Mast Cell Deficient W/W^vMice Lack Stress-Induced Increase in Serum IL-6 Levels, as Well as in Peripheral CRH and Vascular Permeability, a Model of Rheumatoid Arthritis

Abstract

Corticotropin releasing hormone (CRH) and interleukin-6 (IL-6) are implicated in inflammatory diseases triggered by stress. Acute restraint stress increases serum IL-6 in the blood, but its source is not known. Our current study was carried out in order to determine the contribution of mast cells to stress-induced IL-6 release and to investigate skin CRH and vascular permeability in mice. W/W(v) mast cell deficient and their wild type control +/+ mice were stressed in a plexiglass restraint chamber for 60 or 120 min. Serum corticosterone and IL-6 levels were measured. Other mice were injected with (99)Tchnetium gluceptate ((99)Tc) and its extravastion, indicating vascular permeability, was determined along with CRH levels in the skin and knee joints. Acute stress increased serum IL-6 in mice, but was greatly inhibited in W/W(v) mast cell deficient mice. Vascular permeability to (99)Tc, as well as local CRH levels, were also increased by stress, but not in W/W(v) mice. Findings from our current study suggest a link between mast cells and stress-related skin and joint inflammation and may explain initial events in psoriatic and rheumatoid arthritis.