Kidney endocrine functions

Adrenal gland A triangle-shaped organ positioned at the top of the kidney which functions as a double endocrine gland . The larger outer adrenal cortex secretes three classes of steroid hormones glucocorticoids (e.g., cortisol), minerlocorticoids (aldosterone) and small amounts of sex steroids (e.g., testosterone). The inner adrenal medulla secretes catecholamines (e.g., adrenaline and noradrenaline). 

In addition to their involvement in excretion and metabolism, the kidneys also have endocrine functions. They produce the hormones erythropoietin and calcitriol and play a decisive part in producing the hormone angiotensin II by releasing the enzyme renin. Renal prostaglandins (see p. 390) have a local effect on Na resorption. 

This chapter will review current activities and proposed research related to the development of artificial organs and organ-assist devices. While we will focus on the human liver, the discussion is applicable to other organs. The pancreas and the endocrine functions of the kidney follow the same basic path — the culturing of cells on a scaffold. The cells, of course, must function as they do in a natural uncompromised slate while the scaffold provides a permanent or temporary template on which the cells attach and proliferate. 

The kidney is an organ that performs several important functions essential to sustain life. These functions include the regulation of volume and electrolyte homeostasis, control of acid-base balance, and the excretion of waste products. The kidney also has endocrine functions including renin secretion, stimulation of erythropoietin formation, and activation of vitamin D. Numerous disease states (e.g., infections, shock, diabetes, gout) can affect the ability of the kidney to perform its normal functions, and if these diseases are not properly treated, serious illness or death can result. 

In mammalian species, the two kidneys carry out the normal physiological and endocrine functions... 

The endocrine functions of the kidneys may be regarded either as primary, because the kidneys are endocrine organs producing hormones, or as secondary, because the kidneys are a site of action for hormones produced or activated elsewhere. In addition, the kidneys are a site of degradation for hormones such as insuhn and aldosterone. In their primary endocrine function, the kidneys produce erythropoietin (EPO), prostaglandins and thromboxanes, renin, and 1,25(0H2)D3. 

In addition to the consequences of reduced excretory, regulatory, and endocrine function of the kidneys, the uremic syndrome has several systemic manifestations—among them pericarditis, pleuritis, disordered platelet and granulocyte function, and encephalopathy— that have been difficult to explain. 

The Chinese Kidney not only controls fluid metabolism but also stores Jing, or the life force, the primal essence. Without Jing there is no life, no growth, no maturation, no sexual activity or procreation. The Chinese Kidneys control reproductive functions and certain endocrine functions (especially adrenal activity), and, as previously mentioned, governs fluid metabolism. 

Tincture or Tea Formula for Anorexia and Asthenia This formula combines herbs that strengthen the lungs, Chinese Spleen, and Chinese Kidney. It also builds Blood (Xue) and increases energy, endocrine function, and immune response. It is appropriate for weak, deficient people, especially those with anorexia or anemia, andfor thin, tired, asthenic vegans. 

Suboptimal erythropoiesis can be classified by changes in the size of RBCs noted on examination of the peripheral blood. Because the excretory and endocrine functions of the kidney usually mirror each other, renal dysfunction can lead to anemia by reduction in EPO production, resulting in a normochromic, normocytic pattern. Other causes of insufficient erythropoiesis include replacement of bone marrow by fibrosis, solid tumors, or leukemia, as well as defects in erythroid maturation. Relative deficiencies in the cofactors required for heme-RBC synthesis such as iron, folate, and vitamin B may also be important contributors. Structurally, RBC macrocytosis denotes defects in the maturation of the nucleus, whereas microcytosis is indicative of cytoplasmic defects (reduced hemoglobin synthesis). (A detailed description regarding the pathogenesis and treatment of anemic disorders is found in Chap. 99.)... 

In addition, the kidneys have direct endocrine functions. Because they are a major site of synthesis of several hormones, including erythropoietin and 1,25-dihydroxy-cholecalciferol, the kidneys indirectly influence the regulation of blood pressure and vasopressor activity via the renin-angiotensin, prostaglandins, and kallekrein-kinin systems, which exert a regulatory effect on water and electrolyte homeostasis (Harris 1992 Parekh et al. 1993 Gonzalez et al. 1998 Campean et al. 2003 see also Chapters 6 and 10). 

The pathophysiological effects of PG cannot readily be isolated from those of many other hormones and factors which regulate the haemodynamic, tubular and endocrine functions of the kidneys. It is clear that renal PG play a central role in water metabolism and renin release, whereas the effect of PG on transepithelial transport and the pathogenetic potential of other eicosanoids, such as leukotrienes, have not been fully explored. In addition, recent studies have supported the concept that enhanced generation of the vasoconstrictor, TXA2, is prominent in many experimental models of... 

The kidney is a complex and cmcial excretory organ that plays an important role in numerous regulatory processes that include fluid and electrolyte balance (i.e., ultrafiltration, reabsorption, and secretion), control of blood pressure and volume, acid-base balance, and removal of waste products. It also has a significant endocrine function (Stockham and Scott 2008) and plays an important role in dmg disposition, i.e., the absorption, distribution, metabolism, and excretion (ADME) of dmgs. 

Kidneys, pineal gland, and Ihymus may also be considered by some as endocrine glands, and during pr nancy, Ihe placenta has some endocrine functions. The anterior pituitary is also called the adenohypophysis while the posterior ptuitary may he called the neurohypophysis. 

It should be mentioned that while historically dialyzers have been called artificial kidneys, dialysis does not replace the kidneys endocrine or metabolic functions. As a result, dialysis patients are given erythropoietin and intravenous vitamin D analogs to address their anemia and bone disease. This chapter will focus only on the excretory functions carried out by hemodialysis. 

Although current dialysis therapy is life-sustaining, its simple physical transport processes cannot replace the complex transport, metabolic, and endocrine functions of the tubular cells. A bioartificial kidney that includes a conventional dialysis filter and a renal tubule assist device (RenaMed Biologies, formerly Nephros Therapeutics) containing approximately 10 renal proximal tubule cells was recently successfiiUy engineered (Tiranathanagul et al., 2005 Humes et al., 1999). In the renal tubule device, cells are... 

In addition to being involved in the formation of urine, the kidney acts as an endocrine organ secreting renin, erythropoietin, prostaglandins (qv), and kinins it is also capable of synthesizing substances such as la,25-dihydroxycholecalciferol [32222-06-3] One of the principal functions of the... 

The kidneys are located on the posterior part of the abdomen on either side of the spine, below the diaphragm, and behind the liver and stomach. They are bean-shaped and weigh approximately 150 grams (0.33 lb) each. The primary function of the kidneys is excretion. They work to excrete waste products through a series of steps involving glomerular filtration, secretion, and reabsorption. The kidneys also have several endocrine (e.g., production of erythropoietin and renin) and metabolic (e.g., vitamin D activation and drug metabolism) functions. 

The endocrine system is an anatomically diverse assemblage of organs, united by the common fnnetion of secreting hormones. Organs, with qnite different fnnetions, inclnding the kidney, liver and intestine, also secrete hormones and, in this sense, they too are part of the endocrine system. In a functional sense, the endocrine system also inclndes the blood which transports hormones to their target cells, tissues or organs. 

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