bluuebunny/crossref_metadata_2025 huggingface dataset:
Electroacupunture reduces mechanical hyperalgesia produced by repeated intramuscular injections of acidic saline in rats
Authors: Santana Michael Nadson Santos , dos Santos Maciel Leonardo Yung , da Cruz Kamilla Mayara Lucas , de Araújo Ariane Martins , de Amorim Hugo Caxico
Published: June 2021

This study aimed to identify the effects of electroacupuncture in the mechanical hyperalgesia produced by repeated intramuscular injections of acidic saline. Twenty four male Wistar rats were divided in four groups (n = 6, in each group): control, acupuncture, electroacupuncture (EA) 15 Hz and electroacupuncture (EA) 100 Hz. Left gastrocnemius muscle from all animals was injected with 100 μL of sterile saline pH 4.0 twice five days apart. Electroacupuncture, acupuncture or control was daily administered (20 min) for 5 consecutive days under isoflurane anesthesia (1%–2%). Needles were placed in the Zuzanli (St36) and Sanyinjiao (SP6). Paw withdrawal threshold to mechanical stimuli was assessed before the two injections, and before and after the each stimulation by using von Frey filaments. The reduced paw withdrawal threshold that occurs 24 hours after the second injection was significantly reversed by the first administration of EA at both 100 Hz and 15 Hz when compared with sham treatment and baseline measures. The analgesic effect lasted for 4 and 3 days when 15 Hz and 100 Hz were applied, respectively. These data suggest that both 15 Hz and 100 Hz electroacupuncture are effective on reducing secondary mechanical hyperalgesia showing a long‐lasting effect. Research support: CAPES, Fapitec.
Forced exercise enhances functional recovery after focal cerebral ischemia in spontaneously hypertensive rats
Authors: Kim Koo , Hong Yonggeun
Published: June 2021

In the present study, we investigated cerebral ischemia‐induced expression changes in caveolins, regulatory signaling molecules, and autophagy signaling. Cerebral ischemia was induced by middle cerebral artery occlusion (MCAo)–reperfusion in spontaneously hypertensive (SHR) rats (~200 mmHg) and normotensive Wistar Kyoto (WKY) rats. All MCAo surgery groups had neurological deficiency, motor dysfunction, and disruption of balance ability; these pathological changes were more severe in SHR rats compared with WKY rats. Additionally, the caveolin and nNOS levels were decreased in brain tissue of the MCAo group, but the iNOS and GFAP levels were increased. Moreover LC3‐II and beclin‐1 protein expression were elevated in MCAo groups. These results implicate MCAo as a strong causative factor in brain impairment at the molecular level. SHR rats had delayed functional recovery, increased iNOS and autophagic cell death, and decreased caveolin and nNOS levels compared with WKY rats. Therefore, these results suggest that forced exercise is beneficial in promoting brain damage recovery following cerebral ischemia. Finally, improved motor behavioral outcome induced by forced exercise in MCAo rats was associated with altered caveolin expression and caveolin interaction with signaling molecules in ischemic brain regions, which was related to functional rescue of neuromuscular communication.
Treatment of melatonin plus exercise attenuates neuronal senescence of spinal cord and spinal nerve innervated muscle in a spinal cord‐injured animal model
Authors: Kim Joo-Heon , Park Inhee , Hong Yonggeun
Published: June 2021

We hypothesized that the antioxidant, anti‐aging action of melatonin and exercise would slow the aging process following SCI. Rats were randomly divided into five groups: control (sham‐operation), spinal cord injury (SCI), spinal cord injury and melatonin treatment (SCI+MT), spinal cord injury and exercise (SCI+Ex), and spinal cord injury and combined melatonin and exercise treatment (SCI+MT+Ex). We examined the effect of the interventions by measuring inducible nitrous oxide synthetase (iNOS) expression, p21, p16, p53 expression, the autophagy markers, LC3 and Beclin‐1, the skeletal muscle atrophy marker, MuRF1, and the antioxidant enzyme, peroxiredoxin 2, 3, in spinal cord tissue at T9‐11 (contusion segment level), T6‐8 (near contusion rostral level), C5‐7 (far contusion rostral level), and L3‐5 (far contusion caudal level). Melatonin and exercise co‐treatment promoted behavioral recovery and decreased the inflammatory response of iNOS (p < 0.05). Furthermore, combined intervention induced an increase in the cyclin‐dependent kinase inhibitors, p21 and p16, and reduced LC3 expression in a time‐dependant manner. These results suggest that melatonin and exercise co‐treatment attenuates the secondary inflammatory process, autophagic cell death, and the cell cycle arrest.
ANTICIPATORY TESTOSTERONE IN FEMALE COLLEGIATE RUNNERS DURING COMPETITION
Authors: Adams Rebecca Christine , McCall Gary
Published: June 2021

The purpose of the current study was to examine the relationship between competitiveness and the anticipatory total serum testosterone response to athletic competition in female collegiate endurance athletes. Twelve college‐aged female athletes participated in a track relay‐style race. A $10 gift card was awarded to each member of the fastest team. Blood serum was obtained 24 hours prior and 15 minutes prior to a competition. An IMMULITE total serum testosterone competitive chemiluminescent immunoassay was used for analysis. The Revised Competitiveness Index (RCI) was completed. A dependent t‐test was used to calculate differences between the two serum samples and between oral contraceptive groups. A Pearson correlation (α<0.05) assessed the relationship between RCI scores and 15 minute pre‐race serum testosterone levels. No significant differences were found between oral contraceptive groups (p=0.715) or between 24 hour and 15 minute pre‐race serum testosterone levels (p=0.855). There was no correlation between RCI scores and 15 minute pre‐race total serum testosterone level (R=0.05, p=0.915). These results suggest that for this specific population, competitiveness in a simulated race is unaffected by changes in testosterone secretion.
Influence of a redox‐signaling supplement on biomarkers of physiological stress in athletes: a metabolomics approach
Authors: Shanely R. Andrew , Nieman David C. , Henson Dru A. , Knab Amy M. , Cialdella-Kam Lynn , Meaney Mary Pat , Baxter Sara , Sha Wei
Published: June 2021

We determined if drinking ASEA™, a redox‐signaling molecule beverage, would improve cycling performance, counter inflammation, oxidative stress, and immune dysfunction, and alter the metabolite profile. Cyclists (n = 20) participated in a randomized, double blinded, placebo controlled, crossover study. Subjects completed two 75km time trials (TT) after 1 wk ingestion of 118 mL/d ASEA or placebo (PL). Subjects ingested 473 mL ASEA or PL during the TT. Blood samples were taken pre, post, 1h post‐exercise (Ex). ASEA did not improve TT performance (p = .95). The Ex‐induced pattern of change in inflammation, oxidative stress, and immunity did not differ (p>.05) between ASEA vs. PL. The metabolomic profiles (GC/MS) of ASEA and PL samples were clearly separated by partial least square discriminant analysis when using pre‐Ex data (Q2Y = .71), and when using the ratio of 1h post‐Ex to pre‐Ex (Q2Y = .68). Linear modeling found that ASEA supplementation caused a significant shift in 43 metabolites pre‐Ex, especially free fatty acids, suggesting an enhanced fat oxidation and amino acid sparing, with an increase in ascorbic acid, during Ex. Within the context of this study, 1‐wk ASEA supplementation caused extensive fatty acid mobilization before and during Ex, with no apparent influence on TT performance and traditional biomarkers of inflammation, oxidative stress, and immunity.

Funding, Reoxcyn Discoveries Group
The nuclear receptor cochaperone FKBP51 is required for diet‐induced visceral adiposity
Authors: Stechschulte Lance Alan , Warrier Manya , Hinds Terry D. , Sanchez Edwin R.
Published: June 2021

Nuclear receptors are hormone‐regulated transcription factors that form heterocomplexes with Hsp90 and several cochaperones, including FK506‐binding protein‐51 (FKBP51), FKBP52, PP5, and Cyp40. We have evidence that loss of FKBP51 increases glucocorticoid receptor (GR) and decreases peroxisome proliferator‐activated receptor‐γ (PPARγ) transcriptional activity. In this study, we investigate the hypothesis that loss of FKBP51 leads to reciprocal dysregulation of GR and PPARγ, thereby increasing the expression of genes regulating lipid oxidation and/or energy expenditure. FKBP51‐KO mice were subjected to a high fat diet, compared to wild‐type mice, FKBP51‐KO animals were resistant to diet‐induced obesity, with reduced visceral adiposity, serum triglyceride, and free fatty acids. Food consumption, insulin secretion and clearance, and hepatic lipid accumulation were unchanged. Gene profiling of adipose showed elevated expression of thermogenic genes in the KO mice. In vitro adipogenesis studies showed FKBP51‐KO cells to be highly resistant to differentiation and lipid accumulation. The phosphorylation states of GR were tested using phospho‐specific antibodies for serines 212, 220 and 234 – the major sites of hormone‐induced phosphorylation. Results show FKBP51 controls GR phosphorylation at serines 220 and 234. These investigations have uncovered FKBP51 as a key regulator of adipogenesis and thermogenesis and may serve as a new drug target in the treatment of obesity and related disorders.

Supported by NIH grant DK70127 to E.R.S.
The effect of acute oral amino acid intake on fatty acid oxidation
Authors: Hurren Nicholas Michael , Volpi Elena , Yfanti Christina , Chondronikola Maria , Kinsky Michael P , Sidossis Labros S , Børsheim Elisabet
Published: June 2021

We have previously reported a reduced plasma triacylglycerol (TAG) concentration in elderly individuals following chronic intake of amino acids (AAs). To test whether acute intake of AAs increases fatty acid oxidation we compared 13CO2 breath enrichment from 5 elderly hypertriacylglycerolaemic volunteers (mean ± standard deviation (SD): age 66.0 ± 2.9 years; height 1.66 ± 0.04 m; body mass 85.5 ± 19.3 kg; BMI 28.8 ± 6.0 kg·m−2; fasting TAG 192 ± 46 mg·dl−1) during a basal period and a period of acute AA intake, whilst the participants were undergoing a constant infusion of U‐13C16‐palmitate. Participants received a drink containing 1 g of AAs every 10 minutes during the AA period, with 4 breath samples collected, 10 minutes apart, from 1 h 55 min to 2 h 25 min during each period. 13CO2/12CO2 ratio was determined using isotope ratio mass spectrometry. 13C breath enrichment was found to be significantly higher during the AA intake period than during the basal period (mean ± SD: atom % excess 0.22 ± 0.02 vs. 0.09 ± 0.01; P < 0.001). We conclude that acute amino acid intake increases fatty acid oxidation and may constitute a mechanism that contributes to lowering of the plasma TAG concentration. The study is sponsored by 1R01 AG033761 NIH/NIA. Screenings and study visits are being undertaken within the ITS‐Clinical Research Center at UTMB, Galveston, which is funded by grant 1 U54RR026141 from NIH/NCRR.
Alpha‐adrenergic regulation of muscle, adipose tissue and bone blood flow at rest and during exercise in humans
Authors: Heinonen Ilkka , Wendelin-Saarenhovi Maria , Kaskinoro Kimmo , Knuuti Juhani , Kalliokoski Kari
Published: June 2021

Positron emission tomography allows for determination of muscle and tissue‐specific blood flow in humans. Since hamstrings remain inactive during one leg exercise performed by knee extensors, the technique and model provide an opportunity to elucidate the role of nervous control of blood flow in the exercising limb in humans. Here we measured muscle and tissue‐specific blood flow in nine healthy young men under the femoral arterial infusions of norepinephrine (NE) and phentolamine. At rest, NE reduced blood flow by ~40% similarly in all muscles and in bone and adipose tissue. During exercise, NE reduced exercising muscle blood flow by 16%, but did not affect inactive muscle blood flow. Bone blood flow was not affected by NE, but blood flow in adipose tissue was reduced similarly as at rest. Phentolamine elevated blood flow similarly in different muscles and tissues of the limb at rest (by 3.5–6‐fold), and during exercise, the ratio of active‐to‐inactive muscle blood flow reduced from 18.3 ± 10.7 at control to 5.3 ± 4.0 during phentolamine, since blood flow in inactive muscles increased 3.4‐fold, but blood flow in exercising muscle remained essentially comparable to control exercise. In conclusion, the major novel finding here is that the release of á‐adrenergic tone markedly disturbs the distribution of blood flow in exercising human limb by elevating flow especially around inactive muscle fibers.
The effect of hyperoxia on cortical activation following maximal whole body exercise in humans
Authors: Volianitis Stefanos , Bjarrum Mille , Carlson Christine , Rasmussen Peter , Overgaard Anders , Fabricius-Bjerre Anders , Secher Niels H , Nielsen Henning B , Petersen Nicolas C
Published: June 2021

During maximal whole body exercise arterial hypoxemia may reduce cerebral oxygenation and provoke central fatigue, defined as an inability of the central nervous system to fully recruit the involved muscles. This study evaluated the effect of hyperoxia on central fatigue indices, i.e., reduction in maximal voluntary contraction (MVC) and transcranial magnetic stimulated (TMS) force generation. Six competitive rowers performed 2000 m all‐out exercise on a rowing ergometer in normoxia and hyperoxia (30% O2). Arm MVC was assessed with electromyography (EMG) of the m. biceps brachii and the m. brachioradialis. Voluntary activation of the elbow flexor muscles was assessed with TMS single pulses that were delivered to the motor cortex and evoked motor potential in the biceps brachii. Arterial hemoglobin O2 saturation was 92.5 +/− 0.2% during exercise in normoxia, while it was maintained at 98.9 +/− 0.2% in hyperoxia. Maximal rowing in normoxia resulted in a significant reduction (7.4 +/−5.1 %) in MVC, while there was no difference in the extra force produced by TMS. Following hyperoxic exercise the MVC and TMS were not different. These data indicate that following maximal rowing the force generating capacity of the elbow flexor muscles is attenuated but, even though TMS could not confirm a role of central fatigue for the force deficit, hyperoxia may prevent the development of such force deficit.
Differential Adaptations to High‐calorie, Western‐pattern Diet and Exercise Training in Redox Status and Mitochondria of Heart and Skeletal Muscle
Authors: Anderson Ethan J , Fisher-Wellman Kelsey H , Mattox Taylor , Katunga Lalage A , Thayne Kathleen , La Favor Justin , Hickner Robert C , Wingard Christopher J
Published: June 2021

Two interventions known to cause profound changes in cellular metabolism and redox enzyme expression/activity in heart and skeletal muscle are exercise (EX), and high‐fat, high sugar “Western pattern” diet (HFHS). To determine whether heart and skeletal muscle are differentially impacted by HFHS diet and EX, Sprague‐Dawley rats were fed either standard chow (CON) or a HFHS diet for 12 weeks (HFHS). A sub‐group of HFHS rats exercise‐trained 5 days/week for 2 hours/day (HFHS+EX). Following these interventions, mitochondrial H2O2 emission (mH2O2) and Ca2+ tolerance (mCa2+) supported by pyruvate + malate + succinate, and O2 consumption (mO2) supported by glutamate+malate (GM) and palmitoyl‐carnitine (PC) was determined in permeabilized red gastrocnemius (RG) and cardiac fibers. HFHS diet increased mH2O2 ~2‐fold, and HFHS+EX decreased in RG (P<0.05) compared to CON. Surprisingly, the HFHS diet decreased mH2O2 ~2‐fold in heart compared to CON (P<0.05), and was even further decreased in HFHS+EX. Maximal PC‐supported mO2 increased in RG in both HFHS and HFHS+Ex compared to CON (P<0.05), but in heart this was only increased in HFHS+EX. Maximal GM‐supported mO2 decreased in both RG and heart with HFHS, and this decrease was prevented in HFHS+EX. Total mCa2+ increased only with HFHS+EX in both RG and heart compared to CON. These findings suggest that heart and skeletal muscle mitochondria are differentially affected by diet and exercise, which point to adaptations in cellular redox state. (Supported by NIH grant HL098780 to EJA)
p‐Benzoquinone (p‐BQ) , a major cigarette smoke‐derived quinone, inhibits vitamin B1 (thiamin) uptake by human lung cells
Authors: Chatterjee Nabendu Sekhar , Pinkerton Kent E , Said Hamid M
Published: June 2021

Cigarettes smoke (CS) contains about 4000 compounds, including p‐benzosemiquinone (p‐BSQ), a long‐lived radical. p‐BSQ is present in substantial amounts (100–200 μg/cigarette) in smoke from all commercial cigarettes as well as Kentucky research cigarettes. After inhalation of smoke, p‐BSQ is converted to p‐BQ in the lungs by disproportionation and oxidation by transition metal containing proteins. p‐BQ is now well‐established as a major risk factor for different CS‐related diseases. In this study, we examined the effect of acute exposure of human lung epithelial A549 cells to p‐BQ as well as the effect of chronic exposure of rats to CS on physiological and molecular parameter of thiamin (a coenzyme involved in a variety of metabolic reactions and also involved in reducing cellular oxidative stress) uptake process. Our results showed that exposure of A549 cells to p‐BQ leads to a significant inhibition in thiamin uptake. This effect was associated with a significant reduction in level of expression of thiamin transporters 1 and 2 as well as in a reduced promoter activity of their respective genes. Similarly exposure of rats to CS led to a significant reduction in the level of expression of THTR‐1 (THTR‐2 was not detected in normal rat lungs). These results demonstrate for the first time that exposure to p‐BQ/CS leads to negative impact on physiological and molecular parameters of thiamin uptake. [Supported by USIEF and AA018071 grants]
Regulation of ZnT1, Zip6 and MT‐1 mRNA in cultured choroid plexus elicited by manipulation of extracellular zinc (Zn)
Authors: Aquino Mayra , Young Robin K , Villalobos Alice R
Published: June 2021

Regulation of Zn transport in choroid plexus as dietary Zn changes remains elusive. We seek to elucidate the modulation of Zn exporters (ZnTs), Zn importers (ZIPs) and the Zn‐binding protein, metallothionein (MT) in choroid plexus induced as Zn availability changes. To begin, we used real‐time qRT‐PCR to analyze ZnT1, ZIP6 and MT‐1 gene expression in Zn‐deprived and Zn‐supplemented cultured choroid plexus epithelial cells. Cells were treated for 12h‐48h with 10 μM DTPA, an extracellular Zn chelator, or 25 μM ZnCl2. At 12h‐48h, DPTA decreased ZnT1 mRNA by 60% and increased Zip6 mRNA by 75%. MT‐1 mRNA decreased 65% at 12h‐24h and further decreased at 48h. Zn supplementation increased ZnT1 mRNA by 75% at 12h and by 250% at 18h‐48h. Zip6 and MT‐1 mRNA increased 6‐fold and 110‐fold at 12h; Zip6 and MT‐1 mRNA then decreased incrementally, but were 4‐fold and 10‐fold greater than Control at 48h. Although these preliminary data do not reflect integrated changes in the full complement of Zn transporters elicited as Zn intake changes, they suggest coordinated modulation of Zn transporters, e.g., ZnT1 and Zip6, and MT, might regulate Zn transport and intracellular Zn accumulation and availability in choroid plexus.
Dietary niacin supplementation ameliorates ethanol‐induced liver injury in rats through sealing the leaky gut
Authors: Zhong Wei , Li Qiong , Tan Xiaobing , Sun Xiuhua , Sun Xinguo , Jia Wei , Zhou Zhanxiang
Published: June 2021

Niacin deficiency has been documented in alcoholic liver disease. The present study was undertaken to determine whether dietary supplementation with niacin provides beneficial effects on ethanol‐induced liver injury. Male Sprague Dawley rats were pair‐fed the Lieber‐DeCarli liquid ethanol or isocaloric control diet for 8 weeks with or without niacin supplementation to ethanol‐fed rats at 200 mg/kg BW. Chronic ethanol feeding upregulated hepatic mRNA levels CD14, LBP, CINC‐1 and MCP‐1 and cause liver damage, which were attenuated by niacin supplementation. Niacin supplementation also normalized ethanol‐increased plasma endotoxin level. Ethanol feeding remarkably decreased the intestinal mRNA levels of tight junction proteins including claudin‐1, claudin‐5 and ZO‐1, while niacin supplementation dramatically increased the mRNA levels of these tight junction proteins. Ethanol feeding increased intestinal acetaldehyde concentration, which was attenuated by niacin. These results demonstrated that attenuation of gut leakiness and endotoxin signaling in the liver contributes to the protective effects of niacin against alcoholic liver damage.
Modulation of Gastrointestinal Function by MuDelta, a mixed Mu Opioid Receptor Agonist/Delta Opioid Receptor Antagonist
Authors: Hornby Pamela J
Published: June 2021

Background & Purpose

Loperamide is a selective mu (μ) opioid receptor (OR) agonist acting locally in the gastrointestinal (GI) tract as an effective anti‐diarrheal, but can result in ‘rebound’ constipation. We tested whether modulating μOR agonism with δOR antagonism, by combining reference compounds or using a novel compound (“MuDelta”), could normalize GI motility without constipation.

Experimental approach

MuDelta was characterized in vitro as a potent μOR agonist and high affinity δOR antagonist. Compounds were assessed in guinea pig intestinal smooth muscle contractility and mouse intestinal epithelial ion transport. Colonic δOR immunoreactivity was quantified. MuDelta and loperamide were evaluated for upper GI transit, entire GI transit or fecal output in novel environment stressed mice, or four weeks after intracolonic mustard oil.

Key Results

δOR antagonism opposed μOR agonism in isolated intestinal and in vivo motility assays. Stress up‐regulated δOR expression in colonic epithelial cells. MuDelta reduced contractility in intestinal tissue similar to combined μOR agonists and δOR antagonists, and inhibited neurogenically‐mediated secretion. Very low plasma levels of MuDelta were detected after oral administration. In stressed mice, MuDelta normalized GI transit and fecal output to control levels over a wide dose range up to 100 mg/kg p.o, whereas loperamide completely prevented these at 10 mg/kg. MuDelta also reduced upper GI transit in the post‐inflammatory model.

Conclusions and Implications

Mixed μOR agonism/δOR antagonism normalizes, but does not prevent, perturbed GI transit over a wide dose‐range in mice. These data support the assessment of MuDelta in clinical trials in patients with diarrhea‐predominant irritable bowel syndrome.
Involvement of NADPH oxidase in serotonin‐induced angiogenesis
Authors: Kim Hyun-Young , Neupane Ganesh Prasad , Kim Jung-Ae
Published: June 2021

Serotonin (5‐Hydroxytrytamine, 5‐HT), a gastrointestinal paracrine hormone, has been shown to induce angiogenesis. Reactive oxygen species (ROS) play a role in vascular endothelial growth factor (VEGF)‐induced angiogenesis as a receptor downstream signaling molecule. In vascular endothelium, multi‐subunit NADPH oxidase is the predominant contributor of endothelial superoxide generation. In the present study, we investigated whether NADPH oxidase is involved in serotonin‐induced angiogenesis. Seroton‐ininduced‐ angiogenesis was confirmed by in vivo chick chorioallantoic membrane (CAM) assay. In vitro angiogenesis using human umbilical vein endothelial cells (HUVEC), serotonin enhanced cell migration, invasion and tube formation. Such serotonin‐induced‐angiogenesis was inhibited by cyanopindolol, 5‐HT1A receptor antagonist, cinanserin, 5‐HT 2A receptor antagonist, and apocynin, NADPH oxidase inhibitor. Serotonin produced ROS, and such ROS was inhibited by apocynin and diphenyl iodonium (DPI), NADPH oxidase inhibitors, but not by allopurinol (Xantine oxidase inhibitor) and anitmycin A (mitochondrial inhibitor). In conclusion, serotonin‐induced angiogenesis is mediated through 5‐HT1A and 5‐HT2A receptor, which, in turn, activates NADPH oxidase to generate ROS as a a receptor downstream signaling molecule.
Role of Probiotic Bifidobacterium Infantis after Oral Feeding in TNBS Rat Model of Colitis
Authors: Javed Najma Hassan , Furman David
Published: June 2021

Role of dietary factors in disease prevention has recently gained more attention. Bifidobacterium Infantis (BI) are non‐pathogenic living organisms implicated with therapeutic benefits in GI inflammatory disorders. Little is known about the regulatory mechanism of individual probiotics on intestinal function. We studied effects of feeding BI in TNBS rat model of Colitis. Twelve rats were divided into 2 groups. One received oral gavage of 0.205 g of BabyLife B. Infantis in distilled water. Sham‐fed rats were fed veh for 7 days. Colitis was induced and feeding continued for 7 days post induction. Animals were monitored for weight loss, water & food intake, blood loss, stool activity and ranked following a Disease Activity Index. Rats were euthanized and tissues were harvested & examined blindly. Tissues were set up in Ussing Chambers for functional studies. Feeding of BI significantly decreased the inflammation (p=0.007) indicated by decrease ulceration, intestinal and peritoneal adhesions, wall thickness and presence of Peyers patches. Electrical field stimulation indicated a trend towards higher responses in BI fed tissues as compared to sham‐fed colitis tissues. Our study indicates that feeding Bifidobacterium Infantis beneficially modifies the inflammatory responses in rat model of colitis. Study indicates preventive and therapeutic value of probiotics.
Heme oxygenase activity (HOA) in rat liver: Response to severe hemorrhage in an inbred rat strain
Authors: Oh Thomas T , Klemcke Harold G.
Published: June 2021

In efforts to identify cellular mechanisms involved in differences among inbred rat strains in survival time after severe hemorrhage (STaH) (Klemcke et al. Physiol Genomics 43: 758, 2011), we evaluated HOA, a cytoprotective enzyme that catalyzes conversion of cellular heme into biliverdin, free iron (Fe+2), and carbon monoxide. We adapted a HOA procedure used with purified HO (Reed et al, DMD 38: 2060, 2010) for use in tissues (liver microsomal fraction); the assay measures the appearance of Fe+2 using hemin substrate and NADPH as cofactor. HOA had an apparent Km of 7.8 μM of hemin; Vmax= 170 nM Fe+2 /mg protein/min; time period of initial velocity of 0 to 40 min; and a linearity of Fe+2 formation for 0.25 to 3 mg of microsomal protein. Dark Agouti (DA) rats (longest STaH) were assigned to one of three treatments (n=5/ treatment): non‐operated controls, catheterized (CATH) only, or CATH plus hemorrhage (49% of blood volume) 24 h post‐surgery. Rats were euthanized 30 min after handling or after the start of the hemorrhage. HOA increased 32% 24 hrs after CATH alone (4.69 vs 3.54 nmol Fe+2/mg protein/30 min; P = 0.05). HOA increased 36% further after hemorrhage to 6.37 nmol Fe+2/mg protein/30 min (P = 0.01). Hence in liver of DA rats, HOA is increased and may be exerting a cytoprotective effect after stressors such as surgery and hemorrhage. Moreover, this assay allows for an easier, more direct procedure for measuring HOA in tissues.
Reduced ventilatory function and sarcopenia of the diaphragm muscle in a mouse model of advanced aging
Authors: Greising Sarah M. , Sieck Dylan C. , Mantilla Carlos B. , Sieck Gary C.
Published: June 2021

Aging is associated with respiratory complications and muscle dysfunction that may reduce the ability to perform expulsive, non‐ventilatory behaviors. We hypothesized that ventilatory function is impaired with aging and that the diaphragm muscle (DIAm) is susceptible to sarcopenia. Unrestrained‐awake ventilatory function, DIAm specific force, and fiber cross‐sectional area (CSA) were examined in a validated mouse model of advanced aging (expression of a hypomorphic allele (H) of BubR1), naturally aged (28 mo) and adult (5 mo) wild type (wt) mice (same genetic background). Minute ventilation and breathing frequency were decreased 17% in BubR1H/H and 33% in aged wt mice vs. adult wt mice. Tidal volume was not different across groups. DIAm specific force was lower in both aged mice groups compared to the adult wt mice, being 62% lower in BubR1H/H mice. DIAm fiber CSA from BubR1H/H and aged wt mice was smaller than adult wt mice (23 and 10%, respectively). These results indicate that aging is associated with reduced ventilatory function and evidence of DIAm sarcopenia. In addition, aged mice recruit a greater percentage of DIAm fibers for eupneic breathing (greater fraction of maximum force). Together, these age‐related changes may limit the ability to accomplish expulsive, non‐ventilatory behaviors essential for airway clearance, and thus contribute to respiratory complications. Supported by Mayo Clinic.
Tissue concentrations of Doxorubicin and Doxorubicinol 24 and 96 hours following injection in the rat
Authors: Chenard Pam , Fabris Sergio , MacLean David
Published: June 2021

Doxorubicin (DOX) is an anti‐cancer chemotherapeutic and although widely used, its accumulation over time in different tissues has not been thoroughly investigated. The purpose of this study was to examine the concentration of both DOX and its metabolite, doxrubicinol (DOXol) in liver and heart tissue of rats. Two doses (1.5 mg/kg and 4.5 mg/kg) were injected intraperitoneally and tissue samples were collected either 24 or 96 hrs post‐injection. In all tissues DOX and DOXol were elevated (P<0.05) as compared to control at all time points. In both heart and liver the concentration of DOX was higher (P<0.05) following the 4.5 mg/kg as compared to the 1.5 mg/kg dose at 24 and 96 hrs. Heart tissue DOX concentrations decreased (P<0.05) from 0.8±0.1 and 1.8±0.3nmol/g at 24 hrs to 0.4±0.01 and 1.0±0.1 nmol/g at 96 hrs, for the 1.5 and 4.5 mg/kg dose, respectively. Similarly, liver DOX levels decreased (P<0.05) from 3.9±1.1 and 5.3±0.9nmol/g at 24 hrs to 0.6±0.1 and 3.2±0.4 nmol/g at 96 hrs, for the 1.5 and 4.5 mg/kg dose, respectively. DOXol was detectable in all tissues at all time points, however its concentration was lower (P<0.05) than that of DOX. Overall, both heart and liver responded in a dose dependant fashion to the injections of DOX. Furthermore, the accumulation of the drug and its cardiotoxic metabolite decreased over time suggesting that either the drug is rapidly metabolized and/or eliminated or stored in tissues other than the heart and liver.

Supported by NSERC.
Angiotensin II differentially regulates annexin V and glypican 6 in MC3T3 cells and B16 melanoma cells
Authors: Cain Margo , Chernin Mitchell
Published: June 2021

Mouse MC3T3 cells (non‐cancerous) and B16 melanoma cells were transfected with a synthetic gene that expresses angiotensin II (Ang II) directly under the control of a CMV promoter. Previous studies using MALDI‐TOF/MS identified several candidate proteins for western blot analysis; Annexin V and Glypican 6 were chosen for further study. Annexin V is a member of a family of calcium‐binding proteins and has been implicated as a regulator of several processes including cell adhesion and apoptosis. One of the earliest events in apoptosis is the externalization of phosphatidylserine (PS) which is translocated from the cytoplasmic side of the plasma membrane to the cell surface soon after the induction of apoptosis, and that the Annexin V protein has a strong, specific affinity for PS. B16 Melanoma cells showed a marked decrease in Annexin V expression; whereas, MC3T3 cells showed a substantial increase in expression. Glypican 6 is a glycophosphotidylinositol anchored heparin sulfate proteoglycan involved in cell growth and division. It is a putative cell surface co‐receptor for growth factors, extracellular matrix proteins and proteases. Like Annexin V, Glypican 6 was down‐regulated in B16 cells and up‐regulated in MC3T3 cells. These results suggest that Ang II has specific growth effects which are differentially regulated in cancer and non‐cancer cells.
The effect of physical (in)activity on blood pressure and splanchnic sympathetic nerve responses to inhibition of the RVLM
Authors: Dombrowski Maryetta Donna , Azar Toni A , Mueller Patrick J
Published: June 2021

A sedentary lifestyle is a major risk factor for cardiovascular disease (CVD). CVD is often associated with enhanced activation of the sympathetic nervous system. The sympathetic nervous system is under tonic and phasic control by the rostral ventrolateral medulla (RVLM). In sedentary rats, there is enhanced sympathoexcitation in response to glutamatergic activation of the RVLM. Since the activity of RVLM is tonically restrained by γ‐amino‐butyric acid (GABA), we hypothesized that sedentary conditions may also lead to decreased responsiveness to GABA in RVLM when compared to physically active conditions. In Inactin anesthetized, sedentary (SED) or physically active (EX) rats, mean arterial pressure (MAP), heart rate (HR) and splanchnic sympathetic nerve activity (sSNA) were recorded during unilateral microinjection of GABA (30 nl, 0.3–600 mM) into the RVLM. Following GABA injections, the contralateral RVLM was inhibited with 90 nl of 2mM Muscimol and the GABA injections were repeated. There were no significant differences between SED or EX conditions for MAP, HR and sSNA responses to GABA both before and after contralateral blockade of the RVLM. Based on our results the enhanced sympathoexcitation seen in our sedentary model is not due to reduced responsiveness to GABA and may be due to enhanced responsiveness to excitatory neurotransmission. (Supported by R01‐HL096787; R01‐HL096787‐S1)
Mas receptor in the RVLM mediates sympatho‐inhibitory effect in mice with ACE2 overexpression during heart failure
Authors: Xiao Liang , Zucker Irving H
Published: June 2021

Elevated central Ang II signaling contributes to the sustained increase of sympathetic outflow during chronic heart failure (CHF). This is associated with downregulation of central angiotensin‐converting enzyme 2 (ACE2). We have previously shown that sympathetic outflow was attenuated in mice with neuron‐selective ACE2 overexpression (SYN‐hACE2, SA) during CHF. However, it is not clear whether this effect is due to Ang‐(1‐7) and mas receptor signaling in the pre‐sympathetic neurons in these mice. We hypothesized that knock‐down of the mas receptor in the RVLM increases sympathetic drive in SA mice during CHF. Five weeks after coronary artery ligation, mean arterial pressure (MAP) and heart rate (HR) were recorded with telemetry for 3 days. Lentivirus encoding MAS1 shRNA (mas KD) or scrambled shRNA (scrb) were microinjected into the RVLM bilaterally, and MAP and HR were recorded after 7 days of recovery. Although a decrease in MAP and increase in HR were observed as cardiac function deteriorated, mas KD had no effect in wild type mice. In SA mice, HR was maintained after control microinjection (590±4 bpm vs. 588±6 bpm), however mas receptor KD increased HR (595±1 bpm vs. 618±5 bpm, p<0.05). MAP was decreased similarly in two groups. These data suggest that the cardiac sympatho‐inhibitory effect of central ACE2 overexpression is mediated through mas receptor in the RVLM.
A method for long term recording of splanchnic sympathetic nerve activity in conscious rats
Authors: Kuroki Marcos Takuya , Yoshimoto Misa , Guzman Pilar Ariza , Miki Kenju , Osborn John
Published: June 2021

A contributing mechanism for hypertension is an increase in sympathetic nerve activity (SNA) to the periphery. In the angiotensin‐II plus salt (AngII‐salt) model of hypertension, an increase in “sympathetic tone” to non‐renal splanchnic vasculature is correlated with an increase in venous and arteriolar vascular resistance which could hemodynamically play a causal role to the observed hypertension. To date, however, there has been no direct confirmation that an increase in splanchnic SNA is in fact responsible for the enhanced sympathetic tone seen in this model. Measurement of splanchnic SNA in this scenario would require a technique that would allow for long term (>2 weeks) recording in conscious, freely moving rats. We have adapted a technique for recording SNA in renal and lumbar sympathetic nerves to measure splanchnic SNA in conscious rats. Using this technique, we have successfully recorded splanchnic nerve activity for up to 6 weeks. Splanchnic nerve activity measured though this technique is sensitive to acute changes in blood pressure and abolished by ganglionic blockade, suggesting that most of the nerve activity is from barosensitive, post‐ganglionic sympathetic nerves. The longevity of the nerve recording achieved through this technique should allow us to study changes in splanchnic SNA throughout the course of AngII‐salt hypertension in a within animal study design.
A potential acute renal failure marker of MicroRNA494 modulates expression of the inducible transcription factor ATF3 and affects kidney function in a mice model of ischemia reperfusion
Authors: Lan Yi-Fan , Lai Pei Fang , Lin Heng
Published: June 2021

Background

Previous reports have shown ATF3 plays a protective role in acute renal failure, ischemia/reperfusion (I/R) injury. The aim of this study was to analyze the potential regulation of ATF3 expression by microRNAs.

Methods and Results

In this study, we demonstrated that miR‐494 target 3′ untranslated region of ATF3 reporter and decreased ATF3 mRNA expression by reporter assay and molecular analysis. Overexpression lenti‐miR‐494 in mice kidney was significantly attenuate ATF3 mRNA and protein, accompany with I/R induced inflammatory related factor include IL‐6, MCP‐1, P‐selectin resulting cells apoptosis and renal function decreased. Importantly, the mice urinary miR‐494 was increased significantly earlier than serum creatinine after renal I/R. In clinical, the urinary miR‐494 expression was higher in acute kidney injury (AKI) patients than patients with no AKI and normal. Besides, we also find the increasing level of miR‐494 in urine of AKI is consistent with two of comparator AKI biomarker gelatinase‐associated lipocalin (NGAL) and cystatin C.

Conclusion

These data suggest that up‐regulation of miR‐494 contributes to inflammatory factor or adhesion molecule induced kidney injury after I/R via inhibition ATF3 expression and miR‐494 may act as an early specific and non‐invasive biomarker in AKI. The source of research supported from National Science Council (Taiwan).
Angiotensin II causes nitric oxide synthase 3 uncoupling in the thick ascending limb
Authors: Massey Katherine , Saikumar Jagannath J. , Faber Mark D. , Yee Jerry J. , Garvin Jeffrey L.
Published: June 2021

In the thick ascending limb (TAL) luminal flow increases NO production which inhibits flow‐mediated O2− production via a cGMP/PKG dependent pathway. Angiotensin II (Ang II) acutely stimulates TAL NO production by activating the AT2 receptor and stimulates O2− production via the AT1 receptor. We hypothesized that Ang II‐stimulated NO inhibits Ang II‐stimulated O2− via a cGMP‐dependent process. We measured NO production by fluorescence microscopy in isolated TAL. NO production was increased by 0.025 ± 0.004, 0.023 ± 0.014, 0.028 ± 0.007 arbitrary units (AU)/sec by 1, 10 and 100 pM Ang II, respesctively. Scavenging O2− with tempol did not affect Ang II‐stimulated NO production. We then measured O2− production in isolated TAL using a lucigenin‐based assay. Ang II (1 nM) increased O2− production by 1.77 ± 0.26 to 2.62 ± 0.36 AU (p<0.01). Adding L‐arginine (L‐Arg), the substrate for NO production, had no effect on angiotensin II‐induced O2−. In the absence of L‐Arg the NOS inhibitor, L‐NAME, reduced Ang II‐stimulated O2− by 0.82 ± 0.31 AU (p<0.05). In the presence of L‐Arg L‐NAME reduced O2− production by 0.71 ± 0.24 AU, however L‐NAME had no effect on basal O2− production. We conclude that: 1) Ang II increases both O2− production and NO production; 2) unlike flow‐induced NO, Ang II‐induced NO production does not inhibit Ang II‐induced O2− production; and 3) Ang II causes NOS uncoupling. Supported by NIH 5P01HL028982.
Effects of Electroacupuncture and Moxabusrion in the Progression of Renal Disease in Rats
Authors: Paterno Josne Carla , Bergamaschi Cassia toledo , Campos Ruy Ribeiro , Oliveira-Sales Elisabeth B , Teixeira Vicente Paulo Castro
Published: June 2021

Traditional Chinese Medicine (TCM) has been increasingly recognized as an effective therapeutic approach in several fields of medicine. Among its therapeutic strategies are electroacunpucture (EA) and moxibustion (MO). The aim of this study was to investigate the renal and hemodynamic effects of EA‐MO in an experimental model of PDR in rats. Male wistar rats were submitted to 5/6 nephrectomy (5/6 nx) for eight weeks and divided in three groups. Control (NX); Sham‐EA‐MO (NX‐AS): 5/6 nx and EA‐MO session in sham‐points; and EA‐MO (NX‐AM): 5/6 nx and EA‐MO session in real points. Biochemical studies, blood pressure (MAP) and renal sympathetic nerve activity (RSNA) measurement and Nitric Oxide Levels (NO) were assessed.

Groups
24hproteinuria (mg/24h)
MAP (mmHg)
Serum NO (μM)
RSNA (Hz)

NX
153,86±22,93
181,23±20,01
65,02±13,75
207,11±41,82

NXAS
159,37±43,98
174,25±12,17
59,93±14,93
176,52±19,32

NXAM
75,30±8,30*
121,67±15,52*
162,92±42,19*
129,66±10,31*

(p<0,05: * vs NX, NX‐AS)

Our results suggest that EA‐MO had a benefic effects by the modulation of RSNA and increase NO levels, which contribute to the hypotensive effects and attenuated the PDR in the experimental model of 5/6 nephrectomy.

Supported by CNPq
Nonlinear Time‐Domain Analysis of EMG Activity Reveals the Timing of Motor Unit Recruitment in Diaphragm Muscle
Authors: Seven Yasin Baris , Mantilla Carlos B , Sieck Gary C
Published: June 2021

In previous studies, we showed that the root mean square of DIAm EMG correlates with transdiaphragmatic pressure (Pdi) reflecting force generation. We also showed that there is a shift in the power spectral density towards higher frequencies with recruitment of more fatigable fast‐twitch motor units. Recruitment of motor units leads to summation of motor unit action potentials (MUAP) causing non‐stationarity of the mean square value. Accordingly, non‐stationarity of EMG reflects motor unit recruitment. In the present study, we assessed stationarity of DIAm EMG across different ventilator and non‐ventilatory behaviors using a reverse arrangement test for 10‐ms binned mean square values. Stationarity was confirmed if 80% of the mean square calculations were within 2 standard deviations. In adult male rats, EMG recordings were obtained during eupnea, hypoxia‐hypercapnia (5% CO2/10% O2), airway occlusion, and sneezing. At the onset of DIAm activity for each behavior, the EMG was stationary for ~75 ms. The EMG was also stationary for ~150 ms around the peak RMS for all motor behaviors. However, the period of non‐stationarity of DIAm EMG varied across motor behaviors: eupnea and hypoxia‐hypercapnia: 50 ms; airway occlusion: 240 ms; sneezing: 500 ms). Therefore, the duration of non‐stationarity of DIAm EMG increased with increasing force output; thus, reflecting the extent of motor unit recruitment.
Biochemical analysis of the human mismatch repair proteins hMutSalpha MSH2G674A‐MSH6 and MSH2‐MSH6T1219D
Authors: Geng Hui , Sakato Miho , DeRocco Vanessa , Yamane Kazuhiko , Du Chunwei , Erie Dorothy A. , Hingorani Manju , Hsieh Peggy
Published: June 2021

The human MutSalpha protein, a heterodimer between MSH2 and MSH6, initiates DNA mismatch repair (MMR) by recognizing mismatched bases that result from replication errors. Msh2G674A or Msh6T1217D mice that have mutations in or near the ATP binding site of MSH2 or ATP hydrolysis catalytic site of MSH6, respectively, develop cancer and have reduced lifespan due to loss of the MMR pathway. Mouse embryonic fibroblasts from these mice retain an apoptotic response to DNA damage.

Mutant human MutSa proteins, MSH2G674A‐MSH6wt and MSH2wt‐MSH6T1219D, are profiled in a variety of functional assays and, as expected, fail to support MMR in vitro, although they retain mismatch recognition activity. Kinetic analyses of DNA binding and ATPase activities and examination of the excision step of MMR reveal that the two mutants differ in their underlying molecular defects. MSH2wt‐MSH6T1219D fails to couple nucleotide binding and mismatch recognition; whereas, MSH2G674A‐MSH6wt has a partial defect in nucleotide binding. Nevertheless, both mutant proteins remain bound to the mismatch and fail to promote efficient excision thereby inhibiting MMR in vitro in a dominant manner. Our findings highlight differences in the molecular defects of the G674A and T1219D mutant MutSalpha proteins and provide a basis for thinking about how they might mediate the apoptotic response to certain DNA damaging agents.
Use of Concept Mapping in an Undergraduate Introductory Exercise Physiology Course
Authors: Henige Kim
Published: June 2021

Physiology is often considered a challenging course for students. It is up to teachers to structure courses and create learning opportunities that will increase the chance of student success. In an undergraduate exercise physiology course, concept maps are assigned to help students actively process and organize information into manageable and meaningful chunks and to teach them to recognize the patterns and regularities of physiology. Students are first introduced to concept mapping with a commonly relatable non‐physiology concept and are then assigned a series of maps that become more and more complex. Students map the acute response to a drop in blood pressure, the causes of the acute increase in stroke volume during cardiorespiratory exercise, and the factors contributing to an increase in maximal oxygen consumption with cardiorespiratory endurance training. In the process, students draw the integrative nature of physiology, identify causal relationships, and learn about general models and core principles of physiology.
Student learning and academic performance in undergraduate Human Anatomy and Physiology: Student perceptions
Authors: Dobson John , Sturgis Diana , Maurer Trent
Published: June 2021

The aims of the study were to use the Course Valuing Inventory (CVI; Nehari, 1978) to investigate how undergraduate health majors perceived the meaning and value of their learning in a Human Anatomy and Physiology class (HAP) and to analyze the relationship between CVI perceptions and other factors (demographic, study factors, motivation and academic achievement). Volunteers were recruited from HAP I and II courses to complete the survey. The majority of the 458 respondents were sophomores (50.9%), females (74.5%), white (65.5%) and were nursing (46.5%) or allied health (41.7%) majors. Reliability for the CVI was .93 with all subscales significantly different from one another at p<. 001. There were no significant differences on the four CVI subscales between HAP I and II. Regression analyses indicated that both Block 1 (motivation, study hours, readings, attendance, course level, majors), F (7,442)=14.76, p<. 001 and Total CVI, F (8,441)=19.56, p<. 001 were significant predictors of course performance. The results indicated that CVI can be used as an instrument to evaluate student learning in HAP. There was a clear relationship between CVI scores and academic performance, and the relationship was strongest for the course valuing and content learning sections of the inventory. Attendance and motivation were significant in predicting final grades. Nursing outscored Allied Health majors by about 1/3 of a letter grade.