干旱区生态环境知识资源中心

Recent evidence for secretion of H+ (J(H)) and ammonia (J(amm)) and concomitant absorption of bicarbonate and OH- in Malpighian tubules and hindgut (ileum, rectum) of desert locusts is reviewed. We include data in theses on ileal J(H), J(amm), and ammoniagenesis and evidence suggesting their control by neuropeptides from corpus cardiacum and ventral ganglia acting via cyclic AMP. The importance of each segment of the excretory system in acid-base elimination is estimated and compared with data on recovery of whole locusts from acidosis, including composition of the excreta. The capacity of the excretory system is more than adequate to account for the regulation of hemolymph pH in feeding locusts injected with an acid load.