Lateral hypothalamic lesions or transections block bombesin hyperglycemia in rats

The peptide bombesin-14 causes hyperglycemia when injected into the cisterna magna of rats. We report that acute lateral hypothalamic lesions block bombesin hyperglycemia. Lateral thalamic lesions do not have this effect. We further report that transections on the lateral or posterior borders of the lateral hypothalamus also block bombesin hyperglycemia. Cuts on the medial border also somewhat diminish this hyperglycemia, while cuts on the anterior border are not reliably effective. These results suggest that fibers traversing the lateral hypothalamus are involved in the hyperglycemic response to intracisternal bombesin-14.