ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
Sites of aminopeptidase activity in the thymus of the mouse were compared in material incubated in L-leucyl-beta-naphthylamide and in L-leucyl-4-methoxy-beta-naphthylamide hydrochlorides as substrates. Sites of activity were most clearly demonstrated in frozen sections, postfixed in cold acetone, incubated in L-leucyl-4-methoxy-beta-naphthylamide hydrochloride with Naphthanil Diazo Blue B and mounted in glycerogel.In thymuses of young mice, septa, medullary arteries and arterial capillaries were most strongly stained. Cortical lymphocytes and most medullary lymphocytes lacked aminopeptidase activity. In older mice, the high reactivity of the medulla contrasted sharply with the mostly unreactive cortex. In the medulla, the walls of the blood vessels, mesenchymal reticular cells and lymphocytes in the region of blood vessels were reactive. In the cortex, capsule, septa, and arterial capillaries were reactive; mesenchymal reticular cells, weakly so, and lymphocytes, unreactive. It would appear that much of the activity demonstrated by biochemical methods applied to thymic homogenates is a measure of reactive blood vessels and medullae. The general reaction of the medulla and the presence there of scattered, highly reactive cells lends added weight to the conclusion that the metabolic activities within the medulla are not the same as in the cortex.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1091580205
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