Glomerular Immunoglobulin Deposits Induce Glomerular Inflammation in Pregnant but not in Non-pregnant Rats

Authors

  • M.M. Faas,

    1. Reproductive Immunology, Division of Medical Biology, Department of Pathology and Laboratory Medicine, University of Groningen, Groningen, the Netherlands
    Search for more papers by this author
  • G. Van Der Schaaf,

    1. Reproductive Immunology, Division of Medical Biology, Department of Pathology and Laboratory Medicine, University of Groningen, Groningen, the Netherlands
    Search for more papers by this author
  • M. Schipper,

    1. Reproductive Immunology, Division of Medical Biology, Department of Pathology and Laboratory Medicine, University of Groningen, Groningen, the Netherlands
    Search for more papers by this author
  • H. Moes

    1. Reproductive Immunology, Division of Medical Biology, Department of Pathology and Laboratory Medicine, University of Groningen, Groningen, the Netherlands
    Search for more papers by this author

Address reprint requests to M.M. Faas, PhD, Reproductive Immunology, Division of Medical Biology, Department of Pathology and Laboratory Medicine, University of Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands.
E-mail: m.m.faas@med.rug.nl

Abstract

PROBLEM: Does an inflammatory stimulus evoke a more intense inflammatory response in pregnant rats as compared with non-pregnant rats?

METHOD OF STUDY: Non-pregnant rats were injected with antibodies against the glomerular basement membrane (GBM), 14 days before pregnancy, to induce a subclinical glomerulonephritis. Part of the rats were rendered pregnant, the others remained non-pregnant throughout the experiment. Two experiments were performed: in experiment 1, pregnant and non-pregnant rats were killed at various intervals after the injection with antibody and parameters characteristic of a glomerular inflammation were evaluated using immunohistology on cryostat kidney sections and liver sections. In experiment 2, 24-hr urinary protein excretion was measured at various days after the injection in pregnant and non-pregnant rats.

RESULTS: Experiment 1 revealed that a significant glomerular inflammation, as characterized by increased numbers of monocytes and LFA-1 positive cells per glomerulus, was only observed in pregnant rats with glomerulonephritis. Experiment 2 revealed that only pregnant rats with glomerulonephritis showed increased urinary protein excretion.

CONCLUSION: The fact that glomerular inflammation coincides with proteinuria only in pregnant rats with glomerulonephritis, may suggest that these phenomena are causally related and promoted by the pregnant condition.

Ancillary