Phylogenetic specificities

The synthetic tetradecapeptide, either in linear or cyclized form has been shown to suppress growth hormone secretion in man (H3, P6, S8), in animals (Bll), and in isolated pituitary tissue (B8), confirming the lack of phylogenetic specificity seen with the other hypothalamic regulatory hormones. 

Natural venoms are a vast reservoir of toxins with diverse pharmacological properties and phylogenetic specificities. It seems likely that toxin diversity is an evolutionary response of venomous predators to a dynamic heterogeneity of receptors in prey animals. Toxins are thus valuable tools for distinguishing differences in ion channel targets. The potent effects exerted by toxins on the nervous system has obvious applications for both pest control, drug development, and basic neuroscience. 

The biological targets of paralytic conotoxins are presumably ion channels and receptors in the fish neuromuscular system. Amphibian, avian, and mammalian systems may also be affected by a -, a-, and x-conotoxins. However, specific conotoxins vary in their phylogenetic spectrum and detailed physiological effects in vivo. 

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