Erythropoietin secretion decreases in

(Highly crushed renal disease) (677-Ganong 23rd) (459-60-GN) (422-23-Guyton 11th) (72-A.K. Jain 3rd)ERYTHROPOIETIN is a glycoprotein, secreted by peritubular capillaries in the kidney. The principal site of inactivation of erythropoietin is the liver.* * Hypoxia is the main stimulant for the secretion of erythropoitin* Secretion of the hormone is fascilitated by alkalosis that develops at high altitudes* Both norepinephrine and epinephrine and several of the prostaglandins stimulate erythropoietin production (385-Gyton 10th)Anemia in CRF caused by decreased erythropoietin secretion (376-Gyton 10th)Patients with severe CRF, (when renal mass is reduced) or nephrectomy, almost always develop anaemia. The most important cause of this is decreased renal secretion of erythropoietin, which stimulates the bone marrow to produce red blood cells. If the kidneys are seriously damaged, they are unable to form adequate quantities of erythropoietin, which leads to diminished red blood cell production and consequent anemia.Factors affecting Erythropoietin productionIncreaseDecrease1. Hypoxia due to haemorrhage, high altitude, Cardio respiratory disturbance methaemoglobin excess2. Vasoconstrictor agent (Catecholamines) due to renal hypoxia3. Nucleotides eg cAMP NAD an NADP4. Products of RBC destruction called haemolysates5. Hormones - Thyroxine, Anterior pituitary hormone, androgens6. Others Cobalt salts1. Oestrogena. Decrease hepatic synthesis of globinb. Depress the erythropoietic response to hypoxiaThis is why in female, RBC count is less as compared to males2. Chronic renal disease3. Protein deficiency4. Cirrhosis of liver5. Chronic inflammatory diseases