Renin-Angiotensin System Components in the Gingiva Tissue of Rats with Experimentally Induced Periodontitis.

<p><b>A)</b> Results of qPCR analysis for mRNA of various RAS components extracted from the rat gingiva of either sham surgery (sham) or experimentally induced periodontitis (EP) for 14 days; tested RAS components included the following: angiotensinogen (AGT), angiotensin converting enzyme (ACE), angiotensin converting enzyme 2 (ACE-2), angiotensin II receptor type 1A (AT_1AR), angiotensin II receptor type 1B (AT_1BR), angiotensin II receptor type 2 (AT₂R), and Mas receptor (MasR). Graph displays expression levels of the target mRNA relative to β-actin mRNA from 5 rats in duplicate (n = 5). Solid bars represent the means with SD of sham group; whereas, open bars represent animals with EP. A one-way ANOVA and Tukey’s test with statistical significance set at <i>p</i>-value < 0.05 was used. <b>B)</b> All images are at 10x magnification and scale bars indicate a distance of 100 μm. Immunoreactivity (IR) for renin (panels a to d), ACE (panels e to h), AT₁R (panels i to l) or AT₂R (panels m to p) in rat gingiva and bone tissue. Brown staining indicates positive IR. Black arrows indicate some of the positive IR in the positive controls. Negative <b>(panel a)</b> and positive <b>(panel b)</b> control for renin in rat kidney. <b>Panel c)</b> negative control for renin in mandible of rat with 14 d of EP treated with water. <b>Panel d)</b> immunoreactivity for renin in mandible of rat with 14 d of EP treated with water. Negative <b>(panel e)</b> and positive <b>(panel f)</b> control for ACE in a rat kidney. <b>Panel g)</b> negative control for ACE in mandible of rat with 14 d of EP treated with water. <b>Panel h)</b> immunoreactivity for ACE in mandible of rat with 14 d of EP treated with water. Negative <b>(panel i)</b> and positive <b>(panel j)</b> control for AT₁Rs in a rat adrenal gland. <b>Panel k)</b> negative control for AT₁Rs in mandible of rat with 14 d of EP treated with water. <b>Panel l)</b> Immunoreactivity for AT₁Rs in mandible of rat with 14 d of EP treated with water. Negative <b>(panel m)</b> and positive <b>(panel n)</b> control for AT₂Rs in a rat adrenal gland. <b>Panel o)</b> negative control for AT₂Rs in mandible of rat with 14 d of EP treated with water. <b>Panel p)</b> immunoreactivity for AT₂Rs in mandible of rat with 14 d of EP treated with water. <b>C)</b> Table indicating location of immunoreactivity observed in 2 sections of 5 rats with 14 d of EP treated with water for renin, ACE, AT₁Rs and AT₂Rs in different mandibular regions: (-) indicates negative immunoreactivity, (+) indicates positive immunoreactivity and (++) indicates abundant immunoreactivity.