B1 Receptor Agonist Research Articles

Kinin B1- and B2-Receptor Subtypes Contract Isolated Bovine Ciliary Muscle: Their Role in Ocular Lens Function and Intraocular Pressure Reduction

Background: Bradykinin is an endogenously produced nonapeptide with many physiological and pathological functions that are mediated by two pharmacologically defined receptor subtypes, B1- and B2-receptors. Current studies sought to characterize the functional bradykinin (BK) receptors present in freshly isolated bovine ciliary muscle (BCM) using an organ-bath tissue contraction system. Methods: Cumulative longitudinal isometric tension responses of BCM strips (4–5 mm) were recorded before and after the addition of test compounds to BCM strips hooked up to an isometric strain gauge transducer system. Results: BK and its analogs (7–11 concentrations) contracted BCM in a biphasic concentration-dependent manner. The first high affinity/potency phase accounted for 40–60% of the maximal contraction by each of BK (potency, EC50 = 0.9 ± 0.3 nM), Lys-BK (EC50 = 0.7 ± 0.1 nM), Met-Lys-BK (EC50 = 1 ± 0.1 nM), Hyp3-BK (EC50 = 1 ± 0.2 nM), RMP-7 (EC50 = 3.5 ± 0.5 nM), and Des-Arg9-BK (EC50 = 10 ± 0.4nM) (mean ± SEM, n = 3–8). The second lower activity phase of contraction potency values for these peptides ranged between 100 nM and 3 µM. In the presence of a selective B1-receptor antagonist (R715; 0.1–10 µM), the concentration–response curves to Des-Arg9-BK (B1-receptor agonist) were still observed, indicating activation of B2-receptors by this kinin. Likewise, when B2-receptors were completely blocked by using a B2-selective antagonist (WIN-64338; 1–10 µM), BK still induced BCM contraction, now by stimulating B1-receptors. Conclusions: This agonist/antagonist profile of BCM receptors indicated the presence of both B1- and B2-receptor subtypes, both being responsible for contracting this smooth muscle. The BCM kinin receptors may be involved in changing the shape of the ocular lens to influence accommodation, and since the ciliary muscle is attached to the trabecular meshwork through which aqueous humor drains, endogenously released kinins may regulate intraocular pressure.

New ways to repurpose salmeterol in an animal model of fibromyalgia.

Fibromyalgia (FM) is a syndrome of pervasive chronic pain accompanied by low mood, sleep disorders, and cognitive decline. The dysfunction of central pain processing systems along with neurotransmitter disturbances are possible contributing mechanisms. Genetic polymorphism of the 𝛽2 adrenergic receptors is reported in FM patients. It is reported that chronic β2 agonists administration is effective for neuropathic pain alleviation. No current information, however, exists on their potential to alleviate nociplastic pain, such as FM. Therefore, the purpose of the current study is to examine salmeterol's potential antiallodynic effects in experimentally produced FM and explore some of the possible contributing mechanisms. Thirty rats are allocated into three groups (n = 10): a normal group, a reserpine group that received reserpine (1 mg/kg; s.c.) for 3 days, and a reserpine + salmeterol group that received salmeterol (1 mg/kg; i.p.) for 21 consecutive days following last reserpine injection. Reserpine administration resulted in behavioral and biochemical changes consistent with FM, including thermal and mechanical hyperalgesia, depressive behavior, and motor incoordination. This is coupled with disturbed spinal monoamine levels, depressed cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling, disturbed mitochondrial function/dynamics, and compromised blood-nerve barrier integrity. Treatment with salmeterol conceivably reversed these effects. β2 receptor agonists such as salmeterol could be regarded as a promising strategy for the management of FM.

Beta2-Adrenergic Suppression of Neuroinflammation in Treatment of Parkinsonism, with Relevance for Neurodegenerative and Neoplastic Disorders.

There is a preliminary record suggesting that β2-adrenergic agonists may have therapeutic value in Parkinson's disease; recent studies have proposed a possible role of these agents in suppressing the formation of α-synuclein protein, a component of Lewy bodies. The present study focuses on the importance of the prototypical β2-adrenergic agonist epinephrine in relation to the incidence of Parkinson's disease in humans, and its further investigation via synthetic selective β2-receptor agonists, such as levalbuterol. Levalbuterol exerts significant anti-inflammatory activity, a property that may suppress cytokine-mediated degeneration of dopaminergic neurons and progression of Parkinsonism. In a completely novel finding, epinephrine and certain other adrenergic agents modeled in the Harvard/MIT Broad Institute genomic database, CLUE, demonstrated strong associations with the gene-expression signatures of anti-inflammatory glucocorticoids. This prompted in vivo confirmation in mice engrafted with human peripheral blood mononuclear cells (PBMCs). Upon toxic activation with mononuclear antibodies, levalbuterol inhibited (1) the release of the eosinophil attractant chemokine eotaxin-1, which is implicated in CNS and peripheral inflammatory disorders, (2) elaboration of the tumor-promoting angiogenic factor VEGFa, and (3) release of the pro-inflammatory cytokine IL-13 from activated PBMCs. These observations suggest possible translation to Parkinson's disease, other neurodegenerative syndromes, and malignancies, via several mechanisms.

Interaction of Angiotensin-(1−7) with kinins in the kidney circulation: Role of B1 receptors

Changes in renal hemodynamics impact renal function during physiological and pathological conditions. In this context, renal vascular resistance (RVR) is regulated by components of the Renin-Angiotensin System (RAS) and the Kallikrein-Kinin System (KKS). However, the interaction between these vasoactive peptides on RVR is still poorly understood. Here, we studied the crosstalk between angiotensin-(1−7) and kinins on RVR. The right kidneys of Wistar rats were isolated and perfused in a closed-circuit system. The perfusion pressure and renal perfusate flow were continuously monitored. Ang-(1−7) (1.0–25.0 nM) caused a sustained, dose-dependent reduction of relative RVR (rRVR). This phenomenon was sensitive to 10 nM A-779, a specific Mas receptor (MasR) antagonist. Bradykinin (BK) promoted a sustained and transient reduction in rRVR at 1.25 nM and 125 nM, respectively. The transient effect was abolished by 4 μM des-Arg9-Leu8-bradykinin (DALBK), a specific kinin B1 receptor (B1R) antagonist. Accordingly, des-Arg9-bradykinin (DABK) 1 μM (a B1R agonist) increased rRVR. Interestingly, pre-perfusion of Ang-(1−7) changed the sustained reduction of rRVR triggered by 1.25 nM BK into a transient effect. On the other hand, pre-perfusion of Ang-(1−7) primed and potentiated the DABK response, this mechanism being sensitive to A-779 and DALBK. Binding studies performed with CHO cells stably transfected with MasR, B1R, and kinin B2 receptor (B2R) showed no direct interaction between Ang-(1−7) with B1R or B2R. In conclusion, our findings suggest that Ang-(1−7) differentially modulates kinin's effect on RVR in isolated rat kidneys. These results help to expand the current knowledge regarding the crosstalk between the RAS and KKS complex network in RVR.

Genetic Deletion of Carboxypeptidase N Attenuates Angiotensin II-Induced Hypertension and Target Organ Damage

Objectives: Kininase I transforms bradykinin and kallidin, into kinin B1 receptor (B1R) agonists des-Arg9-BK and des-Arg10-kallidin, respectively. Carboxypeptidase M (CPM) is the membrane bound isoform of kininase I and carboxypeptidase N (CPN) is the isoform located in the plasma. Activation of the B1R has been implicated in the development of hypertension, diabetes and atherosclerosis. Pharmacologic inhibition of kininase I is associated with reductions in B1R expression, inflammation, oxidative stress, and improvements in insulin resistance. B1R can interact with aminopeptidase N (CD13) or high-mobility group box 1 (HMGB1) to mediate an inflammatory response. However, the exact role of kininase I in the development of hypertension and the regulation of these B1R-mediated signaling mechanisms remains unknown. In this study, we hypothesize that gene deletion of CPN will prevent B1R activation, reduce inflammation via interfering with CD13 and HMGB1 signaling, and ultimately attenuate the progression of hypertension and target organ damage. Methods and Results: To test our hypothesis we utilized 12-week-old male and female C57BL/6NJ wild-type (WT) and CPN gene knockout (CPNKO) mice. These mice were infused angiotensin II (Ang II, 600 ng/kg/min) or saline (vehicle) via osmotic minipumps for 2 weeks. Vehicle treated CPNKO and WT mice showed no significant difference in mean arterial blood pressure (MAP) (104 ±7 vs 102 ±5 mmHg, n=5, p≤0.05). Ang II-induced elevations in MAP were significantly reduced in CPNKO mice compared to WT mice infused with Ang II (129 ±8 vs 150 ±6 mmHg, n=5, p≤0.05). Interestingly, we did not find any significant sex differences in MAP in CPNKO groups. Additionally, Ang II treatment significantly increased cardiomyocyte hypertrophy in male and female WT mice, but this effect was blunted in CPNKO mice (n=5, p≤0.05; wheat germ agglutinin staining). Ang II infusion promoted collagen deposition in the aorta of WT male and female mice, but not in CPNKO mice (n=5, p≤0.05; picrosirius red/Masson’s trichrome). In male WT mice, Ang II significantly increased the immunoreactivity of CPM in the heart, but this was abrogated in CPNKO mice infused with Ang II (n=4, p≤0.05). Similarly, B1R was also upregulated in male WT mice hearts when compared to CPNKO mice after Ang II infusions (n=3, p≤0.05). We also found that Ang II significantly increased HMGB1 and CD13 in male WT hearts and brains, but not in CPNKO mice (n=4, p≤0.05). In addition, oxidative stress levels in the brain were significantly increased by Ang II in WT mice and was attenuated in CPNKO mice (n=4, p≤0.05; dihydroethidium staining). Conclusions: Genetic deletion of CPN attenuates Ang II-induced hypertension by reducing B1R mediated reductions in CD13 and HMGB1-mediated inflammatory responses and oxidative stress. Our data suggests that targeting kininase I may be a novel therapeutic target for hypertension and target organ damage. Funding: This study was supported by NHLBI/NIH 5R01HL153115 (S. Sriramula). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Determination of 12 prohibited veterinary drug residues in pig urine by ultra high performance liquid chromatography-tandem mass spectrometry

A method was established for the simultaneous detection of 12 prohibited veterinary drugs, including β2-receptor agonists, nitrofuran metabolites, nitroimidazoles, chlorpromazine, and chloramphenicol, in pig urine. The sample was pretreated by enzymolysis, acid hydrolysis/derivatization, and liquid-liquid extraction combined with solid-phase extraction. Detection was performed using ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Ammonium acetate solution (0.2 mol/L, 4.5 mL) and β-glucuronidase/aryl sulfatase (40 μL) were added to the sample, which was subsequently enzymolized at 37 ℃ for 2 h. Then, 1.5 mL of 1.0 mol/L hydrochloric acid solution and 100 μL of 0.1 mol/L o-nitrobenzaldehyde solution were added to the sample. The mixture was incubated at 37 ℃ for 16 h, and the analytes were extracted with 8 mL of ethyl acetate by liquid-liquid extraction. The lower aqueous phase obtained after extraction was extracted and purified using a mixed cation-exchange solid-phase extraction column. The extracts were combined, the extraction solution was blow-dried with nitrogen, and the residue was redissolved for determination. The samples were analyzed under multiple-reaction monitoring mode with both positive and negative electrospray ionization, and quantified using an isotope internal standard method. The correlation coefficients (r) of the 12 compounds were >0.99. The limits of detection (LODs) and quantification (LOQs) of chloramphenicol were 0.05 and 0.1 μg/L, respectively, and the LODs and LOQs of the other compounds were 0.25 and 0.5 μg/L, respectively. The mean recoveries and RSDs at 1, 2, and 10 times the LOQ were 83.6%-115.3% and 2.20%-12.34%, respectively. The proposed method has the advantages of high sensitivity, good stability, and accurate quantification; thus, it is suitable for the simultaneous determination of the 12 prohibited veterinary drug residues in pig urine.

Determination of higenamine in common natural spices by ultrahigh-performance liquid chromatography-tandem mass spectrometry.

Higenamine (HG) is a β2 receptor agonist and was explicitly added to the Prohibited List of the World Anti-Doping Agency in 2017. This compound is prohibited in both in- and out-of-competition athletes and falls under the category of nonthreshold substances. Because of HG presence in numerous plants, as evidenced by a growing body of research data, an exception was made for HG in the TD2017MRPL document, in which adverse analytical findings (AAFs) were not reported if the urinary HG concentration was less than 10ng/mL. In this study, a comprehensive and systematic analysis of the HG content in five batches of samples from each of the 48 natural spices selected for this investigation was conducted using UPLC-MS/MS technology. Method validation was carried out in accordance with the ICH Analytical Procedures and Methods Validation for Drugs and Biologics Guidance, and the experimental results demonstrated that the method provided appropriate sensitivity, precision, stability, linearity, and accuracy. HG was detected for the first time in Houttuynia cordata, Zingiber officinale, Cinnamomum cassia, Stevia rebaudiana, Piper nigrum, Siraitia grosuenorii, Platycodon grandiflorus, and Myristica fragrans. Furthermore, the content of HG was found to vary significantly among the different plant parts of Nelumbo nucifera, such as rhizomes, leaves, seeds, and plumules. This paper provides systematic and comprehensive data to support the safe use of spices in athletes' diets, thereby reducing the risk of food-sourced doping violations.

In vitro EVALUATION of THE EFFECTS of POTENTIAL GSK-3β INHIBITORS TERBUTALINE and ORCIPRENALINE

Lung cancer is a type of cancer that is mostly diagnosed at an advanced stage and has a short survival time despite standard chemotherapy and targeted therapies. Terbutaline and Orciprenaline are bronchodilator agent that are potent and selective β2 receptor agonists. The purpose of this study was to investigate by continuous monitoring to assay the effects of Terbutaline and Orciprenaline on human lung carcinoma cell line. Cells were treated 1, 10, 100, 200, 400 µM concentrations with Terbutaline/Orciprenaline. MTT assay and xCELLigence real-time cell analyzer were used to determine these compounds effect on cell viability. The cell index was monitored continuously by visualizing the impedance of the E-plate wells. Because of GSK3β roles in a diverse range of cellular processes like metabolism, cell proliferation, differentiation and survival and its key position at several signaling pathways, GSK3β inhibition was investigated of these molecules. It has been determined that Terbutaline and Orciprenaline inhibits GSK-3β.
 This is the first known study to demonstrate the effects of Terbutaline and Orciprenaline on A549 and the human bronchial epithelial cell line Beas-2b in real time. In this study, it was detected that Terbutaline and especially Orciprenaline may have potential therapeutic effects in lung carcinoma.

Serotonergic agonism and pharmacologically-induced adolescent stress cause operant-based learning deficits in mice

BackgroundThe interplay between environmental stress and genetic factors is thought to play an important role in the pathogenesis and maintenance of obsessive-compulsive disorder (OCD). However, the relative contribution of these causative antecedents in the manifestation of cognitive inflexibility—a phenotype often seen in obsessive-compulsive (OC)- spectrum disorders—is not fully understood. MethodIn this study, we treated mice with 50 mg/L corticosterone (CORT, a glucocorticoid stress hormone) in their drinking water during adolescence. In adulthood, we assessed anxiety-like behaviour and locomotor activity; along with operant-based discrimination and reversal learning. RU-24969, a selective serotonin receptor 5-HT1A/1B receptor agonist, was used as an acute pharmacological model of OC-like behaviour. RU-24969 (5 mg/kg) was administered prior to each reversal learning testing session. ResultsWe found that acute treatment with 5 mg/kg RU-24969 induced stereotyped hyperlocomotion in vehicle- and CORT-treated mice. Furthermore, pre-treatment with CORT in adolescence produced subtle anxiety-like behaviour in adult mice, and also resulted in an impairment to late-stage discrimination learning and alterations to reversal learning. Finally, acute treatment with 5 mg/kg RU-24969 caused an impairment to early-stage reversal learning. ConclusionWhilst we revealed dissociable detrimental effects of adolescent CORT treatment and acute 5-HT1A/1B receptor agonism on discrimination and reversal learning, respectively, we did not find evidence of additive deleterious effects of these two treatments. We therefore suggest that while disrupted serotonergic signalling is likely to be involved in the cognitive phenotype of OC-spectrum disorders, distinct neuropathological pathways may be at play in mediating the role of stress as an antecedent in OCD and related illnesses.

Impaired Lactate Release in Dorsal CA1 Astrocytes Contributed to Nociceptive Sensitization and Comorbid Memory Deficits in Rodents.

Memory deficits are a common comorbid disorder in patients suffering from neuropathic pain. The mechanisms underlying the comorbidities remain elusive. The hypothesis of this study was that impaired lactate release from dysfunctional astrocytes in dorsal hippocampal CA1 contributed to memory deficits. A spared nerve injury model was established to induce both pain and memory deficits in rats and mice of both sexes. von Frey tests, novel object recognition, and conditioned place preference tests were applied to evaluate the behaviors. Whole-cell recording, fiber photometry, Western blotting, and immunohistochemistry combined with intracranial injections were used to explore the underlying mechanisms. Animals with spared sciatic nerve injury that had displayed nociception sensitization or memory deficit comorbidities demonstrated a reduction in the intrinsic excitability of pyramidal neurons, accompanied by reduced Ca2+ activation in astrocytes (ΔF/F, sham: 6 ± 2%; comorbidity: 2 ± 0.4%) and a decrease in the expression of glial fibrillary acidic protein and lactate levels in the dorsal CA1. Exogenous lactate supply or increasing endogenous lactate release by chemogenetic activation of astrocytes alleviated this comorbidity by enhancing the cell excitability (129 ± 4 vs. 88 ± 10 for 3.5 mM lactate) and potentiating N-methyl-d-aspartate receptor-mediated excitatory postsynaptic potentials of pyramidal neurons. In contrast, inhibition of lactate synthesis, blocking lactate transporters, or chemogenetic inhibition of astrocytes resulted in comorbidity-like behaviors in naive animals. Notably, β2-adrenergic receptors in astrocytes but not neurons were downregulated in dorsal CA1 after spared nerve injury. Microinjection of a β2 receptor agonist into dorsal CA1 or activation of the noradrenergic projections onto the hippocampus from the locus coeruleus alleviated the comorbidity, possibly by increasing lactate release. Impaired lactate release from dysfunctional astrocytes, which could be rescued by activation of the locus coeruleus, led to nociception and memory deficits after peripheral nerve injury.

Kinin B2 Receptor Mediates Cisplatin-Induced Painful Peripheral Neuropathy by Intracellular Kinase Pathways and TRPA1 Channel Sensitisation.

Chemotherapy-induced peripheral neuropathy is a severe clinical problem frequently associated with cisplatin use. Although its pathophysiology is poorly understood, it is known that kinin receptors and the transient receptor potential ankyrin 1 (TRPA1) channel play a significant role in the peripheral neuropathy induced by cisplatin in rodents. However, the role of signalling pathways downstream from B2 kinin receptors activation and sensitisation of the TRPA1 channel remains unknown in this model. The cisplatin-induced neuropathy model caused mechanical and cold allodynia in male Swiss mice. Antagonists for kinin B2 and B1 receptors and the TRPA1 channel attenuated the painful parameters. Local sub-nociceptive doses of kinin B2 receptor (bradykinin) and TRPA1 channel (allyl isothiocyanate; AITC) agonists enhanced the painful parameters in cisplatin-treated mice, which their respective antagonists attenuated. Furthermore, we demonstrated the interaction between the kinin B2 receptor and the TRPA1 channel in cisplatin-induced peripheral neuropathy since phospholipase C (PLC) and protein kinase C epsilon (PKCε) inhibitors attenuated the increase in mechanical and cold allodynia evoked by bradykinin and AITC in cisplatin-treated mice. Therefore, regulating the activation of signalling pathways downstream from the kinin B2 receptors activation and TRPA1 channel sensitisation can mitigate the painful peripheral neuropathy decurrent of the oncology treatment with cisplatin.

Cost-effectiveness of Arg16Gly in ADRB2 pharmacogenomic-guided treatment for pediatric asthma

ABSTRACT Objectives To assess the cost-effectiveness of Arg16Gly ADRB2 pharmacogenomic testing compared with no Arg16Gly ADRB2 testing to guide the use of long-acting β2 receptor agonist (LABA) in asthma patients aged 1 to 5 years in China. Methods This economic evaluation developed a Markov model with four health states (no exacerbation, mild exacerbation, moderate-to-severe exacerbation, and death). Transition probabilities were estimated from the rate of exacerbations, the case-fatality rate of patients hospitalized for exacerbations, and natural mortality. Costs included drug costs and exacerbation management costs. Cost inputs and utilities for each health state were gained from public databases and the literatures. Costs and quality-adjusted life years (QALYs) were estimated for ten years. Deterministic and probabilistic sensitivity analyses were performed. Results In the base case analysis, in contrast to the group without the genotype test, the incremental total cost was -¥334.7, and the incremental QALY was 0.001 in the Arg16Gly ADRB2 genotyping group. Therefore, the Arg16Gly ADRB2 test group was the dominant strategy for children with asthma in China. The sensitivity analyses showed that the model was relatively stable. Conclusion Arg16Gly ADRB2 testing before using LABA is a cost-effective approach compared with no gene testing for pediatric asthma.

One stone two birds: anti-inflammatory bronchodilators as a potential pharmacological strategy for COVID-19.

The ongoing Coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has imposed a huge threat to public health across the world. While vaccinations are essential for reducing virus transmission and attenuating disease severity, the nature of high mutation rate of SARS-CoV-2 renders vaccines less effective, urging quick development of effective therapies for COVID-19 disease. However, developing novel drugs remains extremely challenging due to the lengthy process and high cost. Alternatively, repurposing of existing drugs on the market represents a rapid and safe strategy for combating COVID-19 pandemic. Bronchodilators are first line drugs for inflammatory lung diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Compared to other anti-inflammatory drugs repurposed for COVID-19, bronchodilators are unique in that they have both anti-inflammatory and bronchodilating properties. Whether the dual properties of bronchodilators empower them greater potential to be repurposed for COVID-19 is worth exploring. In fact, clinical and preclinical studies have recently emerged to investigate the benefits of bronchodilators such assalbutamol, formoterol and theophylline in treating COVID-19, and many of them have shown encouraging efficacy on attenuating disease severity of pneumonia and other associated symptoms. To comprehensively understand the latest progress on COVID-19 intervention with bronchodilators, this review will summarize recent findings in this area and highlight the promising clinical benefits and possible adverse effects of bronchodilators as therapeutic options for COVID-19 with a focus on β2 receptor agonists, anticholinergic drugs and theophylline.

Kininase I inhibition reduces B1R mediated signaling and attenuates angiotensin II-induced hypertension

Objectives: Kininase I, or carboxypeptidase M and N (CPM/CPN), metabolizes bradykinin and kallidin into endogenous kinin B1 receptor (B1R) agonists. B1R expression in the brain is linked to neuroinflammation and autonomic dysfunction, and the development of hypertension. The metalloprotease aminopeptidase N (CD13) can interact with B1R to enhance proinflammatory cytokine production. However, the exact role of kininase I in the development of hypertension has not been yet investigated. In the present study, we tested the hypothesis that inhibition of kininase I will prevent the activation of the B1R, and reduce CD13 signaling, thus ultimately attenuating the progression of hypertension. Methods and Results: To inhibit the kininase I activity, we have utilized carboxypeptidase N gene deleted knockout (CPNKO) mice. Twelve-week-old male and female C57BL/6NJ wild-type (WT) and CPNKO mice, were administered angiotensin II (Ang II, 600 ng/kg/min; 2 weeks) or saline (vehicle) via osmotic minipumps. The mean arterial blood pressure (MAP) was measured using radio telemetry probes for 2 weeks. CPNKO mice did not show any significant differences in MAP at baseline. Ang II-infusion significantly increased the MAP in WT mice compared to saline infused control mice (147 ±5 vs 102 ±2 mmHg, n=5, p<0.05), which was attenuated in CPNKO mice (125 ±4 mmHg, n=5, p<0.01). Interestingly, there were no significant differences in MAP following Ang II-infusion in male and female CPNKO mice. Ang II treatment resulted in sympathoexcitation in WT mice, as indicated by increased urinary norepinephrine levels (446 ±38 ng/ml, p<0.05 vs. control), but this increase was blunted in CPNKO mice infused with Ang II (246 ±14 ng/ml, p<0.05 vs. WT+Ang II). WT mice treated with Ang II had increased inflammation, as shown by elevated gene expression (measured by qRT-PCR) of TNF, IL-1β and IL-6 (5-, 3.6-, and 4-fold, respectively, n=6, p<0.01 vs. WT) in the hypothalamic paraventricular nucleus (PVN). The expression of these inflammatory genes was attenuated in CPNKO mice with Ang II infusion. Immunofluorescence staining showed that Ang II-infusion also significantly increased the expression of B1R, CPM, and CD13 in the PVN, a central regulatory center for cardiovascular and autonomic control. CPM has been shown to interact directly with B1R. To further determine interactions between B1R and CPM, we used proximity ligation assay (PLA) to elucidate close (<40 nM) protein-protein interactions, as indicated by fluorescent PLA signals. Our data suggest that direct B1R-CPM interactions occurring within the PVN as the PLA signals are significantly increased by Ang II treatment in WT mice (p<0.05, n=3), and blunted in CPNKO mice. Conclusions: Kininase I inhibition by CPN gene deletion attenuates Ang II-induced hypertension by reducing B1R and CD13 acti vation, sympathoexcitation, and inflammation. Our data suggest that targeting kininase I may be a novel therapeutic target for hypertension. Funding: This study was supported by NHLBI/NIH 5R01HL153115 (S. Sriramula). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

THE SAFETY AND EFFICACY OF SOLIFENACIN AS COMPARED TO MIRABEGRON IN OVERACTIVE BLADDER SYNDROME PATIENTS IN THE ADULT POPULATION OF DERA ISMAIL KHAN

An overactive bladder syndrome is a group of symptoms, i.e., frequency, urgency, nocturia, and sometimes accompanied by urge incontinence. The recent pharmacological options are some drugs, mainly used anti-muscarinic. However, anti-muscarinic drugs have different adverse effects, i.e., constipation and dry mouth. In 2011, a β3 receptor agonist, mirabegron, was studied to treat overactive bladder syndrome. This non-randomized trial was conducted in the Department of Urology, Gomal medical college, D.I. Khan, KPK Pakistan. The study was done from June 2018 to January 2022. We divided 4220 patients into two equal groups. Group a used solifenacin 5 mg for 6 weeks, while group B used mirabegron 50 mg for the same duration. We assessed safety and efficacy after 6 weeks. Most of the adverse effects were mild to moderate severity. Dry mouth occurred in 125 patients out of 2110 (5.92%) in group A and 66 out of 2110 (3.12%) in group B. p-value = 0.0001. Constipation occurred in 53 (2.51%) patients in group A and 46 (2.18%) patients in group B. p-value=0.5417. The improvement in overactive bladder symptoms score (OBSS) occurred in 1443 out of 2110 (68.38%) patients in group A and 1409 out of 2110 (66.77%) patients in group B. p-value=0.2778. Based on the results, it can be concluded that Mirabegron has fewer adverse effects than solifenacin, while both drugs are approximately similar in efficacy.

Cocaine use disorder patients develop distinct patterns of regulation of acth secretion by a vasopressin agonist and oxytocin: Report on a laboratory study

Background: Oxytocin and Vasopressin systems in the brain sustain adaptation to stressors. Cocaine being a stressor, it may alter brain homeostatic function. This dysregulation may entrench cocaine use disorder. Method: This is a human laboratory study of the effects of intranasal desmopressin (a Vasopressin 1b receptor agonist) and oxytocin on ACTH secretion in cocaine use disorder patients versus a control group. It consisted of two endocrine challenges performed on consecutive days. On day 1, the effect of intranasal desmopressin (80 IU) on ACTH secretion was measured. On day 2, a pre-treatment with intranasal oxytocin (24 IU) preceded intranasal desmopressin to monitor its effect on desmopressin-induced ACTH secretion. We hypothesized that the effect of intranasal oxytocin in controls would differ from the effect in cocaine use disorder patients. Results: Forty-three patients were included in this study: 14 controls and 29 cocaine use disorder patients. Significant differences were noted in the direction of change of ACTH secretion between the two groups. In cocaine use disorder patients, overall ACTH secretion was on average 2.7 pg/ml/min higher after intranasal desmopressin than after intranasal oxytocin/desmopressin (t292 = 2.91, p = 0.004). The opposite was observed in controls: overall ACTH secretion averaged 3.3 pg/ml/min less after intranasal desmopressin than after intranasal oxytocin/desmopressin (t292 = -2.35, p = 0.02). Conclusion: Intranasal oxytocin and desmopressin revealed a pattern of ACTH secretion in cocaine use disorder patients that is distinct from a non-addicted control group. (ClinicalTrial.gov00255357, 10/2014)

Dopamine Receptor D1 Is Exempt from Transforming Growth Factor β-Mediated Antifibrotic G Protein-Coupled Receptor Landscape Tampering in Lung Fibroblasts.

Pulmonary fibroblasts are the primary producers of extracellular matrix (ECM) in the lungs, and their pathogenic activation drives scarring and loss of lung function in idiopathic pulmonary fibrosis (IPF). This uncontrolled production of ECM is stimulated by mechanosignaling and transforming growth factor beta 1 (TGF-β1) signaling that together promote transcriptional programs including Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ). G protein-coupled receptors (GPCRs) that couple to G α s have emerged as pharmacological targets to inactivate YAP/TAZ signaling and promote lung fibrosis resolution. Previous studies have shown a loss of expression of "antifibrotic GPCRs"-receptors that couple to G α s, in IPF patient-derived fibroblasts compared with non-IPF samples. Of the 14 G α s GPCRs we found to be expressed in lung fibroblasts, the dopamine receptor D1 (DRD1) was one of only two not repressed by TGF-β1 signaling, with the β2-adrenergic receptor being the most repressed. We compared the potency and efficacy of multiple D1 and β2 receptor agonists +/- TGF-β1 treatment in vitro for their ability to elevate cAMP, inhibit nuclear localization of YAP/TAZ, regulate expression of profibrotic and antifibrotic genes, and inhibit cellular proliferation and collagen deposition. Consistently, the activity of β2 receptor agonists was lost, whereas D1 receptor agonists was maintained, after stimulating cultured lung fibroblasts with TGF-β1. These data further support the therapeutic potential of the dopamine receptor D1 and highlight an orchestrated and pervasive loss of antifibrotic GPCRs mediated by TGF-β1 signaling. SIGNIFICANCE STATEMENT: Idiopathic pulmonary fibrosis (IPF) is a deadly lung disease with limited therapies. GPCRs have emerged as a primary target for the development of novel antifibrotic drugs; however, a challenge to this approach is the dramatic changes in GPCR expression in response to profibrotic stimuli. Here, we investigate the impact of TGF-β1 on the expression of antifibrotic GPCRs and show the D1 dopamine receptor expression is uniquely maintained in response to TGF-β1, further implicating it as a compelling target to treat IPF.

ADME properties of CHF6366, a novel bi-functional M3 muscarinic receptor antagonist and ß2 adrenoceptor agonist (MABA) radiolabelled at both functional moieties

CHF6366, a dual action β2-receptor agonist and M3-muscarinic receptor antagonist developed for chronic obstructive pulmonary disease (COPD) was [14C]-radiolabelled on the two different functional moieties of the molecule (either aminobutanolic or carbamate) to characterise its ADME profile following intravenous (IV), intratracheal (IT) and oral (PO) administration. A very low oral bioavailability and a good balance between absorption and lung retention after IT administration were observed, together with a rapid distribution throughout the body and a complete metabolic transformation of the parent drug without relevant gender difference. CHF6366 was observed fully hydrolysed to alcohol (CHF6387) and carboxylic acid (CHF6361) in plasma and urine after IV and IT administration, and mainly unchanged in faeces only after oral administration. An important number of metabolites containing aminobutanolic moiety was excreted via urine, whereas carbamate-containing derivatives were excreted mainly by bile. The major metabolic routes of the alcoholic moiety (CHF6387) included isomerisation (Ma7), conjugation with glucuronic acid and dehydrogenation, while the carboxylic acid moiety (CHF6361) was mainly metabolised through oxidation, glucuronide conjugation and, in both pathways, combinations of those metabolic reactions. No major differences arose also from in vitro metabolism profiles investigated using liver microsomes and hepatocytes of different species.

Kinin B1 and B2 Receptors Contribute to Cisplatin-Induced Painful Peripheral Neuropathy in Male Mice

Cisplatin is the preferential chemotherapeutic drug for highly prevalent solid tumours. However, its clinical efficacy is frequently limited due to neurotoxic effects such as peripheral neuropathy. Chemotherapy-induced peripheral neuropathy is a dose-dependent adverse condition that negatively impacts quality of life, and it may determine dosage limitations or even cancer treatment cessation. Thus, it is urgently necessary to identify pathophysiological mechanisms underlying these painful symptoms. As kinins and their B1 and B2 receptors contribute to the development of chronic painful conditions, including those induced by chemotherapy, the contribution of these receptors to cisplatin-induced peripheral neuropathy was evaluated via pharmacological antagonism and genetic manipulation in male Swiss mice. Cisplatin causes painful symptoms and impaired working and spatial memory. Kinin B1 (DALBK) and B2 (Icatibant) receptor antagonists attenuated some painful parameters. Local administration of kinin B1 and B2 receptor agonists (in sub-nociceptive doses) intensified the cisplatin-induced mechanical nociception attenuated by DALBK and Icatibant, respectively. In addition, antisense oligonucleotides to kinin B1 and B2 receptors reduced cisplatin-induced mechanical allodynia. Thus, kinin B1 and B2 receptors appear to be potential targets for the treatment of cisplatin-induced painful symptoms and may improve patients' adherence to treatment and their quality of life.

Dysfunction of the noradrenergic system drives inflammation, α-synucleinopathy, and neuronal loss in mouse colon.

Clinical and pathological evidence revealed that α-synuclein (α-syn) pathology seen in PD patients starts in the gut and spreads via anatomically connected structures from the gut to the brain. Our previous study demonstrated that depletion of central norepinephrine (NE) disrupted brain immune homeostasis, producing a spatiotemporal order of neurodegeneration in the mouse brain. The purpose of this study was 1) to determine the role of peripheral noradrenergic system in the maintenance of gut immune homeostasis and in the pathogenesis of PD and 2) to investigate whether NE-depletion induced PD-like α-syn pathological changes starts from the gut. For these purposes, we investigated time-dependent changes of α-synucleinopathy and neuronal loss in the gut following a single injection of DSP-4 (a selective noradrenergic neurotoxin) to A53T-SNCA (human mutant α-syn) over-expression mice. We found DPS-4 significantly reduced the tissue level of NE and increased immune activities in gut, characterized by increased number of phagocytes and proinflammatory gene expression. Furthermore, a rapid-onset of α-syn pathology was observed in enteric neurons after 2 weeks and delayed dopaminergic neurodegeneration in the substantia nigra was detected after 3-5 months, associated with the appearance of constipation and impaired motor function, respectively. The increased α-syn pathology was only observed in large, but not in the small, intestine, which is similar to what was observed in PD patients. Mechanistic studies reveal that DSP-4-elicited upregulation of NADPH oxidase (NOX2) initially occurred only in immune cells during the acute intestinal inflammation stage, and then spread to enteric neurons and mucosal epithelial cells during the chronic inflammation stage. The upregulation of neuronal NOX2 correlated well with the extent of α-syn aggregation and subsequent enteric neuronal loss, suggesting that NOX2-generated reactive oxygen species play a key role in α-synucleinopathy. Moreover, inhibiting NOX2 by diphenyleneiodonium or restoring NE function by salmeterol (a β2-receptor agonist) significantly attenuated colon inflammation, α-syn aggregation/propagation, and enteric neurodegeneration in the colon and ameliorated subsequent behavioral deficits. Taken together, our model of PD shows a progressive pattern of pathological changes from the gut to the brain and suggests a potential role of the noradrenergic dysfunction in the pathogenesis of PD.