Evidence for hormonal effects on metabolism of cockroaches from studies of tissue homogenates

Abstract

Among other functions attributed to the corpora allata of insects is the control of respiratory metabolism. Its exact role has not been clarified and, in fact, some reports tend to be somewhat conflicting. The corpora cardiaca in at least one instance also have been described as having a possible role in respiration. The present investigation began as an attempt to demonstrate the efficacy of the retrocerebral complex components in influencing O 2 consumption by adding extracts of them to muscle and fat body homogenates. It became apparent that while these tissues did yield active extracts, similar effects could be elicited by preparations made from brain and suboesophageal ganglia. The role of the suboesophageal ganglion, in fact, appears to be as great as that of the corpora allata. Therefore, a new synthesis of information to explain the origins of ‘metabolic hormones,’ at least for roaches, seems called for.