Thyroidectomized rats respond with hyperglycemia to non-specific damaging agents which decrease the blood sugar of the normal rat. While a 24 hr. fasting period causes more pronounced hypoglycemia in thyroidectomized than in normal rats, 48 hr. of fasting actually increase the blood sugar of the thyroidectomized rat while in the normal it causes a further decline in blood sugar conc. Thyroidectomized rats exposed to non-specific damaging agents respond with a more pronounced decrease in blood chloride than normal animals. They show hypo-chloremia even under the influence of excessive muscular exercise which raises the blood chloride of the normal rat.