The cells of the macula densa are sensitive to the concentration of sodium chloride in the distal convoluted tubule. In the kidney, the macula densa is an area of closely packed specialized cells lining the wall of the distal tubule, at the point where the thick ascending limb of the loop of henle meets the distal convoluted tubule. The tubuloglomerular feedback mechanism of renal autoregulation is the key function of the macula densa. Macula densa md controls on renin secretion have recently been studied by examining the renin secretory response of the isolated perfused rabbit juxtaglomerular apparatus jga. Single jgas, consisting of a segment of distal tubule including the macula densa, with adherent glomerulus and short vascular fragments, are dissected from rabbit. Dieta y degeneracion macular brightfocus foundation. The first portion of the distal tubule usually 100150. In addition to tubular salt sensing, macula densa cells also sense alterations in tissue metabolism through the accumulation of the krebs cycle intermediate, succinate, in tubular fluid. Dal punto di vista morfologico essa rappresenta il punto di passaggio fra il segmento rettilineo e quello convoluto del tubulo distale. Macula densa control of renin secretion springerlink. Tratamiento del agujero macular american academy of. In the kidney, the macula densa is an area of closely packed specialized cells lining the wall of the distal tubule at the point of return of the nephron to the vascular pole of its parent glomerulus, glomerular vascular pole.
Superoxide o2 enhances tubuloglomerular feedback by scavenging nitric oxide at the macula densa. The macula of utricle allows a person to perceive changes in longitudinal acceleration in horizontal directions only. The macula densa is the thickening where the distal tubule touches the glomerulus the cells of the macula densa are sensitive to the concentration of sodium chloride in the. The macula densa is worth its salt pubmed central pmc. Tgf, a major mechanism by which gross filtrationabsorption mismatches are prevented, is the subject of the article by thomson et al. As shown schematically in figure figure1, 1, in every mammalian nephron, the distal tubule is attached to its glomerulus of origin at a point where normally about 80% of the filtered water and 85. The juxtaglomerular apparatus is a structure in the kidney that regulates the function of each. However, the singling pathway of o2 production in the macula densa is not known.
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