Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1985-11-7
pubmed:abstractText
Inherited deficiency of the enzyme adenosine deaminase (ADA) has been found in a significant proportion of patients with severe combined immunodeficiency disease and inherited defect generally characterized by a deficiency of both B and T cells. Two questions are central to understanding the pathophysiology of this disease: (1) at what stage or stages in lymphocyte development are the effects of the enzyme deficiency manifested; (2) what are the biochemical mechanisms responsible for the selective pathogenicity of the lymphoid system. We have examined the stage or stages of rat T-cell development in vivo which are affected by an induced adenosine deaminase deficiency using the ADA inhibitors, erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) and 2'-deoxycoformycin (DCF). In normal rats given daily administration of an ADA inhibitor, cortical thymocytes were markedly depleted; peripheral lymphocytes and pluripotent hemopoietic stem cells (CFU-S) all were relatively unaffected. Since a deficiency of ADA affects lymphocyte development, the regeneration of cortical and medullary thymocytes and their precursors after sublethal irradiation was used as a model of lymphoid development. By Day 5 after irradiation the thymus was reduced to 0.10-0.5% of its normal size; whereas at Days 9 and 14 the thymus was 20-40% and 60-80% regenerated, respectively. When irradiated rats were given daily parenteral injections of the ADA inhibitor plus adenosine or deoxyadenosine, thymus regeneration at Days 9 and 14 was markedly inhibited, whereas the regeneration of thymocyte precursors was essentially unaffected. Thymus regeneration was at least 40-fold lower than in rats given adenosine or deoxyadenosine alone. Virtually identical results were obtained with both ADA inhibitors, EHNA and DCF. The majority of thymocytes present at Day 9 and at Day 14 in inhibitor-treated rats had the characteristics of subcapsular cortical thymocytes which are probably the most ancestral of the thymocytes. Thus, an induced ADA deficiency blocked the proliferation and differentiation of subcapsular cortical thymocytes which are the precursors of cortical and medullary thymocytes.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0008-8749
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
95
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
297-310
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
The effects of an induced adenosine deaminase deficiency on T-cell differentiation in the rat.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.