Figure 3. Longevity is inversely associated with testicular overall macrophage cell number and expression of macrophage markers. Panel (A) the relative expression levels of CD68 and CD163 (macrophage cell markers) and the relative expression levels of StAR (Leydig cell marker) were determined by real time-PCR in testicular homogenates of short-lived (GH-Tg) and long-lived (GHRH-KO and Ames dwarf) mice and their normal littermates. Results were normalized to GAPDH housekeeping gene and expressed as fold change relative to the control (normal littermates), which was assigned a value of 1. Bar plot graphs represent the mean + SEM; n = 5-7. * p < 0.05, t-Student test. Panels (B and C) Quantification of Iba1-positive macrophages in testes of GH-Tg short-lived mice, GHRH-KO and Ames dwarf long-lived mice and their normal littermates was evaluated using a light microscope with a magnification of 400x and a gridded eyepiece. Results are expressed as macrophages/mm2 (Panel B) and macrophages/tubule (Panel C). Bar plot graphs represent the mean + SEM; n = 5-7. * p < 0.05, t-Student test.