Combined tachykinin receptor antagonists for the treatment of respiratory diseases

The tachykinins, substance P (SP) and neurokinin A (NK-A), are thought to be key players in the process of neurogenic inflammation, which is believed to contribute to the pathogenesis of various respiratory diseases. Due to the additive nature of the respiratory effects of these sensory neuropeptides, inhibiting the effects of tachykinins at both NK₁ and NK₂ receptors may represent a therapeutic advantage for the treatment of asthma, as opposed to receptor-selective antagonists, which have demonstrated only minimal efficacy to date. A number of companies are pursuing small molecule approaches yielding compounds with potent, balanced NK₁ and NK₂ receptor antagonist activities. In allergic rhinitis, NK₁receptor antagonism may complement the actions of antihistamines by addressing nasal congestion, which is largely unrelieved by these otherwise highly efficacious agents. Novel combined H₁/NK₁ receptor antagonists have been developed and may represent a therapeutic option for the treatment of this disease.     

PM2.5‐induced airway inflammation and hyperresponsiveness in NC/Nga mice

The allergic inflammatory effects of particulate matter (PM) 2.5, collected with the cyclone system in Yokohama city in Japan, were investigated in NC/Nga mice, which are hypersensitive to mite allergens. PM2.5 with alum was injected intraperitoneally for sensitization. Five days later, 200 μg of PM2.5 in 25 μL of saline was administered to mice intranasally five times for further sensitization. On the 11th day, PM2.5 was administered as a challenge. On the 12th day, mice were examined for airway hyperresponsiveness (AHR), the bronchoalveolar lavage fluid (BALF) cell count, mRNA expression of Th₁, Th₂ cytokines, and metallothioneins in lung tissue, and histopathology. PM2.5 increased AHR, total cell numbers including eosinophils in BALF, and mRNA levels of IL‐5, IL‐22, eotaxin, eotaxin 2, and metallothionein 3. In PM2.5‐induced lungs, inflammation was observed around the bronchus. These results demonstrate that PM2.5 alone, collected with the cyclone system in Yokohama city in Japan, induces asthma‐like airway inflammation. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1047–1054, 2017.     

Human albumin augmented airway inflammation induced by PM2.5 in NC/Nga mice

The synergic allergic inflammatory effects of particulate matter (PM) 2.5 and human albumin were investigated in NC/Nga mice, which are hypersensitive to mite allergens. PM2.5 or PM2.5 plus human albumin with aluminum oxide was injected twice intraperitoneally for sensitization. After 7 days, PM2.5 or PM2.5 plus human albumin was administered five times intranasally to mice for further sensitization. Subsequently, PM2.5 was administered as a challenge on the 11th day. On the 12th day, mice were examined for airway hyperresponsiveness (AHR), bronchoalveolar lavage fluid (BALF) cell count, mRNA expression of Th₁, Th₂ cytokines, chemokines, and mucus proteins (MUC5AC and MUC5B) in the lung tissue and histopathology. Although PM2.5 or human albumin alone did not induce allergic airway inflammation, simultaneous inoculation of PM2.5 and human albumin‐induced airway inflammation showing increase in AHR, total BALF cell numbers, mRNA levels of IL‐13, eotaxin 1, eotaxin 2, and MUC5AC, and anti‐IG against human serum albumin. Inflammation was observed around the bronchus in PM2.5 plus human albumin‐induced lungs. These results demonstrate that PM2.5 can induce allergic airway inflammation through the synergistic action with human albumin in NC/Nga mice.     

Acetylcholine and tachykinin receptor antagonists attenuate wood smoke-induced bronchoconstriction in guinea pigs

To study the mechanisms of wood smoke-induced bronchoconstriction, we measured total lung resistance (R_L) and dynamic lung compliance (C_dyn) in anesthetized and mechanically ventilated guinea pigs. Airway exposure to various doses of wood smoke (lauan wood; 5, 10, and 15 breaths) resulted in a dose-dependent increase in R_L and decrease in C_dyn. The smoke-induced changes in R_L and C_dyn were significantly attenuated by pretreatment with atropine, CP-96,345 [(2S,3S)-cis-2-(diphenylmethyl)-N-((2-methoxyphenyl)-methyl)-1-azabicyclo(2.2.2.)-octan-3-amine; a tachykinin NK₁ receptor antagonist], and SR-48,968 [(S)-N-methyl-N(4-(4-acetylamino-4-phenylpiperidino)-2-(3,4-dichlorophenyl)-butyl)benzamide; a tachykinin NK₂ receptor antagonist] in combination, atropine alone, and SR-48,968 alone, but were not significantly affected by pretreatment with the inactive enantiomers of CP-96,345 and SR-48,968, CP-96,345 alone, indomethacin (a cyclooxygenase inhibitor), and MK-571 [((3-(3-(2-(7-chloro-2-quinolinyl)ethenyl)phenyl((3-dimethyl amino-3-oxo-propyl)thio)methyl)propanoic acid; a leukotriene D₄ receptor antagonist]. The activity of airway neutral endopeptidase, a major enzyme for tachykinin degradation, was not significantly influenced by wood smoke during the development of bronchoconstriction. We conclude that: (1) both cholinergic mechanisms and endogenous tachykinins, but not cyclooxygenase products or leukotriene D₄, play an important role in the acute bronchoconstriction induced by wood smoke, and (2) the contribution of tachykinins to this airway response is primarily mediated via the activation of tachykinin NK₂ receptors, but is not associated with inactivation of the airway neutral endopeptidase.     

Tachykinin receptor antagonists for asthma and COPD

Asthma and chronic obstructive pulmonary disease (COPD) are common, severe inflammatory diseases of the respiratory tract for which there is an enormous pharmaceutical market. Current therapy for asthma is for the most part effective and comprises bronchodilators and anti-inflammatory glucocorticosteroids. In contrast, pharmacotherapy of COPD is much less effective. In addition, there are potentially undesirable side effects of current treatment of both conditions. Consequently, there are legitimate reasons for seeking alternative or additional therapies for asthma and COPD. There are theoretical reasons, supported by experimental evidence in animals, that sensory-efferent nerves and tachykinins, principally substance P and neurokinin A, contribute to the pathophysiology of asthma and COPD. In contrast, clinical studies to date using tachykinin receptor antagonists do not support a role for tachykinins in these conditions, most particularly asthma. However, confounding influences hinder adequate interpretation of the clinical data. Thus, whether or not tachykinins are involved in the pathophysiology of asthma and COPD is equivocal. Consequently, there is a need to evaluate novel potent tachykinin antagonists, both selective compounds and compounds with activity at multiple receptor subtypes. Recent patent applications from a variety of pharmaceutical companies disclose an array of different structural classes including substituted piperazinyl compounds, piperidine and carboxamide derivatives, oximes, hydrazones and olefins, heterocyclic compounds, peptides and pseudopeptides and drug combinations. The best of these compounds need clinical evaluation in well designed and well conducted studies with appropriate end points for the subtype of tachykinin receptor under consideration. This review encompasses patent applications pertaining to disclosures of tachykinin receptor antagonists of the NK₁, NK₂ and NK₃ subtype.     

Investigational prostaglandin D2 receptor antagonists for airway inflammation

Introduction: By activating DP₁ and DP₂ receptors on immune and non-immune cells, prostaglandin D₂ (PGD₂), a major metabolic product of cyclo-oxygenase pathway released after IgE-mediated mast cell activation, has pro-inflammatory effects, which are relevant to the pathophysiology of allergic airway disease. At least 15 selective, orally active, DP₂ receptor antagonists and one DP₁ receptor antagonist (asapiprant) are under development for asthma and/or allergic rhinitis.

Areas covered: In this review, the authors cover the pharmacology of PGD₂ and PGD₂ receptor antagonists and look at the preclinical, phase I and phase II studies with selective DP₁ and DP₂ receptor antagonists.

Expert opinion: Future research should aim to develop once daily compounds and increase the drug clinical potency which, apart from OC000459 and ADC-3680, seems to be relatively low.

Further research and development of DP₂ receptor antagonists is warranted, particularly in patients with severe uncontrolled asthma, whose management is a top priority. Pediatric studies, which are not available, are required for assessing the efficacy and safety of this novel drug class in children with asthma and allergic rhinitis. Studies on the efficacy of DP₂ receptor antagonists in various asthma phenotypes including: smokers, obese subjects, early vs late asthma onset, fixed vs reversible airflow limitation, are required for establishing their pharmacotherapeutic role.     

速激肽受体拮抗剂对豚鼠组胺反应的影响

目的：探讨速激肽与组胺（Ｈｉｓ）反应的关系。方法：观察速激肽受体拮抗剂对豚鼠Ｈｉｓ的整体和离体的呼吸道和心血管效应。结果：单用或合用速激肽ＮＫ－１受体拮抗剂ＣＰ－９６３４５（１ｍｇ·ｋｇ－１，ｉｐ）及ＮＫ－２受体拮抗剂ＳＲ－４８９６８（１ｍｇ·ｋｇ－１，ｉｐ）均可显著降低清醒豚鼠吸入Ｈｉｓ气雾的气道反应性。ＣＰ－９６３４５（１ｍｇ·ｋｇ－１，ｉｖ）可显著降低静脉注射Ｈｉｓ引起麻醉豚鼠支气管和心房的伊文思蓝渗出，ＳＲ－４８９６８（１ｍｇ·ｋｇ－１，ｉｖ）则对肺内压升高有较弱的抑制作用，两药对平均动脉压降低无明显作用。在豚鼠的离体气管和支气管平滑肌标本，ＣＰ－９６３４５（１μｍｏｌ·Ｌ－１）及ＳＲ－４８９６８（１μｍｏｌ·Ｌ－１）对Ｈｉｓ的Ｅｍａｘ及ｐＤ２无明显作用。结论：速激肽部分参与了豚鼠的Ｈｉｓ炎症反应，速激肽受体拮抗剂有抗炎作用。     

The capsaicin test in mice for evaluating tachykinin antagonists in the spinal cord

A capsaicin test involving peripheral nociception, which produces behaviour similar to that elicited by formalin, is described in mice. Capsaicin was injected subcutaneously (s.c.) into the dorsal surface of a hindpaw and the time the animals spent licking the paw was recorded. Doses of capsaicin of 6.25–1600 ng induced nociception, during a period of 5 min, starting immediately after injection and disappearing completely at 10 min. Intrathecally (i.t.) administered [ -Arg¹, -Trp^7,9, Leu¹¹]substance P (spantide), a tachykinin antagonist and [ -Phe⁷, -His⁹]substance P (6–11), a selective antagonist of substance P (SP), inhibited the capsaicin-induced behaviour, in a dose-dependent manner. This licking behaviour was also inhibited by intrathecal administration of SP antiserum but not by somatostatin (SOM) antiserum. Intrathecal pretreatment with capsaicin resulted in a marked reduction of the licking response, following subcutaneous injection of capsaicin into the paw. Capsaicin-induced licking was not affected by intrathecal administration of cyclo[7-aminoheptanoyl-Phe- -Trp-Lys-(OBz)-Thr], a SOM antagonist and by intrathecal pretreatment with cysteamine, a SOM depletor. This nociceptive test may allow discrimination between SP- and SOM-mediated responses in the spinal cord of the mouse.     

Effects of tachykinin receptor agonists and antagonists on the guinea-pig isolated oesophagus

1. Vagal nerve stimulation of the guinea-pig isolated oesophagus produced a triphasic tetrodotoxin (TTX)-sensitive contractile response. The third phase, which was resistant to ganglion blocking drugs, was selectively abolished by capsaicin, suggesting the involvement of one or more neuropeptides released from afferent neurons. Receptors on cholinergic neurons were subsequently activated because the response was atropine sensitive. Contractile responses resulting from exogenous substance P were abolished by atropine and TTX and enhanced by physostigmine. These findings suggest that the third phase may be mediated by the action of a substance P-like neuropeptide released from sensory nerve endings that subsequently activated cholinergic neurons. 2. The tachykinin receptors in the body of the guinea-pig oesophagus were characterized by determining the relative agonist potencies of natural tachykinins as well as tachykinin receptor-selective analogues. Antagonist affinities were also determined. The results indicated the presence of both NK2 and NK3 receptors. In addition, the effects of a cocktail of peptidase inhibitors (captopril, thiorphan and amastatin) on responses to various tachykinins and synthetic analogues were determined. The results indicate that one or more peptidases are present in this preparation. 3. Experiments using various tachykinin receptor antagonists were performed to determine whether the activation of tachykinin receptors played a role in the mediation of the third phase of the response to vagal nerve stimulation. While this response was unaffected by NK1 and NK2 receptor-selective antagonists, it was only partially inhibited (23%) by the NK3 receptor antagonist SR 142801. Thus, in the guinea-pig oesophagus, it appears that NK3 receptors play only a minor role in mediating a contractile response when afferent neurons are excited by vagal nerve stimulation.     

速激肽受体拮抗剂对白三烯C_4诱导豚鼠气道收缩和微血管渗漏的作用

本实验探讨了内源性速激肽是否参与白三烯Ｃ４（ＬＴＣ４）的气道效应．ＬＴＣ４（０．５μｇｋｇ－１，ｉｖ）可增高豚鼠肺内压（ＩＰＰ）和气道内依文思蓝渗出。速激肽ＮＫ－１受体拮抗剂ＣＰ－９６３４５｛（２Ｓ，３Ｓ）－顺式－２－（二苯甲基）－Ｎ－［（２－甲氧苯）－甲基］－１－杂氮双环［２．２．２］辛烷－３－胺｝１ｍｇｋｇ－１，ｉｖ，可减弱ＬＴＣ４诱导的依文思蓝渗出；ＮＫ－２受体拮抗剂ＳＲ－４８９６８｛（Ｓ）－Ｎ－甲基－Ｎ－［４－（４－乙酰氨基－４－苯基哌啶）－２－（３，４－二氯苯基）丁基］苯甲酰胺｝，１ｍｇｋｇ－１，ｉｖ，可抑制ＩＰＰ的增高．白三烯拮抗剂ＯＮＯ－１０７８（０．０３ｍｇｋｇ－１，ｉｖ）可阻断这两种反应．结果说明内源性速激肽增强ＬＴＣ４的气道作用，其中ＮＫ－１受体介导微血管渗漏，ＮＫ－２受体介导支气管收缩．     

Limonene inhalation reduces allergic airway inflammation in Dermatophagoides farinae-treated mice

Limonene is one of the main flavonoids which is reported to inhibit the inflammatory response by suppressing the production of reactive oxygen species. The aim of this study was to evaluate whether limonene can inhibit Dermatophagoides farinae-induced airway hyperresponsiveness (AHR), eosinophilic infiltration and other histological changes in the lung, T helper (Th) 2 cytokine production and airway remodeling in a mice model of asthma. Treatment with limonene significantly reduced the levels of IL-5, IL-13, eotaxin, MCP-1, and TGF-β₁ in bronchoalveolar lavage fluid. The goblet cell metaplasia, thickness of airway smooth muscle, and airway fibrosis were markedly decreased in limonene-treated mice. Furthermore, AHR to acetylcholine was significantly abrogated in limonene-treated mice. These results indicate that limonene has a potential to reduce airway remodeling and AHR in asthma model.     

速激肽受体拮抗剂对白三烯C4诱导豚鼠气道收缩和微血管渗漏的作用

本实验探讨了内源性速激肽是否参与白三烯C₄(LTC₄)的气道效应. LTC₄(0.5 μg·kg^-1, iv)可增高豚鼠肺内压(IPP)和气道内依文思蓝渗出。速激肽NK-1受体拮抗剂CP-96345｛(2S, 3S)-顺式-2-( 二苯甲基)-N-［(2-甲氧苯)-甲基］-1-杂氮双环［2.2.2］辛烷-3-胺｝ 1 mg·kg^-1，iv，可减弱LTC₄诱导的依文思蓝渗出；NK-2受体拮抗剂SR-48968｛(S)-N-甲基-N-［4-(4-乙酰氨基-4-苯基哌啶)-2-(3,4-二氯苯基)丁基］苯甲酰胺｝，1 mg·kg^-1， iv，可抑制IPP的增高. 白三烯拮抗剂ONO-1078 (0.03 mg·kg^-1, iv)可阻断这两种反应. 结果说明内源性速激肽增强 LTC₄的气道作用，其中NK-1受体介导微血管渗漏，NK-2受体介导支气管收缩.     

牛蒡子苷元通过SIRT1/NLRP3途径减轻哮喘小鼠气道炎症

目的探讨牛蒡子苷元对哮喘小鼠模型中对气道炎症的疗效以及其机制是否与SIRT1/NLRP3信号通路有关。方法选取40只♀清洁级BALB/c小鼠,分为control组,OVA模型组,ATG组(5、10和20 mg·kg^-1)。HE及PAS染色法观察肺组织病理改变;Diff-Quick染色法对小鼠BALF中细胞分类及计数;流式细胞术测定小鼠肺组织中细胞因子在CD4阳性细胞群中的阳性比例;Western blot测定肺组织SIRT1、NLRP3、caspase-1、IL-18和IL-1β蛋白表达;免疫荧光法检测小鼠肺组织中NLRP3荧光强度。结果牛蒡子苷元能抑制OVA诱导的炎症细胞的渗出及杯状细胞增生;牛蒡子苷元抑制小鼠肺泡灌洗液中总细胞数及NEU、EOS、LYM的生成,并升高肺组织中IFN-γ水平的同时降低IL-4的水平;Western blot结果显示,牛蒡子苷元增加SIRT1蛋白表达同时抑制NLRP3、caspase-1、IL-18和IL-1β蛋白表达;免疫荧光结果显示,牛蒡子苷元可以减弱肺组织NLRP3的荧光强度。结论牛蒡子苷元通过SIRT1/NLRP3途径减轻哮喘小鼠气道炎症。     

Obese mice are resistant to eosinophilic airway inflammation induced by diesel exhaust particles

Particulate matter can exacerbate respiratory diseases such as asthma. Diesel exhaust particles are the substantial portion of ambient particulate matter with a <2.5 µm diameter in urban areas. Epidemiological data indicate increased respiratory health effects of particulate matter in obese individuals; however, the association between obesity and diesel exhaust particle‐induced airway inflammation remains unclear. We aimed to investigate the differences in susceptibility to airway inflammation induced by exposure to diesel exhaust particles between obese mice (db/db) and lean mice (db/+m). Female db/db and db/+m mice were intratracheally administered diesel exhaust particles or vehicle every 2 weeks for a total of seven times. The cellular profile of bronchoalveolar lavage fluid and histological changes in the lungs were assessed and the lungs and serum were analyzed for the generation of cytokines, chemokines and soluble intercellular adhesion molecule 1. Diesel exhaust particle exposure‐induced eosinophilic infiltration in db/+m mice accompanied by T‐helper 2 cytokine, chemokine and soluble intercellular adhesion molecule 1 expression in the lungs. In contrast, it induced mild neutrophilic airway inflammation accompanied by elevated cytokines and chemokines in db/db mice. The lungs of db/db mice exhibited decreased expression of eosinophil activators/chemoattractants such as interleukin‐5, interleukin‐13 and eotaxin compared with those of db/+m mice. In addition, serum eotaxin and monocyte chemotactic protein‐1 levels were significantly higher in db/db mice than in db/+m mice. In conclusion, obesity can affect susceptibility to diesel exhaust particle‐induced airway inflammation, which is possibly due to differences in local and systemic inflammatory responses between lean and obese individuals. Copyright © 2013 John Wiley & Sons, Ltd.     

The active contribution of Toll-like receptors to allergic airway inflammation

Epithelia lining the respiratory tract represent a major portal of entry for microorganisms and allergens and are equipped with innate and adaptive immune signaling receptors for host protection. These include Toll-like receptors (TLRs) that recognize microbial components and evoke diverse responses in cells of the respiratory system. TLR stimulation by microorganism-derived molecules activates antigen presenting cells, control T helper (Th) 1, Th2, and Th17 immune cell differentiation, cytokine production by mast cells, and activation of eosinophils. It is clear that TLR are involved in the pathophysiology of allergic airway diseases such as asthma. Dendritic cells (DCs), a kind of antigen presenting cells, which play a key role in the induction of allergic airway inflammation, are privileged targets for pathogen associated molecular patterns (PAMPs). During the allergic responses, engagement of TLRs on DCs determines the Th2 polarization of the T cells. TLR signaling in mast cells increases the release of IL-5, and TLR activation of airway epithelial cells forces the generation of proallergic Th2 type of cytokines. Although these responses aim to protect the host, they may also result in inflammatory tissue damage in the airway. Under certain conditions, stimulation of TLRs, in particular, TLR9, may reduce Th2-dependent allergic inflammation by induction of Th1 responses. Therefore, understanding the complex regulatory roles of TLRs in the pathogenesis of allergic airway inflammation should facilitate the development of preventive and therapeutic measures for asthmatic patients.     

人参总皂苷在巨噬细胞RAW264.7中降低脂多糖诱导的炎症和氧化应激

目的:通过脂多糖诱导巨噬细胞RAW264.7建立炎症和氧化应激模型,探讨人参总皂苷的抗炎和抗氧化效果以及对脂多糖诱导的巨噬细胞RAW264.7自噬水平的影响。方法:培养RAW264.7细胞,给予脂多糖刺激并加入不同浓度人参总皂苷,使用硝酸还原酶法检测细胞内一氧化氮水平;ELISA法检测小鼠肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)的分泌;DCFH-DA荧光探针法检测人参总皂苷处理后活性氧的变化;超氧化物阴离子荧光探针(dihydroethidium, DHE)检测细胞内超氧化物阴离子水平;吖啶橙染色法检测自噬体的形成;Western Blot法检测COX-2、NF-кB、Nrf2、HO-1、GCLC、GCLM、Beclin1、ATG7和LC3的蛋白表达。结果:与脂多糖模型组相比,随着TGS的浓度增加,细胞一氧化氮水平、TNF-α的分泌降低,细胞内活性氧和超氧阴离子的含量降低,巨噬细胞RAW264.7酸性自噬体的数量增加;Nrf2、HO-1、GCLC、GCLM、Beclin1、ATG7及LC3的蛋白表达提高,COX-2、NF-кB的蛋白表达降低。结论:在...     

环孢素A气雾吸入对哮喘大鼠气道炎症的影响

目的研究环孢素A(CsA)气雾吸入对抗原诱导的大鼠过敏性气道炎症的作用。方法用卵白蛋白(OA)致敏大鼠,2周后气雾吸入CsA(5，10，20 g·L^-1),每天1次，连续7 d。大鼠致敏后d 20和d 21用OA(10 g·L^-1，每天1次)攻击，观察第2次OA攻击24 h后支气管肺泡灌洗液及外周血中嗜酸性粒细胞的数量和支气管肺组织病理学改变情况，测定支气管肺泡灌洗液中TNF-α含量。结果CsA气雾吸入能明显降低支气管肺泡灌洗液及外周血中嗜酸性粒细胞的数量，减轻肺组织中炎症细胞特别是嗜酸性粒细胞的浸润,减轻组织水肿及上皮损伤等气道炎症状况,降低支气管肺泡灌洗液中TNF-α含量。结论CsA气雾吸入对大鼠过敏性气道炎症具有抑制作用，其作用机制与细胞因子TNF-α释放减少有关。     

p38蛋白激酶抑制剂SB203580对支气管哮喘小鼠气道炎症和Th2类细胞因子的影响

目的观察特异性p38蛋白激酶(p38 MAPK)抑制剂SB203580对哮喘小鼠气道炎症和Th2类细胞因子的影响。方法BALB/c小鼠30只随机分成3组,即正常对照组、哮喘模型组和SB203580干预组。通过原位分子杂交和酶联免疫吸附法(ELISA)检测肺组织IL-4、IL-5 mRNA和支气管肺泡灌洗液(BALF)中白细胞介素(IL-4、IL-5)含量的变化,并观察BALF中炎症细胞和肺组织病理学改变。结果哮喘模型组小鼠BALF中炎症细胞计数和IL-4、IL-5含量以及肺组织IL-4、IL-5mRNA的表达较正常对照组明显升高,差异具有显著性(P<0.01);SB203580干预组小鼠上述指标较哮喘模型组小鼠明显降低,差异亦具有显著性(P<0.01),肺组织病理学改变明显减轻。结论SB203580能降低气道炎症细胞的聚集和炎症介质的表达。抑制p38 MAPK的活性可能成为哮喘治疗的新途径。     

Neurokinin-3 receptor antagonists in schizophrenia

Two neurokinin-3 receptor (NK3r) antagonists, osanetant and talnetant, have recently shown positive results in clinical trials for schizophrenia. Following these disclosures, research has accelerated significantly. This review focuses on progress for NK3r antagonists since 2004, primarily from the patent literature. The emphasis here is on NK3r antagonists as treatments for schizophrenia. In addition, antagonists of NK3r that have efficacy at NK1r and/or NK2r have also been explored as antipsychotics or as treatments for other psychiatric disorders and these will be included in this review.