A canine model of induced purine nucleoside phosphorylase deficiency
Osborne, W.R.; Deeg, H.J.; Slichter, S.J.
Clinical and Experimental Immunology 66(1): 166-172
1986
ISSN/ISBN: 0009-9104 PMID: 3026696 Document Number: 273130
Purine neucleoside phosphorylase (NP EC 2.4.2.1) deficiency in man is associated with selective T cell dysfunction and normal B cell immunity. To create an in-vivo model of this immune deficiency, we administered 8-aminoguanosine to dogs. This water soluble nucleoside was rapidly converted by NP to the more potent product inhibitor 8-aminoguanine, which had a Ki of 0.52 .mu.M. The accumulation of inosine and exogenous deoxyguanosine in plasma provided evidence that administration of 8-aminoguanosine was effectively inhibiting NP activity. Four dogs given 8-aminoguanosine and deoxyguanosine concurrently for 5 consecutive days showed mean reductions in peripheral blood lymphocytes of 65 .+-. 9% range (55-75%) over the test period. Granulocytes, red blood cells, and plateletes remained within the normal range. Administration of 8-aminoguanosine to dogs provides a model of NP deficiency that will permit studies of the specific control of lymphopoiesis and in-vivo immune function.