Octopamine biosynthesis

For octopamine biosynthesis we used 12 pg of [ H ] p-tyramme in a minimal volume of water. 

The role of the nervous system in pheromone biosynthesis in moths is not clearly understood. Christensen and co-workers [208-211] proposed that the neurotransmitter octopamine may be involved as an intermediate messenger during the stimulation of sex pheromone production in H. virescens. These workers suggested that octopamine was involved in the regulation of pheromone production and that PBAN s role lies in the stimulation of octopamine release at nerve endings. However, contradicting results concerning octopa-mine-stimulated pheromone production were reported in the same species as well as other moth species [163,172,212-214]. 

Biosynthesis of catecholamines. The rate-limiting step, conversion of tyrosine to dopa, can be inhibited by metyrosine (K-methyltyrosine). The alternative pathway shown by the dashed arrows has not been found to be of physiologic significance in humans. However, tyramine and octopamine may accumulate in patients treated with monoamine oxidase inhibitors. 

The most abundant alkaloid in Coryphantha macromeris, normacromerine, has been shown to originate from tyrosine (330). Tyramine and JV-methyltyramine are efficiently incorporated into normacromerine while octopamine and dopamine are poor precursors. Norepinephrine, epinephrine, normetanephrine, and meta-nephrine have all been shown to be biosynthetically incorporated into normacromerine, and they have also been shown to be naturally occurring trace intermediates in this cactus species (331, 334). Normacromerine is only slowly converted to macromerine in C. macromeris (332). The results indicate that alternative pathways to normacromerine exist precise conclusions regarding the biosynthesis of normacromerine must await further studies. 

Ki is the concentration of octopamine agonist necessary for half-maximal inhibition of pheromone biosynthesis activating neuropeptide (PBAN) binding at 1 p mol/intersegment Eq. 51 [215]... 

This chapter describes the use of this sensitive technique to measure rigorously biogenic amine levels in individually isolated insect identified neurons, and we present data from the locust protocerebral medulla 4 (PM4) neurons as a specific example (5). We also describe the use of GC-MS to monitor the biosynthesis of biogenic amines. The example we present is the synthesis ofp-octopamine, in populations of the dorsal unpaired median (DUM) neurons of the locust, by following the fate of one of its precursors in deuterated form, [ Hs] p-tyramine (4). 

The locust CNS contains approx 100 DUM neurons, distributed dorsomedially in the ganglia of the ventral nerve cord. These neurons contain and release p-octopamine (10). It is possible, therefore, to remove and maintain m vitro an approximately homogeneous population of DUM cell bodies to monitor the biosynthesis of p-octopamine (Fig. 2). Because of the stereotyped location and lai ge size of these cells, physiological confirmation of their identity prior to removal is unnecessary... 

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