Medicine and Health Sciences Commons^™

Interaction Between Angiotensin Ii And Bdnf In Modulating Sympathetic Nerve Activity, Bryan K. Becker

Theses & Dissertations

Over activation of the sympathetic nervous system is prevalent in many forms of cardiovascular disease such as chronic heart failure (CHF) and hypertension. Although increased neuronal renin-angiotensin system activity in presympathetic neurons has been well implicated in mediating this sympatho-excitation, many of the neuronal effects of angiotensin II (Ang II) signaling remain poorly understood. One particular mechanism of Ang II-mediated increases in presympathetic neuronal activity is through reductions in voltage-gated K⁺ currents. Another pathway that has profound effects on neuronal K⁺ currents and that has been previously implicated in Ang II-signaling is brain-derived neurotrophic factor (BDNF) activity through …

Comparison Of Modified Warm Water Infusion And Air Insufflation For Colonoscopy In A Rat Colon Cancer Model, Mingjie Qian, Zhenyu Sui, Wen Tang, Shaofeng Wang

The Thai Journal of Veterinary Medicine

Our aim is to compare the effect of warm water infusion and air infusion enteroscopy on the success rate of colonoscopy in a rat model of colorectal cancer. 60 rats with colorectal cancer were divided into 2 groups: the air infusion (AI) group taking air infusion enteroscopy and the warm water infusion (WWI) group taking warm water infusion enteroscopy. The success rate, testing time, pain score and diagnostic value of these two groups were evaluated. There are significant differences between two groups concerning the success rate and the average test time. In the WWI group, the success rate is 83.33% …

Predicting Human Drug Toxicity And Safety Via Animal Tests: Can Any One Species Predict Drug Toxicity In Any Other, And Do Monkeys Help?, Jarrod Bailey, Michelle Thew, Michael Balls

Laboratory Experiments Collection

Animals are still widely used in drug development and safety tests, despite evidence for their lack of predictive value. In this regard, we recently showed, by producing Likelihood Ratios (LRs) for an extensive data set of over 3,000 drugs with both animal and human data, that the absence of toxicity in animals provides little or virtually no evidential weight that adverse drug reactions will also be absent in humans. While our analyses suggest that the presence of toxicity in one species may sometimes add evidential weight for risk of toxicity in another, the LRs are extremely inconsistent, varying substantially for …

Systemic Insulin Sensitivity And Skeletal Muscle Akt Signaling In Rats Artificially Selected For Low And High Aerobic Capacity, Kyle Levi Fulghum

MSU Graduate Theses

The mechanism(s) linking physical inactivity, obesity, and type-II diabetes are unclear. I hypothesized low intrinsic aerobic capacity is associated with reduced systemic insulin sensitivity via skeletal muscle insulin signaling. After 34 generations of selective breeding, high aerobic capacity (HCR) rats exhibited an 8-fold increase in running distance vs low aerobic capacity (LCR) rats (n=14 per group). LCR rats had higher rates of weight gain vs HCR (p<0.05) though food consumption was constant (p=0.86) over a 12-week study. Rats were divided into 4 groups: 1) LCR-Sham Surgery, 2) LCR-Catheterization, 3) HCR-Sham Surgery or 4) HCR-Catheterization (n=7 per group). Euglycemic-hyperinsulinemic clamps on catheterized rats tested insulin sensitivity while sham LCR and HCR were used for basal tissue analysis. Plasma insulin levels did not differ during the clamps, but LCR required lower glucose infusion rates than HCR (p<0.05). Upon insulin stimulation, both absolute and normalized phospho-Akt(Ser473) of soleus muscle were significantly increased in HCR above basal group (p<0.05), but not in LCR. No difference was observed between insulin-stimulated phospho-Akt(Ser473) of HCR and LCR groups . These data support that LCR is linked to a reduction in insulin sensitivity in vivo without impairments of insulin-stimulated skeletal muscle phospho-Akt(Ser473) vs HCR rats.

Response Of Gh, Acth, Tsh And Igf-I To Gonadotropin Releasing Hormone Stimulation In Ovariohysterectomized Rats, Jian-Liang Lin, Li-Shiue Shiu, Hsein-Chi Wang, Wei-Ming Lee

The Thai Journal of Veterinary Medicine

GnRH is not only a primary regulator of gonadal function but also a possible factor which affects other pituitary cells out of gonadotrophs. Recently, it has been reported that GnRH might induce the release of GH, but the effects on GH and other pituitary hormones of GnRH still remained controversial. In this study, OHE was performed in 30-week-old female Sprague Dawley rats as experimental groups. Intact female rats were taken as control group. GnRH stimulation at different weeks (20, 24, and 30) after OHE was examined in all rats. Evaluation of the circulating GH, IGF-I, ACTH, TSH concentrations at different …

Local Modulation And Measurement Of Macrophage-Derived Bioactive Proteins From Implanted Biomaterials In Rat, Geetika Bajpai

Graduate Theses and Dissertations

Fibrosis around the implanted medical devices is a severe problem that can plague long-term device reliability. Activation of macrophage phenotype (macrophage polarization) has emerged as a new and possible means for reducing fibrosis in the fields of biomaterials and regenerative medicine. Macrophages are phagocytic cells that respond to microenvironmental cues that direct their phenotype. Macrophage activation has been widely studied in mouse and human in the context of tumor biology, yet little information is available regarding how macrophage activation could be used in a biomaterials context. Further, rats rather than mice are the common subjects in biomaterials experiments. A significant …

A Non-Invasive Method To Evaluate Gastrointestinal Transit Behaviour In Rat, Geoffrey M. Bove

Biomedical Sciences Faculty Publications

Introduction: Many factors alter gastrointestinal transit. Animal models are useful for preclinical studies of gastrointestinal transit, but terminal methods do not allow later study, and stressful assessment methods will likely alter the transit of the animal. To overcome these factors, we developed a new method to assay rat total gastrointestinal transit.

Methods: Standard plastic cages with their bottoms cut off were placed on wire mesh floors. Custom apparatuses were built to contain fecal pellets as they fell through the floors. Webcams connected to a computer running a security program were placed to image the pellets at regular intervals. Custom food …

Gmo Vs. Non-Gmo: Comparing The Addictiveness Of Corn In Rats, Christian A. Carroll, Sara L. Hill, Kelly A. Huston, Tyler Michael, Courtney Noll, Melissa J. Beck, Ginger D. Cameron

The Research and Scholarship Symposium (2013-2019)

Genetically modified organisms (GMOs) refer to organisms whose DNA has been altered to produce a certain characteristic. GMOs account for a significant proportion of the crops produced in the United States. Specifically, GMO corn accounted for approximately 88% of all corn grown for human and animal consumption in the year 2012. Previously conducted studies have not uniformly demonstrated the safe use of GMO corn, and no studies have been conducted to analyze the addictiveness of GMO corn.

The idea of addiction refers to more than just a physical dependence, but to a psychological dependence on something as well. Addiction is …

Experimental Investigation On The Relationship Between Lead Exposure And Thyroids In Diabetes., Salah Sumar Ali Al-Zadjali

Dissertations

Lead exposure can cause multiple systemic toxicities, particularly affecting the hematopoietic, nervous and renal systems. However, its effects on the thyroid functions are not well elucidated and the published studies are controversial. In addition, although there are several experimental thyroid models, each one of them has its own limitations. According, in this dissertation, we investigated the possible relationship between lead exposure, thyroid functions and short-term systemic toxicity in two animal models, namely normal (non-diabetic) and diabetic animals. We also investigated the possibility of developing a hormonal thyroid model.

In the non-diabetic model, Wistar rats were divided into five groups and …

Experimental Investigation On The Relationship Between Lead Exposure And Thyroids In Diabetes, Salah Sumar Ali Al-Zadjali

Dissertations

Lead exposure can cause multiple systemic toxicities, particularly affecting the hematopoietic, nervous and renal systems. However, its effects on the thyroid functions are not well elucidated and the published studies are controversial. In addition, although there are several experimental thyroid models, each one of them has its own limitations. Accordingly, in this dissertation, we investigated the possible relationship between lead exposure, thyroid functions and short-term systemic toxicity in two animal models, namely normal (non-diabetic) and diabetic animals. We also investigated the possibility of developing a hormonal thyroid model. In the non-diabetic model, Wistar rats were divided into five groups and …

Nicotine Receptors Mediating Sensorimotor Gating And Its Enhancement By Systemic Nicotine, Farena Pinnock, Daniel Bosch, Tyler Brown, Nadine Simons, John R. Yeomans, Cleusa Deoliveira, Susanne Schmid

Anatomy and Cell Biology Publications

Prepulse inhibition (PPI) of startle occurs when intensity stimuli precede stronger startle-inducing stimuli by 10–1000 ms. PPI deficits are found in individuals with schizophrenia and other psychiatric disorders, and they correlate with other cognitive impairments. Animal research and clinical studies have demonstrated that both PPI and cognitive function can be enhanced by nicotine. PPI has been shown to be mediated, at least in part, by mesopontine cholinergic neurons that project to pontine startle neurons and activate muscarinic and potentially nicotine receptors (nAChRs). The subtypes and anatomical location of nAChRs involved in mediating and modulating PPI remain unresolved. We tested the …

Saccharomyces Boulardii And Bismuth Subsalicylate As Low-Cost Interventions To Reduce The Duration And Severity Of Cholera, Johnathan Sheele, Jessica Cartowski, Angela Dart, Arjun Poddar, Shikha Gupta, Ajay Gupta

Computer Science Faculty Publications

We conducted a randomised single-blinded clinical trial of 100 cholera patients in Port-au-Prince, Haiti to determine if the probiotic Saccharomyces cerevisiae var. boulardii and the anti-diarrhoeal drug bismuth subsalicylate (BS) were able to reduce the duration and severity of cholera. Subjects received either: S. boulardii 250 mg, S. boulardii 250 mg capsule plus BS 524 mg tablet, BS 524 mg, or two placebo capsules every 6 hours alongside standard treatment for cholera. The length of hospitalisation plus the number and volume of emesis, stool and urine were recorded every 6 hours until the study subject was discharged (n=83), left against …

Effects Of Prenatally Exposed Diclofenac Sodium On Rat Heart Tissue:A Stereological And Histological Study, Fi̇kret Gevrek, Mi̇kai̇l Kara, Murat Çeti̇n Rağbetli̇, Hüseyi̇n Aslan

Turkish Journal of Medical Sciences

Background/aim: Diclofenac sodium (DS) can cross the placental barrier and affect the fetus, and its consumption during pregnancy may cause developmental malformation of embryos. This study investigates the effect of prenatally applied DS on the quantitative morphology of the adult rat heart. Materials and methods: Pregnant rats were divided into three groups (control, sham, and test). The rats in the test group were injected with DS; the control group received physiological saline (1 mL; 1 mg/kg, i.m.) from the 5th to the 20th day of pregnancy; and the rats in the sham group were not injected at all. At the …

The Effect Of Vitamin E And L-Carnitine Against Methotrexate-Induced Injury In Rat Testis, Mehmet Yüncü, Nezahat Bükücü, Nuray Bayat, Leman Sencar, Mehmet Tarakçioğlu

Turkish Journal of Medical Sciences

Background/aim: Methotrexate (MTX), used commonly as an antimetabolite drug in cancer therapy, leads to acute toxic side effects in tissues or organs containing rapidly dividing cells, such as bone marrow, gastrointestinal mucosa, and seminiferous tubules. In this study, we investigated the protective effects of vitamin E and L-carnitine against MTX-induced injury in rat testis. Materials and methods: Rats were divided into 4 groups, including the control group. The study took 17 days and the animals received daily doses of 0.5 mL/kg saline, 250 mg/kg vitamin E, or 500 mg/kg L-carnitine intraperitoneally. The experimental groups received 20 mg/kg methotrexate intraperitoneally on …

Beneficial Effects Of Melatonin And Bq-123 On The Rat Testis Damage Caused By Cigarette Smoke, Hüseyi̇n Aslan, Hakan Kesi̇ci̇, Zafer İsmai̇l Karaca, Bi̇rsen Özyurt, Ufuk Taş, Fati̇h Eki̇ci̇, Hasan Erdoğan, Fi̇kret Gevrek, Sevi̇l Çayli

Turkish Journal of Medical Sciences

Several studies have demonstrated that cigarette smoke has detrimental effects on testicular function. However, it is unknown whether melatonin or BQ-123 has beneficial effects on the rat testis damage caused by cigarette smoke. The aim of the present study was to investigate the beneficial effects of melatonin or BQ-123 on the testicular damage caused by cigarette smoke. Materials and methods: Twenty Wistar rats were randomly divided into 4 equal groups: control group (n = 5), cigarette smoke group (n = 5), melatonin group (n = 5), and BQ-123 group (n = 5). At the end of 4 weeks, all the …

Efficacy Of Diffusion-Weighted Magnetic Resonance Imaging In The Evaluation Of Extrahepatic Cholestasis-Related Hepatic Fibrosis, Süleyman Ayvaz, Sedat Alpaslan Tuncel, Güray Can, Beki̇r Çağli, Turan Karaca, Seli̇m Demi̇rtaş, Muhammed Elmaoğlu, Mehmet Ercüment Ünlü, Mehmet Pul

Turkish Journal of Medical Sciences

Background/aim: To investigate the efficacy of diffusion-weighted magnetic resonance imaging (DWI) in the diagnosis and staging of fibrosis induced by experimental bile duct ligation (BDL). Materials and methods: Twenty-four rats were divided randomly into four groups: control, BDL - 3 days, BDL - 2 weeks, and BDL - 4 weeks. DWI was performed with b-values of 100 and 500 on the rats from control group at day zero, on the rats from the BDL - 3 days group at the end of day 3, on the rats from the BDL - 2 weeks group at the end of day 14, …

Comparison Of Thiopental And Ketamine+Xylazine Anesthesia Inischemia/Reperfusion-Induced Arrhythmias In Rats, Ersöz Gonca

Turkish Journal of Medical Sciences

Background/aim: To investigate the influence of thiopental (85 mg/kg, intraperitoneally (ip)), and ketamine+xylazine (ketamine 75 mg/kg and xylazine 8 mg/kg, ip) anesthesia on the incidence and duration of ischemia/reperfusion-induced arrhythmias. Materials and methods: Myocardial ischemia was induced by a 6-min ligation of the left anterior descending coronary artery, followed by a 6-min reperfusion. Measurements were taken of the incidence and duration of ventricular arrhythmias, the mean arterial blood pressure and heart rate, and the pressure rate-product (as an index of myocardial oxygen consumption). Results: The arrhythmia score and the incidence of ventricular fibrillation and tachycardia were significantly decreased in the …

Effects Of Melatonin And Theanine Administration On Pentylenetetrazole-Inducedseizures And Brain Tissue Oxidative Damage In Ovariectomized Rats, Shadi Choopankareh, Farzaneh Vafaee, Mohammad Naser Shafei, Hamid Reza Sadeghnia, Reza Salarinia, Leila Zarepoor, Mahmoud Hosseini

Turkish Journal of Medical Sciences

Background/aim: The effects of coadministration of melatonin and theanine (Mel/Thea) on pentylenetetrazole (PTZ)-induced seizures and brain tissue oxidative damage were investigated in ovariectomized (OVX) and sham-operated rats. Materials and methods: The rats were divided into the following groups: 1) sham, 2) ovariectomized (OVX), 3) sham-PTZ, 4) OVX-PTZ, 5) sham-Mel/Thea-PTZ, and 6) OVX-Mel/Thea-PTZ. Groups 1-4 received saline, while groups 5 and 6 received a combination of Mel/Thea for 6 weeks. All animals except for those in groups 1 and 2 received a single injection of PTZ. Results: The OVX-PTZ group had higher generalized tonic-clonic seizure (GTCS) latency compared to the sham-PTZ …

A New Obesity Model Reveals The Hypophagic Properties Of Pacap Involve The Regulation Of Homeostatic Feeding In The Ventromedial Hypothalamic Nucleus And Hedonic Feeding In The Nucleus Accumbens, Matthew M. Hurley, Brian Maunze, Jon M. Resch, Mogen M. Frenkel, M. J. Reilley, Megan E. Block, David A. Baker, Sujean Choi

Biomedical Sciences Faculty Research and Publications

Binge eating in humans is a complex disorder that often involves discrete, compulsive feeding sessions of highly palatable foods even in the absence of a deprivation state or hunger. Binging can be effectively modeled in rodents by providing subjects with limited access to a palatable food source (Western Diet; WD) as an adjunct to ad lib access to normal chow (Standard Chow; SC). Although this design recapitulates several fundamental characteristics observed in binge eating disorder, the binge eating observed in this paradigm is likely a product of both hedonic and homeostatic drives with the need to balance energy stores still …