The Impact of Gender on the Inflammatory Parameters and Angiogenesis in the Rat Air Pouch Model of Inflammation

Air pouch is a well-established inflammatory model in which fluid extravasations; leukocyte migration, angiogenesis and other parameters involved in the inflammatory response can be measured. In this study, the influence of gender on inflammatory parameters has been examined in the air pouch model. To induce air pouch, adult male and female Wistar rats were anesthetized, then 20 ml and 10 ml of sterile air were injected subcutaneously on the back on day 0 and day 3, respectively. On day 6, inflammation was induced by injection of 1 ml of carrageenan 1% into pouches. After 6 and 72 hr, the rats were sacrificed, pouch fluid was collected in order to determine exudates volume and the accumulated cells were counted using a hemocytometer. Pouches were dissected out and weighed. Angiogenesis of granulomatous tissue was assayed using hemoglobin kit. Analysis of our data demonstrated a sexually dimorphic pattern in inflammation parameters both in acute and chronic forms (P<0.05). The value of angiogenesis in the air pouch model in male rat was higher than that female rats (P<0.001). The degree of inflammation and angiogenesis induced in Wistar rat air pouch model is gender-dependent, suggesting that gender may be a key consideration in the design of inflammation experiments.