Effect of norepinephrine on diaphragm contractility and blood flow

1990 ◽  
Vol 69 (6) ◽  
pp. 2019-2028 ◽  
Author(s):  
G. S. Supinski ◽  
A. F. DiMarco ◽  
J. Gonzalez ◽  
M. D. Altose

Recent studies have shown that diaphragm fatigue can be reversed by mechanical augmentation of phrenic arterial flow. The purpose of the present experiment was to determine whether it was possible to pharmacologically augment diaphragm blood flow and reverse fatigue by the administration of norepinephrine. Four groups of studies were performed, all employing our previously described in situ isometric canine diaphragm strip preparation (Supinski et al., J. Appl. Physiol. 60: 1789-1796, 1986). Group I studies examined the effects of norepinephrine on the contractility of the nonfatigued diaphragm in normotensive dogs, group II studies examined the effects of this drug on the contractility of the fatigued diaphragm in normotensive animals, and group III studies examined the effect of this drug on the contractility of the fatigued diaphragm in hypotensive animals. Group IV studies examined the effect of norepinephrine in normotensive animals in which the phrenic artery was cannulated and pump perfused at constant flow. Fatigue was induced in group II, III, and IV studies by rhythmically stimulating the diaphragm via intramuscular electrodes. Norepinephrine had no effect on the contractility of the nonfatigued diaphragm (group I). In normotensive (group II) and hypotensive animals (group III), norepinephrine elicited dramatic increases in arterial blood pressure and phrenic arterial flow and produced a significant upshift in the force-frequency curve of the fatigued diaphragm. However, when phrenic flow was held constant (group IV experiments), norepinephrine failed to augment the contractility of the fatigued diaphragm. These results indicate that 1) norepinephrine can increase phrenic blood flow and augment the contractility of the fatigued diaphragm in both normotensive and hypotensive conditions and 2) this effect of norepinephrine to partially reverse fatigue is secondary to its action to augment diaphragmatic blood flow.

2019 ◽  
Vol 8 (4) ◽  
pp. 464 ◽  
Author(s):  
Marcin Majos ◽  
Agata Majos ◽  
Michał Polguj ◽  
Konrad Szymczyk ◽  
Jakub Chrostowski ◽  
...  

Background: The most common renal fusion anomaly is horseshoe kidney (HSK), a condition associated with variable arterial blood supply. The aim of this study was to determine whether the height of origin of the renal artery determines its diameter and whether it differs from the mean diameter of the renal arteries of normal kidneys (NK). Methods: Computer tomography angiography (CTA) studies of 336 patients (88 HSK and 248 NK) were obtained in a search of renal arteries; these were than classified into four groups according to height of its origin: Group I, branching from the aorta superior to the inferior mesenteric artery (IMA); Group II, branching from the aorta below the IMA; Group III, branching from the iliac artery; and Group IV, originating from the internal and external iliac artery. Results: The HSK group included 398 arteries (mean diameter 4.30 mm) and the NK group 598 (5.52 mm) (p < 0.0001). In the HSK group, the mean diameters according to groups were: Group I, 4.54 mm; Group II, 4.28 mm; Group III, 3.41 mm; and Group IV, 3.43 mm. Statistically significant differences were found between arteries originating from the aorta and arteries branching from the iliac arteries (p < 0.0001). In the NK group, the corresponding values were: Group I, 5.53 mm; and Group II, 4.45 mm. The number of arteries supplying the HSK wider than 3.0 mm were: Group I, 83.0%; Group II, 82.4%; Group III, 68.4%; and Group IV, 66.6%. Conclusions: The renal arteries of the HSK branch from their parental vessels at lower levels and have smaller diameters than those of NK.


1993 ◽  
Vol 74 (4) ◽  
pp. 1543-1548 ◽  
Author(s):  
R. J. Leone ◽  
G. S. Friedrichs ◽  
G. F. Merrill

Twenty-six beagles of either sex, weighing 10.4 +/- 0.3 kg, were used to investigate the role of adenosine in the genesis of ventricular arrhythmias during systemic hypoxia. After instrumentation dogs were randomly assigned to one of four treatment groups: 14 dogs were pretreated before hypoxia with adenosine deaminase (n = 7, group I) or its vehicle (n = 7, group II) while 12 other dogs were pretreated with the A1 selective adenosine receptor antagonist BW A1433U (n = 6, group III) or its vehicle (n = 6, group IV). Each dog was exposed to a 3-min period of hypoxic ventilation [3% O2–5% CO2–92% N2; PO2 in arterial blood 96 +/- 3 Torr (before hypoxia), 21 +/- 1 Torr (during hypoxia)]. The percentages of ventricular ectopic beats (19) experienced in the four groups after 3 min of hypoxia were 21 +/- 10% (group I, P < 0.05 relative to group II), 50 +/- 2% (group II), 15 +/- 8% (group III, P < 0.05 relative to group IV), and 42 +/- 7% (group IV). Ventricular bigeminy, the most prominent arrhythmia seen in this study, was significantly reduced by adenosine deaminase and BW A1433U. No significant differences in other monitored cardiovascular variables were seen between adenosine deaminase and BW A1433U treatment groups and their corresponding vehicles. These findings implicate endogenous adenosine as an arrhythmogenic mediator during hypoxia and point to a mechanism involving the A1 adenosine receptor.


2015 ◽  
Vol 18 (3) ◽  
pp. 098
Author(s):  
Cem Arıtürk ◽  
Serpil Ustalar Özgen ◽  
Behiç Danışan ◽  
Hasan Karabulut ◽  
Fevzi Toraman

<p class="p1"><span class="s1"><strong>Background:</strong> The inspiratory oxygen fraction (FiO<sub>2</sub>) is usually set between 60% and 100% during conventional extracorporeal circulation (ECC). However, this strategy causes partial oxygen pressure (PaO<sub>2</sub>) to reach hyperoxemic levels (&gt;180 mmHg). During anesthetic management of cardiothoracic surgery it is important to keep PaO<sub>2</sub> levels between 80-180 mmHg. The aim of this study was to assess whether adjusting FiO<sub>2</sub> levels in accordance with body temperature and body surface area (BSA) during ECC is an effective method for maintaining normoxemic PaO<sub>2</sub> during cardiac surgery.</span></p><p class="p1"><span class="s1"><strong>Methods:</strong> After approval from the Ethics Committee of the University of Acıbadem, informed consent was given from 60 patients. FiO<sub>2</sub> adjustment strategies applied to the patients in the groups were as follows: FiO<sub>2</sub> levels were set as 0.21 × BSA during hypothermia and 0.21 × BSA + 10 during rewarming in Group I; 0.18 × BSA during hypothermia and 0.18 × BSA + 15 during rewarming in Group II; and 0.18 × BSA during hypothermia and variable with body temperature during rewarming in Group III. Arterial blood gas values and hemodynamic parameters were recorded before ECC (T1); at the 10th minute of cross clamp (T2); when the esophageal temperature (OT) reached 34°C (T3); when OT reached 36°C (T4); and just before the cessation of ECC (T5).</span></p><p class="p1"><span class="s1"><strong>Results:</strong> Mean PaO<sub>2</sub> was significantly higher in Group I than in Group II at T2 and T3 (<em>P</em> = .0001 and <em>P</em> = .0001, respectively); in Group I than in Group III at T1 (<em>P</em> = .02); and in Group II than in Group III at T2, T3, and T4 <br /> (<em>P</em> = .0001 for all). </span></p><p class="p1"><span class="s1"><strong>Conclusion: </strong>Adjustment of FiO<sub>2</sub> according to BSA rather than keeping it at a constant level is more appropriate for keeping PaO<sub>2</sub> between safe level limits. However, since oxygen consumption of cells vary with body temperature, it would be appropriate to set FiO<sub>2</sub> levels in concordance with the body temperature in the <br /> rewarming period.</span></p>


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Kang-Sheng Liu ◽  
Xiao-Dong Mao ◽  
Feng Pan ◽  
Rui Fang An

AbstractRecent years have seen a rising incidence of male infertility, mostly caused by the decline of sperm quality. The ratio of infertile males to infertile females has escalated from 3:7 in 2013 to current 5:5, which turns male infertility into the research focus of reproductive medicine. This study aimed to clarify the effect of reproductive tract infection by ureaplasma urealyticum (UU) and chlamydia trachomatis (CT) on the DNA integrity and routine semen parameters of infertile males. A retrospective study was performed. A total of 259 infertile males who were treated at the Andrological Laboratory Examination and Reproductive Medicine Center in our hospital were analyzed. qRT-PCR was used to examine the infection status of CT and UU. According to the eligibility criteria, we evaluated the semen parameters and biochemical data of 253 men. Based on the results of PCR, the subjects were divided into four groups: Group I (CT positive, 63 cases), Group II (UU positive, 60 cases), Group III (CT positive and UU positive, 62 cases), and Group IV (no infection, 68 cases). DNA fragmentation index (DFI), sperm count, vitality and morphology, elastase level, seminal plasma malondialdehyde (MDA), and total antioxidant capacity (TAC) were assessed. Compared to Group IV, three groups (Group I, Group II and Group III) showed difference in semen volume, proportion of sperm with normal morphology, sperm motility, progressive motility, and vitality (P < 0.05). Compared to Group IV, Group II and Group III showed difference in DFI (P < 0.05). Compared to Group IV, Group II and Group III showed difference in elastase level (P < 0.05). VCL, VSL, VAP, WOB, ROS, TM, HDS showed differences between groups of abnormal/normal WBC (*P < 0.01).UU infection significantly increased the level of seminal leukocytes only in Group II, but not in the other three groups, indicating that UU is a factor to increase the level of seminal leukocytes. Compared with the normal leukocyte group, there were significant differences in total motility, forward motility and normal sperm ratio between the two groups. The proportion of sperm with abnormal morphology (mostly in the head) showed obvious difference between groups of high and normal seminal leukocytic levels. At the same time, in this study, SCGE and SCD verified that leukocytes could damage sperm DNA by increasing ROS, which ultimately affects male fertility.


1982 ◽  
Vol 242 (2) ◽  
pp. F190-F196 ◽  
Author(s):  
R. L. Chevalier

To determine whether reduced renal mass in the newborn results in acceleration of normal renal development, the response to unilateral nephrectomy (N) before 36 h of age was compared with sham-operated (S) guinea pigs during the period of most rapid nephron maturation. Studies were performed at 7-13 days (group I) and 19-25 days (group II). Mean arterial blood pressure (AP), left kidney glomerular filtration rate (LKGFR), and urine sodium excretion (UNaV) were measured. Superficial single nephron GFR (sSNGFR) and proximal fractional water reabsorption (FRH2O) were measured by micropuncture, and the number of glomeruli (NG) was determined by India ink perfusion. In view of the susceptibility of the neonate to extracellular fluid loss, groups I and II were plasma infused to maintain euvolemia and group II was compared with 19- to 25-day-old hydropenic animals (group III). Increase in body weight with age was unaffected by neonatal N. In group IN, the compensatory increase in sSNGFR was greater than SNGFR for deeper nephrons, which normally contribute most to GFR at this age. In group IIN there was an 80% adaptive increase in LKGFR that could not be entirely explained by the rise in SNGFR. Since NG in group IIN was greater than in group IIS and similar to that in adulthood, the enhanced adaptation in LKGFR in group IIN may be due in part to earlier recruitment of a population of underperfused glomeruli. FRH2O did not change significantly with age and did not differ in N and S groups. Animals in group III developed a rise in hematocrit during the experiment, and AP, LKGFR, and UNaV were lower in group IIIN than in group IIN. It is concluded that following N at birth, the sequence of renal functional maturation is accelerated while glomerulotubular balance is preserved. As a result of these adaptative changes, homeostasis is maintained and body growth proceeds without impairment.


1994 ◽  
Vol 267 (5) ◽  
pp. F703-F708 ◽  
Author(s):  
M. Giordano ◽  
P. Castellino ◽  
E. L. McConnell ◽  
R. A. DeFronzo

We evaluated the dose-response relationship between the plasma amino acid (AA) concentration and renal hemodynamics in eight normal subjects. After an overnight fast, a balanced 10% AA solution was infused for 180 min at five separate infusion rates: 0.5 (group I), 1.0 (group II), 2.0 (group III), 4.0 (group IV), and 6.0 (group V) ml.kg-1.min-1 on separate days. Basal plasma AA concentration was 1.87 +/- 0.1 mmol/l and increased to 2.26 +/- 0.1 (group I), 2.66 +/- 0.2 (group II), 3.79 +/- 0.5 (group III), 5.81 +/- 0.4 (group IV), and 7.41 +/- 0.4 mmol/l (group V). Basal glomerular filtration rate (GFR) and renal plasma flow (RPF) averaged 95 +/- 4 and 476 +/- 29 ml.1.73 m-2.min-1, respectively, and rose to 98 +/- 5 and 506 +/- 40 (group I) [P = not significant (NS)], 102 +/- 3 and 533 +/- 30 (group II) (P < 0.05 vs. basal), 110 +/- 4 and 567 +/- 29 (group III), 115 +/- 7 and 610 +/- 55 (group IV), and 117 +/- 7 and 614 +/- 66 ml.1.73 m-2.min-1 (group V) (P = NS vs. group IV). Basal plasma glucagon concentration averaged 68 +/- 10 pg/ml and increased to 74 +/- 10 (group I), 83 +/- 11 (group II) (P < 0.05 vs. basal), 100 +/- 14 (group III), 121 +/- 14 (group IV), and 229 +/- 35 pg/ml (group V) (P < 0.01 vs. basal). Increases in plasma growth hormone (GH) and insulin levels were observed only during groups IV and V.(ABSTRACT TRUNCATED AT 250 WORDS)


2013 ◽  
Vol 5 (2) ◽  
pp. 101 ◽  
Author(s):  
Ritawaty Ritawaty ◽  
Indriyanti Rafi Sukmawati ◽  
Ilhamjaya Patellongi ◽  
Ferry Sandra

BACKGROUND: Gamma glutamyltransferase (GGT) was reported recently to be associated with inflammation, oxidative stress and increased amino acid. However, role of GGT in insulin resistance pathomechanism is not exactly known. Therefore correlation of GGT with inflammation, oxidative stress and elevated amino acid, in men with central obesity need to be confirmed.METHODS: A cross-sectional study was designed. Men with central obesity were recruited and selected. Anthropometric parameters, creatinine, hs-CRP, fasting glucose, fasting insulin, glutathione peroxidase (GPx) activity, GGT, plasma total cysteine (tCys) and fatty liver were measured. Subjects were then divided in 4 groups based on waist circumference (WC) and fatty liver: Group I: WC ≤100 cm, without fatty liver; Group II: WC ≤100 cm, with fatty liver; Group III: WC >100 cm, without fatty liver; Group IV: WC >100 cm, with fatty liver. All biochemical characteristics in each group were then statistically analyzed.RESULTS: Seventy-two men with central obesity were selected. Numbers of subjects in each group were: Group I: n=33; Group II: n=5; Group III: n=17; Group IV: n=17. We found significant difference of HOMA-IR between Group I and IV, significant correlation between GGT and HOMAIR, and significant negative correlation between tCys with HOMA-IR in Group IV.CONCLUSION: GGT was significantly correlated with HOMA-IR in men with WC >100 cm and fatty liver. Further investigation with more subjects is necessary to determine clear GGT cut-off to distinguish subjects with fatty liver and insulin resistance.KEYWORDS: GGT, hs-CRP, GPx, tCys, HOMA-IR, insulin resistance


2009 ◽  
Vol 56 (1) ◽  
pp. 35-40 ◽  
Author(s):  
A. Mikic ◽  
I. Pendjer ◽  
Z. Dudvarski ◽  
A. Trivic ◽  
M. Kreacic

Introduction: treatment of locoregional advanced hypopharyngeal cancers of grades III and IV would be surgery and/or radiotherapy. An increasing number of authors has emphasized favorable effects of neoadjuvant chemotherapy and radiotherapy with potentiation. The aim: the authors presented therapeutical results of three-year survived patients with squamocellular cancers of the hypopharynx (SCC Hy), grades III and IV, in relation to specific modalities of therapeutical approach. Methods: a series of 207 patients with grades III and IV of SCC Hy, treated in the period 1982 to 2002, was analyzed. Group I consisted of 131 patients who had surgery and postoperative radiotherapy (SUR-RT). Group II included 16 patients who underwent induction chemotherapy, surgery and postoperative radiotherapy (IC-SURRT). Group III consisted of 60 patients, who had primary radiotherapy (RT). Group IV involved 29 patients who were treated, in the period 2003-2006, by neoadjuvant chemotherapy followed by radiotherapy with potentiation (CHT-RT). Results: three-year survival in Group I was 67.94%, Group II - 50%, Group III - 30%, and in Group IV was 51.72%. Five-year survival was analyzed only in group IIII. The longest survival was observed in Group I - 33.59%. Conclusion: the best therapeutical results were achieved in patient group that was primarily operated on and then had postoperative radiotherapy, while the worst survival was recorded in patients who had primary radiotherapy.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Shaminur Rahman ◽  
M. Nazmul Hoque ◽  
Joynob Akter Puspo ◽  
M. Rafiul Islam ◽  
Niloy Das ◽  
...  

AbstractThe microbiome of the anaerobic digester (AD) regulates the level of energy production. To assess the microbiome diversity and composition in different stages of anaerobic digestion, we collected 16 samples from the AD of cow dung (CD) origin. The samples were categorized into four groups (Group-I, Group-II, Group-III and Group-IV) based on the level of energy production (CH4%), and sequenced through whole metagenome sequencing (WMS). Group-I (n = 2) belonged to initial time of energy production whereas Group-II (n = 5), Group-III (n = 5), and Group-IV (n = 4) had 21–34%, 47–58% and 71–74% of CH4, respectively. The physicochemical analysis revealed that level of energy production (CH4%) had significant positive correlation with digester pH (r = 0.92, p < 0.001), O2 level (%) (r = 0.54, p < 0.05), and environmental temperature (°C) (r = 0.57, p < 0.05). The WMS data mapped to 2800 distinct bacterial, archaeal and viral genomes through PathoScope (PS) and MG-RAST (MR) analyses. We detected 768, 1421, 1819 and 1774 bacterial strains in Group-I, Group-II, Group-III and Group-IV, respectively through PS analysis which were represented by Firmicutes, Bacteroidetes, Proteobacteria, Actinobacteria, Spirochaetes and Fibrobacteres phyla (> 93.0% of the total abundances). Simultaneously, 343 archaeal strains were detected, of which 95.90% strains shared across four metagenomes. We identified 43 dominant species including 31 bacterial and 12 archaeal species in AD microbiomes, of which only archaea showed positive correlation with digester pH, CH4 concentration, pressure and temperature (Spearman correlation; r > 0.6, p < 0.01). The indicator species analysis showed that the species Methanosarcina vacuolate, Dehalococcoides mccartyi, Methanosarcina sp. Kolksee and Methanosarcina barkeri were highly specific for energy production. The correlation network analysis showed that different strains of Euryarcheota and Firmicutes phyla exhibited significant correlation (p = 0.021, Kruskal–Wallis test; with a cutoff of 1.0) with the highest level (74.1%) of energy production (Group-IV). In addition, top CH4 producing microbiomes showed increased genomic functional activities related to one carbon and biotin metabolism, oxidative stress, proteolytic pathways, membrane-type-1-matrix-metalloproteinase (MT1-MMP) pericellular network, acetyl-CoA production, motility and chemotaxis. Importantly, the physicochemical properties of the AD including pH, CH4 concentration (%), pressure, temperature and environmental temperature were found to be positively correlated with these genomic functional potentials and distribution of ARGs and metal resistance pathways (Spearman correlation; r > 0.5, p < 0.01). This study reveals distinct changes in composition and diversity of the AD microbiomes including different indicator species, and their genomic features that are highly specific for energy production.


2020 ◽  
Vol 5 (1) ◽  
pp. 153-155
Author(s):  
Sanjay Melville Masih ◽  
Rakesh Kumar Gupta

Background: The present study was conducted to assess the outcome of intrathecal analgesia in multiparous women undergoing vaginal delivery. Subjects and Methods: The present study was conducted among 80 multiparous women ages ranged 18- 40 years. All patients received 0.5 ml of intrathecal injection of 2.5 mg bupivacaine 0.5% and 1 ml dexamethasone 4 mg plus a 0.5 ml adjuvant. The adjuvants in group I patients were 100 μg morphine, 25 μg fentanyl in group II, 5 μg dexmedetomidine in group III and normal saline in group IV (control group). The primary and secondary outcome was the duration of pain relief, the analgesia onset time, the maximum level of sensory block, the visual analogue scale (VAS) was recorded. Results: The mean duration of analgesia in group I was 182.4 minutes, in group II was 170.5 minutes, in group III was 200.4 minutes and in group, IV was 140.2 minutes. The onset of analgesia was 3.9 minutes, 2.8 minutes, 2.7 minutes and 4.5 minutes in group I, II, III and IV respectively. S1 sensory regression time (minutes) was 181.4, 157.4, 185.3 and 130.6 in group I, II, III and IV respectively. Modified Bromage scale 5 minutes, 15 minutes and 30 minutes after IT in all groups was 0.0. VAS was 1.3, 1.6, 1.6 and 3.1 with significant differences in all groups (P< 0.05). There was non- significant difference in mean age, weight, height and gestational age between all groups (P> 0.05). There was a non- significant difference in APGAR 1, 5, umbilical pH immediately after delivery, neonatal HR after 5minute, 15 minutes and 30 minutes in all groups (P> 0.05). Conclusion: The authors found that dexmedetomidine is a safe and effective adjuvant to intrathecal bupivacaine-dexamethasone in multiparous women undergoing normal vaginal delivery.


Sign in / Sign up

Export Citation Format

Share Document