Cockroach allatostatin-immunoreactive neurons and effects of cockroach allatostatin in earwigs.

摘要

A monoclonal antibody to allatostatin I of Diploptera punctata was used to demonstrate the presence of allatostatin-immunoreactive cells and fibre tracts in the neuroendocrine system of the earwig Euborellia annulipes. The corpora cardiaca cells were not immunoreactive, nor were the neurosecretory endings of fibre tracts from the brain to the corpora cardiaca. No immunoreactive material was detected in the corpus allatum, although the corpus allatum contained neurosecretory endings, and some cellsof the brain, including medial and lateral protocerebral cells, showed immunoreactivity. In addition, the recurrent and esophageal nerves were allatostatin-positive. The last abdominal ganglion contained immunoreactive somata, and immunoreactive axons ofthe proctodeal nerve innervated the rectum, anterior intestine, and posterior midgut. Reactive endocrine cells were not detected in the midgut. Allatostatin I at concentrations of 10-5 and 10-7 M did not inhibit juvenile hormone biosynthesis by E. annulipes corpora allata in vitro. This was true for glands of low activity from 2-day females and brooding females, as well as for relatively high activity glands from 10-day females. In contrast, 10-7 M allatostatin I significantly and reversibly decreasedhindgut motility. Motility was decreased in hindguts of high endogenous motility from 2-day females and in those of relatively low activity from brooding females. These results support the idea that a primary function of allatostatin might be to reduce gut motility.