On the natural tendency to progressive loss of remaining kidney function in patients with impaired renal function

What role does dietary protein restriction play in the management of chronic renal failure in dogs?

Dietary protein restriction has been the mainstay of conservative medical management of canine renal failure for many years. Although dietary protein restriction minimizes many signs of uremia, its potential benefits to the progression of renal failure are now being questioned. Two case scenarios of different degrees of renal failure are described; guidelines for dietary protein restriction are based on currently available scientific knowledge.

Hypertension and endstage renal disease

OBJECTIVE

To review current literature regarding the development of hypertensive renal disease, its epidemiology, and its pathophysiology. This review focuses on strategies to slow or halt the progression of endstage renal disease (ESRD) in hypertension, including the role of blood pressure control, different types of antihypertensive agents, early treatment, and dietary considerations.

DATA SOURCES

Information was retrieved from searching the MEDLINE database for articles consisting of epidemiologic studies, clinical studies, and review articles pertaining to hypertension and ESRD. Information also was obtained from the US Renal Data System annual data reports.

STUDY SELECTION

Emphasis was placed on clinical trials in the English language addressing issues in hypertension and ESRD. Clinical trials reporting relationships between blood pressure control and ESRD, as well as those comparing different antihypertensive agents, were evaluated.

DATA EXTRACTION

The methodology and results from clinical trials were evaluated. Studies were assessed according to the measures of renal function used, baseline data collected, degree of blood pressure control, and antihypertensive therapy.

DATA SYNTHESIS

Clinical trials including patients with essential hypertension, diabetes mellitus, and renal insufficiency of various etiologies were evaluated. The recommendations from these evaluations were based on study design and the types of populations used (i.e., blacks vs. whites, diabetics vs. nondiabetics).

CONCLUSIONS

Blood pressure control is currently the most important strategy to slow or halt the progression of renal insufficiency in hypertensive individuals. Whether specific antihypertensives are renal protective is still controversial, but results from clinical trials are promising.

LDL stimulates mesangial fibronectin production and chemoattractant expression

Hyperlipidemia has been associated with glomerulosclerosis and a glomerular monocyte infiltrate in models of progressive renal insufficiency. The pathogenesis of hyperlipidemia-induced renal injury remains unknown. We postulated that the effect of hyperlipidemia may be mediated through LDL-induced activation of mesangial cells, which have recently been shown to possess LDL receptors. To test this hypothesis, cultured human mesangial cells were co-incubated with human LDL. Monolayers treated with LDL demonstrated a greater level of tissue culture supernatant fibronectin than control mesangial cells. This correlated with enhanced expression of fibronectin mRNA in LDL-treated mesangial cells. Additionally, LDL conditioning of mesangial cells caused a dose- and time-dependent increase in the expression of monocyte chemoattractant protein-1 mRNA, a monocyte specific chemotactic factor, as well as an increase in the monocyte chemotactic activity of mesangial supernatants. Thus, the deleterious effects of hyperlipidemia on the kidney may be mediated by the mesangial cell through an increase in production of mesangial matrix and recruitment of inflammatory cells to the glomerulus.