摘要:

AbstractOmental adipose tissue from twelwe fasted dogs of both sexes was incubated in vitro and the glycerol release determined as a measure of lipolysis. The effect of addition of noradrenaline, prostaglandin E1(PGE1) and nicotinic acid into the medium was studied. On basal lipolysis the following effects were obtained with PGE.,0.1 μgPGE Inhibition 4 dogs, no effect 6 dogs. 1 μg PGE1:Inhibition 1 dog, no effect 5 dogs, stimulation 6 dogs,10 pg PGE1: Inhibition 1 dog, no effect 3 dogs, stimulation 8 dogs. A dualistic action of PGE1was seen in some of the dogs. PGE1, 1 μg, inhibited lipolysis stimulated by noradrenaline only in those dogs where the same amount of PGE1either inhibited or did not modify basal lipolysis. In those dogs where 1 μg of PGE1stimulated basal lipolysis, this dose did not inhibit the stimulation caused by noradrenaline. The β‐adrenergic blocker Kö 592 inhibited the stimulation of lipolysis caused by PGE, only slightly while Kö 592 completely inhibited the stimulation elicited by noradrenaline.Nicotinic acid inhibited the basal lipolysis in five of ten dogs and the stimulation induced by noradrenaline in three of ten. In those dogs where nicotinic acid inhibited lipolysis PGE1was in general also in

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04714.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractACTH, 50, 10, 2 and 0.5 IU/kg b.w. and noradrenaline, 1.0 μg/kg/min were given i.v. to fed, unanesthetized rabbits either pretreated with nicotinic acid or not.Both ACTH and noradrenaline increased arterial concentration of free fatty acids (FFA). For noradrenaline this effect was present only in rabbits with lower body weight and furthermore the effect was less pronounced and of shorter duration than for ACTH.Nicotinic acid inhibited partly the increase of plasma FFA caused by 0.5 IU of ACTH but not that after the higher doses. Nicotinic acid had sometimes but not always an inhibitory effect on the increase caused by noradrenaline while nicotinic acid by itself did not change the basal levels of plasma FFA

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04715.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractIn order to study effects of increased cerebrospinal fluid pressure upon brain tissue concentrations of bicarbonate, lactate, pyruvate, ATP, ADP, AMP and phosphocreatine, the metabolites were measured in cortical tissue of 37 dogs frozen in situ during and after a 15 min decrease of the cerebral perfusion pressure to 30–35 mm Hg, induced by connecting the cisterna magna to a reservoir with artificial CSF. The intracranial hypertension was found to give a variable but marked increase in tissue lactate and pyruvate, and in the lactate/pyruvate ratio, as well as a corresponding decrease in the bicarbonate concentration. Marked decreases in the ATP and phosphocreatine concentrations were also seen. Resting values for these metabolites were not approached until 30–90 min after restitution of normal perfusion pressure. Since the changes in ATP and phosphocreatine corresponded in time to the changes in the lactate, pyruvate and bicarbonate concentrations it is concluded that the decrease in the cerebral perfusion pressure gave rise to a longlasting disturbance of the oxidative metabolism, possible due to reversible structural tissue damage. Cerebral blood flow measured in 10 of the dogs showed varying decreases of cerebral blood flow during the intracranial hypertension period. Usually, hyperemia of 30–90 min duration followed when the CSF pressure was released. The hyperemia and the metabolic changes were of approximately the same dur

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04716.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractAn approach of analyzing the initial phase of the active state in single skeletal muscle fibres of the frog has been designed. The fibre was stimulated to generate a series of four incompletely fused isometric twitches with the object of producing distinct peaks and throughs in the myo‐gram. The peaks and troughs of the records both represent the tension output when the contractile unit was stationary. The tension recorded at these instances therefore provided an adequate measure of the intensity of the active state at respective times after the stimulus. By releasing the fibre at different moments during the third cycle it was possible to define 1. the decay phase of the active state in the third cycle and 2. a substantial portion of the rising phase of the active state in the fourth cycle. It was found that the active state underwent a very rapid increase starting at 12 msec after the stimulus (at 1–2° C). Only 3–4 msec were required for the active state to rise from 25 to 65 per cent of its peak value. The rate of rise of the active state was independent of the sarcomere length (between 2.8 μ and 2.0 μ) and of the degree of activity existing in the fibre when the fourth stimulus was applied. The implications of the results with respect to the kinetics of the calcium‐activator mechanism in the excitation‐contraction coupling a

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04717.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe submandibular salivary gland in cats has been perfused undcr conditions of constant volume inflow with red blood cells suspended in normal cat plasma. Such a method is favourable for studying the time course of changes in glandular vascular resistance. A 30 sec supra‐maximal stimulation of the chordo‐lingual nerve caused the vascular resistance to fall markedly within 1–6 sec. When the nerve stimulation was finished, a further decrease in perfusion pressure was usually observcd, whereafter a slow increase in vascular resistance took place.The rapidity with which the vascular response occurred indicates an initial direct action of true vasodilator nerve fibres.The second phase of the vasodilatation, outlasting the chorda stimulation itself, is claimed to be mediated by kinin formation in the activated gland:a) When the gland was perfused with normal cat plasma, so that resting perfusion pressure was low (under 55 mm Hg), then the vasodilator response to chorda stimulation changed, developing gradually and outlasting the nerve stimulation.b) Reduction of kininogen 2 in the plasma perfusate resulted then in a reduced vasodilator response to chorda stimulation.c) With no kininogen 2 in the cell‐free perfusate, stimulation of the chordo‐lingual nerve caused only a very small vasodilatation or no vasodilatation at all.d) Addition of partly purified kininogen 2 to such perfusate did then restore the chorda‐induced vas

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04718.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe vasodilatation caused by stimulation of the chordo‐lingual nerve has been studied in the cat submandibular salivary gland perfused under conditions of constant volume inflow, at a rate equal to the flow existing in the resting organ.When a perfusate of red cells suspended in normal plasma was used at perfusion pressures of 55–120 mm Hg, a typical two‐phasic and long‐lasting vasodilatation was observed as a response to nerve stimulation. This vasodilator pattern was maintained when repeated nerve stimulations were carried out during a single perfusion period. Wlien the gland was perfused continuously with red cells suspended in a kininogen‐free solution then one of two different response patterns could be seen, When a low perfusion pressure prevailed (below 55 mm Hg), then the chorda‐mediated vasodilatation was reduced or abolished on repeated nerve stimulation. At conditions with a higher perfusion pressure (60–120 mm Hg) there developed on chorda stimulation a one‐phasic, short‐lasting vasodilatation, which was not reduced on repeated stimulations.In another series of experiments the kinin‐destroying activity of a perfusate of red cells in normal plasma was increased by addition of carboxypeptidase‐B. Chorda stimulation then caused a short‐lasting vasodilatation of the type seen when a red cell perfusate containing no kininogen was used.It is concluded from these findings that functional vasodilatation in the submandibular salivary gland is probably initiated by the effect of vasodilator nerve fibres and supported and maintained by the action of kinins formed

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04719.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe present study deals with the effect of different pharmacological agents on the secretory and vasodilator responses caused by stimulation of the chordo‐lingual nerve in cat submandibular salivary glands perfused under conditions of constant volume inflow.When the gland was perfused with red cellsiuspended in normal cat plasma or in kininogen‐free solutions, the vasodilator and secretory responses raused by stimulation of the chordo‐lingual nerve were mimicked by close arterial injections of acetylcholine. Atropine injected intravenously in doses of 0.5–1 mg/kg did not affect the chorda‐induced vasodilatation while salivary secretion was blocked. Increasing doses of atropine caused a successive reduction in the chorda‐mediated vasodilatation.Close arterial injections of isoprenaline caused vasodilatation, but no secretion of saliva. Propranolol in doses of 10–200 μg infused into the gland, abolished the effect of injected isoprenaline, but caused a small reduction of the chorda‐mediated vasodilatation. The combined action of propranolol and atropine depressed the long‐lasting vasodilator phase of chorda stimulation while the initial decrease in perfusion pressure was not affected.The findings suggest that the chordo‐lingual fibres to this gland all are cholinergic and that the nerve‐effector transmissions vary in their atropine sensitivity. The neuroglandular synapse responsible for secretion of watery saliva is easily blocked by atropine. The neuro‐vascular transmission and the neuro‐glandular connection responsible for release of kallikrein, are both rel

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04720.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractThe development of the collagenous tissue in the myocardium was studied in rats aged one day to 18 months. During the first three weeks a rapid exponential increase of both the heart weight and the total amount of myocardial hydroxyproline occurred, although the concentration of total and insoluble hydroxyproline as estimated per mg of dry tissue showed no significant change. Thereafter the growth rates of the heart weight and total and insoluble hydroxyproline fell with increasing age. The growth rate of total hydroxyproline fell more slowly, however, and a slight increase in the content of total and insoluble hydroxyproline per dry tissue was noted with increasing age. The proportion of neutral salt‐soluble collagen hydroxyproline in the myocardium dropped from an initial value of 30 per cent of the total hydroxyproline in newborn rats to 10 per cent at the age of three weeks. After this the proportion of soluble hydroxyproline remained almost unchanged. At the same time the proportion of free hydroxyproline dropped from 25 per cent of the total hydroxyproline in newborn rats to 1.3 per cent at the age of 6 months. The results seem to suggest that during the postnatal period insoluble mature collagen develops rapidly, and therefore with increasing age constitutes a slowly rising proportion of the myocardial collagenous framework. This seems to be a response to the functional demand on the growing heart for increased tensile strengt

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04721.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractNo change in the myocardial mucopolysaccharide (MPS) content, measured as uronic acid of alkali‐extracted tissue or hexosamine in papain‐digests of fresh tissue, was observed in rats from the age of 7 days to 18 months. When MPS from papain‐digested myocardial and aortic tissue was separated by electrophoresis on cellulose acetate, three Akian blue‐positive fractions were demonstrated. Identification of the fractions was attempted on the basis of their electrophoretic mobility, their response to testicular hyaluronidase and autoradiography of35S‐containing fractions. The slowest fraction (fraction 1) was designated hyaluronic acid (HA), fraction 2 was thought to be identical with heparitin sulphate (HS) and fraction 3 with chondroitin sulphate A/C (CS‐A/C). Fractions 1 and 2 in myocardium and aorta had the same electrophoretic properties, while fraction 3 from the two tissues differed in this respect. As calculated from photoscanned strips, HA was predominant in the myocardium and the HS‐like fraction in the aorta. The HA‐peak showed a slight proportional increase in the myocardium with increasing age, corresponding to a decrease in CS‐A/C. The results suggested that the MPS pattern of the myocardium is definitely formed at an early foetal stage and postnatally undergoes only s

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04722.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY

摘要:

AbstractIt is shown that amiloride is a potent inhibitor for the active sodium transport across tht‐isolated frog skin. The percentage inhibition produced by various amiloride concentrations was not dependent on the initial short‐circuit current but rather on the phase of the moulting cycle at which the skin was tes

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1970.tb04723.x

出版商:Blackwell Publishing Ltd    

年代:1970

数据来源: WILEY