Effects of unilateral lesions of retrotrapezoid nucleus on breathing in awake rats

1997 ◽  
Vol 82 (2) ◽  
pp. 469-479 ◽  
Author(s):  
Manjapra R. Akilesh ◽  
Matthew Kamper ◽  
Aihua Li ◽  
Eugene E. Nattie
Keyword(s):  
Excitatory Amino Acid ◽  
Ibotenic Acid ◽  
Whole Body ◽  
Lesion Group ◽  
Control Groups ◽  
Lesion Effect ◽  
Retrotrapezoid Nucleus ◽  
Reticular Activating System ◽  
Facial Nerve Stimulation ◽  
Awake Rats

Akilesh, Manjapra R., Matthew Kamper, Aihua Li, and Eugene E. Nattie. Effects of unilateral lesions of retrotrapezoid nucleus on breathing in awake rats. J. Appl. Physiol. 82(2): 469–479, 1997.—In anesthetized rats, unilateral retrotrapezoid nucleus (RTN) lesions markedly decreased baseline phrenic activity and the response to CO2 (E. E. Nattie and A. Li. Respir. Physiol. 97: 63–77, 1994). Here we evaluate the effects of such lesions on resting breathing and on the response to hypercapnia and hypoxia in unanesthetized awake rats. We made unilateral injections [24 ± 7 (SE) nl] of ibotenic acid (IA; 50 mM), an excitatory amino acid neurotoxin, in the RTN region ( n = 7) located by stereotaxic coordinates and by field potentials induced by facial nerve stimulation. Controls ( n = 6) received RTN injections (80 ± 30 nl) of mock cerebrospinal fluid. A second control consisted of four animals with IA injections (24 ± 12 nl) outside the RTN region. Injected fluorescent beads allowed anatomic identification of lesion location. Using whole body plethysmography, we measured ventilation in the awake state during room air, 7% CO2 in air, and 10% O2 breathing before and for 3 wk after the RTN injections. There was no statistically significant effect of the IA injections on resting room air breathing in the lesion group compared with the control groups. We observed no apnea. The response to 7% CO2 in the lesion group compared with the control groups was significantly decreased, by 39% on average, for the final portion of the 3-wk study period. There was no lesion effect on the ventilatory response to 10% O2. In this unanesthetized model, other areas suppressed by anesthesia, e.g., the reticular activating system, hypothalamus, and perhaps the contralateral RTN, may provide tonic input to the respiratory centers that counters the loss of RTN activity.

scholarly journals Growth and zinc homeostasis in the severely Zn-deficient rat

1984 ◽  
Vol 52 (3) ◽  
pp. 545-560 ◽  
Author(s):  
R. Giugliano ◽  
D. J. Millward
Keyword(s):  
Body Weight ◽  
Growth Rates ◽  
Control Diet ◽  
Rate Of Change ◽  
Zinc Homeostasis ◽  
Whole Body ◽  
Zn Deficiency ◽  
Control Groups ◽  
Body Weights ◽  
Cyclic Changes

1. Male weanling rats were fed on diets either adequate (55 mg/kg), or severely deficient (0.4 mg/kg) in zinc, either ad lib. or in restricted amounts in four experiments. Measurements were made of growth rates and Zn contents of muscle and several individual tissues.2. Zn-deficient rats exhibited the expected symptoms of deficiency including growth retardation, cyclic changes in food intake and body-weight.3. Zn deficiency specifically reduced whole body and muscle growth rates as indicated by the fact that (a) growth rates were lower in ad lib.-fed Zn-deficient rats compared with rats pair-fed on the control diet in two experiments, (b) Zn supplementation increased body-weights of Zn-deficient rats given a restricted amount of diet at a level at which they maintained weight if unsupplemented, (c) Zn supplementation maintained body-weights of Zn-deficient rats fed a restricted amount of diet at a level at which they lost weight if unsupplemented (d) since the ratio, muscle mass:body-weight was lower in the Zn-deficient rats than in the pair-fed control groups, the reduction in muscle mass was greater than the reduction in body-weight.4. Zn concentrations were maintained in muscle, spleen and thymus, reduced in comparison to some but not all control groups in liver, kidney, testis and intestine, and markedly reduced in plasma and bone. In plasma, Zn concentrations varied inversely with the rate of change of body-weight during the cyclic changes in body-weight.5. Calculation of the total Zn in the tissues examined showed a marked increase in muscle Zn with a similar loss from bone, indicating that Zn can be redistributed from bone to allow the growth of other tissues.6. The magnitude of the increase in muscle Zn in the severely Zn-deficient rat, together with the magnitude of the total losses of muscle tissue during the catabolic phases of the cycling, indicate that in the Zn-deficient rat Zn may be highly conserved in catabolic states.

Stress-induced attenuation of the hypercapnic ventilatory response in awake rats

2001 ◽  
Vol 90 (5) ◽  
pp. 1729-1735 ◽  
Author(s):  
Richard Kinkead ◽  
Lydie Dupenloup ◽  
Nadine Valois ◽  
Roumiana Gulemetova
Keyword(s):  
Control System ◽  
Immobilization Stress ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Respiratory Control ◽  
Whole Body ◽  
Respiratory Homeostasis ◽  
Whole Body Plethysmography ◽  
Ventilatory Response To Hypoxia ◽  
Awake Rats

To test the hypothesis that stress alters the performance of the respiratory control system, we compared the acute (20 min) responses to moderate hypoxia and hypercapnia of rats previously subjected to immobilization stress (90 min/day) with responses of control animals. Ventilatory measurements were performed on awake rats using whole body plethysmography. Under baseline conditions, there were no differences in minute ventilation between stressed and unstressed groups. Rats previously exposed to immobilization stress had a 45% lower ventilatory response to hypercapnia (inspiratory CO2 fraction = 0.05) than controls. In contrast, stress exposure had no statistically significant effect on the ventilatory response to hypoxia (inspiratory O2 fraction = 0.12). Stress-induced attenuation of the hypercapnic response was associated with reduced tidal volume and inspiratory flow increases; the frequency and timing components of the response were not different between groups. We conclude that previous exposure to a stressful condition that does not constitute a direct challenge to respiratory homeostasis can elicit persistent (≥24 h) functional plasticity in the ventilatory control system.

scholarly journals Effect of the Combined Intervention with Passive Whole-Body Vibration and Auriculotherapy on the Quality of Life of Individuals with Knee Osteoarthritis Assessed by the WHOQOL-Bref: A Multi-Arm Clinical Trial

2020 ◽  
Vol 10 (6) ◽  
pp. 1956 ◽  
Author(s):  
Marcia Cristina Moura-Fernandes ◽  
Eloá Moreira-Marconi ◽  
Alexandre Gonçalves de Meirelles ◽  
Ana Paula Ferreira de Oliveira ◽  
Aline Reis Silva ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Knee Osteoarthritis ◽  
Whole Body Vibration ◽  
Whole Body ◽  
Pharmacological Interventions ◽  
Control Groups ◽  
Peak Displacement ◽  
Body Vibration ◽  
Combined Intervention

The aim of this study was to determine the effect on the quality of life of two non-pharmacological interventions isolated or in combination: (i) passive whole-body vibration exercise (WBVE), and (ii) auriculotherapy (AT). One hundred three participants with knee osteoarthritis (KOA) were allocated to: (a) a vibration group (WBVEG; n = 17) that performed WBVE (peak-to-peak displacement: 2.5 to 7.5 mm, frequency: 5 to 14 Hz, Peak acceleration: 0.12 to 2.95 g), two days/weekly for five weeks, (b) an AT group (ATG; n = 21), stimulation of three specific auriculotherapy points (Kidney, Knee and Shenmen) in each ear pavilion, (c) WBVE + AT (WBVE + AT; n = 20) and (d) respective control groups (WBVE_CG, n = 15; AT_CG, n = 12; WBVE + AT_CG, n = 18). The participants filled out the WHOQOL-bref Questionnaire before the first and after the last sessions. Statistical differences in the various domains of the WHOQOL-bref were not found. In conclusion, WBVE or AT alone or combined did not contribute in altering the quality of life of individuals exposed to these interventions.

ChemInform Abstract: Design of Excitatory Amino Acid Receptor Agonists, Partial Agonists, and Antagonists: Ibotenic Acid as a Key Lead Structure

ChemInform ◽  
2010 ◽  
Vol 27 (46) ◽  
pp. no-no
Author(s):  
P. KROGSGAARD-LARSEN ◽  
B. EBERT ◽  
T. M. LUND ◽  
H. BRAEUNER-OSBORNE ◽  
F. A. SLOEK ◽  
...  
Keyword(s):  
Amino Acid ◽  
Excitatory Amino Acid ◽  
Ibotenic Acid ◽  
Excitatory Amino Acid Receptor ◽  
Lead Structure ◽  
Acid Receptor ◽  
Receptor Agonists ◽  
Partial Agonists

scholarly journals Effect of reduced dietary zinc intake on carbohydrate and Zn metabolism in the genetically diabetic mouse (C57BL/KsJ db+/db+)

1988 ◽  
Vol 60 (3) ◽  
pp. 499-507 ◽  
Author(s):  
Susan Southon ◽  
Z. Kechrid ◽  
A. J. A. Wright ◽  
Susan J. Fairweather-Tait
Keyword(s):  
Blood Glucose ◽  
Control Diet ◽  
Fasting Blood Glucose ◽  
Liver Glycogen ◽  
Diabetic Mouse ◽  
Whole Body ◽  
Diabetic Mice ◽  
Control Groups ◽  
Glucose Levels ◽  
Blood Glucose Levels

1. Male, 4–5-week-old, genetically diabetic mice (C57BL/KsJ db/db) and non-diabetic heterozygote litter-mates (C57BL/KsJ db/+)were fed on a diet containing 1 mg zinc/kg (low-Zn groups) or 54 mg Zn/kg (control groups) for 27 d. Food intakes and body-weight gain were recorded regularly. On day 28, after an overnight fast, animals were killed and blood glucose and insulin concentrations, liver glycogen, and femur and pancreatic Zn concentrations were determined.2. The consumption of the low-Zn diet had only a minimal effect on the Zn status of the mice as indicated by growth rate, food intake and femur and pancreatic Zn concentrations. In fact, diabetic mice fed on the low-Zn diet had a higher total food intake than those fed on the control diet. The low-Zn diabetic mice had higher fasting blood glucose and liver glycogen levels than their control counterparts. Fasting blood insulin concentration was unaffected by dietary regimen.3. A second experiment was performed in which the rate of loss of 65Zn, injected subcutaneously, was measured by whole-body counting in the two mouse genotypes over a 28 d period, from 4 to 5 weeks of age. The influence of feeding low-Zn or control diets was also examined. At the end of the study femur and pancreatic Zn and non-fasting blood glucose levels were determined.4. All mice fed on the low-Zn diet showed a marked reduction in whole-body 65Zn loss compared with those animals fed on the control diet. In the low-Zn groups, the loss of 65Zn from the diabetic mice was significantly greater than that from heterozygote mice. This difference was not observed in the control groups. Blood glucose levels were elevated in the low-Zn groups. Possible reasons for these observations are discussed.5. The present study demonstrates an adverse effect of reduced dietary Zn intake on glucose utilization in the genetically diabetic mouse, which occurred before any significant tissue Zn depletion became apparent.

scholarly journals Phox2b mutation mediated by Atoh1 expression impaired respiratory rhythm and ventilatory responses to hypoxia and hypercapnia

2021 ◽  
Author(s):  
Caroline B Ferreira ◽  
Talita M Silva ◽  
Phelipe E Silva ◽  
Catherine Czeisler ◽  
Jose J Otero ◽  
...  
Keyword(s):  
Respiratory Rhythm ◽  
Adult Life ◽  
Respiratory Control ◽  
Lineage Tracing ◽  
Whole Body ◽  
Transgenic Mouse Line ◽  
Ventilatory Responses ◽  
Retrotrapezoid Nucleus ◽  
Adult Mice ◽  
Hypoventilation Syndrome

Retrotrapezoid nucleus (RTN) neurons are involved in central chemoreception and respiratory control. Lineage tracing studies demonstrate RTN neurons to be derived from Phox2b and Atoh1 expressing progenitor cells in rhombere 4. Phox2b exon 3 mutations cause congenital central hypoventilation syndrome (CCHS), producing an impaired respiratory response to hypercapnia and hypoxia. Our goal was to investigate the extent to which a conditional mutation of Phox2b within Atoh1-derived cells might affect a) respiratory rhythm; b) ventilatory responses to hypercapnia and hypoxia and c) number of RTN-chemosensitive neurons. Here, we used a transgenic mouse line carrying a conditional Phox2bΔ8 mutation activated by cre-recombinase. We crossed them with Atoh1Cre mice. Ventilation was measured by whole body plethysmograph during neonate and adult life. In room air, experimental and control groups showed similar basal ventilation; however, Atoh1Cre/Phox2bΔ8 increased breath irregularity. The hypercapnia and hypoxia ventilatory responses were impaired in neonates. In contrast, adult mice recovered ventilatory response to hypercapnia, but not to hypoxia. Anatomically, we observed a reduction of the Phox2b+/TH- expressing neurons within the RTN region. Our data indicates that conditionally expression of Phox2b mutation by Atoh1 affect development of the RTN neurons and are essential for the activation of breathing under hypoxic and hypercapnia condition, providing new evidence for mechanisms related to CCHS neuropathology

scholarly journals Fibroglandular Tissue and Background Parenchymal Enhancement on Breast MR Imaging Correlates With Breast Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Xiaoxin Hu ◽  
Luan Jiang ◽  
Chao You ◽  
Yajia Gu
Keyword(s):  
Breast Cancer ◽  
Lesion Group ◽  
Control Group ◽  
Control Groups ◽  
Fibroglandular Tissue ◽  
Cancer Group ◽  
Background Parenchymal Enhancement ◽  
Significant Difference ◽  
Benign Group ◽  
Parenchymal Enhancement

ObjectivesTo evaluate the association of breast cancer with both the background parenchymal enhancement intensity and volume (BPEI and BPEV, respectively) and the amount of fibroglandular tissue (FGT) using an automatic quantitative assessment method in breast magnetic resonance imaging (MRI).Materials and MethodsAmong 17,274 women who underwent breast MRI, 132 normal women (control group), 132 women with benign breast lesions (benign group), and 132 women with breast cancer (cancer group) were randomly selected and matched by age and menopausal status. The area under the receiver operating characteristic curve (AUC) was compared in Cancer vs Control and Cancer vs Benign groups to assess the discriminative ability of BPEI, BPEV and FGT.ResultsCompared with the control groups, the cancer group showed a significant difference in BPEV with a maximum AUC of 0.715 and 0.684 for patients in premenopausal and postmenopausal subgroup, respectively. And the cancer group showed a significant difference in BPEV with a maximum AUC of 0.622 and 0.633 for patients in premenopausal and postmenopausal subgroup, respectively, when compared with the benign group. FGT showed no significant difference when breast cancer group was compared with normal control and benign lesion group, respectively. Compared with the control groups, BPEI showed a slight difference in the cancer group. Compared with the benign group, no significant difference was seen in cancer group.ConclusionIncreased BPEV is correlated with a high risk of breast cancer While FGT is not.

scholarly journals Effects of Metazachlor on Vitellogenin Induction in Zebrafish (Danio rerio)

2007 ◽  
Vol 76 (8) ◽  
pp. S61-S66 ◽  
Author(s):  
J. Jurčíková ◽  
P. Mikula ◽  
R. Dobšíková ◽  
D. Némethová ◽  
Z. Svobodová
Keyword(s):  
Danio Rerio ◽  
Sandwich Elisa ◽  
Whole Body ◽  
Control Fish ◽  
Ambient Water ◽  
Control Groups ◽  
Water Exposure ◽  
Vitellogenin Synthesis ◽  
Chloroacetanilide Herbicide

The influence of metazachlor on vitellogenesis in juvenile (20 days old) zebrafish (Danio rerio) was investigated after ambient water exposure to concentrations of 0.1, 1.0 and 5.0 mg l-1 of the chloroacetanilide herbicide Butisan 400 SC containing approximately 35.6% (w/w) metazachlor. After 20 days of exposure, vitellogenin concentrations in whole-body homogenates of the fish were measured by direct sandwich ELISA. The results were compared to vitellogenin concentrations in fish from both negative (no exposure) and positive (exposed to natural oestrogen 17β-oestradiol) control groups. Exposure to Butisan 400 SC at a concentration of 5.0 mg l-1 induced vitellogenin synthesis significantly compared to the control fish (p < 0.05). The oestrogenic effect of 17β-oestradiol was confirmed.

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