摘要:

AbstractThe monoamine oxidase (MAO) activity of sympathetic ganglia and isolated ganglion cells of the cat has been studied by a micromodification of the radiochemical method of McCamanet al. (1965a) using (14C) tyramine. The superior cervical, stellate and coeliac ganglia showed a high MAO activity, the coeliac having almost twice the activity of the others. The 6th and 7th lumbar and the 1st sacral ganglia showed lower and approximately the same activity. No significant change in MAO activity could be detected in the lumbo sacral ganglia three to four weeks after denervation.The 7th lumbar ganglion was used for the single cell experiments. 73 per cent of the ganglion cells had measurable MAO activity with a range from 1 to 41 moles of product x10‐12/hr (mean ±S.E. =5.5±0.57). The results support the previous suggestion that the sympathetic ganglia of the cat contain two distinct cell populations; firstly, a cholinergic population, representing in L7about 10–15 per cent of the ganglion cells, characterized by the presence of ChAc, high concentrations of AChE and the absence of monoamine fluorescence and MAO activity; secondly, an adrenergic population, about 73–88 per cent of the ganglion cells, which exhibits fluorescence for noradrenaline and MAO activity, contains low or moderate AcChE and no measurahle ChAc a

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04263.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThe kinetics of the disappearance of acetic acid and sodium acetate from the stomach during secretion and secretory arrest was studied in anesthetized cats. Model experiments were also performed in which the solutes diffused through a cellophane membrane. On instillation of acetic acid into non‐secreting stomachs, the hydrogen ion concentration decreased significantly more rapidly than the acetate concentration (p<0.05). The increase in the combined sodium and potassium ion concentrations was significantly greater than the increase in the chloride ion concentration. Thus, in addition to molecular diffusion of acetic acid, exchange diffusion took place between hydrogen ions and sodium ions. A small amount of secretion masked this exchange. The acetate disappeared more rapidly on instillation of acetic acid than on installa‐. tion of sodium acetate. Acetic acid increases the ionic permeability of the gastric mucosa and has inhibitory effect on secretion. It has been reported that this secretory inhibition persists for up to 24 hrs. By repeated instillation experiments in the cat it was found that the permeability effects of a 30 min installation of 170 mM acetic acid did not persist for longer than 90 min. Sodium acetate per se probably had no effect on the ionic permeability of the gastric mucosa. It is suggested that the permeability increasing effect of acetic acid is related to transient intracellular accumulation of the diffusing acid. Epithelial abrasion that would give rise to an increased permeability by decreasing the diffusion distance requires restoration of the surface epithelium within 90 min and in fact, no abrasion was observed as an affect on acetic acid on the muc

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04264.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractAfter intravenous injection of heparin (in aniounts related to the body‐weight) thc blood plasma diamine oxidase(DAO‐) activity increased transiently in all vertebrates studied (cod, frog, fowl, mouse, white rat, golden hamster, guinea‐pig, rabbit, cat, dog, goat, sheep and cow). The DAO‐response to heparin varied strongly between the species. Often with a bi‐phasic ascent, it showed a maximum (within a few minutes to about one hour) and then decreased, often in a “monoexponential” fashion, in the course of the next few hours. In anodons no significant DAO‐activity was found.—The biological significance of the heparin effect upon DAO is discussed with special reference to the coexistence of heparin and histamine

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04265.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractExperiments are described which demonstrate that both hypercapnia and hypoxia exert a potent relaxing influence on the resistance vessels of the denervated intestine. The effects on the capillary fluid exchange capacity, as indicated by the capillary filtration coefficient (CFC), are, however, more complex. During local hypoxia CFC increases considerably, probably reflecting a direct relaxing influence on the precapillary sphincter section. In contrast, during hypercapnia CFC decreases in spite of an augmented blood flow. This is assumed mainly to be due to an increased myogenic activity in the same sphincter section, elicited locally by a raised transmural pressure and blood flow. Functional implications of the results are briefly discussed. They suggest that neither high Pco2accompanied by a low pH, nor low Po2are of major importance for a functional intestinal hyperemia during digestion.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04266.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractProtamine and heparin form a water‐insoluble complex (PHC) at pH 7. This complex has the ability to bind sodium, histamine and monoamines electrostatically. Titrations have suggested the PHC to be formed by a linkage between the guanidino groups of the protamine and the sulphuric acid and most of the carboxylic acid groups of the heparin. The cationic binding properties of the PHC may be assigned to the terminal COO group of the protamine poly‐peptide chain. The qualitative similarities in the cationic binding properties of the PHC and rat mast cell granules are discussed, with special reference to the mechanism of histamine storage in the mast cell granu

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04267.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractAn assay system is described to evaluate the palmityl‐CoA synthetase activating capacity of particle‐free supernatant from different sources. With relatively small amounts of tissue, the activating capacity was proportional to the amount of supernatant present. The palmityl‐CoA synthetase activity in whole homogenates of rat liver was reduced after feeding with sucrose, and increased after fasting. The palmityl‐CoA synthetase activating capacity of rat liver supernatant was also significantly increased after fasting. MgCl2increased the inactivation of microsomal palmityl‐CoA synthetasein vitro, NaCl and NaF reduced the inactivation, and ATP prevented any inactivation. CaCl2, but not KCl, also reduced the inactivation invitro. Inactivated microsomal palmityl‐CoA synthetase was partially re‐activated by incubation with particle‐free supernatant and ATP. The results suggest that two forms of palmityl‐CoA synthetase may be interconvertible through reversible phosphorylation, catalyzed by two different enzymes, viz. the supernatant activating factor and a phosphopr

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04268.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThree neutral polymers, ficoll, dextran and polyethyleneglycol, all inhibit hemoglobin liberation in hypotonic electrolyte solutions. If red cells are suspended in a hypotonic solution which, in the absence of a polymer, would hemolyse all the cells, only a part of the hemoglobin is liberated. The polymer does not alter the fragility but only the amount of hemoglobin liberated from the individual cells. The inhibitory effect is proportional to the weight concentration of the polymer and independent of the mol. wt. within wide limits. The inhibitor molecules must presumably have a critical minimal size since the trisaccharide raffinose did not inhibit hemoglobin liberation under similar conditions. From the data on the lowest molecular weight dextran fraction it was concluded that the lower limit for dextran was below a molecular weight of about 1700. Complete inhibition of hemoglobin liberation was never obtained and from the evidence available it is suggested that the first 20 per cent, at least, of the hemoglobin may escape with a bulk outflow. The colloid osmotic relationships of the cell during and after hemolysis are discussed and it is concluded that cannot be decided whether the polymer effect is colloid osmotic in nature.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04269.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThe formation of extracellular adenosine triphosphate by human erythrocytes was studied. The red cells were incubated with (32P)‐orthophosphate, together with all necessary substrates and co‐factors of the glyceraldehyde‐3‐phosphate dehydrogenase and phosphoglycerate kinase reactions (complete system), and also with anincomplete systemlacking the phosphorylated substrates and cofactors. Finally, the red cells were incubated with the complete system lacking only one phosphorylated cofactor. All incubations were performed under isotonic conditions.At I min incubation, three times more AP32P was formed by the red cells incubated with the complete system than with those incubated with the incomplete system. All the resulting AP32P formed by the added phosphorylated substrates and cofacton present in the complete system could be recovered in the extracellular medium. Only an insignificant part of this AP32P was probably formed by enzymes which were eluted out into the surrounding medium. It is therefore reasonable to infer that most of the AF32P present in the extracellular medium was formed by the enzymes located on the surface of the red cells. No AP32P was found in the extracellular medium of red cells incubated with the incomplete system, nor with the complete system lacking only one phosphorylated cofactor. Thus, none of the intracellular ADP, NAD+or glyceraldehyde‐3‐phosphoric acid could be utilized in ATP formation on the red c

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04270.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThe purpose of the present investigation was to examine the suggestion advanced by Saugman (1957) that differing mechanisms of renal tubular reabsorption of chloride and bromide might be detected by studying the anion excretion during water diuresis. Simultaneous excretion of Cl and82Br‐was therefore studied before and during water diuresis in 10 normal human subjects. The excreted fraction of filtered bromide was invariably 30–35 per cent lower than that of chloride, independently of serum bromide concentration (range 0.001–10 meq/litre), excretion percentage of chloride (0.3–2.4 per cent), and of the rate of urinary production (0.6–14.7 ml/min). It was concluded that there is no evidence that the renal reabsorption distinguishes selectively between chloride and bromide.Simultaneous determination of chloride, bromide, and thiocyanate excretion confirmed that only the excretion of thiocyanate is increased during water diuresis.The ultrafiltrability of the three anions was determined and considered when the filtered amounts were calculated. The ratios between anion concentration in ultrafiltrate and serum water were: chloride 1.02, bromide 0.98 and thiocya

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04271.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractIntracellular distribution of lipase (glycerolester hydrolase EC 3.1.1.3.), cholesterol esterase (sterol ester hydrolase EC 3.1.1.13.), phospholipase (EC 3.1.1.4.) and of carboxylic ester hydro‐lases (EC 3.1.1.1.) has been studied using isopycnic gradient centrifugation of rat pancreatic homogenates. The identity of the fractions obtained has been established using phase contrast and electron microscopy. Zymogen granules equilibrated at a mean density of 1.224 in aqueous sucrose gradients, mitochondria and cytomembranes at a mean density of 1.19 and 1.16–1.14, respectively. The zymogen fraction accounted for 25–45%of the total activities of lipase, cholesterol esterase and phospholiphase. The specific activities (activity per mg protein) in the zymogen fraction were 5–7 times higher than those of the other cell fractions. A bile salt stimulated carboxylic ester hydrolase was found concentrated to the zymogen granules. The membrane and cell sap fractions accounted for almost all of the remaining lipolytic enzyme act

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1968.tb04272.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY