Phosphate depletion arrests progression of chronic renal failure independent of protein intake

Abstract

Following 5/6 nephrectomy, 18 rats were fed a normal diet. After 30 days, serum creatinine (SCr), urine protein excretion and urine volume were increased compared to pre-nephrectomy (0.27 +/- 0.1 vs. 1.62 +/- 0.6 mg/deciliter, 17.0 +/- 10.3 vs. 257.6 +/- 13.4 mg/24 hr, and 16.6 +/- 4.4 vs. 39.2 +/- 11.7 ml/24 hr, respectively, all P less than 0.001). At this time, when serum phosphorus (SPi) and serum calcium (SCa2+) were normal, the rats were separated into two groups, matched and paired by body weight and SCr, and housed separately in metabolic cages. Animals of one group ingested a normal diet supplemented with dihydroxyaluminum aminoacetate (DHAAA), 15 g%, to induce phosphate depletion (PD). The second group ingested the same diet supplemented with 7.5% glycine and was the phosphate replete (PR) group. All rats were pair fed throughout the study to maintain similar caloric, protein, carbohydrate, vitamin, and mineral intakes. At six weeks after separation, SPi was decreased in PD vs. PR group (2.85 +/- 0.8 vs. 6.71 +/- 1.2 mg/deciliter, P less than 0.001) and SCa2+ was increased in the PD group (11.98 +/- 0.7 vs. 10.03 +/- 0.7 mg/deciliter, P less than 0.001). Urine urea nitrogen, body weight, and sodium, potassium and solute excretion were similar between the groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Association of mineral levels with Chronic Kidney Disease (CKD-MBD) – A hospital based retrospective study

“…11 The impact of phosphorus level on progression of CKD & on mortality has been examined, with two studies showing different results 4,12 , but the effect of bone-mineral abnormalities on kidney function is unclear. Our study shows that higher serum phosphorus was associated with significantly higher risk for progression of CKD, these findings complements earlier primary studies that showed a beneficial effect of dietary phosphorus restriction on progression of CKD in experimental animals 13 & in humans. 14 Our findings of a significant quantitative interaction between serum phosphorus & calcium levels supports the hypothesis that tissue calcification may be reason behind observed association.…”

The Effects of Sevelamer Hydrochloride and Calcium Carbonate on Kidney Calcification in Uremic Rats

“…In addition to the described effects regarding bone resorption, high PTH may also cause metastatic microcalcifications through elevations in cytosolic Ca (9,10). In rats, Borle et al (16) showed that high P-induced hyperparathyroidism caused nephrocalcinosis. Elevated levels of serum PTH induced intracellular Ca accumulation and Ca-P deposition in renal tissue (16).…”

“…In contrast, high dietary P induced a rapid deterioration of renal function (16). Phosphorus toxicity associates with renal calcium-phosphate precipitation and tubulointerstitial damage, resulting in acceleration of nephrocalcinosis (17).…”

Beneficial Effects of Aluminum on the Progression of Lead‐Induced Nephropathy in Rats

“…However, aluminum seems to protect lead-induced renal dysfunction in a time-and dose dependent manner. Aluminum has been shown to arrest the chronic renal disease in several experiments (Lemlertgul et al 1986;Shimamura & Okada. 1988).…”