Erythropoietm and the Kidney

Abstract

Erythropoietin is a polypeptide hormone, which is produced in response to a deficit in the delivery of oxygen to the tissues relative to their oxygen needs; although other feedback mechanisms also modulate its production. The kidneys play a major role in the elaboration of this hormone. However, the precise action of the kidney is not yet known. Diseases of the kidneys cause profound alteration in the normal regulation of erythropoiesis. Some of these are reviewed here.

On the Inhibitory Effect of the Serum of Uraemic Children on Erythropoiesis

“…These results agree with those obtained by a great number of authors [3,18,19,43,49]. The lowered reticulocyte count reflects the hyporegeneration of the anaemia.…”

“…This hormone is a glyco protein with a molecular weight of about 41,000, which acts on the differentiation of the erythroid stem cells [23, 24, 44, 48J. The main site of ESF production is the kid ney [14,19].So far there is only little and contradic tory information available on the inhibitory factors of erythropoiesis. Inhibitory factors were found in the serum of polycythaemic animals after transfusion [15,27,31,51], in highlanders that were rapidly moved down to sea level [41,45], and in the plasma and urine of newborn children [8,28,36].…”

“…A hyporegeneratory anaemia devel ops with an increasing restriction of kidney function. There exists a close relationship between the degree of kidney insufficiency and the degree of anaemia [19,38,49], Re duction of ESF production is certainly one of the causes of renal anaemia. This situa…”

Hyperparathyroidism and Anemia in Chronic Renal Failure

“…The etiology is multifactorial, but is usually associated with decreased erythropoietin production and a hypoplastic bone marrow [5]. Recently, the occurrence of myelofibrosis in chronic renal failure has been described and an association with severe hyperparathyroidism is suggested [6,8].…”

Serum Erythropoietin Concentration in Anephric Patients

“…The anephric state is nearly always accom panied by severe anemia [9,21], which is be lieved to be primarily caused by erythropoietin (Ep) deficiency [6,22], Several investigators were able to demonstrate Ep in the serum of bilateral nephrectomized patients, proving the existence of extrarenal production sites for Ep [2,5,7,[13][14][15]. However, in the majority of the studies performed the percentage of sera with measureable Ep activity was small [5,7,14,15].…”