Research the causes of these diseases that are similar to, or related to, Autoimmune Urticaria: 1  Idiopathic urticaria without angioedema. 2  Chronic urticaria.  Occult infection (e.g., sinusitis, oral infection, cholecystitis, vaginitis, prostatitis, hepatitis, HIV, tinea manus or pedis)
In muscle cells, it's stored in the sarcoplasmic reticulum. In other tissue cells, it's stored in the smooth endoplasmic reticulum.
Sodium-Calcium Exchange in Cardiac Cells. Intracellular calcium concentrations in both cardiac and vascular smooth muscle cells range from 10 -7 to 10 -5 M. Extracellular concentration of calcium is about 2 Ã 10 -3 M (2 mM).Therefore, there is a chemical gradient for calcium to diffuse into the cell.ecause cells have a negative resting membrane potential (about -90 mV in a cardiac myocyte), there is also an electrical force driving calcium into the cell. However, except during action potentials when the cell membrane permeability to calcium increases, there is little leakage of calcium into the cell.