Testosterone Enhances KV Currents and Airway Smooth Muscle Relaxation Induced by ATP and UTP through P2Y4 Receptors and Adenylyl Cyclase Pathway.

Numerous studies suggest the involvement of adenosine-5'-triphosphate (ATP) and similar nucleotides in the pathophysiology of asthma. Androgens, such as testosterone (TES), are proposed to alleviate asthma symptoms in young men. ATP and uridine-5'-triphosphate (UTP) relax the airway smooth muscle (ASM) via purinergic P2Y2 and P2Y4 receptors and K+ channel opening. We previously demonstrated that TES increased the expression of voltage-dependent K+ (KV) channels in ASM. This study investigates how TES may potentiate ASM relaxation induced by ATP and UTP. Tracheal tissues treated with or without TES (control group) from young male guinea pigs were used. In organ baths, tracheas exposed to TES (40 nM for 48 h) showed enhanced ATP- and UTP-evoked relaxation. Tetraethylammonium, a K+ channel blocker, annulled this effect. Patch-clamp experiments in tracheal myocytes showed that TES also increased ATP- and UTP-induced K+ currents, and this effect was abolished with flutamide (an androgen receptor antagonist). KV channels were involved in this phenomenon, which was demonstrated by inhibition with 4-aminopyridine. RB2 (an antagonist of almost all P2Y receptors except for P2Y2), as well as N-ethylmaleimide and SQ 22,536 (inhibitors of G proteins and adenylyl cyclase, respectively), attenuated the enhancement of the K+ currents induced by TES. Immunofluorescence and immunohistochemistry studies revealed that TES did not modify the expression of P2Y4 receptors or COX-1 and COX-2, while we have demonstrated that this androgen augmented the expression of KV1.2 and KV1.5 channels in ASM. Thus, TES leads to the upregulation of P2Y4 signaling and KV channels in guinea pig ASM, enhancing ATP and UTP relaxation responses, which likely limits the severity of bronchospasm in young males.

Bio-guided study of the antinociceptive, anti-inflammatory, and free-radical scavenging capacity of the leaves of Rhus virens Lindh. ex A. Gray and its possible mechanism of antinociception.

ETHNOPHARMACOLOGICAL RELEVANCE: Rhus genus is commonly known as sumac and widely used in the folk medicine. Rhus virens is a plant commonly used to treat diabetes or pain in the northern territory of Mexico. Even though R. virens is used in the folk medicine there is still a lack of evidence about the pharmacological effect of this species. AIM OF THE STUDY: The aim of this study was to determine the antinociceptive, anti-inflammatory and antioxidant effect of R. virens through a bio-guided chemical separation. MATERIALS AND METHODS: The aqueous, methanolic, and hexane extract of R. virens were obtained and tested in the formalin test, TPA-induced ear edema, and DPPH, ABTS, and FRAP assay. Also, possible interaction of pain pathways was studied using naloxone, bicuculline, L-NAME, ODQ, and glibenclamide in the formalin test in mice. RESULTS: Rhus virens methanolic extract (30 mg/kg, p.o.) produced higher antinociceptive activity in both the early and late phases of the formalin test (35.0 and 52.9%, respectively). Also, pre-administration with naloxone, bicuculline, L-NAME, ODQ and glibenclamide prevented the antinociceptive effect of R. virens in the early phase of the formalin test. Meanwhile, only naloxone and bicuculline prevented the antinociceptive effect on the late phase of the formalin test. Chemical separation of methanolic extract allowed to isolate 1,2,3,4,6-penta-O-galloyl-glucopyranose (PGG), it was tested in the formalin test, producing an antinociceptive effect on the late phase of the formalin test. On the other hand, topical application of the derivatives of R. virens methanolic extract produced an anti-inflammatory effect in the TPA-induced ear edema, being PGG an anti-inflammatory molecule. Lastly, radical scavenging activity was higher in the extracts of higher polarity, comparable to the standard used Camellia sinensis. CONCLUSIONS: In conclusion, R. virens produce an antinociceptive, anti-inflammatory and free-radical scavenging activity. The antinociceptive effect could be related to the opioidergic, GABAergic, and NO-GMPc-K + ATP channels pathways. These effects could be partially produced by the presence of PGG.

Effect of the Melanocortin 4-Receptor Ile269Asn Mutation on Weight Loss Response to Dietary, Phentermine and Bariatric Surgery Interventions.

The loss of function melanocortin 4-receptor (MC4R) Ile269Asn mutation has been proposed as one of the most important genetic contributors to obesity in the Mexican population. However, whether patients bearing this mutation respond differently to weight loss treatments is unknown. We tested the association of this mutation with obesity in 1683 Mexican adults, and compared the response of mutation carriers and non-carriers to three different weight loss interventions: dietary restriction intervention, phentermine 30 mg/day treatment, and Roux-en-Y gastric bypass (RYGB) surgery. The Ile269Asn mutation was associated with obesity [OR = 3.8, 95% CI (1.5-9.7), p = 0.005]. Regarding interventions, in the dietary restriction group only two patients were MC4R Ile269Asn mutation carriers. After 1 month of treatment, both mutation carriers lost weight: -4.0 kg (-2.9%) in patient 1, and -1.8 kg (-1.5%) in patient 2; similar to the mean weight loss observed in six non-carrier subjects (-2.9 kg; -2.8%). Phentermine treatment produced similar weight loss in six carriers (-12.7 kg; 15.5%) and 18 non-carriers (-11.3 kg; 13.6%) after 6 months of pharmacological treatment. RYGB also caused similar weight loss in seven carriers (29.9%) and 24 non-carriers (27.8%), 6 months after surgery. Our findings suggest that while the presence of a single MC4R loss of function Ile269Asn allele significantly increases obesity risk, the presence of at least one functional MC4R allele seems sufficient to allow short-term weight loss in response to dietary restriction, phentermine and RYGB. Thus, these three different interventions may be useful for the short-term treatment of obesity in MC4R Ile269Asn mutation carriers.

Genome-Wide Association Study Identifies a Functional SIDT2 Variant Associated With HDL-C (High-Density Lipoprotein Cholesterol) Levels and Premature Coronary Artery Disease.

Objective: Low HDL-C (high-density lipoprotein cholesterol) is the most frequent dyslipidemia in Mexicans, but few studies have examined the underlying genetic basis. Our purpose was to identify genetic variants associated with HDL-C levels and cardiovascular risk in the Mexican population. Approach and Results: A genome-wide association studies for HDL-C levels in 2335 Mexicans, identified four loci associated with genome-wide significance: CETP, ABCA1, LIPC, and SIDT2. The SIDT2 missense Val636Ile variant was associated with HDL-C levels and was replicated in 3 independent cohorts (P=5.9×10−18 in the conjoint analysis). The SIDT2/Val636Ile variant is more frequent in Native American and derived populations than in other ethnic groups. This variant was also associated with increased ApoA1 and glycerophospholipid serum levels, decreased LDL-C (low-density lipoprotein cholesterol) and ApoB levels, and a lower risk of premature CAD. Because SIDT2 was previously identified as a protein involved in sterol transport, we tested whether the SIDT2/Ile636 protein affected this function using an in vitro site-directed mutagenesis approach. The SIDT2/Ile636 protein showed increased uptake of the cholesterol analog dehydroergosterol, suggesting this variant affects function. Finally, liver transcriptome data from humans and the Hybrid Mouse Diversity Panel are consistent with the involvement of SIDT2 in lipid and lipoprotein metabolism. Conclusions: This is the first genome-wide association study for HDL-C levels seeking associations with coronary artery disease in the Mexican population. Our findings provide new insight into the genetic architecture of HDL-C and highlight SIDT2 as a new player in cholesterol and lipoprotein metabolism in humans.

Evaluation of the Antinociceptive, Antiallodynic, Antihyperalgesic and Anti-Inflammatory Effect of Polyalthic Acid.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are very commonly used, but their adverse effects warrant investigating new therapeutic alternatives. Polyalthic acid, a labdane-type diterpenoid, is known to produce gastroprotection, tracheal smooth muscle relaxation, and antitumoral, antiparasitic and antibacterial activity. This study aimed to evaluate the antinociceptive, antiallodynic, antihyperalgesic and anti-inflammatory effect of polyalthic acid on rats. Moreover, the effectiveness of treating hyperalgesia with a combination of polyalthic acid and naproxen was analyzed, as well as the type of drug-drug interaction involved. Nociception was examined by injecting 1% formalin into the right hind paw and thermal hyperalgesia and inflammation by injecting a 1% carrageenan solution into the left hind paw of rats. Allodynia was assessed on an L5/L6 spinal nerve ligation model. Polyalthic acid generated significant antinociceptive (56-320 mg/kg), antiallodynic (100-562 mg/kg), and antihyperalgesic and anti-inflammatory (10-178 mg/kg) effects. Antinociception mechanisms were explored by pretreating the rats with naltrexone, ODQ and methiothepin, finding the effect blocked by the former two compounds, which indicates the participation of opioid receptors and guanylate cyclase. An isobolographic analysis suggests synergism between polyalthic acid and naproxen in the combined treatment of hyperalgesia.

Benefits of prolonged-release pirfenidone plus standard of care treatment in patients with advanced liver fibrosis: PROMETEO study.

BACKGROUND AND AIMS: Pirfenidone (PFD), an oral antifibrotic drug, has been authorized by the EMA and FDA for treatment of idiopathic pulmonary fibrosis. Few studies have addressed its use in advanced liver fibrosis (ALF). We evaluated a prolonged-release formulation (PR-PFD) plus standard of care on disease progression in ALF. METHODS: 281 ALF patients from 12 centers receiving PR-PFD (600 mg bid) were screened; 122 completed 1 year of treatment. Additionally, 74 patients received only standard of care regimen. Average age was 64 ± 12 years, 58% female. 43.5% had fatty liver disease (NAFLD), 22.5% viral hepatitis C (VHC), 17% autoimmune hepatitis (AIH), and 17% alcoholic liver disease (ALD). Baseline fibrosis was F4 in 74% and F3 in 26%. Antifibrotic effects were assessed by transient elastography (Fibroscan®) and Fibro Test® (FT); Cytokines and PFD plasma levels were tracked and quality of life evaluated. RESULTS: We found a significant reduction in fibrosis in 35% of PR-PFD patients and only in 4.1% in non PR-PFD patients. Child-Pugh score improved in 29.7%. Biochemical values remained stable; 40.6% and 43.3% decreased ALT or AST, respectively. TGFß1 (pg/mL) levels were lower in PFD-treated patients. PFD serum concentration (µg/mL) was higher (8.2 ± 1.7) in fibrosis regression profile (FRP) patients compared to fibrosis progression profile (FPP) patients (4.7 ± 0.3 µg/mL, p < 0.01). 12% reported transient burning or nausea and 7% photosensitivity. Quality of life (Euro-Qol scale) improved from 62 ± 5 to 84 ± 3 (p < 0.001) and from 32 ± 3 to 42 ± 2 (p < 0.008) (FACIT scale). CONCLUSIONS: PR-PFD is efficacious and safe in ALF and associated with promising antifibrotic effects. TRIAL REGISTRATION: Clinical trial number: NCT04099407.

Zinc and selenium indicators and their relation to immunologic and metabolic parameters in male patients with human immunodeficiency virus.

OBJECTIVES: Micronutrient deficiencies are common among people living with HIV (PLWHIV). The clinical and immunologic consequences of micronutrient deficiencies have been poorly explored in the context of human immunodeficiency virus (HIV) infection. The aim of this study was to determine the prevalence of zinc and selenium deficiency (dietary intake and serum concentrations) and analyze their associations with absolute CD4+ T-cell counts, inflammation markers, and metabolic disorders in a cohort of antiretroviral-experienced HIV-infected individuals. METHODS: The zinc and selenium intakes of 124 HIV-infected men were estimated using 3-d food records. In a subcohort of 45 individuals, serum zinc and selenium concentrations and proinflammatory cytokines were determined. Body composition, bone mineral density (BMD), CD4+ T-cell counts, lipid profile, glucose, and blood pressure were determined and were associated with zinc and selenium dietary intake and serum concentrations. RESULTS: Of the PLWHIV studied, 58% had suboptimal intake of zinc and 8% demonstrated suboptimal intake of selenium. Serum deficiencies for zinc and selenium were 23.9% and 65.9%, respectively. Zinc and selenium intake were correlated with increased muscle mass. Selenium intake was associated with increased BMD of the lumbar region. An inverse correlation between serum selenium concentration and several proinflammatory cytokines (interleukin-1ß, interleukin-6, and tumor necrosis factor-α) was found. CONCLUSION: Suboptimal zinc and selenium intake and serum concentration deficiencies are highly prevalent in treated HIV-positive individuals and are associated with body composition, BMD, and inflammation. Clinical trials should be designed to explore the effect of zinc and selenium supplementation on metabolic, inflammatory, and immunologic parameters on the HIV-positive population.

Possible involvement of peripheral TRP channels in the hydrogen sulfide-induced hyperalgesia in diabetic rats.

BACKGROUND: Peripheral diabetic neuropathy can be painful and its symptoms include hyperalgesia, allodynia and spontaneous pain. Hydrogen sulfide (H2S) is involved in diabetes-induced hyperalgesia and allodynia. However, the molecular target through which H2S induces hyperalgesia in diabetic animals is unclear. The aim of this study was to determine the possible involvement of transient receptor potential (TRP) channels in H2S-induced hyperalgesia in diabetic rats. RESULTS: Streptozotocin (STZ) injection produced hyperglycemia in rats. Intraplantar injection of NaHS (an exogenous donor of H2S, 3-100 µg/paw) induced hyperalgesia, in a time-dependent manner, in formalin-treated diabetic rats. NaHS-induced hyperalgesia was partially prevented by local intraplantar injection of capsazepine (0.3-3 µg/paw), HC-030031 (100-316 µg/paw) and SKF-96365 (10-30 µg/paw) blockers, at 21 days post-STZ injection. At the doses used, these blockers did not modify formalin-induced nociception. Moreover, capsazepine (0.3-30 µg/paw), HC-030031 (100-1000 µg/paw) and SKF-96365 (10-100 µg/paw) reduced formalin-induced nociception in diabetic rats. Contralateral injection of the highest doses used did not modify formalin-induced flinching behavior. Hyperglycemia, at 21 days, also increased protein expression of cystathionine-ß-synthase enzyme (CBS) and TRPC6, but not TRPA1 nor TRPV1, channels in dorsal root ganglia (DRG). Repeated injection of NaHS enhanced CBS and TRPC6 expression, but hydroxylamine (HA) prevented the STZ-induced increase of CBS protein. In addition, daily administration of SKF-96365 diminished TRPC6 protein expression, whereas NaHS partially prevented the decrease of SKF-96365-induced TRPC6 expression. Concordantly, daily intraplantar injection of NaHS enhanced, and HA prevented STZ-induced intraepidermal fiber loss, respectively. CBS was expressed in small- and medium-sized cells of DRG and co-localized with TRPV1, TRPA1 and TRPC6 in IB4-positive neurons. CONCLUSIONS: Our data suggest that H2S leads to hyperalgesia in diabetic rats through activation of TRPV1, TRPA1 and TRPC channels and, subsequent intraepidermal fibers loss. CBS enzyme inhibitors or TRP-channel blockers could be useful for treatment of painful diabetic neuropathy.

Hipertensión arterial pulmonar asociada a virus de la inmunodeficiencia humana / Pulmonary arterial hypertension associated to human immunodeficiency virus

A partir de la presentación del tratamiento antirretroviral altamente efectivo, la esperanza de vida de los pacientes con virus de la inmunodeficiencia humana ha aumentado de manera significativa. En la actualidad, las causas de muerte son las complicaciones no infecciosas. Entre ellas, la hipertensión arterial pulmonar tiene una importancia especial. Es relevante la detección temprana para establecer la terapéutica con el objetivo de prevenir el desenlace fatal a futuro.

From the advent of the highly effective antiretroviral treatment, the life expectancy of patients with human immunodeficiency virus has increased significantly. At present, the causes of death are non-infectious complications. Between them, the pulmonary arterial hypertension has a special importance. It is important early detection to establish the therapeutic, with the objective of preventing a fatal outcome to future.

Participation of peripheral P2Y1, P2Y6 and P2Y11 receptors in formalin-induced inflammatory pain in rats.

Metabotropic P2Y receptors subfamily consists of eight functional mammalian receptors. Specifically, P2Y1, P2Y6 and P2Y11 receptors have been described in the sensory nervous system, but their participation, at peripheral level, in behavioral pain models is scarcely understood. This study assessed the role of peripheral P2Y1, P2Y6 and P2Y11 receptors in formalin-induced inflammatory pain. Ipsilateral, but not contralateral peripheral pre-treatment with the endogenous P2Y1 (ADP, 100-1000nmol/paw), P2Y6 (UDP, 180-300nmol/paw) and P2Y11 (ATP, 100-1000nmol/paw), or selective P2Y1 (MRS2365, 0.1-10nmol/paw), P2Y6 (PSB0474, 0.1-0.10pmol/paw) and P2Y11 (NF546, 0.3-3nmol/paw) receptor agonists increased 0.5% formalin-induced flinching behavior. Concordantly, peripheral pre-treatment with the selective P2Y1 (MRS2500, 0.01-10pmol/paw), P2Y6 (MRS2578, 3-30nmol/paw) and P2Y11 (NF340, 1-10nmol/paw) receptor antagonists significantly decreased 1% formalin-induced flinching behavior. Furthermore, the pronociceptive effect of ADP (100nmol/paw) or MRS2365 (10nmol/paw), UDP (300nmol/paw) or PSB0474 (10pmol/paw) and ATP (1000nmol/paw) or NF546 (3nmol/paw) was blocked by the selective P2Y1 (MRS2500, 0.01nmol/paw), P2Y6 (MRS2578, 3nmol/paw), and P2Y11 (NF340, 1nmol/paw) receptor antagonists, respectively. Western blot analysis confirmed the presence of P2Y1 (66kDa), P2Y6 (36kDa) and P2Y11 (75kDa) receptors in dorsal root ganglia (DRG) and sciatic nerve. Results suggest that peripheral activation of P2Y1, P2Y6 and P2Y11 receptors plays a pronociceptive role in formalin-induced pain.

Anti-inflammatory and cytotoxic activities of chichipegenin, peniocerol, and macdougallin isolated from Myrtillocactus geometrizans (Mart. ex Pfeiff.) Con.

The oleanane-type triterpene chichipegenin and the sterols peniocerol and macdougallin, isolated from Myrtillocactus geometrizans, showed anti-inflammatory activities in both the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema model and the carrageenan-induced rat paw edema model. All tested compounds inhibited the TPA-induced edema in a dose-dependent manner, with ED50 values less than or equal to that shown by indomethacin. Among them, peniocerol was the most active compound. However, only peniocerol and macdougallin reduced carrageenan-induced rat paw edema. On the other hand, peniocerol and macdougallin showed cytotoxicity against several human cancer cell lines. These results indicate that compounds isolated from M. geometrizans possess antiinflammatory and cytotoxic properties, and the presence of chichipegenin in the aerial parts could justify the medicinal uses attributed to the plant.

Pharmacokinetics of oral ranitidine in Mexicans

The pharmacokinetics of oral ranitidine were studied in 24 Mexican male healthy volunteers. Subjects received a tablet containing 150 mg of ranitidine (Azantac TM, Glaxo de Mexico, Mexico, City) after an overnight fast and blood samples were drawn at several times for a period of 24 h. Ranitidine concentration in plasma was measured by high performance liquid chromatography and pharmacokinetic parameters were determined by non-compartmental analysis. Ranitide plasma concentration increased with time, reaching a maximum of (mean ñ SEM) 484 ñ 34 ng/ml in 2.7 ñ 0.2 h. Plasma levels then decayed with a terminal half-life of 4.8 ñ 0.3 h. The area under the plasma concentration against time curve was 2440 ñ 126 ngh/ml. Oral ranitidine pharmacokinetic parameters in mexicans appeared to be similar to those previously reported for caucasians

Comparison between sprague-dawley and wistar rats as an experimental model of pharmacokinetic alterations induced by spinal cord injury

Two strains of rats, Sprague-Dawley and Wistar, were assayed in order to determine which strain is the more suitable experimental model for the study of pharmacokinetic alterations inuced by spinal cord injury. Animals were submitted to spinal cord contusion at the T8-T9 level by the weight drop method. A single acetaminophen oral dose (100 mg/kg) was administered 24 h after injury and blood samples were drawn for a period of 4 h. Acetaminophen concentration in whole blood was determined by high performance liquid chromatography and pharmacokinetic parameters were estimated. For both strains, Cmax and AUC were significantly lower, whereas tmax remained uchanged, in injured animals compared to sham-injured controls. Circulating acetaminophen concentrations were higher; therefore, pharmacokinetic alterations were more easily discerned, in Sprague-Dawley than in Wistar rats. It is concluded that the Sprague-Dawley strain is a more suitable model for the study of pharmacokinetic alternations induced by spinal cord injury

Determination of oral rifampin pharmacokinetic parameters in Mexicans and comparison with other populations: absence of evidence for interethnic variability

Oral pharmacokinetics of rifampin were studied in eight Mexican young healthy male volunteers after administration of a 600 mg oral dose. After and overnight fast, subjects received medication and blood samples were drawn at selected time over a 24-h period. Rifampin plasma levels were determined by HPLC. Pharmacokinetic parameters (mean ñ SEM) were: Cmax 13.514 ñ 1.775 µg/ml, tmax 1.88 ñ 0.30 h, AUC 73.61 ñ 9.48 µg.h/ml anf half-life 2.98 ñ 0.29 h. Results were compared with those obtained for the other populations under similar conditions in order to explore the possibility of interethnic variability, since it has been reported that rifampin pharmacokinetics in Indonesian subjects differ from those found in Europeans. Pharmacokinetic data found in Mexican were comparable with those observed in Brithis, Indian, Japanese and Italian individuals. As the parmacokinetics of rifampin seem to be similar different populations, it is concluded that ethnic origin does not a appear to play and important role. Therefore, dosing regimens designed for Caucasians can be extrapolated for other populations