Oxygen Consumption of the Auricles, Right and Left Ventricles of the Normal, Hypothyroid and Hyperthyroid Rat Heart

1957 ◽  
Vol 188 (3) ◽  
pp. 514-518 ◽  
Author(s):  
Kong-oo Goh ◽  
R. Duncan Dallam

A study of the oxygen consumption of the atrium, right and left ventricles from rat heart has been reported. The response of these heart regions to the in vitro and in vivo addition of thyroxine has been reported. Results obtained were: a) The oxygen consumption of the left ventricle from normal animals was found to be about 25% greater than that of the right ventricle and atrium. b) In animals whose thyroid activity was depressed the oxygen consumption of the atrium and the right and left ventricles was proportionately decreased about 25%. c) Animals whose thyroid activity was increased were found to have an increased oxygen consumption in all areas of the heart, however, not proportionately. d) The in vitro addition of thyroxine to the three heart areas from animals with decreased thyroid activity and normal animals caused an increase in oxygen consumption, whereas it did not appreciably affect the oxygen consumption of the heart areas from animals with increased thyroid activity.

2006 ◽  
Vol 397 (3) ◽  
pp. 427-436 ◽  
Author(s):  
Neslihan Toyran ◽  
Peter Lasch ◽  
Dieter Naumann ◽  
Belma Turan ◽  
Feride Severcan

Diabetes mellitus is associated with a high incidence and poor prognosis of cardiovascular disease. The aim of the present study was to examine the effect of relatively short-term (5 weeks) Type I diabetes on the left ventricle, the right ventricle and the vessel (vein) on the left ventricle of the myocardium at molecular level by FTIR (Fourier-transform infrared) microspectroscopy. The rats were categorized into two groups: control group (for the left ventricle myocardium, n=8; for the right ventricle myocardium, n=9; for the vein, n=9) and streptozotocin-induced diabetic group (for the left ventricle myocardium, n=7; for the right ventricle myocardium, n=9; for the vein, n=8). Two adjacent cross-sections of 9 μm thickness were taken from the ventricles of the hearts in two groups of rats by using a cryotome. The first sections were used for FTIR microspectroscopy measurements. The second serial sections were stained by haematoxylin/eosin for comparative purposes. Diabetes caused an increase in the content of lipids, an alteration in protein profile with a decrease in α-helix and an increase in β-sheet structure as well as an increase in glycogen and glycolipid contents in both ventricles and the vein. Additionally, the collagen content was found to be increased in the vein of the diabetic group. The present study demonstrated that diabetes-induced alterations in the rat heart can be detected by correlating the IR spectral changes with biochemical profiles in detail. The present study for the first time demonstrated the diabetes-induced alterations at molecular level in both ventricle myocardia and the veins in relatively short-term diabetes.


2021 ◽  
Vol 28 (1) ◽  
pp. 47-54
Author(s):  
Н. I. Condori Leandro ◽  
A. D. Vakhrushev ◽  
L. E. Korobchenko ◽  
E. G. Koshevaya ◽  
L. B. Mitrofanova ◽  
...  

Aim. To study and compare the lesions characteristics of laser energy in heart ex vivo and in experimental large animals.Materials and methods. For the ex vivo experiment a pig heart was obtained from a local slaughterhouse. Laser applications were applied using power 15-30 W in the left and right ventricles 5-50 seconds in duration. Immediately after ablation, examination was performed to determine myocardial damage characteristics at each point. In the experimental study, 7 sheep were included, laser applications were performed under fluoroscopic control in the right atrium with power 10, 15 and 20 W, 10-25 s; in the right ventricle 20, 25 and 30 W for 10-40 s; and in the left ventricle 20, 25 and 30 W for 20-40 s. The animals were euthanized and macroscopic examination of laser lesions was performed.Results. A total of 27 laser applications were performed on the heart ex vivo, all lesions were visualized as white spots on the endocardial surface. The maximum lesion depth was 9 mm achieved when using 20 W /50 s, the maximum lesion diameter was 6 mm, when using 25 W /40 s. The minimum lesion diameter and depth were observed when using 30 W /5 s, 2x1 mm. A total of 48 laser applications were performed in experimental animals, in one experimental animal was observed a transmural lesion in the right atrium when using 15 W /20 s. In 3 out of 7 experimental animals, transmural lesions were observed in the right ventricle when using 20 W /30 s; 20 W /40 s and 30 W /10 s. In the left ventricle, transmural lesions were observed in 2 animals, using 15 W /20 s and 20 W /40 s. In the ex vivo study, there was a strong positive correlation between ablation energy and lesion depth (R=0.91, P<0.05) and lesion volume (R=0.73, P<0.05); while there was no such statistical correlation in vivo.Conclusions. Laser ablation 15-20 W for 15-40 s seems to be optimal for achieving the deepest lesions in the atrium and ventricular myocardium. In our small pilot study with fiberoptic catheter ablation on a beating heart there was no correlation between energy delivered and the depth and volume of necrotic myocardium.


1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.


1997 ◽  
Vol 77 (02) ◽  
pp. 376-382 ◽  
Author(s):  
Bruce Lages ◽  
Harvey J Weiss

SummaryThe possible involvement of secreted platelet substances in agonist- induced [Ca2+]i increases was investigated by comparing these increases in aspirin-treated, fura-2-loaded normal platelets and platelets from patients with storage pool deficiencies (SPD). In the presence and absence of extracellular calcium, the [Ca2+]i response induced by 10 µM ADP, but not those induced by 0.1 unit/ml thrombin, 3.3 µM U46619, or 20 µM serotonin, was significantly greater in SPD platelets than in normal platelets, and was increased to the greatest extent in SPD patients with Hermansky-Pudlak syndrome (HPS), in whom the dense granule deficiencies are the most severe. Pre-incubation of SPD-HPS and normal platelets with 0.005-5 µM ADP produced a dose-dependent inhibition of the [Ca2+]i response induced by 10 µ M ADP, but did not alter the [Ca2+]i increases induced by thrombin or U46619. Within a limited range of ADP concentrations, the dose-inhibition curve of the [Ca2+]i response to 10 µM ADP was significantly shifted to the right in SPD-HPS platelets, indicating that pre-incubation with greater amounts of ADP were required to achieve the same extent of inhibition as in normal platelets. These results are consistent with a hypothesis that the smaller ADP-induced [Ca2+]i increases seen in normal platelets may result from prior interactions of dense granule ADP, released via leakage or low levels of activation, with membrane ADP receptors, causing receptor desensitization. Addition of apyrase to platelet-rich plasma prior to fura-2 loading increased the ADP-induced [Ca2+]i response in both normal and SPD-HPS platelets, suggesting that some release of ADP derived from both dense granule and non-granular sources occurs during in vitro fura-2 loading and platelet washing procedures. However, this [Ca2+]i response was also greater in SPD-HPS platelets when blood was collected with minimal manipulation directly into anticoagulant containing apyrase, raising the possibility that release of dense granule ADP resulting in receptor desensitization may also occur in vivo. Thus, in addition to enhancing platelet activation, dense granule ADP could also act to limit the ADP-mediated reactivity of platelets exposed in vivo to low levels of stimulation.


2021 ◽  
Vol 9 (5) ◽  
pp. 1107
Author(s):  
Wonho Choi ◽  
Yoshihiro Yamaguchi ◽  
Ji-Young Park ◽  
Sang-Hyun Park ◽  
Hyeok-Won Lee ◽  
...  

Agrobacterium tumefaciens is a pathogen of various plants which transfers its own DNA (T-DNA) to the host plants. It is used for producing genetically modified plants with this ability. To control T-DNA transfer to the right place, toxin-antitoxin (TA) systems of A. tumefaciens were used to control the target site of transfer without any unintentional targeting. Here, we describe a toxin-antitoxin system, Atu0939 (mazE-at) and Atu0940 (mazF-at), in the chromosome of Agrobacterium tumefaciens. The toxin in the TA system has 33.3% identity and 45.5% similarity with MazF in Escherichia coli. The expression of MazF-at caused cell growth inhibition, while cells with MazF-at co-expressed with MazE-at grew normally. In vivo and in vitro assays revealed that MazF-at inhibited protein synthesis by decreasing the cellular mRNA stability. Moreover, the catalytic residue of MazF-at was determined to be the 24th glutamic acid using site-directed mutagenesis. From the results, we concluded that MazF-at is a type II toxin-antitoxin system and a ribosome-independent endoribonuclease. Here, we characterized a TA system in A. tumefaciens whose understanding might help to find its physiological function and to develop further applications.


2021 ◽  
Vol 22 (16) ◽  
pp. 8367
Author(s):  
Hien Lau ◽  
Shiri Li ◽  
Nicole Corrales ◽  
Samuel Rodriguez ◽  
Mohammadreza Mohammadi ◽  
...  

Pre-weaned porcine islets (PPIs) represent an unlimited source for islet transplantation but are functionally immature. We previously showed that necrostatin-1 (Nec-1) immediately after islet isolation enhanced the in vitro development of PPIs. Here, we examined the impact of Nec-1 on the in vivo function of PPIs after transplantation in diabetic mice. PPIs were isolated from pancreata of 8–15-day-old, pre-weaned pigs and cultured in media alone, or supplemented with Nec-1 (100 µM) on day 0 or on day 3 of culture (n = 5 for each group). On day 7, islet recovery, viability, oxygen consumption rate, insulin content, cellular composition, insulin secretion capacity, and transplant outcomes were evaluated. While islet viability and oxygen consumption rate remained high throughout 7-day tissue culture, Nec-1 supplementation on day 3 significantly improved islet recovery, insulin content, endocrine composition, GLUT2 expression, differentiation potential, proliferation capacity of endocrine cells, and insulin secretion. Adding Nec-1 on day 3 of tissue culture enhanced the islet recovery, proportion of delta cells, beta-cell differentiation and proliferation, and stimulation index. In vivo, this leads to shorter times to normoglycemia, better glycemic control, and higher circulating insulin. Our findings identify the novel time-dependent effects of Nec-1 supplementation on porcine islet quantity and quality prior to transplantation.


1994 ◽  
Vol 239 (2) ◽  
pp. 216-223 ◽  
Author(s):  
Arnold C. G. Wenink ◽  
Bert J. Wisse ◽  
Pieter M. Groenendijk

EP Europace ◽  
2017 ◽  
Vol 19 (suppl_3) ◽  
pp. iii339-iii339
Author(s):  
U. Gulan ◽  
AM. Saguner ◽  
D. Akdis ◽  
C. Brunckhorst ◽  
M. Holzner ◽  
...  

2015 ◽  
Vol 10 (3) ◽  
pp. 548 ◽  
Author(s):  
Musaddique Hussain ◽  
Shahid Masood Raza ◽  
Khalid Hussain Janbaz

<p class="Abstract"><em>In vitro</em> and<em> in vivo</em> studies were undertaken to evaluate the pharmacologically mechanistic background to validate the traditional uses of <em>Rumex acetosa</em> in the treatment of emesis and gastrointestinal motility disorders such as constipation and diarrhea. In rabbit jejunum preparation, methanolic extract of <em>R. acetosa</em> (0.01-1.0 mg/mL) caused a transient spasmogenic effect, followed by the spasmolytic effect (3-10 mg/mL). In presence of atropine, spasmogenic effect was blocked while spasmolytic effect was emerged, suggesting that spasmogenic effect was mediated through activation of muscarinic receptors. Extract inhibited the K<sup>+ </sup>(80 mM)-induced contraction, suggesting Ca<sup>2+</sup>-cha-nnel blockade, which was further confirmed when pretreatment of tissue with extract shifted the Ca<sup>2+ </sup>concentration-response curves to the right, similarly as verapamil.<em> R. acetosa</em> also exhibited the significant antiemetic activity (p&lt;0.05) against different emetogenic stimuli, when compared with chlorpromazine. This study confirms the presence of gut modulator (spasmogenic and spasmolytic) and antiemetic activates, validating its traditional uses.</p><p> </p>


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