The Thyroid Gland in Infections; The Effect Upon the Basal Metabolic Rate*

The fact that the thyroid gland plays a very important role in the growth of an animal and in the regulation of the body metabolism has been recognized for some time. In a recent communication (1) we called attention to the fact that in certain systemic infections and in severe toxemias very definite chemical as well as histological changes in the thyroid gland could be demonstrated. These changes varied considerably with the severity of the infection. Microscopically we were able to show that in the more virulent infections there was desquamation and death of many of the acinous cells, loss of colloid and hyperplasia of many of the remaining cells. This resulted in a marked change in the normal architecture of the gland (Fig. 1). There was a concomitant enlargement of the gland. Upon chemical analysis, however, the iodine content per gram of tissue was found to be about half the amount found in the thyroid glands of the control animals. Such facts are not surprising when one considers the important part the thyroid plays in the metabolism of the body. It has long been an established fact that in infections there is an increase in metabolism. More recently calorimetric studies of the increase in heat production have been made by Barr and DuBois in malaria (2), Coleman and DuBois in typhoid fever (3) and McCann and Barr in tuberculosis (4). Likewise it has been found by Schick, Cohen and Beck (5) that during convalescence after pneumonia the basal metabolic rate is often lower than normal. They found this true in other diseases associated with a low pulse rate during convalescence (6).