[3] Kassinin is one of the tachykinin peptides, which interacts with NK2 receptor to increase short circuit current (SCC), resulting in an ion transportation in frog skin.

Substance P (SP) was originally considered the only neuropeptide in mammals capable of neuromodulation, with the X position of the carboxyl sequence typical for these polypeptides having a Phe residue.

[5] In 1983, two neuropeptides with X = Val were discovered from bovine spinal serum, and bioassays to test for the measured synaptic response and their inhibition by known antagonists revealed that this was a novel discovery that differed from SP.

Testing the hypothesis that SP-E receptors were potent because they must have another ligand of greater specificity led to the discovery of the aforementioned novel neuropeptides.

Throughout the duration of study, sodium excreted through urine is also low in concentration, and given that the amount of water intake after 6 hours is not sufficient to restore osmotic balance, scientists hypothesize that kassinin triggers an osmotic exchange between intra and intercellular components to maintain water potential.