Mechanisms of Calcium Transport in the Thick Ascending Limb of the Loop of Henle
In the micropuncture segment between late proximal convoluted tubule and early distal tubule, approximately 20–25% of the filtered load of calcium is transported1. An undetermined fraction of the transport may occur in the proximal straight tubule where studies by Rouse, et al2 in the isolated perfused superficial straight tubule of the rabbit have suggested a substantial calcium efflux from the lumen. Beyond this segment, the thick ascending limb would appear to account for the hulk of calcium transport which occurs in the loop of Henle. Thus, studies by Rocha, et al,3 and Rouse, et al2 have shown a very low bidirectional permeability to calcium and little if any net flux in the thin descending and ascending loop segments.
KeywordsCalcium Transport Frog Skin Chloride Transport Chloride Secretion Thick Ascending Limb
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