Haemopoietic organs

The effect of androgens is promoted by various metabolites in a very subtle manner, subject to significant developmental change. It is currently advocated that 5j8-reduced metabolites act directly on erythropoietic stem cells, whereas 5 -reduced derivatives enhance the level of erythropoietin. Interestingly, mutant mice with testicular feminization (TfmlY) actively maintain erythropoiesis, suggesting that androgenic effects on red cell formation are not mediated by conventional receptor mechanisms antiandrogens are either of variable or no influence. 

As well reviewed elsewhere [2], the control exerted by 5a-reduced steroids on erythropoiesis is best explained by transcriptional control of the erythropoietin gene. Certainly, such androgens are actively concentrated in the nuclear chromatin of bone marrow, both in vivo and in vitro. By contrast, the situation is entirely different with respect to 5/3-reduced steroids. In the embryonic and fetal organs of many animals, aetiocholanolone or 5/3-DHT regulate the appearance of a 5 cap-recognition protein, without which the translation of the mRNAs for haemoglobin E (embry- 

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Antwerp University. 1990. Study of murine stroma in fetal and postnatal haemopoietic organs and after radiocontamination with 241-americium utero and as adults. Wilrijk, Belgium Department of Biology, Antwerp University. NTIS/DE92001322. 

Schoeters G, Van Den Heuvel R, Hurtgen C, et al. 1987. 241Am distribution in foetal haemopoietic organs of balb/c mice. In Age-related factors in radionuclide metabolism and dosimetry. Netherlands Kluwer Academic Publishers, 193-200. 

A clinical comparison of oxyphenbutazone with phenylbutazone has shown that the two drugs are similarly effective and that the incidence of side effects is the same . Other controlled trials of oxyphenbutazone have also been reported . As with amidopyrine, prolonged use of phenylbutazone and oxyphenbutazone has been restricted by the fear of dangerous side effects, particularly those on the blood and haemopoietic organs . ... 

The G-CSF receptor has been well characterized. It is a single transmembrane polypeptide found on the surface of neutrophils, as well as in various haemopoietic precursor cells, platelets, endothelial cells and, notably, various myeloid leukaemias. (Myeloid means derived from bone marrow leukaemia refers to a cancerous condition in which there is uncontrolled overproduction of white blood cells in the bone marrow or other blood-forming organs. The white cells produced are generally immature/abnormal and result in the suppression of production of healthy white blood cells.)... 

In the animal body, of course most of the cells stick to one another to form solid tissues and organs. The cells of one particular tissue, blood, are derived from stem cells in the haemopoietic tissue but are non-adhesive for the majority of their short, mature lives. Thus, blood was an early subject for calorimetric study, largely by some of the clinical scientists in Lund, the city that is the spiritual home of the LKB/Thermometric calorimeters. In the early days when batch vessels had no stirrers and were only rotated, the cells were pumped through a flow calorimeter because sedimentation in batch vessels caused the crowding effect (see Section 3.2.1) due to the onset of anoxic conditions. 

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