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