Gap junctions in Malpighian tubules of Aedes aegypti.

We present electrical, physiological and molecular evidence for substantial electrical coupling of epithelial cells in Malpighian tubules via gap junctions. Current was injected into one principal cell of the isolated Malpighian tubule and membrane voltage deflections were measured in that cell and in two neighboring principal cells. By short-circuiting the transepithelial voltage with the diuretic peptide leucokinin-VIII we largely eliminated electrical coupling of principal cells through the tubule lumen, thereby allowing coupling through gap junctions to be analyzed.

Involvement of calcitonin gene-related peptide and its receptor in anti-nociception in the periaqueductal grey of rats.

The present study investigated the role of calcitonin gene-related peptide (CGRP) in the modulation of nociception in periaqueductal grey (PAG) of rats. Hindpaw withdrawal latencies (HWLs) were tested by hot-plate and Randall Selitto tests. The HWLs to thermal and mechanical stimulation increased significantly after intra-PAG administration of 0.

The V-type H(+)-ATPase in Malpighian tubules of Aedes aegypti: localization and activity.

The V-type H(+)-ATPase is thought to provide the driving force for transepithelial electrolyte and fluid secretion in Malpighian tubules. To confirm the presence of this proton pump in Malpighian tubules of the yellow fever mosquito Aedes aegypti, we used several antibodies raised against the V-type H(+)-ATPase of Manduca sexta. Western blot analysis confirmed the presence of the V-type H(+)-ATPase in Malpighian tubules of Aedes aegypti.