The effect of oxygen and the volume restrictions of extracellular medium on enzyme release from heart cells in culture

133EFFECT OF CREATINE PHOSPHATE ON ATP AND CP CONTENTS ADMINISTRATION. G. Piacenza, R. Borgoglio, R. Osella. Schiapparelli

OF RAT HEART AND BLOOD AFTER Research

Centre,

Turin,

I.V.

Italy.

(CP) has been shown to protect the myocar Exogenous supply of Creatine Phosphate both "in vitro" and "in viva". Metabolic studies dium against the effect of ischaemia have demonstrated that the "in vitro" protective effect of CP is associated with an increase of the myocardial High-Energy-Phosphates (HEP) pool. To evaluate the hypothesis that also the "in viva" protective effect of CP is associated with increase of the myo cardial HEP, we have injected CP (50 mg/kg) into the tail vein of rats and after 607 120,180,240 and 300 minutes we have determinated myocardial ATP and CP contentsand the ATP and CP Kinetics in the whole blood. We have detectedasignificant increase (p
134 THE EFFECT OF OXYGEN AND THE VOLUME RELEASE FROM HEART CELLS IN CULTURE Shu'a

Yagev,

Michael

Heller

Laboratory for Myocardial Hebrew University-Hadassah

and Arie Research, Medical

RESTRICTIONS

OF EXTRACELLULAR

MEDIUM

ON ENZYME

Pinson Institute School,

of Biochemistry, Jerusalem, Israel

Conditions have been defined for studying the effect of oxygen restriction on release was detected already after 30 min. The heart cells in culture. Enzymes' kinetics of different cytoplasmic and lysosomal enzymes' release were studied under conditions defined as hypoxia, anoxia and ischaemia. Restrictions of the volume of the extracellular medium caused a rapid release of cytoplasmic enzymes upon oxidation restriction ("experimental ischaemia") whereas lysosomal enzymes were detected only after 3 hours. Microscopic examination of the cultures and evaluation of DNA release as an index of cell disruption, pinpoint the relation between leakage of lysosomal enzymes and the eventual 'point of no return' in myocardial cells. Supported by grants Ministry of Education Heart Research from

from:The Chief Scientist, Ministry of and Sciences, State of Niedersachssen Mr and Mrs Vidal-Majar, Paris (France).

135THE EFFECT OF QUINIDINE AND ITS OF HEART CELLS IN CULTURE Abdullah

Haj-Yehia,

Yehuda

Laboratory for Myocardial Hebrew University-Hadassah

SYNTHETIC

DERIVATIVES

Health, (FRG)

State of Israel; and a grant for

ON THE OXIDATION

Yanuka,

Michael

Heller

and Arie

Research, Medical

Institute School,

of Biochemistry Jerusalem, Israel

& CONTRACTION

Pinson & Department

of

Pharmacy

Quinidine, Hydroquinidine, Quinidine-lO,ll, Dihydrodiol and Quinidinal at 5x10w7M decreased palmitate oxidation by 25,22,20 and 14 percent of controls respectively. Ouabain at 5x10-6M stimulated oxidation of palmitate by 20%. When cells were preincubated with Ouabain, Quinidinediol was more effective than the othercardiotropic agents in reducing palmitate oxidation (72% of controls). Ouabain (5x10-8M or 5x10-7M) increased the rate and amplitude of contractions of cultured cells by 28%. Quinidine alone (lo-7M1) reduced contractions by 10%. "Arrythmias" in cells started when cells were incubated with lo-511 of Ouabain and could be eliminated both by Quinidine and Hydroquinidine. Supported

by

grant

for

Heart

Research

from

Mr and Mrs

Vidal-Majar,

Paris

(France)