ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01530.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.In granulocytes and lymphocytes separated from the blood of the rabbit the incorporation of radioactive59Fe into the haemin fraction was investigated.Evidence is presented that the iron is incorporated into the haemins during the formation of these cells and remains in them during their life time. From the change of the specific activity of the haemin iron with time the average life span of both lymphocytes and granulocytes can thus be calculated.The mean age of the granulocytes was found to be 8.8 days. It is presumably composed of two populations of about the same frequency but varying life time, one having a life span of 4.4, the other of 13.2 days. The mean age of 8.8 days is identical with the result obtained by Ottesenfrom32P data of DNA isolated from granulocytes.A very appreciable part of lymphocytes has a life span amounting to 145 days; 10 % only having one of 3 days. An almost identical result was arrived at by Ottesenin his DNA studies. A part of the lymphocytes entering the blood stream is still going on to incorporate haemin iron, thus to build up haemin.

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01531.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.The oxygen dissociation curve of the common silver hake (Merluccius bilineatus) is described at pH 5.9—7.7 and pO20.2—140 atmospheres. At pH 7 the curve has a conspicuous plateau before it reaches full saturation at about 100 atmospheres. It is pointed out that high pressure curves from fish in general cannot readily be described or interpreted in terms of current theories evolved for mammalian bl

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01532.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.The present studies were made on mast cells in the rat mesentery.The disruption of mast cells by 48/80 was inhibited by various metal salts and other enzyme inhibitors.Among numerous enzymes studied, only lecithinase A had the ability to disrupt mast cells. Trypsin, fibrinolysin, ribonuclease, hyaluronidase, etc. were inactive.The disruptive action of lecithinase A was inhibited by the same agents which inhibited the action of 48/80.The action of 48/80 was temperature‐dependent. It was inhibited below 20°C and above 45°—50°C. The inhibition above 45°—50°C was irreversible.The effect of 48/80 was inhibited by incubation with acetic anhydride and 1,3‐diphosphoimidazole. The acetylation was not reserved under conditions which hydrolyzed phenyl acetate and thiol acetate. Dephosphorylation caused a disruption without the addition of a liberator.Polyvalent immune serum against snake venom, “Antivenin”, and specific immune serum (from rabbits) against lecithinase A (from bee venom), blocked in high doses the disruptive action of both lecithinase A and of 48/80.The observations are considered to support the hypothesis that 48/80 acts by activating a lytic anzyme attached to the mast cell mebrane. The activity of the enzyme is normally blocked by an inhibitor. When this inhibitor is removed, as by liberators such as 48/80, the enzyme becomes active and the membrane structures are attacked.The implications of our mast cell enzyme theory for the histamine release produced by other releasers, for that occurring in anaphylactic reactions, etc., are discussed. Attention is drawn to the possible applicability of similar enzyme theories to biologically occurring and pharmacologically produced changes in membr

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01533.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY

摘要:

Summary.1) An investigation of the effect of temperature on the neuromuscular block caused by magnesium in the isolated phrenic nerve diaphragm preparation from the rat has been carried out. The effect of tetraethylammonium (TEA) on the neuromuscular depression produced by magnesium has been investigated in the rat diaphragm preparation as well as in nerve muscle preparationsin situin rabbits and cats.2) A concentration of 6 mM magnesium in the bath just produced complete neuromuscular block of the responses to single nerve shocks at 37°C. At 22° C 10 mM magnesium was needed. In the presence of a neuromuscular block due to magnesium at 37° C, lowering the temperature to 22° C restored transmission.3) TEA in a concentration of 1 mM in the bath partly restored neuromuscular transmission depressed by magnesium. The β‐hydroxy‐derivative of TEA and choline only increased the magnesium block. In the rabbit and cat TEA in a dose of 4 to 7 mg per kg body weight injected intravenously restored neuromuscular transmission strongly depressed by continuous infusion of magnesium. In spite of continuous magnesium infusion, the restoration of muscle contractions obtained with the single dose of TEA was far more sustained than the blood pressure fall caused by TEA.4) The sensitivity of the motor end plate to externally applied acetylcholine was not increased after TEA had restored transmission in the magnesium‐blocked rat diaphragm.5) The end plate potential obtained under a magnesium block was increased in amplitude without significant change in time course, when TEA was added.It is concluded that TEA like calcium antagonizes the neuromuscular block caused by magnesium by effecting an increased output of acetylcholine from the presyna

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1957.tb01534.x

出版商:Blackwell Publishing Ltd    

年代:1957

数据来源: WILEY