Release of choline in the isolated heart, an indicator of ischemic phospholipid degradation and its protection by ischemic preconditioning: No evidence for a role of phospholipase D

Beneficial Effects of Phosphatidylcholine During Hindlimb Reperfusion

“…These findings suggest that this ubiquitous membrane-forming entity may become exhausted in response to noxious stimuli, and replenishment of the endogenous PC pool could be of importance under critical circumstances [9]. In line with this, it has been shown that PC supplementation could ameliorate the harmful consequences of myocardial I-R [11].…”

“…It has been shown that I-R is associated with physical membrane defects, PC degradation and the exhaustion of endogenous PC sources [9,16,17], whereas ischemic preconditioning restores the membrane stability with the simultaneous prevention of phospholipid degradation [9]. These findings suggest that this ubiquitous membrane-forming entity may become exhausted in response to noxious stimuli, and replenishment of the endogenous PC pool could be of importance under critical circumstances [9].…”

“…Endogenous PC influences several pathways of the bone physiology, including the induction of bone formation [6], the modulation of resorption [7] and calcification [8]. It has also been demonstrated that the membrane PC is depleted after I-R [9] and the liberated choline can play an important protective role during intracellular redox imbalances [10]. Exogenous PC likewise exerts beneficial effects during ischemia [11], but its role in I-R-related microvascular changes is yet undefined.…”

Choline in acute coronary syndrome: an emerging biomarker with implications for the integrated assessment of plaque vulnerability

“…Choline has been discussed as a marker of ischemia [1,4,5]. This is supported by studies on global ischemia of the isolated rat heart, which demonstrated that choline is released together with troponin I from the myocardium in a biphasic manner and that this release is related to cytosolic PLA 2 and not to PLD [31]. As discussed below, clinical data suggest that (plasma) choline actually is not a sensitive marker for minor or transient …”

Phospholipid-mediated signaling in diseased myocardium

“…Nonetheless, the elucidation of the detailed mechanism of PLD activation by thiol-modulating agents will be of importance for clearly understanding the oxidant-induced signal transduction pathways and PLD regulation under different types of oxidative stress. It should be noted that most of the aforementioned studies measure PLD-derived PA; however, choline released into the heart perfusate is found to be a useful indicator of phospholipid degradation caused by I-R and PLD activity [110]. It is pointed out that LPC is an important precursor for the formation of LPA by lysophospholipase D (also termed autotoxin) [111,112].…”