Mystic Aquarium & Institute for Exploration

University of Connecticut

Hormonal regulation of muscle development: Evaluation of components of the somatotropic axis to assess growth and health status of young marine mammals

The somatotropic axis, including growth hormone (GH), insulin-like growth factor (IGF)-I, and IGF binding proteins (BP), has been used to bridge the gap between growth rate and nutritional status in domestic animals. The domestic animal model of the somatotropic axis has been used to evaluate changes in these components due to nutritional status. The data has shown that this is a useful model to evaluate nutritional status in Steller sea lions and harbor seals. By monitoring blubber depth with ultrasound and evaluating the pattern of hormones in the blood it can be determined whether animals are in a positive, neutral or negative energy balance. This is very important in assessing animal health when animals are fed a new diet. By continuing to evaluate these hormones during dietary changes, along with other parameters, more information will be gained on nutritional status of these animals.