(+)-u-50488 hydrochloride is a selective agonist for κ-opioid receptor [1].the κ-opioid receptor (kor) is a type of opioid receptor for opioid peptide dynorphin and controls addiction. also, kor plays an important role in stress, anxiety, anhedonia, depression and increased drug-seeking behavior.(+)-u-50488 hydrochloride is a selective kor agonist [1]. in isolated rat drg neurons, u-50488 (0.3-40 μm) inhibited voltage-independent ca2+ channel currents. in hela cells that didn’t express kor, u-50488 (20 μm) blocked ca2+ channels [2].in rhesus monkeys, u-50488 exhibited potent antinociceptive activity and produced diuresis [1]. u-50488 enhanced contraction of the rabbit vas deferens induced by electrically with ic50 value of 26.5 nm. in mice, u-50488 impaired motor function with ed50 value of 15.3 mg/kg and reduced spontaneous activity [3]. in adult rats, u-50488 increased the threshold required to maintain self-stimulation responding, a depressive-like effect. while, males were significantly more sensitive than females to the threshold-increasing effects [4].
[1]. tang ah, collins rj. behavioral effects of a novel kappa opioid analgesic, u-50488, in rats and rhesus monkeys. psychopharmacology (berl), 1985, 85(3): 309-314.
[2]. hassan b, ruiz-velasco v. the κ-opioid receptor agonist u-50488 blocks ca2+ channels in a voltage- and g protein-independent manner in sensory neurons. reg anesth pain med, 2013, 38(1): 21-27.
[3]. lu sn, ma sc, zhang kg, et al. comparison of pharmacological profile of selective kappa-opioid agonist k-ii and u-50488. yao xue xue bao, 1991, 26(3): 171-174.
[4]. russell se, rachlin ab, smith kl, et al. sex differences in sensitivity to the depressive-like effects of the kappa opioid receptor agonist u-50488 in rats. biol psychiatry, 2014, 76(3): 213-222.
