AJP - Renal Physiology, Vol 261, Issue 3 537-F544, Copyright © 1991 by American Physiological Society
Effects of PGE2 and a thromboxane A2 analogue on uptake of IgG complexes and LDL by mesangial cells
P. C. Singhal, S. Gupta, Z. Shen and D. Schlondorff
Department of Medicine, Long Island Jewish Medical Center, New Hyde Park, New York 11042.
Vasoactive agents such as angiotensin (ANG) and eicosanoids can influence
macromolecular deposition in the glomerular mesangium. We studied whether
prostaglandin E2 (PGE2) and U-46619 (a stable analogue of thromboxane A2)
could directly affect the uptake of immunoglobulin G (IgG) complexes or
low-density lipoprotein (LDL) by cultured rat mesangial cells (MC).
Preincubation of MC with PGE2 (10(-6) M) resulted in decreased uptake (in
counts.min-1.well-1) of IgG complexes (PGE2, 2,589 +/- 72; control, 3,840
+/- 114; P less than 0.001) and LDL particles (PGE2, 23,176 +/- 1,145;
control, 37,216 +/- 4,520; P less than 0.05). MC preincubated with
forskolin (10(-5) M) also showed decreased uptake of IgG complexes
(forskolin, 2,896 +/- 196; control, 3,840 +/- 114; P less than 0.005) and
LDL particles (forskolin, 23,176 +/- 1,145; control, 37,216 +/- 4,520; P
less than 0.05). In contrast, preincubation with ANG II (5 x 10(-7) M)
showed significantly higher uptake of IgG complexes (ANG II, 4,475 +/- 282;
control, 3,787 +/- 277; P less than 0.05) and LDL (ANG II, 48,573 +/-
1,079; control, 44,697 +/- 770; P less than 0.05). Similarly, preincubation
with U-46619 (10(-6) M) resulted in significantly higher uptake of IgG
complexes (U-46619, 5,370 +/- 300; control, 3,659 +/- 307; P less than
0.02) and LDL (U-46619, 48,298 +/- 1,418; control, 44,697 +/- 770; P less
than 0.05). After preincubation with cyclooxygenase inhibitor meclofenamate
(10(-6) M), ANG II (5 x 10(-7) M) resulted in a significantly higher uptake
of IgG complexes compared with uptake by MC treated with ANG II alone (P
less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
