Regulatory neuropeptides

There is ample documentation, obtained primarily in mammals, for the concept that the biosynthesis of the great majority of regulatory neuropeptides occurs by way of enzymatically cleaved large precursor molecules produced under the direction of mRNA templates. Future work will have to show to which extent these and the subsequent steps (posttranslational processing, release, and degradation of these products) also occur in insects. 

The wide distribution of regulatory neuropeptides throughout the animal kingdom, and their close chemical similarity or even identity... 

Rameshwar P. Substance P a regulatory neuropeptide for hematopoiesis and immune functions. Clin Immunol Immunopathol 1997 85(2) 129-33. 

Neuromodulator A neuropeptide that co-exists with an amine neurotransmitter in the synaptic bouton and has a modulatory (regulatory) effect on the release of the amine. 

Maule, A.G., Shaw, C., Halton, D.W., Thim, L., Johnston, C.F., Fairweather, I. and Buchanan, K.D. (1991) Neuropeptide F a novel parasitic flatworm regulatory peptide from Moniezia expansa (Cestoda Cyclophyllidea). Parasitology 102, 309-316. 

It is imperative to demonstrate whether JH HI operates directly on pheromone glands or whether it facilitates the activity of other pheromonotropic regulators. Studies of mated females, which produce JH III but not pheromone, have made it abundantly clear that unknown regulatory elements downstream of the action of JH must be involved. These factors probably interact with inhibitory signals from the terminal abdominal ganglion that ascend the VNC and control CNS activity. A concerted effort is needed to identify neuropeptides and other factors that activate and terminate pheromone production, emission, and sexual receptivity. 

Peptide neurotransmitters and hormones are collectively termed neuropeptides. Neuropeptides typically consist of small peptides of approximately 3 0 residues. Several neuropeptides and several of their regulatory functions are listed these neuropeptides and others function in multiple roles as physiological regulators (too numerous to hst in this short table). Ahhreviations are adrenocorticotropin hormone (ACTH), a-melanoc)de stimulating hormone (a-MSH), neuropeptide Y (NPY), and pituitary adenylate cyclase-activating peptide (PACAP). 

Thus, through disruption of the balance between contractile and relaxant neuropeptides in the lung, inflammadon can promote non-specific airway hyper-responsiveness. It is increasingly clear that regulatory enzymes affect both contractile and relaxant pathways. The implication is that the net effect of altered enzyme activity must be judged by assessing changes in the metabolism of both the relevant relaxant and the relevant contractile peptides. 

Larhammar, D. (1996) Evolution of neuropeptide Y, peptide YY, and pancreatic polypeptide. Regulatory Peptides 62, 1-11. 

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