The effect of azathioprine (Imuran) on the kinetics of monocytes and
macrophages during the normal steady state and an acute inflammatory
reaction
AE Gassmann and R van Furth
The effect of azathioprine on the kinetics of peripheral blood monocytes
and peritoneal macrophages was studied in normal mice and in mice in which
an inflammatory reaction was provoked. Two dosage levels were used: a high
dose of 200mg/kg which is the maximum tolerated daily dose in mice, and low
dose of 3 mg/kg which is about equivalent to a nontoxic, immunosuppressive,
anti-inflammatory dose in man. The number of peripheral blood monocytes
decreases gradually during azathioprine treatment of normal mice, the
extent and duration being dependent on the dose and duration of
administered over a period of 9 days gives an almost complete reduction,
and a low dose (3 mg/kg) given for the same period results in a reduction
of about 50%. This effect seems to be reversible, because when treatment is
stopped the number of monocytes starts to increase 24-48 hr later. The
number of peritoneal macrophages is only affected when a high dose (200
mg/kg) is given over a long period; a low dose has virtually no effect. In
mice in which an inflammatory reaction was prevoked in the peritoneal
cavity, the normally occurring increase in the numbers of both peripheral
blood monocytes and peritoneal macrophages was suppressed, the extent being
dependent on the dose of azathioprine administered. Labeling studies with
3H-thymidine indicated that the reduction of peripheral blood monocytes and
peritoneal macrophages in the inflammatory exudate is due to a diminished
monocyte production.
Volume 46,
Issue 1,
pp. 51-64,
07/01/1975
Copyright © 1975 by The American Society of Hematology
