AQP1 in the Gastrointestinal Tract of Mice: Expression Pattern and Impact of AQP1 Knockout on Colonic Function.

Aquaporin 1 (AQP1) is one of thirteen known mammalian aquaporins. Its main function is the transport of water across cell membranes. Lately, a role of AQP has been attributed to other physiological and pathological functions including cell migration and peripheral pain perception.

Aqp5 mice exhibit reduced maximal body O consumption under cold exposure, normal pulmonary gas exchange, and impaired formation of brown adipose tissue.

The fundamental body functions that determine maximal O uptake (V̇o) have not been studied in Aqp5 mice (aquaporin 5, AQP5). We measured V̇o to globally assess these functions and then investigated why it was found altered in Aqp5 mice. V̇o was measured by the Helox technique, which elicits maximal metabolic rate by intense cold exposure of the animals.

O permeability of lipid bilayers is low, but increases with membrane cholesterol.

Oxygen on its transport route from lung to tissue mitochondria has to cross several cell membranes. The permeability value of membranes for O (P), although of fundamental importance, is controversial. Previous studies by mostly indirect methods diverge between 0.

CO permeability of the rat erythrocyte membrane and its inhibition.

We have studied the CO permeability of the erythrocyte membrane of the rat using a mass spectrometric method that employs O-labelled CO. The method yields, in addition, the intraerythrocytic carbonic anhydrase activity and the membrane HCO permeability. For normal rat erythrocytes, we find at 37 °C a CO permeability of 0.