Nephrons pathophysiology

Pathophysiology Non-potassium-sparing diuretics are the treatment of choice to reduce fluid retention and dyspnea. Acting at specific sites of nephrons, they inhibit sodium and water reabsorption. Loop diuretics act on the loop of Henle, producing a maximal diuretic effect equivalent to 20% to 25% of the filtered sodium load and promoting the free water clearance. Currently available loop diuretics include furosemide, bumetanide, torsemide, and ethacrynic acid. Because of their potency, they are generally effective in patients with advanced renal insufficiency (glomerular filtration rates <25 ml/min) (49). 

To date, the in vitro perfused juxtamedullary nephron preparation has not been used to examine the effects of nephrotoxic agents. However the preparation has been used to examine the pathophysiology of tubuloglomerular feedback. It has also been used to study the effect of mediators like adenosine, oxygen radicals and nitric oxide. Some recent studies are discussed below. 

Kirk KE, Schaefer JA. Water transport and osmoregulation by antidiuretic hormone in terminal nephron segments. ln The kidney physiology and pathophysiology. Seldin DW, Giebisch G (editors). Raven Press, New York 1992 p. 1693-1725. 

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