Figure 3.

LPS-Induced Hepatic Desensitization to GH, as Assessed Noninvasively by Bioluminescence Imaging in C3H/HeJ Mice

A and B, Effect of LPS pretreatment. See Materials and Methods for details. Mice (n = 7 per condition) infected with Ad-GHRE-luc, as in Fig. 2, were treated with LPS (10 μg/g ip) or saline 3 h before being administered GH (3 μg/g) and imaged 3 h thereafter. A, Two representative mice are compared. One received PBS pretreatment, and the other received LPS, as indicated. Each was then administered GH (3 μg/g). Images of each are compared. B, Regions of interest analyses of liver luciferase expression for two groups presented in A. LPS treatment led to a statistically significant (P < 0.05) fall in GH-induced hepatic bioluminescence. Data in 3B are expressed as means ± sem. Mean basal (pre-GH treatment) bioluminescence was similar between the two groups (119 counts/sec and 140 counts/sec for PBS- and LPS-treated mice, respectively).