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Role of sphingomyelin in the plasma membrane damage due to a cytotoxin from pseudomonas aeruginosa
8th Wodd ~
CORONARY
oa AJ~ml, P I ~ t ~ d M k ~ b i s l To~l~
VASOSP~ AS THE PRIMARY CAUSE OF DEKTH DOE TO ~ T H E B U R R O W I N G ASP, ATRACTASPIS ENGADDENSIS
VENOm
OF
SHU-YUE LEE I'2, Co Y° LEE I , Yo M° CHEN I and Eo KOCHVA 3 Departments of Pharmacology I and Clinical Pathology 2 , College of Medicine, National ~Talwan University, Talpel, Taiwan, R°O.C° and Department of Zoology ~, George S° Wise Faculty of Life Sciences, Tel Avlv University, Tel Aviv, Israel. The venom from the snake Atractaspls enqaddensls has been shown to be cardiotoxic in anesthetized mice (Welser e t al~, 1984)o The effects of the venom were further tested on both atrial and Langendorff heart preparations of rats, in addition to its cardiovascular effects in anesthetized mice° The venom (0.1 ms/ks, i°v°) produced a transient hypertension followed by fluctuation of arterial blood pressure, leading to cardiac failure within minutes° Various kinds of ECG changes, including S-T depression and A~V block were observed within 10 sac after injection. A dose as low as I u g of venom injected into the parfuslon system produced a marked coronary vasospasm, a decrease of ventricular contractility and frequent arrhythmlas in the Langendorff heart preparation, whereas no deleterious effect was found in the atrial preparation at a concentration as high as 10 pg/mlo It is concluded that the cardlotoxlc effects of the venom are primarily due to myocardial anoxla caused by coronary vasospaSmo R~E~ENCES Weiser, E., Wollberg, Z°, Kochva, E° and Lee, S°Y° (1984}
Toxlcon 22, 767
KEY
Atractaspis en~addensis venom; coronary vasospasm; cardiotoxiclty°
ROLE OF SPHINGOMYELIN IN T H E P L A S M A M E M B R A N E D A M A G E D U E T O A CYTOTOXIN FROM PSEUDOMONAS AERUGINOSA By N. LEWICKI and F. LUTZ, Institute of Pharmacology and Toxicology, University of Giessen, D-6300 Giessen, FRG. An acidic polypeptlde (25,100 Da) which could be detected in all clinical strains of P. aeru~inosa caused an increase of pla m m membrane permeability via s i t tranmaatbrane hydrophilic "holes" (NAURER and LUTZ, 1984 ; SUTTORP et al, 1985}. The effects in Ehrlich asoltes cells were studied after pretreatment with phospholipases. For the breakdown of 50 % o~ cellular cation gradient within 60 sin at 37°C 2.5 ~g cytotoxin Per 3xi0 cells/ml was needed. When the cells were prelncubated for 30 sin with phosphollpase8 (40 U/ml each of phospholipase D from cabbage or phospholipase C from B. cereus) which do not hydrolyze sphlngomyelin, no influence on the cy~otox--1"n'-~tion was seen. Preincubation of the cells with phospholipases splitting 8phlngomyelin resulted in time- and dose-dependent enhancement of the cytotoxin effect: phospholipase C fron _C. perfringens was effective at >0.2 U/ml, 8phingomyelin a s a from B. cereus at ~0.01 U/ml. Correspondingly, cytotoxin action was not observed ~n~---c~pla_-,~_tales which lack sphingomyalin {LUTZ et al, 1983}. On the other hand, the binding of iodinated cytotoxin to high affinity binding site of isolated plasma membranes from Ehrlich cells was not affected by phospholiRase C from C. perfrinqen8 (I U/O. I mg membrane protein for 30 sin at 25vC) or phospholipase D frol cabbage (60 U) ° The facilitation of cytotoxin-induced p e r ~ i l i t y following the sphlngo~lin degradetlon suggests that sphingomyelin might play an important role in the creation of m h r a n a "holes" by the pseudomonal cytotoxin. ~ERENCES
Lutz,F., Seeger,W., ~ h i s c h k e , B . , Welner,R. and Scbarmann,W. (1983} Toxlcon, Suppl. 3, 257. Maurer,M and Lutt,F (1984) Hoppe-Seyler's Z.Physlol.Chom. 365, 1031. Suttorp, N., Seegar,W., Uhl,J., Lutz,F. and Roka,L. (1985) J°Coll° Physiol., in press. K E Y WORDS aarualnosa; cytotoxin; 8phingomyelln.
CORONARY
oa AJ~ml, P I ~ t ~ d M k ~ b i s l To~l~
VASOSP~ AS THE PRIMARY CAUSE OF DEKTH DOE TO ~ T H E B U R R O W I N G ASP, ATRACTASPIS ENGADDENSIS
VENOm
OF
SHU-YUE LEE I'2, Co Y° LEE I , Yo M° CHEN I and Eo KOCHVA 3 Departments of Pharmacology I and Clinical Pathology 2 , College of Medicine, National ~Talwan University, Talpel, Taiwan, R°O.C° and Department of Zoology ~, George S° Wise Faculty of Life Sciences, Tel Avlv University, Tel Aviv, Israel. The venom from the snake Atractaspls enqaddensls has been shown to be cardiotoxic in anesthetized mice (Welser e t al~, 1984)o The effects of the venom were further tested on both atrial and Langendorff heart preparations of rats, in addition to its cardiovascular effects in anesthetized mice° The venom (0.1 ms/ks, i°v°) produced a transient hypertension followed by fluctuation of arterial blood pressure, leading to cardiac failure within minutes° Various kinds of ECG changes, including S-T depression and A~V block were observed within 10 sac after injection. A dose as low as I u g of venom injected into the parfuslon system produced a marked coronary vasospasm, a decrease of ventricular contractility and frequent arrhythmlas in the Langendorff heart preparation, whereas no deleterious effect was found in the atrial preparation at a concentration as high as 10 pg/mlo It is concluded that the cardlotoxlc effects of the venom are primarily due to myocardial anoxla caused by coronary vasospaSmo R~E~ENCES Weiser, E., Wollberg, Z°, Kochva, E° and Lee, S°Y° (1984}
Toxlcon 22, 767
KEY
Atractaspis en~addensis venom; coronary vasospasm; cardiotoxiclty°
ROLE OF SPHINGOMYELIN IN T H E P L A S M A M E M B R A N E D A M A G E D U E T O A CYTOTOXIN FROM PSEUDOMONAS AERUGINOSA By N. LEWICKI and F. LUTZ, Institute of Pharmacology and Toxicology, University of Giessen, D-6300 Giessen, FRG. An acidic polypeptlde (25,100 Da) which could be detected in all clinical strains of P. aeru~inosa caused an increase of pla m m membrane permeability via s i t tranmaatbrane hydrophilic "holes" (NAURER and LUTZ, 1984 ; SUTTORP et al, 1985}. The effects in Ehrlich asoltes cells were studied after pretreatment with phospholipases. For the breakdown of 50 % o~ cellular cation gradient within 60 sin at 37°C 2.5 ~g cytotoxin Per 3xi0 cells/ml was needed. When the cells were prelncubated for 30 sin with phosphollpase8 (40 U/ml each of phospholipase D from cabbage or phospholipase C from B. cereus) which do not hydrolyze sphlngomyelin, no influence on the cy~otox--1"n'-~tion was seen. Preincubation of the cells with phospholipases splitting 8phlngomyelin resulted in time- and dose-dependent enhancement of the cytotoxin effect: phospholipase C fron _C. perfringens was effective at >0.2 U/ml, 8phingomyelin a s a from B. cereus at ~0.01 U/ml. Correspondingly, cytotoxin action was not observed ~n~---c~pla_-,~_tales which lack sphingomyalin {LUTZ et al, 1983}. On the other hand, the binding of iodinated cytotoxin to high affinity binding site of isolated plasma membranes from Ehrlich cells was not affected by phospholiRase C from C. perfrinqen8 (I U/O. I mg membrane protein for 30 sin at 25vC) or phospholipase D frol cabbage (60 U) ° The facilitation of cytotoxin-induced p e r ~ i l i t y following the sphlngo~lin degradetlon suggests that sphingomyelin might play an important role in the creation of m h r a n a "holes" by the pseudomonal cytotoxin. ~ERENCES
Lutz,F., Seeger,W., ~ h i s c h k e , B . , Welner,R. and Scbarmann,W. (1983} Toxlcon, Suppl. 3, 257. Maurer,M and Lutt,F (1984) Hoppe-Seyler's Z.Physlol.Chom. 365, 1031. Suttorp, N., Seegar,W., Uhl,J., Lutz,F. and Roka,L. (1985) J°Coll° Physiol., in press. K E Y WORDS aarualnosa; cytotoxin; 8phingomyelln.