Red blood cell oxygen has been released the resulting deoxyhemoglobin is of a dark red burgundy color. However, blood can appear bluish when seen through the vessel wall and skin. Pulse oximetry takes advantage of the hemoglobin color change to directly measure the arterial blood oxygen saturation using colorimetric techniques. Hemoglobin also has a very high affinity for carbon monoxide, forming carboxyhemoglobin which is a very bright red in color. Flushed, confused patients with a saturation reading of 100% on pulse oximetry are sometimes found to be suffering from carbon monoxide poisoning. Having oxygen-carrying proteins inside specialized cells (as opposed to oxygen carriers
Blood doping used by cyclists in combination with cobalt chloride/desferrioxamine stimulate and de-regulate the natural production of erythropoietin hormone. At physiologically low PaO around 40 mmHg, EPO is released from the kidneys to increase hemoglobin transportation. The combination of drugs consistently releases EPO due to increased transcription at the cellular level. The effect wears off when the HIF stabilizers, cobalt chloride/desferrioxamine is excreted and/or decayed by the body. Myo-inositol trispyrophosphate (ITPP), also known as compound number OXY111A, is an allosteric effector of hemoglobin which causes a rightward shift in the oxygen–hemoglobin dissociation curve, increasing the amount of oxygen released from red blood