This article provides a review of cerebral tissue oxygenation during immediate transition after birth in human neonates. Recommended routine monitoring, especially if resuscitation is needed, during this period includes arterial oxygen saturation and heart rate measured by pulse oximetry and electrocardiogram. However, there is increasing interest to monitor in addition with near-infrared spect...

METHEMOGLOBIN (metHb), resulting from the oxidation of iron in hemoglobin from the ferrous state to ferric state, cannot bind oxygen and thereby leads to a displacement of the hemoglobin dissociation curve to the left. It can, therefore, impair tissue oxygen delivery. Methemoglobinemia, which is characterized by the presence of a higher-than-normal level of metHb, either can be congenital (due ...

Acute normovolemic hemodilution (ANH) compromizes intestinal microcirculatory oxygenation; however, the underlying mechanisms are incompletely understood. We hypothesized that contributors herein include redistribution of oxygen away from the intestines and shunting of oxygen within the intestines. The latter may be due to the impaired ability of erythrocytes to off-load oxygen within the micro...

Erythrocytes are the key target in 5'-AMP induced hypometabolism. To understand how regulation of endogenous erythrocyte AMP levels modulates systemic metabolism, we generated mice deficient in both CD73 and AMPD3, the key catabolic enzymes for extracellular and intra-erythrocyte AMP, respectively. Under physiological conditions, these mice displayed enhanced capacity for physical activity acco...

Many fish species adapt to hypoxia by reducing their metabolic rate and increasing hemoglobin-oxygen (Hb-O(2)) affinity. Pilot studies with young broods of cichlids showed that the young could survive severe hypoxia in contrast with the adults. It was therefore hypothesized that early exposure results in improved oxygen transport. This hypothesis was tested using split brood experiments. Broods...

Cabrales, Pedro, Nirmala Devi Kanika, Belur N. Manjula, Amy G. Tsai, Seetharama A. Acharya, and Marcos Intaglietta. Microvascular PO2 during extreme hemodilution with hemoglobin site specifically PEGylated at Cys-93( ) in hamster window chamber. Am J Physiol Heart Circ Physiol 287: H1609–H1617, 2004. First published June 10, 2004; 10.1152/ajpheart.00146.2004.—The oxygen transport capacity of no...

Hemoglobin function can be modulated by the red cell membrane but some mechanistic details are incomplete. For example, the 43-kDa chymotryptic fragment of the cytoplasmic portion of red cell membrane Band 3 protein and its corresponding N-terminal 11-residue synthetic peptide lower the oxygen affinity of hemoglobin but effects on cooperativity are unclear. Using highly purified preparations, w...

We use optical spectroscopy to characterize the influence of mammographic-like compression on the physiology of the breast. We note a reduction in total hemoglobin content, tissue oxygen saturation, and optical scattering under compression. We also note a hyperemic effect during repeated compression cycles. By modeling the time course of the tissue oxygen saturation, we are able to obtain estim...