Mast Cell Count in the Peritoneal Fluid of Rats with Adjuvant-Induced Polyarthritis

Abstract

Adjuvant-arthritis was induced in rats by means of a subplantar injection (left hind paw) of M. butyricum in paraffine oil and the severity of the disease determined volumetrically on the right, uninjected hind paw when the secondary lesions had reached near-maximal extent. One group of the rats was treated on days 18 to 21 post-adjuvant with hydrocortisone at a daily oral dose of 30 mg/kg and the therapeutic effect assessed in terms of gross paw-oedema changes and of certain parameters mentioned hereafter Using a variety of ‘clinical parameters’ (ESR, albumin/globulin ratio, fibrinogen, fibrinolysis, serum iron and serum copper) as well as other parameters still under experimental evaluation (peritoneal mast cells and ‘inflammatory’ rest cells) it was found that: (a) the ‘clinical parameters’ undergo much the same changes in adjuvant-induced arthritis in the rat as they do in human rheumatoid arthritis; (b) steroid therapy reverses such changes to normal in the rat in a fashion similar to that obtained in man suffering from rheumatoid arthritis and the like; (c) peritoneal mast cell count is low and peritoneal ‘inflammatory’ rest cell count high in full-blown adjuvant-arthritis; (d) a short-term steroid therapy tends to normalise the changes mentioned under (c).

Decrease in peritoneal mast cell count in rats with adjuvant arthritis. I. Time course and interstrain difference

“…On the contrary, not only the histamine content but also the mast-cell count in the mesentery increased after adjuvant injection in contrast with the decrease in mast-cell count in the peritoneal fluid. Therefore, the decrease in the mast-cell count observed in the present experiments cannot be ascribed to the disruption of these cells as JAQUES et al [1] assumed.…”

“…JAQUES et al [1] first described a marked decrease in mast-cell count of the peritoneal washings of SD rats with full-blown polyarthritis induced by adjuvant injected into a site different from the peritoneal cavity. J6KAY et al [12] reported that many substances with adjuvant activity decreased mast-cell count in the peritoneal fluid of mice within 4 days after intraperitoneal injection.…”

“…It has been shown by JAQUES et al [1] that the mast-cell count of the peritoneal fluid of rats with full-blown adjuvant-arthritis is markedly lower than that of normal rats. They supposed that this phenomenon might be due to disruption of mast cells caused by components of migrated polymorphonuclear leukocytes such as !ysosomal cationic proteins [2][3][4].…”