Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Myocardial cell vulnerability to phospholipase C (PC-PLC) attack was investigated in three different preparations of rat myocardial cells: triacylglycerol (TG)-loaded, hypothermic/rewarmed and energy depleted myocytes. The attack by PC-PLC was evaluated as PC-PLC induced glycerol output due to the combined action of phospholipase C and intracellular lipases. PC-PLC induced glycerol output was significantly higher (p < 0.05) in all three myocyte preparations, compared to their respective controls. Cell morphology (% rod shaped myocytes) of TG-loaded or hypothermic/rewarmed myocytes was not different from their controls, whereas energy depleted myocytes almost exclusively were rounded up, due to hypercontraction of the myofilaments. Hypothermic/rewarmed and energy depleted myocytes showed a significantly higher release of lactate dehydrogenase (LDH), compared to their controls although the difference was much more pronounced in the latter. Finally, the cellular contents of ATP were maintained both in TG-loaded and hypothermic rewarmed myocytes, while energy depleted myocytes contained only about 25% of the normal ATP level. These results demonstrate that attack from exogenously added phospholipases can occur, not only in seriously damaged cardiac myocytes, but in myocytes with a more subtle damage as well.
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PMID:Myocardial cell vulnerability to exogenous phospholipase attack. 148 Jan 54

The combined action of phosphatidylcholine preferring phospholipase C (PC-PLC) and intracellular lipases has recently been shown to cause glycerol output in energy deprived rat cardiomyocytes. In the present study we examined the effect of hypothermia and rewarming on PC-PLC evoked glycerol output in freshly isolated, calcium-tolerant myocytes. The cells were preincubated for 60 min at hypothermic (5 degrees C) or normothermic (37 degrees C) conditions in Krebs-Henseleit bicarbonate buffer (pH 7.4) supplemented with 1 mM DL-carnitine, 1% B.S.A. and 5 mM glucose. Addition of PC-PLC resulted in a significantly higher (P less than 0.05) output of glycerol in myocytes undergoing rewarming than in myocytes kept constantly at 5 degrees C or 37 degrees C. The values obtained for PC-PLC induced glycerol output (difference in glycerol output between incubations with and without PC-PLC) were 6.77 +/- 2.6 (37 degrees C), 4.54 +/- 1.7 (5 degrees C) and 22.85 +/- 5.9 (5-37 degrees C) nmol/10(6) cells.h. Rewarming in addition caused a significantly higher (P less than 0.05) leakage of lactate dehydrogenase (LDH) from the rewarmed cells as compared to cells at constant temperatures (5 degrees C or 37 degrees C). However, there was no additional effect of PC-PLC on LDH leakage. The elevated PC-PLC induced glycerol output in rewarmed myocytes was not related to a fall in the percentage of rod-shaped cells or a reduced cellular content of ATP, since no differences could be detected between the various myocyte preparations with respect to these parameters.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of hypothermia and rewarming on phospholipase C-evoked glycerol output in rat myocardial cells. 163 71