bluuebunny/crossref_metadata_2025_split huggingface dataset:
c‐Fos Responses Produced by the Central Microinjection of Salvinorin A in Conscious Rats
Authors: Ali Aboozar , Franklin Cynthia , Rangel Yolanda , Gottlieb Helmut 
Published: June 2021

Intracerebroventricular (ICV) injection of the kappa opioid agonists produces a marked diuresis in rats via inhibition of vasopressin secretion. Salvinorin A (SalA) is a plant‐derived high affinity agonist for the kappa opioid receptor (KOR). Previous studies have proposed that SalA has similar potency and efficacy as other synthetic kappa agonists in mediating the CNS effects of KOR activation. The present study examines the expression of the proto‐oncogene c‐fos in several forebrain regions of rats treated with SalA as compared to either acetonitrile or saline vehicle treated animals. SalA is a highly lipophilic drug and past studies utilized drug dissolving vehicles (e.g., DMSO) that produced significant cardiovascular and renal effects. In this study, we dissolved SalA in acetonitrile/saline (1:9 dilution) to minimize solvent viscosity and cardiovascular effects.MethodsAnimals were habituated to a metabolic cage and injected with either SalA, acetonitrile or saline. Urine samples were collected during two 15 min control periods and six 15 min periods beginning 15 min after injection into the lateral ventricle. After 90 minutes, animals were perfused with a phosphate buffer and PFA. Brains were removed and cut on a cryostat (40 μm thick). Brain sections were processed for c‐fos using a commercially available antibody. Sections were also double labeled with oxytocin to define anatomically specific forebrain regions.ResultsSalA decreased c‐fos expression in the parvocellular PVN, magnocellular PVN, supraoptic (SON) and median pre‐optic (MnPO) nucleus relative to the acetonitrile group. However, only in the parvocellular PVN was the decrease in c‐fos expression statistically significant (p<0.001). In contrast, there was no difference in c‐fos expression between SalA and saline vehicle treated rats, with the exception of the MnPO in which c‐fos expression was markedly increased (P<0.001).ConclusionThe ability of kappa opioid receptor agonists to increase diuresis and decrease osmolality may be associated with changes in c‐fos expression in the PVN and lamina terminalis. Previous studies in our lab, demonstrated a small increase in urine excretion rate following ICV administration of SalA and is consistent with the present findings in which there is a concomitant decrease in c‐fos expression in the magnocellular PVN and SON forebrain regions in SalA treated animals. However, the decrease was not a prominent as observed with U50488H, a synthetic KOR agonist. These results support the findings that the diuretic effects of SalA are not as potent as synthetic kappa opioid agonists.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Female rats eating high fat chow acquire methamphetamine self‐administration faster than rats eating standard chow
Authors: Galindo Kayla I , Beltran Nina M , Serna Paloma , Ramos Jeremiah , Serafine Katherine M 
Published: June 2021

Eating a diet that is high in fat contributes to increased risk of chronic diseases and mortality, even in the absence of obesity. Eating a high fat diet can also impact the same brain reward pathways that are targeted by drugs of abuse. Preclinical studies have demonstrated that rats eating high fat chow are more sensitive to the unconditioned behavioral effects of drugs that act on dopamine systems (e.g., cocaine). However, the majority of evidence demonstrating that diet can impact drug sensitivity has investigated only male subjects, despite probable sex differences. To test the hypothesis that eating high fat chow increases sensitivity of rats to the positive reinforcing effects of methamphetamine (0.01–1.78 mg/kg/infusion), female Sprague‐Dawley rats (n = 30) were fed either standard (17% kcal from fat) or high fat chow (60% kcal from fat) for 6 weeks prior to self‐administration procedures. Following i.v. catheter implantation, rats were trained to respond for 0.1 mg/kg/infusion methamphetamine under a Fixed Ratio 1 schedule of reinforcement. Rats eating high fat chow met acquisition criteria faster (14 +/−2 days) than rats eating standard chow (25 +/− 4 days). Preliminary (n = 5–8/group) dose‐response curve assessments under a Fixed Ratio 5 schedule of reinforcement revealed that rats eating high fat chow respond less for methamphetamine than rats eating standard chow, at least at the training dose (0.1 mg/kg/infusion). These results suggest that rats eating high fat chow are more sensitive to the reinforcing effects of methamphetamine than rats eating standard chow. Future work will examine the relative reinforcing effectiveness of methamphetamine in rats eating different diets using a progressive ratio schedule of reinforcement. These data expand previous research and add to the growing literature on the effects of diet on drug sensitivity.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Comparison between the effects of propofol and midazolam on pentylenetetrazole kindled convulsions in rats
Authors: Hasan Zuheir A , Abdul Razzak Rima L 
Published: June 2021

Propofol, a short acting intravenous anesthetic which is wildly used for induction and maintenance of anesthesia. In addition, propofol has been successfully used in the management of status epileptics. However, sporadic reports of the occurrence of seizures or seizure like phenomena in epileptic and non‐epileptic patients continue to appear. The purpose of the present study is to examine the effects of intravenous (IV) administration of various doses of propofol and midazolam on pentylentetrazole (PTZ) kindled convulsions in rat.Experiments were conducted in adult females Sprague–Dawley rats (230–250 g). PTZ kindling was induced by intraperitoneal (IP) injection of a subconvulsivant dose of PTZ (35 mg/kg) every alternate day. After each injection of PTZ rats were placed in plexy glass cages and were monitored for 30 minutes for the occurrence of behavioral seizures. Severity of behavioral seizures and seizure score was rated according to Racine scale (Racin, 1972). An animal was considered fully‐kindled when it has had stage 4–5 seizure score on two consecutive trials. To examine the effects of propofol on PTZ kindled convulsions, fully kindled rats (8–10 animals per group) were injected with various doses of propofol (2.5, 5, 10 mg/Kg) prior to PTZ challenge. The drug was administered IV as a single dose through the dorsal tail vein via a 25G butterfly scalp vein cannula. Control animals received an equal volume of saline. Few minutes following drugs or saline injection, rats were challenged with a subconvulsant dose of PTZ (35 mg/Kg) and seizure score for individual animals was recorded. To compare the effects of midazolam on PTZ kindled seizures with these of propofol, the same animal groups were administered various doses of midazolam (2.5, 5, 10 mg/Kg). A period of a two weeks washout was allowed prior to midazolam treatment.The result of our study shows that both anesthetic agents suppressed PTZ kindled seizures in a dose dependent manner indicating that both agents protects against PTZ kindled seizures. However, the effects of midazolam were more profound. Dose response analysis of percent inhibition of kindled seizures shows that the ED50 for midazolam was 1.85 mg/Kg with 95 % CI of (1.71–2.05), whereas the estimated ED50 of propofol was 5.36 mg/kg with 95 % CI of (4.85–5.96).The data of the present study shows that propofol is an effective anticonvulsant against PTZ kindled seizures and provides further support of the anticonvulsant properties reported in different experimental seizures models.Support or Funding InformationThe research was supported by a grant from Arabian Gulf University.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Characterizing a Novel RGS14:MyosinV/VI Interaction in Brain
Authors: Montanez‐Miranda Carolina , Evans Paul R. , Gerber Kyle J. , Seyfried Nicholas T. , Hepler John R. 
Published: June 2021

RGS14 is a complex multifunctional signaling protein that integrates G protein, Ras/ERK and Ca++/CaM/CaMKII signaling pathways. The protein is composed of an RGS domain that binds active Gαi/o, two tandem Ras/Rap binding domains (R1, R2) which bind active H‐Ras‐GTP and Rap2A‐GTP to regulate MAP kinase signaling, a G protein regulatory (GPR) motif that binds inactive Gαi1/3, and a Ca++/CaM binding site. RGS14 is highly expressed in the hippocampus, the brain center for learning and memory, which is composed of areas CA3, CA2, and CA1. Schaffer collateral (SC) projections from CA3 to CA1 display long term potentiation (LTP), a stable potentiation in post‐synaptic strength in response to brief periods of synaptic stimulation such as during learning in animals. Within the hippocampus RGS14 is highly expressed in postsynaptic dendrites and spines of area CA2, where SC inputs from CA3 to CA2 neurons show a surprising resistance to LTP. CA2 has been shown to be important for social learning and memory, and we have shown that RGS14 is a natural suppressor of LTP and synaptic plasticity in this area. That is, loss of RGS14 in CA2 (RGS14‐KO) restores synaptic plasticity (LTP) in CA2 and markedly enhances hippocampal learning. However, it remains unknown how RGS14 interacts with other signaling proteins to regulate synaptic plasticity. In proteomic studies, RGS14 recovered from mouse brain by immunoprecipitation was subjected to mass spectrometry and proteomic analysis, showing its association with a high molecular‐weight protein complex including actin‐based myosin motor proteins (Myosin V, Myosin VI and Myosin II) and their regulatory proteins, among others. MyoV is involved in activity‐dependent insertion of AMPA glutamate receptor subunits (GluR1, GluR2) and NMDA receptors, regulation of calcium and proper positioning of calcium intracellular stores. MyoVI is enriched at the postsynaptic density where it regulates AMPA receptor recycling. These myosin classes have crucial roles in regulating synaptic plasticity and LTP. Follow up studies have shown RGS14 in complex with MyoV and MyoVI in whole brain lysates. However, it remains unclear how RGS14 interacts with MyoV/VI to regulate synaptic plasticity. Ongoing studies will determine if RGS14 binds directly or indirectly to MyoV/VI and how that is regulated, as well as elucidate the physiological function of this interaction, thereby providing insight into the functions of both RGS14 and MyoV/VI in their roles in modulating synaptic plasticity and hippocampal‐dependent learning and memory.Support or Funding InformationThis research was supported by grants NIH/NINDS to JRH (5R01NS37112 and 1R21NS074975), and in part by the Emory Neuroscience NINDS Core Facilities and NIH/NINDS under award number P30NS055077.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Antioxidant Activity of Ruthenium Complexes Containing Nitro‐imidazole Derivatives
Authors: DA SILVA ANA VIRGINIA LIMA , SASAHARA GREYCE LURI , GOUVEIA FLORÊNCIO SOUSA , RODRIGUES RAPHAEL OLIVEIRA , DE FRANÇA LOPES LUIZ GONZAGA , DE SOUSA EDUARDO HENRIQUE SILVA , SANTOS FLÁVIA ALMEIDA , NAGAO‐DIAS APARECIDA TIEMI 
Published: June 2021

Ruthenium‐based coordination complexes are compounds with great pharmacological potential. Once their toxicity and pharmacokinetics properties can be easily modulated changing the ligands on the six coordination sites of the metal, those species can present a broad spectrum of applications, such as: antineoplastic, bactericide, antiparasitic, vasorelaxant, among others. However, antioxidant properties of that kind of substance is still poorly explored, even after recent works have shown evidence that nitrosyl ruthenium complexes can scavenger free radicals. In addition, nitro‐imidazole derivatives are organic compounds with antioxidant properties and are able to work as ligands in coordination complexes. Considering that, the compounds cis‐[Ru(NO2)(bpy)2(4NIMN)](PF6) (1) and cis‐[RuCl(bpy)2(MTZ)](PF6) (2), where bpy=2,2′‐bipyridine, 4NIMN=4‐nitroimidazole and MTZ=metronidazole, were selected for analysis. Thus, the aim of the present study was to investigate in vitro antioxidant activity of those ruthenium complexes. The complexes were synthesized using microwave‐assisted synthesis, adapting methods previously described. Structural characterization was held through spectroscopic and spectrometric techniques, confirming the proposed structures. Cytotoxicity of the compounds at 3.12 to 100.0 μM was evaluated on A549 human lung carcinoma, RAW 264.7 murine macrophages, AGS human gastric carcinoma cells and human neutrophils at 5×106 cells/mL. No significant cytotoxicity was observed at any concentration of the compounds. Antioxidant properties were evaluated by quantifying malondialdehyde (MDA) and reactive oxygen species (ROS) production, and by evaluating superoxide dismutase activity in LPS‐stimulated RAW 264.7 cells treated with 1 and 2 at 3 – 25 μM. All the concentrations of both complexes were able to significantly reduce the production of superoxide anion in relation to the vehicle group, similarly to the reference treatment (α – tocopherol) All concentrations could also reduce the amount of MDA and ROS produced. Finally, the ruthenium complexes 1 and 2 were not cytotoxic to human neutrophils, lung and gastric carcinomas, and presented potent antioxidant properties. Tests are being carried out in order to elucidate antioxidant mechanisms and to analyze possible anti‐inflammatory effects.Support or Funding InformationCAPES; CNPqThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Investigation of Novel Inhibitor for the Serotonin 5HT2A Receptor
Authors: Alshbool Fatima Z , Karim Zubair A , Khasawneh Fadi T 
Published: June 2021

The serotonin 5HT2A Receptor (5HT2AR) signaling pathway plays a vital role in platelet function in vivo, and has been implicated in the genesis of several forms of cardiovascular disorders. However, despite its clear involvement in such processes, there are no antagonists that are currently available for managing thrombotic disease which target this pathway. In light of the fact that the ligand binding of 5HT2AR is contained, at least in part, within the second extracellular loop (EL2), we investigated the function‐blocking activity of an antibody (abbreviated EL2Ab) that targets this domain. Our results revealed that 100 nM of EL2Ab significantly inhibited the “limited” human platelet aggregation and shape change induced by 15 μM 5HT. Moreover, 100 nM of EL2Ab also significantly reversed the ability of serotonin to enhance ADP‐induced platelet aggregation. This inhibitory effect was found to be dose dependent. Also, we found that EL2Ab (100 nM) did not have any detectable effects on aggregation by 10 μM of the agonist ADP alone. Similar results were also obtained under in vitro conditions in mouse platelets. In terms of ex vivo platelet aggregation, injections of 150 nM EL2Ab into live C57BL/6 mice before their blood was collected for testing, revealed complete blockade of (15 μM) serotonin‐induced aggregation/shape change, substantial‐ and dose‐dependent reversal‐ of serotonin‐enhanced, ADP‐induced aggregation; but no effect on aggregation by 1 μM U46619 control. As for its in vivo activity, it was found that injections of 150 nM EL2Ab prolonged the time for occlusion in a carotid artery thrombosis model, indicating that EL2Ab protects against thrombogenesis. Collectively, these results clearly demonstrate that EL2Ab exerts 5HT2AR‐specific anti‐platelet effects, thus making it the first function‐blocking antibody against these receptors and a potential therapeutic agent. Moreover, the identification of a functionally active 5HT2AR sequence should significantly aid molecular modeling study predictions for organic derivatives which possess in vivo activity.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Biochemical and Histological Studies on the Effect of African Iba, a Herbal Purgative, in Albino Rats
Authors: Ushedo Kelly , Adegbola Mosebolatan , Otuechere Chiagoziem 
Published: June 2021

Limited data is available about the toxicity of herbal remedies used for self‐medication. Since a popular herbal remedy, African Iba Herbal Mixture (AFRIM), contains various bioactive molecules, the present study aimed to observe the biochemical and histological changes in the hepato‐renal system of albino rats. Four groups of six male rats per group were used for the study. To group A was administered distilled water and served as control, while groups B, C and D were respectively administered with 100, 200 and 400 mg/kg body weight of AFRIM via gastric intubation for 14 days. Thereafter, animals were anaesthetized and sacrificed by cervical dislocation; blood samples were collected for biochemical assays while the liver and kidney were processed for histopathological studies. While the administration of AFRIM did not significantly alter the levels of calcium, potassium and alanine aminotransferase across all treatment groups, aspartate aminotransferase, albumin, blood urea nitrogen were significantly (p < 0.05) reduced, especially at 200 and 400 mg/kg doses. Furthermore, there was a significant (p < 0.05) elevation in uric acid levels at the higher doses of AFRIM. Liver sections revealed mild to severe infiltration of inflammatory cells in zone 2 at 100 and 200 mg/kg of AFRIM. Kidney sections illustrated engorged glomeruli which appear shrunken with hyper‐cellularity of mesangial cells at the 200 mg/kg dose. In light of this, caution and adherence to dosage prescription is strongly advised. This study is a contribution to scientific knowledge on the safety/toxicity profile of African Iba Herbal Mixture among the growing list of Nigerian herbal remedies.Support or Funding InformationThis research did not receive any funding from any granting body.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Interactions of Hydroxylated Tetrabromodiphenyl Ethers with Phase II Enzymes
Authors: Cisneros Katherine Viviana , Agarwal Vinayak , James Margaret O. 
Published: June 2021

Polybrominated diphenyl ethers (BDEs) have been used as flame retardants since the 1970s, and some congeners are classified as persistent and bioaccumulative. There is evidence that hydroxy and hydroxy‐methyl tetra‐BDEs are also natural products, as their synthesis has been demonstrated in marine bacteria, sponges, and macroalgae. Despite the prevalence of BDEs in the environment, their biotransformation has not been extensively studied, however it is known that they can be debrominated or monooxygenated at varying rates and to varying degrees depending on degree of bromination and species of animal, thus producing metabolites that have proven to be more reactive or toxic, such as hydroxylated‐polybrominated diphenyl ethers (OH‐BDEs). The present studies examined the human hepatic phase II metabolism of three natural product OH‐BDEs (6‐OH‐BDE47, 2‐OH‐BDE68, and 2‐OH‐6′methoxy‐BDE68) and a synthetic OH‐BDE (4‐OH‐BDE68), which was synthesized to study structure‐metabolism activity. Human liver microsomes and cytosol were prepared from de‐identified tissue bank samples from two female and five male donors aged 31 to 75 under an exempt protocol approved by the University of Florida IRB. Recombinant human SULT1A1, 1B1 and 1E1 enzymes were expressed and purified from bacterial expression systems. Sulfonation and glucuronidation of each OH‐BDE were studied using radiolabeled co‐substrates, 3′phosphoadenosine‐5′phospho‐35S‐sulfate or uridine diphospho‐β‐D‐14C‐glucuronic acid. The sulfated or glucuronidated products were extracted as ion‐pairs into ethyl acetate and quantitated or were separated by TLC and quantified by imaging the radioactivity. The OH‐BDEs studied were somewhat more efficiently glucuronidated than sulfonated. Of the compounds studied, 2‐OH‐BDE68 was most readily conjugated, and exhibited an efficiency (Vmax/Km) of glucuronidation of 0.256 ± 0.095 ml/min/mg protein, mean ± S.D., n=3, while that for sulfonation was 0.179 ± 0.030 ml/min/mg protein. For both pathways, Km values were in the low μM range. Studies with human SULT enzymes showed that sulfonation of all four substrates was readily catalyzed by SULT1B1 and SULT1E1, but not SULT1A1. OH‐BDEs inhibited SULT1A1 activity at concentration ranges between 0.2 μM – 20 μM. These OH‐BDEs also inhibited SULT1E1 sulfonation activity with Ki constants ranging between 0.725 nM–219 nM. However, assuming that the glucuronide and sulfate conjugates are non‐toxic and readily excreted, as is the case for most such conjugates, these studies suggest that OH‐BDEs should not accumulate in people to the same extent as the parent BDEs.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.
Crystal Structure of CYP2C9*2 Genetic Variant in Complex with an Angiotensin II Receptor Blocker Drug Losartan
Authors: Shah Manish B. , Parikh Sonia 
Published: June 2021

Cytochrome P450 (CYP)‐dependent monooxygenases are a superfamily of heme‐containing enzymes involved in the metabolism of various xenobiotics. The drug metabolizing CYP2C9 enzyme metabolizes up to 20% of the clinical drugs that include losartan, warfarin, ibuprofen, tolbutamide, and glimepiride. The CYP2C9*2 and *3 are the two prevalent genetic variants that demonstrate significant reduction of the catalytic activity compared to the wild‐type (WT) enzyme for many important CYP2C9 substrates. Despite the abundant structural information available regarding various CYPs, the structural information about the effect of genetic polymorphisms on drug binding has remained scant. The CYP2C9*2 variant represents an amino acid change from arginine to cysteine at position 144, also referred to as R144C. To understand how genetic variation in CYP2C9 affects drug binding and oxidation, we solved the crystal structure of CYP2C9*2 in complex with the antihypertensive drug losartan using X‐ray crystallography. The prodrug losartan is an angiotensin II receptor antagonist that is predominantly metabolized by CYP2C9 and CYP3A4. The overall structure of the CYP2C9*2‐losartan complex illustrate remarkable differences compared to the WT complex. These include altered conformation of important secondary structural elements and residue side chains previously shown to be responsible for binding interactions with different substrates. Furthermore, the new structure revealed significant changes in binding of losartan compared to the previously solved losartan complexes of the CYP2C9 WT, *3 and *30. The structure highlights how single nucleotide polymorphism affects drug binding and yield insights into altered metabolism. Overall, the structural complex provides a useful framework to study, computationally as well as biophysically, the binding of different substrates to genetic variants of CYP2C9 and understand the effect of amino acid substitution in decreased hydroxylation activity of the enzyme.Support or Funding InformationThe authors are grateful to Albany College of Pharmacy and Health Sciences for funding.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.