Altered pressure-volume relation of right atrium and venoatrial junction in diabetic rats

1992 ◽  
Vol 263 (4) ◽  
pp. H1017-H1020
Author(s):  
M. B. Patel ◽  
P. L. Zhang ◽  
A. C. Patel ◽  
K. P. Patel
Keyword(s):  
Right Atrium ◽  
Insulin Treatment ◽  
Isotonic Saline ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Volume Loading ◽  
Additional Group ◽  
The Mean ◽  
Volume Relation ◽  
The Right

Previous studies have indicated a blunted volume reflex in diabetic rats. This alteration of the volume reflex may be due to differences in distensibility of the right atrium and venoatrial junction, which contain a large number of volume receptors. This study was designed to determine whether the distensibility of the right atrium and venoatrial junction is altered in the diabetic rat. The distensibility was assessed by measuring the stiffness constants [slope of pressure-volume (P-V) curve] of the right atrium and venoatrial junction in 2-wk streptozotocin-induced diabetic rats. The P-V data of the right atrium and venoatrial junction were measured in control and diabetic rats over a range of 0-10 mmHg by infusion of isotonic saline in KCl-arrested, in situ hearts. Similar P-V data also were determined in an additional group of diabetic rats under daily insulin treatment, which normalized plasma glucose. The mean slope of the P-V curve of the right atrium and venoatrial junction in the diabetic rats was significantly greater than the mean slope of the control and insulin-treated diabetic rats. The results indicate that diabetic rats have stiffer right atria and venoatrial junctions, which may reduce stimulation of the volume receptors to acute volume loading. In addition, the increased stiffness in the diabetic rats was prevented by chronic insulin treatment. An altered afferent limb of the volume reflex in diabetic rats contributing to blunted diuretic and natriuretic responses to volume loading may be due to these documented changes in the distensibility of the right atrium and venoatrial junction.

scholarly journals Oxidative Stress in Rats After 60 Days of Hypergalactosemia or Hyperglycemia

2003 ◽  
Vol 22 (6) ◽  
pp. 423-427 ◽  
Author(s):  
Mary Otsyula ◽  
Matthew S. King ◽  
Tonya G. Ketcham ◽  
Ruth A. Sanders ◽  
John B. Watkins
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Superoxide Dismutase ◽  
Glutathione Peroxidase ◽  
Insulin Treatment ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Glutathione Disulfide ◽  
Hepatic Lipid Peroxidation ◽  
Streptozotocin Diabetic Rats

Two of the models used in current diabetes research include the hypergalactosemic rat and the hyperglucosemic, streptozotocin-induced diabetic rat. Few studies, however, have examined the concurrence of these two models regarding the effects of elevated hexoses on biomarkers of oxidative stress. This study compared the activities of superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase and the concentrations of glutathione, glutathione disulfide, and thiobarbituric acid reactants (as a measure of lipid peroxidation) in liver, kidney, and heart of Sprague-Dawley rats after 60 days of either a 50% galactose diet or insulin deficiency caused by streptozotocin injection. Most rats from both models developed bilateral cataracts. Blood glucose and glycosy-lated hemoglobin A1c concentrations were elevated in streptozotocin diabetic rats. Streptozotocin diabetic rats exhibited elevated activities of renal superoxide dismutase, cardiac catalase, and renal and cardiac glutathione peroxidase, as well as elevated hepatic lipid peroxidation. Insulin treatment of streptozotocin-induced diabetic rats normalized altered markers. In galactosemic rats, hepatic lipid peroxidation was increased whereas glutathione reductase activity was diminished. Glutathione levels in liver were decreased in diabetic rats but elevated in the galactosemic rats, whereas hepatic glutathione disulfide concentrations were decreased much more in diabetes than in galactosemia. Insulin treatment reversed/prevented all changes caused by streptozotocin-induced diabetes. Lack of concomitance in these data indicate that the 60-day galactose-fed rat is not experiencing the same oxidative stress as the streptozotocin diabetic rat, and that investigators must be cautious drawing conclusions regarding the concurrence of the effects of the two animal models on oxidative stress biomarkers.

Acute insulin withdrawal contributes to ischemic heart failure in spontaneously diabetic BB Wistar rats

1990 ◽  
Vol 68 (3) ◽  
pp. 462-466 ◽  
Author(s):  
Gary D. Lopaschuk ◽  
Marguerite A. Spafford
Keyword(s):  
Fatty Acids ◽  
Metabolic Control ◽  
Wistar Rats ◽  
Insulin Treatment ◽  
Serum Glucose ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Metabolic Demand ◽  
Significant Deterioration ◽  
Direct Demonstration

The contribution of poor metabolic control to myocardial ischemic failure was determined in isolated working hearts from insulin-dependent BB Wistar rats. Removal of insulin treatment 24 h prior to study (uncontrolled diabetic rats) resulted in significant increases in serum glucose, serum fatty acids, and myocardial triglyceride, compared with animals in which insulin treatment was not withheld (insulin-treated diabetic rats). Isolated working hearts obtained from these two groups were subjected to a 40% reduction in coronary flow in the presence of a maintained metabolic demand (hearts were paced at 200 beats/min and perfused at an 80 mmHg (1 mmHg = 133.3 Pa) left aortic afterload, 11.5 mmHg left atrial preload). Within 15 min of ischemia, a significant deterioration of mechanical function occurred in the uncontrolled diabetic rats, whereas function was maintained in the insulin-treated diabetic rats. Oxygen consumption by the two groups of hearts was similar prior to the onset of ischemia and decreased during ischemia in parallel with the work performed by the hearts. This suggests that the accelerated failure rate in uncontrolled diabetic rat hearts is unlikely a result of an increased oxygen requirement. These data are a direct demonstration that acute changes in metabolic control of the diabetic can contribute to the severity of myocardial ischemic injury.Key words: diabetes, heart, ischemia, fatty acids.

scholarly journals Measurement of Right Atrial Volume and Diameters in Healthy Nepalese with Normal Echocardiogram

2015 ◽  
Vol 12 (2) ◽  
pp. 110-112
Author(s):  
DB Karki ◽  
S Pant ◽  
SK Yadava ◽  
A Vaidya ◽  
DK Neupane ◽  
...  
Keyword(s):  
Right Atrium ◽  
Right Atrial ◽  
Short Axis ◽  
Atrial Volume ◽  
Western Population ◽  
The Mean ◽  
The Right ◽  
Right Atrial Volume ◽  
Echocardiographic Findings ◽  
Volume Size

Background The size of right atrium is expected to be different in diverse healthy ethnic groups. It is important to know the normal size of right atrium in our healthy population.Objective The study aimed to find out the normal values of right atrial volume, right atrial short axis diameter and right atrial long axis diameter in healthy Nepalese population with normal echocardiographic findings. It also looked at correlations between right atrial dimensions and the right atrial volume.Method Verbal consent was taken from all the participants. One hundred participants between the age of 18 and 60 years with normal echocardiographic findings and without any chronic disease were included in this study. Right atrial volume was measured by using area length method. Right atrial short axis diameter and Right atrial long axis diameter were measured in the four chamber view.Result The mean right atrial volume was 23.64±5.36 ml (range 11.30 - 40.00 ml).The range of right atrial short axis diameter and right atrial long axis diameter were 1.34-3.80 cm and 2.4-4.7 cm respectively.Conclusion The size of right atrium in the Nepalese population is smaller compared to western population. Male right atrial volume size is greater than female in Nepalese population similar to western population. The findings of normal value of right atrial volume and right atrial diameter in Nepalese population will help the physician to assess patients with various conditions affecting the right atrium.Kathmandu University Medical Journal Vol.12(2) 2014: 110-112

Insulin reversal of biochemical changes in hearts from diabetic rats

1986 ◽  
Vol 251 (3) ◽  
pp. H670-H675
Author(s):  
S. Bhimji ◽  
D. V. Godin ◽  
J. H. McNeill
Keyword(s):  
Insulin Treatment ◽  
Serum Insulin ◽  
Complete Recovery ◽  
Magnesium Content ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Biochemical Changes ◽  
Diabetic Rat ◽  
Lysosomal Hydrolase ◽  
Rat Hearts

Reversal of myocardial biochemical changes with insulin treatment (4 and 8 wk) was studied in 8 and 12 wk streptozotocin (STZ)-diabetic rats. STZ-induced diabetes was characterized by elevations in blood glucose, serum cholesterol, and triglycerides and depressed serum insulin levels. Insulin treatment for 4 and 8 wk completely restored the serum alterations to control values. The polyuria, polydipsia, and polyphagia were also markedly diminished by the insulin treatment. Diabetic rats had pronounced decreases in body, heart, and left ventricular weights, all of which were completely reversed by the insulin treatment. Hydroxyproline accumulation in diabetic rat hearts was only reversed by the 8-wk and not by the 4-wk insulin treatment. STZ produced a significant depletion of left ventricular magnesium content as well as depression of K+-stimulated sarcoplasmic reticulum and myofibrillar ATPase activities. Both the 4- and 8-wk insulin treatment produced a complete recovery of the myocardial magnesium content. No significant changes in sarcolemmal Na+-K+-ATPase and K+-stimulated p-nitrophenyl phosphatase activities were observed in diabetic animals compared with control. The decreased latency of the lysosomal hydrolase, N-acetyl-beta-glucosaminidase, and the increased collagen deposition observed in the diabetic hearts were only partially reversed by the 4-wk insulin treatment, but completely reversed by the 8-wk treatment period.

Reduced activity of mtTFA decreases the transcription in mitochondria isolated from diabetic rat heart

2002 ◽  
Vol 282 (4) ◽  
pp. E778-E785 ◽  
Author(s):  
Akio Kanazawa ◽  
Yoshihiko Nishio ◽  
Atsunori Kashiwagi ◽  
Hidetoshi Inagaki ◽  
Ryuichi Kikkawa ◽  
...  
Keyword(s):  
Insulin Treatment ◽  
Mitochondrial Protein ◽  
Mitochondrial Respiratory Chain ◽  
Binding Activity ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Mitochondrial Transcription Factor ◽  
Loop Region ◽  
Rat Hearts ◽  
D Loop

To evaluate abnormalities in the mitochondrial transcription factor A (mtTFA) function as a cause of mitochondrial dysfunction in diabetes, we measured the mRNA contents of the proteins consisting of the mitochondrial respiratory chain as well as transcriptional and translational activities in the mitochondria isolated from controls and streptozotocin-induced diabetic rat hearts. Using Northern blot analysis, we found 40% reduced mRNA contents of mitochondrial-encoded cytochrome b and ATP synthase subunit 6 in diabetic rat hearts compared with control rats ( P< 0.05). These abnormalities were completely recovered by insulin treatment. Furthermore, the mitochondrial activities of transcription and translation were decreased significantly in mitochondria isolated from diabetic rats by 60% ( P < 0.01) and 71% ( P < 0.01), respectively, compared with control rats. The insulin treatment also completely normalized these abnormalities in diabetic rats. Consistently, gel retardation assay showed a reduced binding of mtTFA to the D-loop of mitochondrial DNA in diabetic rats, although there was no difference in the mtTFA mRNA and protein content between the two groups. On the basis of these findings, a reduced binding activity of mtTFA to the D-loop region in the hearts of diabetic rats may contribute to the decreased mitochondrial protein synthesis.

Accuracy of Central Venous Pressure Measuremet From the Abdominal Inferior Vena Cava

PEDIATRICS ◽  
1992 ◽  
Vol 89 (3) ◽  
pp. 506-508
Author(s):  
THOMAS R. LLOYD ◽  
RICHARD L. DONNERSTEIN ◽  
ROBERT A. BERG
Keyword(s):  
Inferior Vena Cava ◽  
Central Venous Pressure ◽  
Right Atrium ◽  
Inferior Vena ◽  
Venous Pressure ◽  
Vena Cava ◽  
Pressure Measurements ◽  
Central Venous ◽  
The Mean ◽  
The Right

Central venous pressure measurements in the abdominal inferior vena cava were compared with measurements in the right atrium in 10 infants and 10 children during cardiac catheterization. At end expiration, the mean pressures at these two sites were within 1 mm Hg of each other in all 20 patients, with a mean difference of 0.0 ± 0.36 mm Hg. The abdominal inferior vena cava is a safe and convenient site for measurement of central venous pressure, and our study confirms that such measurements are accurate.

Quantification of effect of pericardium on LV diastolic PV relation in dogs

1987 ◽  
Vol 252 (5) ◽  
pp. H963-H968 ◽  
Author(s):  
M. Junemann ◽  
O. A. Smiseth ◽  
H. Refsum ◽  
R. Sievers ◽  
M. J. Lipton ◽  
...  
Keyword(s):  
Pericardial Effusion ◽  
Right Ventricle ◽  
Diastolic Pressure ◽  
Left Ventricular ◽  
Volume Loading ◽  
Upward Shift ◽  
Volume Curve ◽  
Pericardial Pressure ◽  
Volume Relation ◽  
The Right

The aim of the present study was to quantify the effect of the pericardium on the left ventricular (LV) diastolic pressure-volume relation. The experiments were done in 10 anesthetized closed-chest dogs. Pericardial and cardiac volumes were determined by computed tomography. Pericardial effusion (n = 5) and volume loading (6% dextran iv; n = 5) were used to increase pericardial volume. Volumes were normalized as multiples of the LV volume measured when LV transmural pressure was 6 mmHg (VLV6). Using the data from the pericardial effusion experiments, we calculated the best-fit exponential equations for the pericardial pressure-volume relations. From these equations we calculated that the changes in pericardial volume necessary to shift the LV diastolic pressure-volume curve upward by 2, 5, 10, and 20 mmHg were 0.6 +/- 0.1, 1.1 +/- 0.2, 1.6 +/- 0.2, and 2.2 +/- 0.3 times VLV6, respectively. Using the data from the volume loading experiments, we also calculated the degree of upward shift of the LV pressure-volume relation caused by volume loading, which increased LV mean diastolic pressure by 12 mmHg. (The upward shift is that increment in pericardial pressure caused by the total increase in volume of the extra-LV contents of the pericardium, i.e., the atria, the right ventricle, and any pericardial effusion.) This volume loading increased the total volume of the right ventricle and the atria by 1.0 +/- 0.1 VLV6, which, in itself, increased pericardial pressure by 3.6 +/- 0.8 mmHg. We conclude that in situations in which heart or pericardial volume increases acutely, the pericardium shifts the diastolic pressure-volume relation of the LV upward by a significant amount.

Osmolal effects on vasopressin secretion in the streptozotocin-diabetic rat

1982 ◽  
Vol 242 (6) ◽  
pp. E411-E417 ◽  
Author(s):  
C. M. Van Itallie ◽  
J. D. Fernstrom
Keyword(s):  
Hypertonic Saline ◽  
Water Injection ◽  
Isotonic Saline ◽  
Passive Immunization ◽  
Urine Osmolality ◽  
Serum Levels ◽  
Diabetic Rats ◽  
Serum Osmolality ◽  
Diabetic Rat ◽  
Steady State Levels

To determine the relationships between serum levels of arginine vasopressin (AVP) and serum osmolality and sodium in diabetic rats, we measured these variables in streptozotocin-diabetic and normal animals treated with water, isotonic saline, or hypertonic saline. Serum osmolality was higher and sodium lower in untreated diabetics than in controls; these variables increased in both groups after hypertonic saline. Serum AVP levels (measured by radioimmunoassay in Amberlite-extracted serum) were 2.3 +/- 0.5 and 9.8 +/- 1.7 pg/ml in control and diabetic rats, respectively, injected with isotonic saline. AFter injection of hypertonic saline, serum AVP levels rose to 14.5 +/- 2.3 pg/ml in controls and 18.7 +/- 1.7 pg/ml in diabetics. Water injection decreased serum AVP in diabetics (as in normals), but only to 5.8 +/- 1.0 pg/ml. To assess indirectly whether the chronically high levels of AVP in serum had an impact on kidney function, diabetic rats were studied after passive immunization with an anti-AVP serum. This treatment increased urine flow and decreased urine osmolality in dehydrated diabetic rats. Taken together, these data affirm in diabetic rats, as in humans, the occurrence of 1) elevated steady-state levels of AVP in serum; 2) abnormal sensitivity of AVP secretion to changes in serum sodium and osmolality; and 3) an apparently intact end-organ responsiveness to AVP.

Prevention and reversal of altered myocardial function in diabetic rats by insulin treatment

1983 ◽  
Vol 61 (5) ◽  
pp. 516-523 ◽  
Author(s):  
Arun G. Tahiliani ◽  
Rao V. S. V. Vadlamudi ◽  
John H. McNeill
Keyword(s):  
Insulin Treatment ◽  
Myocardial Function ◽  
Diabetic Rats ◽  
Left Ventricular ◽  
Diabetic Rat ◽  
Myocardial Performance ◽  
Perfused Heart ◽  
Rat Hearts ◽  
Heart Preparation ◽  
Developed Pressure

Isolated perfused hearts from diabetic rats exhibit a decreased responsiveness to increasing work loads. However, the precise time point at which functional alterations occur is not clearly established. Previous observations in our laboratory have suggested that the alterations in myocardial function are not apparent at 30 days whereas they are clearly seen 100 days after streptozotocin-induced diabetes. We studied the cardiac function of 6-week diabetic rats using the isolated perfused heart preparation. The 6-week time period was found to be sufficient to cause depression of myocardial function in these animals. We also studied the effect of insulin treatment on myocardial performance of diabetic rats. Insulin treatment was initiated 3 days and 6 weeks after injection of streptozotocin (STZ). The treatment was continued for 6 and 4 weeks in the respective groups. Hearts from 6-week diabetic animals exhibited a depressed left ventricular developed pressure (LVDP) and positive and negative dP/dt at higher filling pressures when compared with 6-week control animals. However, the depression was not seen in the 6-week insulin-treated diabetic animals. Ten-week diabetic rat hearts also showed a depression of LVDP and positive and negative dP/dt when compared with 10-week controls. The group of animals that had been diabetic for 6 weeks and then treated for 4 weeks with insulin exhibited a reversal of the depressed myocardial function. These results demonstrate that depression of myocardial performance, which is evident 6 weeks after diabetes is induced, can be prevented if insulin treatment is initiated as the disease is induced. Further, insulin treatment is capable of reversing the abnormalities after they have occurred.

scholarly journals Perturbation of the mucosa-associated anaerobic gut microbiota in streptozotocin-induced diabetic rats

2021 ◽  
Vol 65 (1) ◽  
pp. 75-84
Author(s):  
Roland Wirth ◽  
Nikolett Bódi ◽  
Zita Szalai ◽  
Lalitha Chandrakumar ◽  
Gergely Maróti ◽  
...  
Keyword(s):  
Insulin Treatment ◽  
Relative Number ◽  
Diabetic Rats ◽  
Diabetic Rat ◽  
Tissue Samples ◽  
Next Generation Dna Sequencing ◽  
Chronic Hyperglycaemia ◽  
And Control ◽  
Diabetic Rat Model ◽  
Anaerobic Environment

Our aim was to map the gut region-specific differences of the mucosa-associated microbiome distribution in a streptozotocin-induced diabetic rat model. Tissue samples from the duodenum, ileum and colon were collected 10 weeks after the onset of hyperglycaemia to analyse the mucosa-associated microbiota using next-generation DNA sequencing. Striking differences were observed in the mucosa-associated microbiota of the duodenum between diabetic and control rats. A significant invasion of the aerobic genus Mycoplasma was apparent in diabetes, and the abundance of the anaerobic phylum Firmicutes decreased massively. It is noteworthy that insulin treatment eliminated the Mycoplasma invasion in the duodenum and apparently restored the anaerobic environment in the mucosa. In the ileum the abundance of the phylum Firmicutes increased in the diabetic samples. Although the proportion of the phylum Proteobacteria decreased moderately, its composition changed significantly, and insulin treatment induced only minor alterations. In the diabetic samples of colon, the abundance of the phylum Firmicutes decreased slightly, the relative number of the bacteria in the phylum Bacteroidetes increased strongly as compared to the control values, and after insulin treatment this increase was more significant. Chronic hyperglycaemia has the most prominent effect on the mucosa-associated microbiota in the duodenum.

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