Brenner And Rectors The Kidney 10th Edition Pdf 50 !!EXCLUSIVE!!
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Brenner And Rectors The Kidney 10th Edition Pdf 50
Loop diuretics inhibit reabsorption by the tubular macula densa segment at the end of the LH that normally initiates afferent arteriolar vasoconstriction by the tubuloglomerular feedback response. Thus, tubuloglomerular feedback blockade by loop diuretics should increase the RBF and GFR. 27 Indeed, furosemide increases the GFR in dogs. 28 However, it normally reduces the GFR and the RBF in rats, 29 mice, 30 and humans. 31 The GFR falls by 23% after furosemide 13, 18, 23 or torsemide 22 in normal subjects or those with HF. 26, 32 The fall in GFR in rats is independent of volume depletion or activation of the RAAS 33 but entails reflex renal vasoconstriction. 33, 34 Inhibition of tubular fluid reabsorption increases the tubular fluid volume 35 and this increases the intrarenal pressures since the kidney is encapsulated. 36, 37 This increase in renal turgor will directly restrict the RBF 38 but also will raise the renal interstitial pressure that activates the interstitial baroreceptors. In parallel, the diuretic will increase the urinary NaCl concentration that will activate the renal pelvic chemoreceptors. The ensuing increase in renal afferent nerve discharge should initiate a reno-renal reflex to increase renal efferent nerve activity and reduce the GFR and RBF 39 ( Figure 4 ). Indeed, the fall in GFR with furosemide in rats is mitigated by renal nerve deafferentation. 33, 34 Renal afferent nerve activity is increased in rats with HF and enhances tubular Na+ reabsorption, renin release, and renal vasoconstriction. 40 Although radiofrequency renal nerve ablation for patients with HF reduces parameters of volume overload and symptoms modestly, 4143 any effects on diuretic resistance have yet to be studied.
carbonic anhydrase inhibitors are useful to increase the urinary excretion of na+ by inhibiting na+ absorption in the pt, where it normally crosses the luminal membrane by an anion exchange mechanism, and by altering the na+ gradient across the basolateral membrane. the na+ absorption in the pt is largely mediated by the na+ -glucose cotransporter, sglt2. inhibition of the sglt2 can increase the osmolarity of the pt interstitium, thereby increasing the reabsorption of water and na+ by the pt, and inhibiting tubuloglomerular feedback. effects of sglt2 inhibitors on the gfr are similar to those of loop diuretics. 41 in addition, the small increase in rbf will produce a large increase in glomerular filtration rate because of the high filtration fraction in the normal kidney. the renal interstitium is remarkably thin, and thus, the effects of the increase in intrarenal osmolarity are limited to a small volume of the renal cortex. in humans, dapagliflozin is approximately 6 to 12 times more potent than canagliflozin and ipragliflozin in inhibiting the sglt2. indeed, dapagliflozin increases the gfr by 15% to 25% in normal subjects. 42 dapagliflozin is effective in hf. in one study of dapagliflozin in patients with hf, the gfr increased by 8% at the end of the titration period and by another 5% to 12% during the 1-year follow-up period. 43
the adrenal glands are most often incidentally discovered on ultrasonography. in general, they are most frequently identified in the right lower quadrant (70%-80%). in the upper quadrants, the adrenal glands are most frequently seen in the right upper quadrant (40%-50%). a normal adrenal gland is typically seen as a rounded hyperechogenic structure 3 mm in size. it may be located in the normal anatomic position in the adrenal cortex and may be well visualized on the transverse images obtained in a coronal plane. the adrenal gland can be localized in the medial portion of the kidney, lateral to the renal vein, or below the diaphragm. small cystic lesions may be found in normal children, but these are usually not dynamic. if a cyst is identified, most pediatric radiologists will not report it unless it increases in size, unless the patient has symptoms suggestive of other pathology such as the flank mass syndrome. (8)