Pc. Singhal et al., MORPHINE MODULATES CATHEPSIN-B AND CATHEPSIN-L ACTIVITY IN ISOLATED GLOMERULI AND MESANGIAL CELLS, Inflammation, 19(1), 1995, pp. 67-73
Altered matrix degradation may be playing a role in the development of
initial mesangial expansion and subsequent glomerulosclerosis in pers
ons with heroin abuse. We studied whether morphine, a metabolite of he
roin, had any effect on lysosomal content of cathepsin B and L in mesa
ngial cells. Morphine (10(-6) M) increased (P < 0.01) mesangial cathep
sin B and L activity (control, 22.1 +/- 2.2 vs. morphine, 31.4 +/- 1.4
mol NMec/mu g protein, N = 5). Morphine (10(-6) M) also increased (P
< 0.01) glomerular cathepsin B and L activity (control, 0.1 +/- 0.01 v
s. morphine, 2.2 +/- 0.2 pmol NMec/mu g protein, N = 3). This effect o
f morphine occurred in a dose-dependent manner. These results suggest
that morphine enhances cathepsin B and L activity in mesangial cells a
nd isolated glomeruli. This effect of morphine may enhance capacity of
mesangial cells to degrade increased amount of mesangial macromolecul
es.