Role of P-selectin and nitric oxide in leukocyte-endothelial interaction in the rat mesenteric microcirculation

Kelly Lyn Davenpeck, Thomas Jefferson University

Abstract

P-selectin, a member of the selectin family of adhesion molecules, is believed to play a significant role in mediating leukocyte-endothelial interaction during the inflammation response. To examine the role of P-selectin in the rat mesenteric microcirculation following splanchnic arterial occlusion/reperfusion (SAO/R), pentobarbital anesthetized rats were subjected to 60 minutes of celiac and superior mesenteric artery occlusion followed by 120 minutes of reperfusion. SAO/R resulted in a significant increase in P-selectin expression on the venular endothelium as determined immunohistochemically. This increase in P-selectin expression correlated to a significant increase in leukocyte rolling along and adherence to the venular endothelium as observed via intravital microscopy. Administration of the P-selectin neutralizing monoclonal antibody, PB1.3, 10 minutes prior to reperfusion significantly attenuated leukocyte rolling and leukocyte adherence following splanchnic ischemia-reperfusion, thus indicating a significant role for P-selectin in splanchnic ischemia-reperfusion induced leukocyte-endothelial interaction in the rat. Blocking leukocyte-endothelial interaction in this manner, significantly decreased leukocyte accumulation in the post-ischemic tissue as quantified by tissue myeloperoxidase activity, and decreased tissue injury as evidenced by a decreased plasma free amino-nitrogen concentration. Similarly, administration of the potent nitric oxide donor S-nitroso-N-acetylpenicillamine (SNAP) just prior to reperfusion significantly attenuated the ischemia-reperfusion induced increases in leukocyte-endothelial interaction. Immunohistochemical localization of P-selectin following SAO/R in SNAP treated rats revealed a significant decrease in ischemia-reperfusion induced P-selectin expression, thus indicating a regulatory role for nitric oxide in P-selectin expression. To confirm the relationship between nitric oxide and endothelial expression of P-selectin, endothelial NO was directly inhibited by superfusion of the rat mesentery with the NO synthase inhibitor, N$\sp{\rm G}$-nitro-L-arginine methyl ester (L-NAME). Inhibition of endothelial NO resulted in a significant increase in P-selectin expression on the venular endothelial surface and a significant increase in P-selectin mediated leukocyte-endothelial interaction. The increased P-selectin expression observed following L-NAME superfusion was effectively blocked by simultaneous infusion of L-arginine, the substrate for NO synthase, thereby demonstrating that the effects of L-NAME were the result of NO inhibition. Thus, the data presented in this thesis indicate an important role for P-selectin in leukocyte-endothelial interaction following splanchnic arterial occlusion/reperfusion in the rat, and demonstrate a novel role for nitric oxide in regulating the expression of this adhesion molecule.

Subject Area

Anatomy & physiology|Animals

Recommended Citation

Davenpeck, Kelly Lyn, "Role of P-selectin and nitric oxide in leukocyte-endothelial interaction in the rat mesenteric microcirculation" (1994). ETD Collection for Thomas Jefferson University. AAI9426833.
https://jdc.jefferson.edu/dissertations/AAI9426833

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