scholarly journals Integrative pattern of vasomotor efficiency in SHR during ontogenesis

2008 ◽  
pp. 677-684
Author(s):  
M Gerová ◽  
F Kristek

Numerous studies concerning the cardiovascular system in SHR often yield controversial data. The background of this diversity has various roots, ranging from different vascular segments or areas studied up to the different age of experimental animals. Our study aimed to follow the BP as an integrated response of vascular system. This approach was justified since stabilized cardiac output in SHR was proved till 1 year of age. The groups of male SHR (aged 3, 5, 9, 17 and 52 weeks) and age-matched Wistar rats were used. Significant basal BP difference between SHR and Wistar rats was found at 9 weeks of age and continued till the age of 52 weeks, reaching 189.6±11.9 mm Hg in SHR and 117.3±6.9 mm Hg in Wistar rats (P<0.01). The significant difference in BP increase to two doses of noradrenaline (0.1 μg and 1 μg) between SHR and control rats was also found at the age of 9 weeks. At 52 weeks the BP increment to two doses of noradrenaline was in SHR 19.7±2.0 mm Hg and 60.5±3.9 mm Hg and in Wistar rats 7.4±1.9 mm Hg and 40.5±3.2 mm Hg (P<0.01). The hypotensive response to acetylcholine (0.1 μg, 1 μg and 10 μg) in SHR was enhanced at 17 weeks of age only and this amplification persisted till the age of 52 weeks. In 52- week-old SHR the hypotensive response to three doses was 69.9±10.2 mm Hg, 87.5±11.8 mm Hg and 103.4±10.6 mm Hg, while in Wistar rats it was 37.4±4.2 mm Hg (P<0.01), 62.3±3.5 mm Hg (P<0.01) and 73.5±2.8 mm Hg (P<0.05). In conclusion, the efficiency of cardiovascular system of SHR to respond to noradrenaline was already enhanced from 9 weeks of age, whereas the response to acetylcholine was not augmented before the age of 17 weeks.

2008 ◽  
pp. 137-139
Author(s):  
S Čačányiová ◽  
F Kristek ◽  
J Kuneš ◽  
J Zicha

We investigated the effect of pertussis toxin (PTX) on hypotensive response induced by acetylcholine (ACh) and bradykinin (BK) and on noradrenaline (NA)-induced pressor response in spontaneously hypertensive rats (SHR). Fifteenweek-old Wistar rats and age-matched SHR were used. Half of SHR received PTX (10 µg/kg/i.v.) and the experiments were performed 48 h later. After the anesthesia the right carotid artery was cannulated in order to record blood pressure (BP). The hypotensive response to ACh was enhanced in SHR compared to Wistar rats. After pretreatment of SHR with PTX the hypotensive response to ACh was reduced compared to untreated SHR and it was also diminished in comparison to Wistar rats. Similarly, the hypotensive response to BK was also decreased after PTX pretreatment. The pressor response to NA was increased in SHR compared to Wistar rats. NA-induced pressor response was considerably decreased after PTX pretreatment compared to untreated SHR. In conclusion, the enhancement of hypotensive and pressor responses in SHR was abolished after PTX pretreatment. Our results suggested that the activation of PTXsensitive inhibitory Gi proteins is involved in the regulation of integrated vasoactive responses in SHR and PTX pretreatment could be effectively used for modification of BP regulation in this type of experimental hypertension.


1961 ◽  
Vol 200 (4) ◽  
pp. 824-826 ◽  
Author(s):  
Edwin L. Stewart ◽  
Louis G. Welt

Pregnant rats were provided with a potassium-deficient diet on the day of mating. One group was sacrificed at 12–13 days of gestation and another group at 21 days. A third group was depleted of potassium acutely by utilizing peritoneal dialysis with an isotonic NaHCO3 solution. In all groups maternal serum and muscle potassium were found to be significantly lower and maternal serum CO2 significantly higher in the experimental animals than in the controls. However no significant difference in total fetal potassium concentrations was found when experimental and control animals were compared. As late as 15–17 days of gestation the total fetal potassium concentrations were found to be nearly double those of maternal skeletal muscle, but on day 21 the total fetal and the maternal muscle values were roughly equivalent. The mean dry weight of the experimental 21-day fetuses was significantly lower than that of the control fetuses. The mechanism of fetal sparing in maternal potassium depletion cannot be determined from the present data.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S El Kadi ◽  
L Qian ◽  
P Zeng ◽  
J Lof ◽  
E Stolze ◽  
...  

Abstract Background The use of intermittent high mechanical index (HMI) ultrasound impulses in combination with intravenously administered microbubbles (MB) has been shown to dissolve arterial and microvascular thrombi. The recent development of liquid droplets with nanoscale diameter from commercially available microbubbles may optimize thrombus permeation and subsequent thrombus dissolution. Methods Thrombi were formed from fresh porcine arterial whole blood mixed with thrombin, and placed in a vascular system mimicking branching epicardial coronary circulation (Figure 1A) at 37 Celsius and flow rate. A diagnostic ultrasound system with a tissue mimicking phantom was placed on top of the thrombus to simulate transthoracic echocardiography. Thrombus treatment consisted of a 10-minute infusion of either diluted nanodroplets (ND) or MB (same concentration) with intermittent HMI fundamental multipulse (3 usec pulse duration; FUS) or single pulse harmonic (HUS) impulses. All treatments were randomized and compared with HMI impulses alone. Efficacy was evaluated by percentage thrombus dissolution (%TD). Transmission electron microscopy (TEM) of residual thrombi after treatment was performed to examine for droplet permeation and resultant formed microbubble size. Results A relatively monodisperse nanodroplets size distribution was formed from microbubble cooled compression (mean diameter was 147±54 nm). A total of 60 porcine arterial thrombi were tested, 20 in each MB and ND treated group (20 control). Overall, there was a significant difference in %TD between ND treated thrombi (combining HUS and FUS HMI treated groups) versus MB treated thrombi and control (p&lt;0.0001 and p=0.02, respectively; ANOVA, Figure 1B). The highest %TD was seen in the FUS HMI treated ND group (mean 51±17%; Figure 1B). TEM of the DND treated group demonstrated significant expansion (diameters of 6 microns; Figure 1 C) of acoustically activated droplets embedded within the thrombi. Conclusion ND in combination with intermittent HMI ultrasound resulted in significantly greater thrombolysis compared to MB. In-vivo studies on nanodroplet mediated sonothrombolysis for vascular and microvascular thrombi should be performed with this modification of a commercially available microbubble. Figure 1 Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): Theodore F. Hubbard Foundation


1972 ◽  
Vol 14 (2) ◽  
pp. 341-345 ◽  
Author(s):  
N. Gilliavod ◽  
A. Léonard

Adult male BALB/c mice and adult male Wistar rats were given whole body X-irradiation with 300 R. Irradiated and control animals were killed after 120 days to study in dividing spermatocytes the rate of translocation induced in spermatogonial stages. No significant difference was recorded between the two species with respect to the rate of cells with translocation configurations.


2008 ◽  
Vol 27 (12) ◽  
pp. 895-900 ◽  
Author(s):  
AM Domijan ◽  
D Želježić ◽  
M Peraica ◽  
G Kovačević ◽  
G Gregorović ◽  
...  

Mycotoxin fumonisin B1 (FB1) is hepatotoxic and carcinogenic in experimental animals. It is known that long-term exposure of experimental animals to FB1 causes apoptosis and lipid peroxidation. In this study, male adult Wistar rats were treated with single FB1 doses (5, 50, and 500 μg/kg b.w.) and sacrificed 4, 24, and 48 hours after treatment. Parameters of oxidative stress, histopathological changes, and DNA damage were monitored in the liver of treated and control animals. Parameters of oxidative stress were not affected by such treatment. A significant increase in apoptotic cells appeared in animals when 5 μg/kg b.w. dose was given and sacrificed after 24 hours with further increase at higher doses. In contrast to the number of mitotic figures and karyomegaly seen mostly at lower FB1 doses, necrosis was the prominent feature at higher doses. Significant increase in liver cells DNA mobility was observed 48 hours following treatment with 50 and 500 μg/kg b.w. as compared to control (tail length 15.2 ± 0.3, 16.4 ± 0.5, and 13.5 ± 0.1 μm, respectively). Tail intensity appeared to be more sensitive parameter for detecting DNA damage even at 5 μg/kg b.w. after 48 hours (1.69 ± 0.27% DNA; control 0.59 ± 0.11% DNA). This study proved that FB1-induced DNA damage is time- and dose-dependent, and that it could be caused in Wistar rats by a single dose.


1959 ◽  
Vol 197 (4) ◽  
pp. 725-729
Author(s):  
Durwood J. Smith ◽  
Robert C. Parker ◽  
Calvin Hanna ◽  
Henry E. Curley

A battery of in vivo and in vitro tests of cardiovascular performance were used to assess the effects of whole-body gamma radiation (cobalt-60) upon the cardiovascular system of dogs. A new method for study of the pressure-volume relations of isolated surviving arteries is described. Groups of six beagles were exposed to 30 r and 100 r 22 months before death and compared with littermate controls. No differences between irradiated and control dogs could be demonstrated. Eight mongrel dogs received 300 r 30 days before death and were compared with five mongrel controls. The only significant difference observed was in the pressure-volume curves of arteries from irradiated dogs, these vessels having a greater initial tone than control arteries. It is concluded that 30 r and 100 r of whole-body gamma radiation have no demonstrable effect upon the cardiovascular system of dogs irradiated 22 months before study, but that 300 r of gamma radiation does produce a significant abnormality of blood vessels.


2020 ◽  
Vol 20 (2) ◽  
pp. 14-21
Author(s):  
D Maleev ◽  
E Vinogradov ◽  
A Isaev ◽  
V Khodkevich

Aim. The article deals with theoretical and experimental substantiation of the effectiveness of basic and ergogenic (hypoxic-hypercapnic exposures) aids in the preparation of 16–17-year-old biathletes. Materials and methods. The study involved two groups of 16–17-year-old biathletes. All athletes underwent an in-depth medical examination at the beginning of the experiment. Throughout the study, their functional status was assessed by the premorbid index of the cardio-vascular system obtained with the CardioSoft diagnostic system (USA). Results. Hypoxic-hypercapnic exposures in sports training along with the general training program aimed at deve­loping local-regional muscle endurance is a promising approach that can ensure a high level of functional abilities in athletes and improve their sports results. Conclusion. The results of the study contribute to the improvement of the training system for 16-17-year-old biathletes at the basic stage of sports preparation. The study proves that the innovative method proposed is effective for controlling the premorbid state of the cardiovascular system in athletes.


Author(s):  
Masoud Nasiri ◽  
Saja Ahmadizad ◽  
Mehdi Hedayati ◽  
Tayebe Zarekar ◽  
Mehdi Seydyousefi ◽  
...  

Abstract. Physical exercise increases free radicals production; antioxidant supplementation may improve the muscle fiber’s ability to scavenge ROS and protect muscles against exercise-induced oxidative damage. This study was designed to examine the effects of all-trans resveratrol supplementation as an antioxidant to mediate anti-oxidation and lipid per-oxidation responses to exercise in male Wistar rats. Sixty-four male Wistar rats were randomly divided into four equal number (n = 16) including training + supplement (TS), training (T), supplement (S) and control (C) group. The rats in TS and S groups received a dose of 10 mg/kg resveratrol per day via gavage. The training groups ran on a rodent treadmill 5 times per week at the speed of 10 m/min for 10 min; the speed gradually increased to 30 m/min for 60 minutes at the end of 12th week. The acute phase of exercise protocol included a speed of 25 m/min set to an inclination of 10° to the exhaustion point. Superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) activity, non-enzymatic antioxidants bilirubin, uric acid, lipid peroxidation levels (MDA) and the total antioxidant capacity (TAC) were measured after the exercise termination. The data were analyzed by using one-way ANOVA. The result showed that endurance training caused a significant increase in MDA level [4.5 ± 0.75 (C group) vs. 5.9 ± 0.41 nmol/l (T group)] whereas it decreased the total antioxidant capacity [8.5 ± 1.35 (C group) vs. 7.1 ± 0.55 mmol/l (T group)] (p = 0.001). In addition, GPx and CAT decreased but not significantly (p > 0.05). The training and t-resveratrol supplementation had no significant effect on the acute response of all variables except MDA [4.3 ± 1.4 (C group) vs. 4.0 ± 0.90 nmol/l (TS group)] (p = 0.001) and TAC [8.5 ± 0.90 (C group) vs. 6.6 ± 0.80 mmol/l (TS group)] (p = 0.004). It was concluded that resveratrol supplementation may prevent exercise-induced oxidative stress by preventing lipid peroxidation.


2019 ◽  
Vol 4 (1) ◽  
pp. 39
Author(s):  
Renu Agarwal ◽  
SK Gupta ◽  
Sushma Srivastava ◽  
Rohit Saxena

Introduction: Ocimum basilicum (OB), a herb known for its antihypertensive, anticholinesterase and antioxidant properties was investigated for possible intraocular pressure (IOP) lowering effects in rabbits with ocular hypertension (OHT). Methods: The IOP lowering effect of a single drop of OB extract (OBE) was evaluated in oculonormotensive rabbits using three concentrations (0.25, 0.5 and 1% w/v). The concentration showing maximum IOP reduction was further evaluated in rabbits with water-loading and steroid-induced OHT. Results: IOP lowering effect of OBE 0.5% in oculonormotensive rabbit eyes was significantly greater compared to OBE 0.25% (p<0.05) but was comparable (p>0.05) to OBE 1%. Therefore, 0.5% concentration was selected for further evaluation. Pretreatment with OBE (0.5%) caused significantly lower increase in IOP after water loading amounting to 23.39% above baseline as compared to 54.00% in control eye, 15 minutes post water loading. At 60 minutes, post water loading, mean IOP rise was 95.12% and 63.58% in control and test eyes, respectively. Significant difference between the mean IOP of two eyes persisted during the 2nd hr. In rabbits with steroid induced OHT, OBE 0.5% produced a mean IOP reduction of 24.73% at the end of first hr and the mean peak IOP reduction of 31.63% was observed at the end of 2 hr. A significant difference between the IOP of test and control eyes persisted from 1 to 6 hr. Conclusions: Ocimum basilicum seed extract showed significant IOP lowering effect in rabbits with water loading and steroid induced OHT, however, its utility as an effective antiglaucoma medication needs further investigations.


2016 ◽  
Vol 1 (1) ◽  
pp. 22
Author(s):  
Nazli Zainuddin ◽  
Nurul Azira Mohd Shah ◽  
Rosdan Salim

Introduction: The role of virgin coconut oil in the treatment of allergic rhinitis is controversial. Thus, the aim of the present study is to determine the effects of virgin coconut oil ingestion, in addition to standard medications, on allergic rhinitis. We also studied the side effects of consumption of virgin coconut oil. Methods: Fifty two subjects were equally divided into test and control groups. All subjects received a daily dose of 10mg of loratadine for 28 days. The test group was given 10ml of virgin coconut oil three times a day in addition to loratadine. The symptoms of allergic rhinitis were scored at the beginning and end of the study. Results:, the symptom score were divided into nasal and non-nasal symptom scores. Sneezing score showed a significant difference, however the score was more in control group than test group, indicating that improvement in symptom was more in control group. The rest of the nasal symptom and non-nasal symptom score showed no significant difference between test and control groups. Approximately 58% of the test subjects developed side effects from consumption of virgin coconut oil, mainly gastrointestinal side effects. Conclusion: In the present study, ingestion of virgin coconut oil does not improve the overall and individual symptoms of allergic rhinitis, furthermore it has side effects.


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