FIG. 4.

Diurnal regulation of glucose metabolism genes in liver from uninjured rats, and from sham/ spinal cord injury (SCI) rats at 2 days post-injury (dpi). (A) Plasma glucose in female and male rats is significantly increased by SCI. Plasma glucose was increased in females and males at 2 dpi. Females, but not males, showed persistent SCI-induced dysregulation at 7 and 14 dpi. (B) Female and male rat livers display circadian rhythms in glucose metabolism gene expression. Glut2 and AldoB showed significant time-of-day regulation; G6pt1 and Pck1 had significant interaction between Zeitgeber time (ZT) and sex (males > females at specific times). (C) SCI disrupts glucose metabolism gene expression in the liver. SCI increased expression of glucose metabolism genes, including Glut2, G6pt1, Pck1, and AldoB. G6pt1 was also differentially regulated by sex, and Pck1 was also differentially expressed by sex and by Zeitgeber time. Black ∼ indicates that females or males for that gene show significant rhythm; red + indicates injury difference (sham vs. SCI), p < 0.05; yellow hourglass indicates time difference, p < 0.05; blue gender symbol indicates sex difference, p < 0.05; * indicates difference between 2 dpi and pre-SCI, p < 0.05; † indicates significant difference between 14 dpi and pre-SCI, p < 0.05. Symbols at the top of each graph indicates significant main effect; symbols above/below data indicate significant interactions. Color image is available online.