Fig. 8.
The mTOR inhibitor rapamycin influences the brain-pituitary-gonadal axis at multiple levels in male Astatotilapia burtoni. (A) Relative levels of the downstream phosphorylated-p70S6 kinase are lower in the whole brain at 48 hrs after intraperitoneal (IP) injection of rapamycin compared to vehicle-injected (control) fish. Inset at top shows representative examples of western blots from whole brains of control vehicle and rapamycin-injected fish. Lower band represents the quantified p-p70S6 isoform, and upper band represents the p-p85S6 isoform also detected with this antibody. (B) Relative levels of p-p70S6K are also lower in the testes of IP rapamycin-injected fish compared to controls. (C) Circulating levels of luteinizing hormone (LH) are higher in fish IP injected with rapamycin compared to controls. (D) Circulating levels of follicle stimulating hormone (FSH) are also higher in fish IP injected with rapamycin compared to controls. All measurements were done at 48 hrs after IP rapamycin or vehicle injections. Box boundaries show 25th and 75th percentiles, solid and dotted lines are the median and the mean, respectively. Different letters indicate statistical differences at p<0.05 and sample sizes are shown in parentheses.