Effect of estradiol and progesterone on the low-dose endotoxin-induced glomerular inflammatory response of the female rat

Faas MM, Bakker WW, Valklzof N, Schuiling GA. Effect of estrudiol and progesterone on the low-dose endoto.uin-induced glonzerular inj7ainmatorj response of’ the fernule rat. AJRI 1999; 41:224-231 0 Munksguurd, Copenhugen PROBLEM: Is the endotoxin-induced glomerular inflammatory response of the female rat under ovarian control? METHOD OF STUDY: Ovariectomized rats (OVX), with or without progesterone (OVX-P) or estradiol (OVX-E) treatment, as well as rats in the follicular or luteal phase of the ovulatory cycle were infused with endotoxin or saline and sacrificed 3 days later. Cryostat kidney sections were immunohistologically stained for the presence of neutrophils and monocytes (M0) and the expression of adhesion molecules. RESULTS: After endotoxin, the glomerular number of neutrophils and the number of MAC-1 positive cells were increased in luteal-phase and in OVX-P rats, and the number of glomerular M0 was increased in luteal-phase, OVX, OVX-E, and OVX-P rats. Endotoxin increased ICAM-1 expression in all groups of rats, except in follicularphase rats. The glomerular number of LFA-1 - and VLA-4-positive cells following endotoxin were only increased in OVX rats. CONCLUSIONS: It is concluded that endotoxin-induced monocyte infiltration and ICAM-1 expression are inhibited by a factor produced during the follicular phase, probably by developing follicles. Infiltration of neutrophils and expression of MAC-1, LFA-I, VLA-4 seem to be under control of progesterone or estradiol.