Luzindole

The value of applying a melatonin antagonist (Luzindole) in improving the success rate of the bipedal rat scoliosis model.[Pubmed:28376758]

BMC Musculoskelet Disord. 2017 Apr 4;18(1):137.

BACKGROUND: An ideal animal model has always been the key to research the pathogenesis and treatment of adolescent idiopathic scoliosis (AIS), while available methods have obvious disadvantages. The deficiency of melatonin has been proved relating to AIS. In this research, we intended to apply Luzindole, the melatonin antagonist, in bipedal rat model, for the block of combination of melatonin and its receptor, to inhibit the melatonin effect, and then to understand whether this method can effectively improve the scoliosis rate of bipedal rat model, and investigate the role of melatonin in scoliosis. To investigate the feasibility of improving the success rate of bipedal rat scoliosis model via intraperitoneal injection of melatonin antagonist (Luzindole). METHODS: A total of 60 3-weeks-old Sprague-Dawley rats were included in this study, and were divided into 3 groups (A, B and C). Each group included 20 rats. Osteotomy of the bilateral proximal humerus and proximal tailbone was performed in group A and group B; intraperitoneal injection of Luzindole (0.2 mg/kg) was performed in group A and group C. X-rays were taken before the surgery, 1 month after the surgery, 3 months after the surgery, and 6 months after the surgery, to calculate the Cobb's angle of the spine (>10 degrees was considered scoliosis). The weight of every rat was also measured at the same time. Rats were euthanized 6 months after surgery to determine the calmodulin level in thrombocytes. RESULTS: The rate of scoliosis in group A (14/20) was significantly higher than those in group B (6/20) and group C (0/20) (P < 0.05). The differences in the weights of the 3 groups were non-significant; as were differences in the calmodulin level in thrombocytes. CONCLUSION: The application of the melatonin antagonist of Luzindole can improve the success rate of the bipedal rat scoliosis model. Meanwhile, this study indicates that a decreased melatonin level is not the primary cause of scoliosis, but that it may increase the likelihood and severity of scoliosis.

Chronic administration of a melatonin membrane receptor antagonist, luzindole, affects hippocampal neurogenesis without changes in hopelessness-like behavior in adult mice.[Pubmed:26686389]

Neuropharmacology. 2016 Apr;103:211-21.

Melatonin is involved in the regulation of hippocampal neuronal development during adulthood. Emerging evidence indicates that exogenous melatonin acts during different events of the neurogenic process and exerts antidepressant-like behavior in rodents. Thus, melatonin might act through different mechanism, including acting as an antioxidant, interacting with intracellular proteins and/or activating membrane receptors. The melatonin membrane receptors (MMRs; Mt1/Mt2) are distributed throughout the hippocampus with an interesting localization in the hippocampal neurogenic microenvironment (niche), suggesting the involvement of these receptors in the beneficial effects of melatonin on hippocampal neurogenesis and behavior. In this study, we analyzed the participation of MMRs in the baseline neurogenesis in C57BL/6 mice. To this end, we used a pharmacological approach, administering Luzindole (10 mg/kg) for 14 days. We observed a decrease in the absolute number of doublecortin-positive cells (49%) without changes in either the dendrite complexity of mature doublecortin-cells or the number of apoptotic cells (TUNEL). However, after the chronic administration of Luzindole, cell proliferation (Ki67) significantly decreased (36%) with increasing (>100%) number of neural stem cells (NSCs; GFAP(+)/Sox2(+)) in the subgranular zone of the dentate gyrus of the hippocampus. In addition, Luzindole did not affect hopelessness-like behavior in the forced swim test (FST) or changes in the novelty suppressed feeding test (NST) after 14 days of treatment either neuronal activation in the dentate gyrus after FST. These results suggest that the MMRs are involved in the effects of endogenous melatonin to mediate the transition from NSCs and proliferative cells to the following developmental stages implicated in the hippocampal neurogenic process of adult female C57BL/6 mice.

The influence od melatonin receptors antagonists, luzindole and 4-phenyl-2-propionamidotetralin (4-P-PDOT), on melatonin-dependent vasopressin and adrenocorticotropic hormone (ACTH) release from the rat hypothalamo-hypophysial system. In vitro and in vivo studies.[Pubmed:25554981]

J Physiol Pharmacol. 2014 Dec;65(6):777-84.

Melatonin exerts its biological role acting via G protein-coupled membrane receptors - MT1 and MT2, as well as through cytoplasmic and/or nuclear receptors. Melatonin has previously been shown to change vasopressin (AVP) and adrenocorticotropic hormone (ACTH) secretion dependently on its concentration. To determine whether the response of vasopressinergic neurones to different concentrations of melatonin is mediated through the membrane MT1 and/or MT2 receptors, the influence of Luzindole - an antagonist of both MT1 and MT2 receptors, and 4-phenyl-2-propionamidotetralin (4-P-PDOT) - a selective MT2 receptor antagonist, on melatonin-dependent AVP release from the rat hypothalamo-neurohypophysial (H-NH) system was studied in vitro (melatonin at the concentrations of 10(-9), 10(-7) and 10(-3) M) and in vivo (melatonin at the concentrations of 10(-9) and 10(-7) M). Moreover, the second goal of this study was to find out whether melatonin receptors MT1 and/or MT2 are involved in the regulation of ACTH and corticosterone secretion into the blood. We have demonstrated that melatonin, at the concentrations of 10(-9) and 10(-7) M, significantly inhibited AVP secretion from isolated rat H-NH explants when antagonists solvent (i.e. 0.1% DMSO) was present in the medium. Neither Luzindole, nor 4-P-PDOT, applied without melatonin, did influence AVP release in vitro. Luzindole applied together with melatonin (10(-7) M and 10(-9) M) significantly suppressed melatonin-dependent effect, while 4-PPDOT did not eliminate the inhibitory influence of 10(-7) M and 10(-9) M melatonin on AVP secretion from isolated rat H-NH explants. Melatonin at a concentration of 10(-3) M significantly increased AVP release when the H-NH explants were incubated in the medium containing Luzindole or 4-P-PDOT. Under present experimental in vivo conditions, infused intracerebroventricularly (i.c.v.) melatonin, at a concentration close to its physiological level in the blood, significantly diminished AVP secretion into the blood, however, at higher concentration (10(-7) M) it remained inactive in this process. Moreover, melatonin at both concentrations of 10(-9) M and 10(-7) M, was able to inhibit AVP secretion into the blood (and increase its neurohypophysial content) when animals were previously i.c.v. injected with 4-P-PDOT, but not with Luzindole. Blood plasma concentration of ACTH was diminished significantly by 10(-7) M melatonin in DMSO-infused, but not in Luzindole- or 4-P-PDOT-injected rats, however, it remained inactive in modifying the corticosterone blood plasma concentrations in any of the studied subgroups. The present study demonstrates that subtype MT1 membrane receptor may contribute to the inhibitory effect of physiological concentration of melatonin on functional regulation of vasopressinergic neurones in the rat. However, for the stimulatory effect of pharmacological dose of the hormone on AVP secretion in vitro, mechanisms different from membrane MT1/MT2 receptors are involved. The present experiment do not determines whether MT1 and/or MT2 receptors affect the function of the rat pituitary-adrenal cortex axis.

Melatonin receptors: are there multiple subtypes?[Pubmed:7762083]

Trends Pharmacol Sci. 1995 Feb;16(2):50-6.

There is now evidence for more than one site of action for the hormone melatonin (N-acetyl-5-methoxy-tryptamine). Recent pharmacological and molecular advances are providing the tools to address the characterization of melatonin receptor subtypes. The development of novel melatonin receptor agonists and antagonists, high-affinity radioligands, quantitative bioassays, and the recent cloning of melatonin receptors are furthering our understanding of native and recombinant melatonin receptors. In this article, Margarita Dubocovich discusses the properties of melatonin receptors, and the basis for their classification into at least two subtypes, the ML1 and ML2.

Antidepressant-like activity of the melatonin receptor antagonist, luzindole (N-0774), in the mouse behavioral despair test.[Pubmed:2168835]

Eur J Pharmacol. 1990 Jul 3;182(2):313-25.

The anti-immobility effect of the selective melatonin receptor antagonist, Luzindole, was investigated in the behavioral despair test using three different strains (C3H/HeN, C57BL/6J and albino ND/4) of mice. The time of immobility of the C3H/HeN during the 240 s swimming period measured at noon (12:00 to 14:00 h) was 47.8 +/- 3.0 s (n = 63) and at midnight (00:00 to 02:00 h) was 67.7 +/- 2.8 s (n = 68) (P less than 0.001, when compared with the noon value), when the levels of endogenous melatonin are presumably low and high, respectively. Melatonin (30 mg/kg) given i.p. did not modify the time of immobility at either time of measurement. Luzindole (30 mg/kg i.p.) reduced the time of immobility in a dose-dependent manner, the effect being more pronounced at midnight (60% reduction) than at noon (39% reduction). The effect of Luzindole was time-dependent, showing a maximal effect at 60 min. The anti-immobility effect of Luzindole (10 mg/kg i.p.) was prevented by the administration of melatonin (30 mg/kg i.p.). Luzindole (30 mg/kg i.p.) did not modify the time of immobility either at noon or midnight in the albino ND/4 mouse, or in the C57BL/6J mouse, which does not produce melatonin. Our results suggest that endogenous melatonin plays a role during swimming in the C3H/HeN mouse behavioral despair test. We conclude that Luzindole may exert antidepressant-like activity in the C3H/HeN mouse by antagonizing the action of endogenous hormone.

Luzindole (N-0774): a novel melatonin receptor antagonist.[Pubmed:2843633]

J Pharmacol Exp Ther. 1988 Sep;246(3):902-10.

The pharmacological potencies of 2-substituted N-acetyltryptamines were determined on the presynaptic melatonin receptor site of rabbit retina labeled in vitro with [3H]dopamine. Calcium-dependent release of [3H]dopamine was elicited by electrical stimulation at 3 Hz for 2 min (20 mA, 2 msec). Melatonin (5-OCH3-N-acetyltryptamine) and 6-chloromelatonin were equipotent in inhibiting the calcium-dependent release of [3H]dopamine (IC50 = 40 pM). 2-Substituted N-acetyltryptamines with a methyl (i.e., 6,7-dichloro-2-methylmelatonin, IC50 = 10 pM) or iodine (i.e., 2-iodomelatonin, IC50 = 5 pM) group were more potent than melatonin in inhibiting [3H]dopamine release. I report here the pharmacological properties of the novel N-acetyltryptamine, 2-benzyl-N-acetyltryptamine (N-0774, Luzindole) on the presynaptic melatonin receptor of rabbit retina. Luzindole (0.1-10 microM) did not affect the spontaneous outflow of radioactivity or the stimulation-evoked release of [3H]dopamine when added alone. However, Luzindole (0.1-10 microM) shifted the concentration effect curve for melatonin to the right in a parallel fashion. The pA2 extrapolated from the Schild plot (slope, 0.91) was 7.7, with a KB = 20 nM. The dissociation constants for Luzindole (KB), determined in the presence of 6,7-dichloro-2-methylmelatonin (10 pM-1 nM) or 6-chloromelatonin (10 pM-100 nM) were 16 and 40 nM, respectively. These data suggest that Luzindole and the various melatonin agonists are competing for the same presynaptic melatonin receptor site in the rabbit retina.(ABSTRACT TRUNCATED AT 250 WORDS)

Luzindole (N-0774) is a selective melatonin receptor antagonist. Luzindole preferentially targets MT2 (Mel1b) over MT1 (Mel1a) with Ki values of 10.2 and 158 nM for human MT2 and MT1, respectively. Luzindole suppresses experimental autoimmune encephalomyelitis (EAE), and exerts antidepressant-like activity.

Luzindole,117946-91-5,Natural Products,Melatonin Receptors, buy Luzindole , Luzindole supplier , purchase Luzindole , Luzindole cost , Luzindole manufacturer , order Luzindole , high purity Luzindole