐like effects on gastric acid secretion. The results indicate that the adrenergic nerves innervating the stomach normally exert no direct influences on basal acid secretion or on the excitability of the parietal cells to the secretory stimuli used and it was concluded that the hypersecretion of reserpine treated cats is not directly due to the reduced or abolished influences of the adrenergic nerves on the st

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02869.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractObservations were made on the circulatory effects of an occlusion cuff applied distally to a forearm segmental plethysmograph. Measurements of the forearm blood flow (plethysmographically and with thermal conductivity recorders) and the pressure in the brachial artery, were performed. The plethysmographic registration of blood flow (arterial inflow) in a forearm segment necessitates a temporary blockade of the more peripheral venous return. The commonly used arterial occlusion was shown to be only partially adequate; besides other disadvantages, it was regularly accompanied during the first 1–2 min by a gradual increase of the blood flow in forearm muscle and skin, and there was also an immediate rise of the local arterial blood pressure. The distal occlusion cuff had to be kept in a constant position as a displacement in the distal direction of only 1–2 cm frequently gave rise to a considerable increase of the plethysmographically measured blood flow values, especially when the forearm or hand circulation was high. A cuff position directly distal to the plethysmograph should be avoided as it causes proximal tissue displacement and probably vessel compression. Every mode of application of the distal occlusion cuff is a compromise between different disadvantages. For venous occlusion plethysmography this means that it is impossible to measure accurately the true blood flow (arterial inflow) in limb segments. On forearm the optimal results were frequently obtained with the cuff 1–2 cm distal to the plethysmograph, and with simultaneous inflation of the distal occlusion and proximal collecting cuff to the same venous occlusion pressure (i. e. about 50–80 mm Hg under normal cond

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02870.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThrough measurements of the uptake and the excretion of radioactive calcium, Ca47, in normal and rachitic rats it is shown that the reduced retention of Ca47in the rachitic rats corresponds to an increased excretion in the urine due mainly to a higher specific activity in the blood. In previously rachitic rats treated with vitamin D almost normal values for retention and excretion as well as for the specific activity in the blood are obtained.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02871.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractThe incorporation of radioactive diisopropyl phosphorofluoridate (DF32P) in the subcellular fractions of rat liver cells has been studied when injected alone or followed or preceded by pyridine‐2‐aldoxime methane sulphonate (P28), N,N'‐trimethylene‐bis‐(pyridinium‐4‐aldoxime) (TMB‐4) and atropine. In experiments with only DF32P the total labelled phosphorus (32P) incorporated in the liver as well as the amounts taken up in the microsomal and mitochondrial fractions attain a maximum value in 20 min, but there is a considerable readjustment of32P between the nuclear and supernatant fractions even at 60 min. The oximes administered prophylactically or therapeutically affect both the rate of uptake of DF32P and the quantity incorporated. The effects are explained on the basis of the rate of penetration of DF32P in the cell and possible direct action of the oximes. Atropine has a high retarding effect on the uptake of DF32P in the liver, the total quantity incorporated being reduced to 5–10% of the control in

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02872.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY

摘要:

AbstractDuring uninterrupted work on the bicycle ergometer the blood flow to the legs was suddenly interrupted by means of blood pressure cuffs. In the period with blocked circulation CO2was added to the inspired air in such amounts that the alveolar PCO2was maintained constant. The excess work O2‐uptake decreased up to 50%. The pulmonary ventilation, the pulse rate and the systolic blood pressure showed a steady and considerable increase. The cardiac output remained nearly constant with a tendency to decrease during the blocking period. The (a—v̄)O2‐difference and the mixed venous PCO2consequently decreased considerably. These changes in respiratory and circulatory functions were well reproducible and the scattering of the values only small. It was concluded that the observed changes are neurogenic and caused by the increasing anaerobiosis in the blocked muscles. The nervous impulses involved may be elicited from muscle chemoreceptors, or they may stem from mechanoreceptors being activated through an observed recruitment of new motor units necessitated by the anaero

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1964.tb02873.x

出版商:Blackwell Publishing Ltd    

年代:1964

数据来源: WILEY