Venoms 5-hydroxytryptamine

There is 5-hydroxytryptamine in weever fish venom besides protein. It is believed that local pain is attributed to the presence of 5-hydroxytryptamine (27). Other small compounds such as histamine, adrenaline, and noradrenaline are also present in the weever fish (28). 

Hydroxytryptamine is widely distributed in plant and animal tissues, mast cells, platelets, the enterochromaffin cells located throughout the gastrointestinal tract, and in certain regions of the brain. It is also present in the venoms and stings. Some fruits such as bananas, pineapples, tomatoes and plums contain considerable amount of 5-HT. 

Bufotenin (5-Hydroxy-N,N-dimethyltryptamine) is a constituent of toad venom (Lyttle 1993) and various legumes. Synthetic preparation of 5-hydroxytryptamines (Ek 1953) (Justoni 1960) (Speeter 1955). 

Cesar LMM, Tormena CF, Marques MR, Silva GVJ, Mendes MA, Rittner R, et al. Structure determination of hydroxytryptamine a new tetrahydro-beta-caiboline toxin from the venom of spider Parawixia bistriata. Helv Chim Acta 2005 88(4) 796-801. 

When Wieland et al. (1934) and Jensen and Chen (1936) isolated bufotenine (iV,N-dimethyl-5-hydroxytryptamine) and related indoleamines from the toad venom gland, they considered them as poisons peculiar to this species of animal. About twenty years elapsed before Rapport et al. (1948) isolated serotonin (5-hydroxytryptamine) from beef blood and determined its structure (Rapport, 1949). With the isolation of serotonin the full significance of the indoleamines in nature began to unfold. 

A relationship similar to that between tyrosine and dopamine exists between the amino-acid tryptophan and the brain substance serotonin or 5-hydroxytryptamine (Figure 8.9). Tryptamine is known in the venom of scorpions, while serotonin is found widely in the venom of honeybees, centipedes, and at least two spiders. Serotonin is not found in the venom of ants or solitary wasps but social wasps have it in quantity, as much as 1 pg per insect. It is present in the barbs of the larvae of the Tiger moth Arctia caja (Plate 11) and a satumid butterfly larva. Their origins in insect venoms are presumably from phenylalanine but this has not been proven. The same substance is in the hairs of the common stinging nettle Urtica dioica. 

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