Figure 5
IGF-1 radioactivity in kidney, liver, skeletal muscle and urine after its intraventricular injection. Kidneys were always seen to preferentially sequester IGF-1 from blood in the first 90 min after injection. Appreciable amounts of radioactivity began to appear in the urine after an initial lag period of ~5 min. After 20 min, radioactivity in urine rose almost linearly with time whereas that in the kidneys began dropping after 90 min. Liver and skeletal muscle had comparatively very little radioactivity throughout the period of study. The inset shows the tissue radioactivity for the first 20 min that may not be evident on the main graph. All data are mean ± SD at the various times.