Pathogenic Mechanisms



The great majority of tubulointerstitial disor­ders occur as a result of one of three general mech­anisms: heredity, toxic injury, or a change in tub­ule regulation by drugs or hormones. Polycystic kidney disease, familial nephrogenic diabetes in­sipidus, and Fanconi’s syndrome are disorders of hereditary origin. The specific genetic defects are unknown. Analgesic nephropathy, lead nephro­pathy, and some types of renal tubular acidosis are representative of toxic injuries. Pituitary di­abetes insipidus (ADH deficiency), adrenal salt wasting (deficient mineralocorticoid), and di­uretic administration are examples of the last cat­egory .