Balance kidneys

Dendrimers are small (typically less than lOnm in diameter) in comparison to other drug-delivery vehicles such as linear polymers, micelles (50-200 nm), and liposomes (100-1000nm). The small size results in rapid renal filtration and elimination via the urine compared to larger carriers. To reach an effective therapeutic concentration of the drug in the tumor tissue, a dendritic drug carrier needs to balance kidney clearance and elimination via the fiver and reticuloendothelial system (RES) against the passive accumulation resulting from the EPR effect. RES clearance is more pronoimced for... 

Effects of repeated ethylene glycol peroral overexposure in treated rats and mice can result in kidney, Hver, and nervous system damage. The most sensitive indicators of ethylene glycol toxicity are disturbances in acid—base balance and nephrotoxic (kidney) effects. Effects of repeated chronic peroral overexposure of diethylene glycol in treated rats result in kidney and Hver damage (48). 

Bisoprolol fumarate is a long-acting, cardioselective -adrenoceptor blocker, and is the most potent cardioselective -adrenoceptor blocker available. Bisoprolol has no ISA. At high concentrations it has membrane-stabilizing activity. The dmg has a "balanced clearance", ie, half is excreted by the kidneys and half is eliminated by the Hver and its excretion is not affected by functional impairment of either organ. It is approved in Europe for hypertension and is being studied in angina (43). 

The integrity of mammalian kidneys is vital to body homeostasis, because the kidneys play the principal role in the excretion of metabolic wastes and the regulation of extracellular fluid volume, electrolyte balance, and acid-base... 

Aldosterone, the most potent of the mineralocorticoids (Figure 25.43), is involved in the regulation of sodium and potassium balances in tissues. Aldosterone increases the kidney s capacity to absorb Na, Cl, and HgO from the glomerular filtrate in the kidney tubules. 

AQP6 is expressed in the intercalated cells of the kidney collecting duct. This channel is hardly permeable to water, but capable of transporting anions, including chloride, and is therefore thought to play a role in maintenance of body acid-base balance or in intracellular vesicle acidification. 

Til tee successive tubule portions contribute to the ASDN the late portion of the distal convoluted tubule, the connecting tubule, and the collecting duct. The recent observation that collecting duct-specific inactivation of aENaC in the mouse kidney does not impair sodium and potassium balance, suggests that the more proximal nephron segments (late distal convoluted tubule, connecting tubule) are mainly important for-achieving sodium and potassium balance. 

Respiration—transport of oxygen from the lungs to the tissues and of COj from the tissues to the lungs Nutrition—transport of absorbed food materials Excretion—transport of metabolic waste to the kidneys, lungs, skin, and intestines for removal Maintenance of the normal acid-base balance in the body... 

Reduction in dietary protein intake has been shown to slow the progression of kidney disease.8 However, protein restriction must be balanced with the risk of malnutrition in patients with CKD. Patients with a GFR less than 25 mL/minute/ 1.73 m2 received the most benefit from protein restriction 8 therefore, patients with a GFR above this level should not restrict protein intake. The NKF recommends that patients who have a GFR less than 25 mL/minute/1.73 m2 who are not receiving dialysis, however, should restrict protein intake to 0.6 g/kg per day. If patients are not able to maintain adequate dietary energy intake, protein intake maybe increased up to 0.75 g/kg per day.15 Malnutrition is common in patients with ESRD for various reasons, including decreased appetite, hypercatabolism, and nutrient losses through dialysis. For this reason, patients receiving dialysis should maintain protein intake of 1.2 g/kg per day to 1.3 g/kg per day. 

Sodium and water balance are primarily regulated by the kidney Reductions in nephron mass decrease glomerular filtration and subsequent reabsorption of sodium and water, leading to edema. 

Sodium and water balance can be maintained despite wide variations in intake with normal kidney function. The fractional excretion of sodium (FENa) is approximately 1% to 3%... 

The kidney is unable to adjust to abrupt changes in sodium intake in patients with severe CKD. Therefore, patients should be advised to refrain from adding salt to their diet, but should not restrict sodium intake. Changes in sodium intake should occur slowly over a period of several days to allow adequate time for the kidney to adjust urinary sodium content. Sodium restriction produces a negative sodium balance, which causes fluid excretion to restore sodium balance. The resulting volume contraction can decrease perfusion of the kidney and hasten the decline in GFR. Saline-containing intravenous (IV) solutions should be used cautiously in patients with CKD because the salt load may precipitate volume overload. 

Potassium balance is also primarily regulated by the kidney via the distal tubular cells. Reduction in nephron mass decreases tubular secretion of potassium, leading to hyperkalemia. Hyperkalemia is estimated to affect more than 50% of patients with stage 5 CKD.28... 

As kidney function declines, bicarbonate reabsorption is maintained, but hydrogen excretion is decreased because the ability of the kidney to generate ammonia is impaired. The positive hydrogen balance leads to metabolic acidosis, which is characterized by a serum bicarbonate level of 15 to 20 mEq/L (15 to 20 mmol/L). This picture is generally seen when the GFR declines below 20 to 30 mL/minute.38... 

The posterior pituitary is innervated by direct nervous stimulation from the hypothalamus, resulting in the release of specific hormones. The hypothalamus synthesizes two hormones, oxytocin and vasopressin. These hormones are stored in and released from the posterior pituitary lobe. Oxytocin exerts two actions (1) it promotes uterine contractions during labor, and (2) it contracts the smooth muscles in the breast to stimulate the release of milk from the mammary gland during lactation. Vasopressin is an antidiuretic hormone (ADH) essential for proper fluid and electrolyte balance in the body. Specifically, vasopressin increases the permeability of the distal convoluted tubules and collecting ducts of the nephrons to water. This causes the kidney to excrete less water in the urine. Consequently, the urine becomes more concentrated as water is conserved. 

Renin-angiotensin-aldosterone system (RAAS) The hormonal system controlled mainly by the kidneys and adrenal glands that regulates blood pressure, blood volume, and electrolyte balance. 

The kidneys are organs specialized to filter the blood. As such, they make an important contribution to the removal of metabolic waste products as well as to maintenance of fluid and electrolyte balance. Specific functions of the kidneys include ... 

Although the kidneys are not considered endocrine glands per se, they are involved in hormone production. Erythropoietin is a peptide hormone that stimulates red blood cell production in bone marrow. Its primary source is the kidneys. Erythropoietin is secreted in response to renal hypoxia. Chronic renal disease may impair the secretion of erythropoietin, leading to development of anemia. The kidneys also produce enzymes. The enzyme renin is part of the renin-angiotensin-aldosterone system. As will be discussed, these substances play an important role in the regulation of plasma volume and therefore blood pressure. Other renal enzymes are needed for the conversion of vitamin D into its active form, 1,25-d i hyd ro xyv itamin D3, which is involved with calcium balance. 

Muscles (heart, etc.) Stomach/intestine Liver Kidney (bowel) Reproductive organs Glands Brain (Chapter 9) Sense organs Digestion, fluid circulation, motion, mechanical work Major zones of digestion Major zone of synthesis Major external rejection ion/water balance Reproduction Chemical controls Electrical control Environmental detectors... 

Normally everything is in balance. The lungs have the numerator (pC02), and the kidneys have the denominator ([HCO 3]). The amount of C02 produced by metabolism is balanced by the amount of C02 blown off by the lungs and let go by the kidney. It s the same way with the other metabolic acids—they leave the body as C02 or they are excreted by the kidneys. If everything always stayed in balance, you wouldn t have to learn all this—but as usual it doesn t, and you do. 

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