calcium content fluctuation is the key to cardiac alternans.
Their actions on the uterus are probably a result of their agonist properties against adrenergic [alpha]-receptors; these receptors, when stimulated, lead to IP3 release and to calcium mobilization from the sarcoplasmic reticulum
. To date, there is only one prospective study in the English literature on this topic.
Ultrastructural analysis showed swollen sarcoplasmic reticulum
, dilated t tubes and areas with sarcomere disruption (Figure 4e).
Popov, "Differences in the force-interval relationship of isolated human myocardium with chronic coronary artery disease with and without type 2 diabetes mellitus and the role of sarcoplasmic reticulum
[Ca.sup.2+]-ATPase," Human Physiology, vol.
Association of glycogenolysis with cardiac sarcoplasmic reticulum
Chronic heart failure (HF) is a progressive, multifactorial, and debilitating disease that is often characterized by the impairment of systolic function and the loss of calcium homeostasis due to insufficient reuptake of calcium ions back into sarcoplasmic reticulum
(SR) using Ca [sup]2+-ATPase and/or insufficient inflow of calcium ions into myocytes through using Na [sup]+/Ca [sup]2+ exchanger.[sup], Ca [sup]2+ is a central player in the excitation-contraction coupling of cardiac myocytes that keeps heart to contract and relax.[sup],,,,, Disturbances in Ca [sup]2+ homeostasis in myocytes are associated with a diverse range of human pathological conditions, such as myocardial infarction (MI) and HF.
Ryanodine binds to CRAC in the sarcoplasmic reticulum
of cardiac and skeletal muscles as well as to the endoplasmic reticulum of various tissues [54, 55].
reported that an increased mitochondrial calcium content (induced by LPS) was associated with reduced calcium uptake by and increased calcium leakage from the sarcoplasmic reticulum
and it was also associated with decreased [DELTA]p, mitochondrial uncoupling, altered state 3 respiration, and impaired RCR.
Ji et al., "Astragaloside IV improved intracellular calcium handling in hypoxia-reoxygenated cardiomyocytes via the sarcoplasmic reticulum
[Ca.sup.2+]-ATPase," Pharmacology, vol.
Alterations in the expression of sarcoplasmic reticulum
calcium ATPase2a (SERCA2a) lead to contractile deficiency and pathological remodeling in HF.
In addition, sarcoplasmic reticulum
calcium-ATPase (SERCA2a) function decreased in ischemia, thus resulting in intracellular Ca (Cai) alternans of small magnitude.
The reduced stock in Calcium in the sarcoplasmic reticulum
leads to the abnormal contractility observed.