Senktide

Senktide is a potent, selective agonist of the neuromedin K3 (NK3) receptor (EC₅₀=0.5-3 nM). Senktide less potently agonizes the NK1 receptor (EC₅₀=35 µM). Senktide is promising for research of neurological disease^{[1][2][3][4][5]}. IC50 & Target:NK₃ receptor^[1] In Vitro:The selective NK₃ receptor agonist Senktide excites 24 of 31 dopaminergic neurons in the substantia nigra pars compacta in a concentration-dependent manner. The effective concentration range is between 3 to 3000 nm. The mean EC₅₀ for Senktide is 41.2±9 nm (n=5)^[2]. In Vivo:I.c.v. injection of Senktide causes a dose-dependent increase in total distance traveled (F_6,72=6.344, P<0.001). This increase reaches statistical significance compare to the vehicle-treated group at 0.06 nmol and higher. The Senktide-induced increase in locomotor activity brought about by 0.1 nmol of Senktide is significantly and dose-dependently decreased by the tachykinin NK₃ receptor antagonists talnetant at 30 mg/kg and SB222200 at 30 mg/kg, but not by osanetant, when tested in parallel in a single experiment (F_7,78=10.32, P<0.001), although a non-significant reduction is observed. However, when tested using another vehicle (Vitamin E and glycofurol), osanetant does decrease activity significantly compare to Senktide-treated gerbils (F_2,30=10.10, P<0.001)^[1].