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A Nygren

Publications and source records attributed to A Nygren.

At least 127 records · Page 7Linked to original sources

Post-ischaemic administration of hyperosmolar mannitol enhances erythrocyte trapping in outer medullary vasculature in the rat kidney.

Mannitol is widely used as a therapeutic agent in the management of acute renal failure. We sought to determine whether mannitol influences the trapping of red blood cells (RBCs) in renal microvasculature, as measured from the distribution of 51Cr-labelled RBCs, in the rat kidney after ischaemia. The results indicate that administration of hyperosmolar mannitol after an ischaemic insult increases RBC trapping in the outer renal medulla in a dose-dependent manner. This was found to occur even though parameters of nephron function were unaffected or even improved.

Acute Kidney Injury↗

Mathematical model of an adult human atrial cell: the role of K+ currents in repolarization.

We have developed a mathematical model of the human atria myocyte based on averaged voltage-clamp data recorded from isolated single myocytes. Our model consists of a Hodgkin-Huxley-type equivalent circuit for the sarcolemma, coupled with a fluid compartment model, which accounts for changes in ionic concentrations in the cytoplasm as well as in the sarcoplasmic reticulum. This formulation can reconstruct action potential data that are representative of recordings from a majority of human atrial cells in our laboratory and therefore provides a biophysically based account of the underlying ionic currents. This work is based in part on a previous model of the rabbit atrial myocyte published by our group and was motivated by differences in some of the repolarizing currents between human and rabbit atrium. We have therefore given particular attention to the sustained outward K+ current (I[sus]), which putatively has a prominent role in determining the duration of the human atrial action potential. Our results demonstrate that the action potential shape during the peak and plateau phases is determined primarily by transient outward K+ current, I(sus) and L-type Ca2+ current (I[Ca,L]) and that the role of I(sus) in the human atrial action potential can be modulated by the baseline sizes of I(Ca,L), I(sus) and the rapid delayed rectifier K+ current. As a result, our simulations suggest that the functional role of I(sus) can depend on the physiological/disease state of the cell.

Action Potentials↗