Effects of vasoactive agents on uptake of immunoglobulin G complexes by mesangial cells.
Mesangial handling of immune complexes may be important in immune injury. We examined whether vasoactive agents, independent of hemodynamic effects, could directly influence uptake of immunoglobulin G (IgG) complexes by mesangial cells (MC). Under basal conditions, MC took up more gold particles coated with IgG2b (P less than 0.05) than coated with IgG2a. Preincubation of MC with angiotensin II (ANG II) (5 x 10(-7) M) resulted in enhancement of uptake (P less than 0.05) of IgG2b-gold [7,578 +/- 968 counts per minute (cpm) per well], IgG2a-gold (4,566 +/- 295 cpm/well; P less than 0.01), and bovine serum albumin (BSA)-gold (2,532 +/- 66; P less than 0.05) when compared with respective controls (IgG2b-gold, 5,513 +/- 762 cpm/well; IgG2a-gold, 3,282 +/- 439; BSA-gold, 2,279 +/- 97). Cytochalasin B produced a significant reduction of uptake of IgG2b-gold (2,224 +/- 88 cpm/well) when compared with the uptake by control cells (3,711 +/- 287 cpm/well) (P less than 0.05). Pretreatment of MC with atrial natriuretic peptide (ANP, 10(-9) M) slightly decreased uptake of IgG-gold under basal conditions (P less than 0.05) and decreased the response to ANG II (P less than 0.05). Similarly, dopamine (DA, 10(-6) M) attenuated uptake of IgG2b-gold under basal (P less than 0.01) as well as ANG II-stimulated (P less than 0.01) states. ANP increased mesangial guanosine 3',5'-cyclic monophosphate (cGMP), DA, adenosine 3',5'-cyclic monophosphate (cAMP) content.(ABSTRACT TRUNCATED AT 250 WORDS)
Singhal
P C
PC
Department of Medicine, Long Island Jewish Medical Center, New Hyde Park, New York 11042.
Santiago
A
A
Satriano
J
J
Hays
R M
RM
Schlondorff
D
D
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis; D003571:Cytochalasin B / Q000494:pharmacology; D003995:Dibutyryl Cyclic GMP / Q000494:pharmacology; D004298:Dopamine / Q000494:pharmacology*; D005920:Glomerular Mesangium / Q000166:cytology / Q000378:metabolism*; D006046:Gold / Q000378:metabolism; D007074:Immunoglobulin G / Q000378:metabolism*; D011961:Receptors, Fc / Q000378:metabolism; D012710:Serum Albumin, Bovine / Q000378:metabolism; D013997:Time Factors
D007074:Immunoglobulin G; D011961:Receptors, Fc; D000804:Angiotensin II; D012710:Serum Albumin, Bovine; D003995:Dibutyryl Cyclic GMP; D003571:Cytochalasin B; D003994:Bucladesine; D006046:Gold; D009320:Atrial Natriuretic Factor; D000242:Cyclic AMP; D004298:Dopamine