GENERAL PRINCIPLES

1 GENERAL PRINCIPLES



Shannon Jones Hostetter, Claire B. Andreasen



1 What is erythropoietin, where is it produced, and what are its principal effects?


Erythropoietin is a glycoprotein hormone produced by the peritubular capillary endothelium of the kidney in response to reduced oxygen tension (hypoxia). Erythropoietin’s principal site of action is the bone marrow.


The effects of erythropoietin include stimulation of growth and differentiation of both erythroid and platelet progenitors and the induction of hemoglobin synthesis in dividing erythrocyte precursors. Increased erythropoietin release can ultimately lead to increased hematocrit, total red blood cell (RBC) numbers, and platelet count.



2 How is iron, either dietary or recycled, transported through the body?


Iron is transported in the blood by transferrin, a β-globulin (serum protein), from the site of absorption in the intestine or from macrophage stores to the marrow and tissues. Iron can then be incorporated into hemoglobin during heme synthesis.



3 How are aged or damaged erythrocytes normally removed from circulation?


Aged or damaged erythrocytes have changes in either their cell membranes or cytosolic enzymes that allow them to be recognized by macrophages within the spleen and liver. These erythrocytes are subsequently phagocytosed by the macrophages and removed from circulation. Additionally, a small percentage of “old” or abnormal erythrocytes are removed from circulation through intravascular hemolysis.



4 What is the average erythrocyte life span in the dog and cat?


The average RBC life span in the dog is approximately 110 days. It is significantly shorter in the cat, approximately 70 days.

Related posts:

  1. ERYTHROCYTE DISORDERS
  2. MYELODYSPLASTIC SYNDROMES
  3. LABORATORY TESTING FOR THYROID DISEASE
  4. METABOLIC ACID-BASE ABNORMALITIES

Stay updated, free articles. Join our Telegram channel
Tags:
Aug 26, 2016 | Posted by in INTERNAL MEDICINE | Comments Off on GENERAL PRINCIPLES

Full access? Get Clinical Tree
Get Clinical Tree app for offline access