ORIGINAL_ARTICLE
Closed and open loop mechanisms controlling arterial blood pressure in waking state in human and experimental animal
Time-honored indices of classical, closed loop arterial blood pressure (BPa) control have recently been supplemented by analyses thought to be sensitive to both closed and open loop mechanisms. These newer tools include, among others, power spectral analyses of heart rate (HR) and BPa, and the cross-correlation between changes in BPa and changes in HR or R-R interval. The „baroreceptor effectiveness index‟ (BEI) is significantly larger in supine, healthy individuals as compared to diabetic patients with peripheral neuropathy. Such findings give promise that BEI may provide a means to assess the development of autonomic neuropathy in diabetic or in other at-risk patients. The cross-correlation between BPa and heart rate in man includes a peak where the two are positively correlated with HR changes leading pressure changes, suggestive of open loop control, and a sharp nadir where the two are negatively correlated and BPa changes precede HR changes, suggestive of closed loop control. In rat the positive cross-correlation depends upon intact spinal sympathetic pathways. The magnitudes of both the positive and negative cross correlations are weaker in tetraplegic patients as compared to neutrally intact subjects. Both peaks remain relatively strong in healthy subjects during the challenge of head up tilt, but decline precipitously in tetraplegic patients. The recognition that both closed and open loop mechanisms are operative and functionally important suggests multiple additional possible etiologies for cardiovascular dysfunctions, including hypertension. The advent of non-invasive means to quantify autonomic function promises new insights into control of the cardiovascular system in health and disease
https://besps.journals.ekb.eg/article_34018_8e901b0399af258398ec0001931d6ae2.pdf
2014-06-01
1
10
10.21608/besps.2014.34018
Open and closed loop
Mechanisms
ABP
Waking
Man
Experimental animals
David
Randall
1
Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY
LEAD_AUTHOR
David
Brown
2
Department of Physiology, College of Medicine, University of Kentucky, Lexington, KY
AUTHOR
ORIGINAL_ARTICLE
Effects of co-application of corticosterone and growth hormone on hippocampal neurons involve nmda receptor upregulation of nr2b protein expression and increasing nr2b/nr2a ratio
Objectives to investigate the possible mechanism underlying the protective effect of growth hormone (GH) on hippocampal function during periods of acute stress. Methods the effects of co-application of GH and corticosterone (CORT) at different concentration on field excitatory postsynaptic potential (fFEPSPs) of hippocampal slices of rats at two different age groups were examined. Also, the protein expression of N-methyl-D-aspartate receptor (NMDARs) subunits; NR1, NR2B, and NR2A in hippocampal brain slices treated with artificial cerebrospinal fluid (ACSF) or low concentration of CORT alone or both CORT and GH for three hours were measured. Results We found an additive effect of co-application of CORT and GH on hippocampal synaptic transmission compared to CORT alone. Furthermore, we found that the combined use of low concentration of GH and CORT have significantly higher effects on enhancement of fFEPSPs in old rats compared to young ones. We showed that both GH and CORT enhanced protein expression of NR2A subunit of NMDARs. Meanwhile, we demonstrated that the coexposure to low concentration of GH and CORT significantly enhanced NR2B expression and increased the NR2B/NR2A. In contrast, perfusion with CORT alone caused significant suppression in NR1 and NR2B protein expression and decrease in NR2B/NR2A. Conclusion we suggest that NMDARs provide potential target for mediating GH potential protective effect against stress and age related memory and cognitive impairment
https://besps.journals.ekb.eg/article_34019_f9bb816c67490eca45a6dd86f6fe5a5d.pdf
2014-06-01
11
26
10.21608/besps.2014.34019
Growth hormone (GH)
Corticosterone (CORT)
Stress
Field excitatory postsynaptic potentials (FEPSPs)
N-methyl-D-aspartate receptors (NMDARs)
Hippocampus
Synaptic plasticity
Ghada
Mahmoud
1
Department of Medical Physiology, Faculty of Medicine, Assiut University, Assiut, Egypt.
LEAD_AUTHOR
Ayman
Amer
2
Department of Human Anatomy and Embryology, Faculty of Medicine, Assiut University, Assiut, Egypt.
AUTHOR
ORIGINAL_ARTICLE
The effect of resveratrol on insulin resistance, metabolic syndrome and hepatic oxidative stress in fructose- fed rats
Mtabolic syndrome and oxidative stress are common complications of type 2 diabetes mellitus. The aim of this work was to study the effect of resveratrol, a widely used nutritional supplement on insulin sensitivity, some metabolic parameters and hepatic oxidative stress in high fructose- fed rats. Material & methods: Male Wister rats (180-200g) were divided into 3 groups 10 per each. G1: Control group was fed 65% corn starch diet. G2: Fructose-fed insulin resistant group (HFD) was fed 65% fructose diet. G3: (HFD + Resveratrol) was fed with 65% fructose along with a single dose of 10 mg/kg/day of resveratrol orally through intra gastric tube for a period of 8 weeks. Results: At the end of the feeding schedule, HFD group had significant hyperglycemia, hyperinsulinemia and insulin resistance as evident by HOMA IR. There were significant increase in triglyceride and nitric oxide levels as well as in hepatic ThioBabituric Acid Reactive Substance (TBARS) and significant decrease in vitamin C in HFD group compared with control group. Administration of resveratrol significantly improved the altered metabolic parameters, hepatic oxidative stress parameters and significantly reduced inflammatory markers (Monocyte Chemoattractant Protein -1(MCP-1), Tumor Necrosis Factora (TNFa) and Regulated on Activation Normal T cells Expressed and Secreted (RANTES). Conclusion: Resveratrol supplementation might attenuate the insulin resistance, hepatic oxidative stress state and inflammatory state in metabolic syndrome
https://besps.journals.ekb.eg/article_34020_592df688dfffe0ab88e2eb210e9cd79a.pdf
2014-06-01
27
42
10.21608/besps.2014.34020
Resveratrol
High fructose diet
Metabolic syndrome
Hepatic oxidative stress
Ahmed
Abdalfattah
pacemaker107@gmail.com
1
Department of Physiology, Faculty of Medicine, Tanta University, Egypt
LEAD_AUTHOR
ORIGINAL_ARTICLE
Effect of systemic ghrelin administration on experimental myocardial infarction induced by isoproterenol in rats
Objective: Is to investigate the possible effects of ghrelin administration on isoproterenol (ISO)-induced myocardial infarction (MI) in albino rats of local strain. Methods: 30 adult male albino rats were divided into 3 groups, each consisted of 10 rats. Group I: received saline as a control group. Group II: ISO injected subcutaneously to rats (100 mg/kg) at an interval of 24 h for 2 days. Group III: rats were pretreated with ghrelin (150 μg/kg, s.c.) for 15 days and at the 14th and 15th days received ISO as in group II. Levels of serum cardiac enzymes (CK, CK-MB fraction and LDH), lipid profiles and plasma TNF-α and IL-6 were evaluated. Specimens from heart were obtained to measure the levels of TNF-α, IL-6, lipid peroxidation products (MDA,GSH)and endogenous antioxidants enzymes activities (CAT,SOD,PON1). Results: ISO- treated rats showed significant increase in the activities of serum cardiac enzymes, plasma and cardiac tissues TNF-α and IL-6, as well as in heart tissues level of MDA and GSH and in serum cholesterol, triglycerides, LDL-cholesterol, VLDL .On the other hand there are significant decrease in tissues SOD and PON1 enzyme activities and serum HDL-cholesterol when these results were compared to control rats. Pretreatment with ghrelin significantly attenuated these changes as compared to ISO treated rats (group I). Conclusions: This finding demonstrated that ghrelin may be considered as promising new therapies for MI.
https://besps.journals.ekb.eg/article_34394_3239d640c6146c1d2f0f450c9e742cfc.pdf
2014-06-01
43
56
10.21608/besps.2014.34394
Isoproterenol
myocardial infarction
Creatine kinase-MB
Paraoxonase
Abeer
Abozeid
1
Department of Physiology, Biochemistry ,Faculty of Medicine, Tanta University, Tanta, Egypt
LEAD_AUTHOR
Ghada
Abou Fard
2
Departments of Physiology, Faculty of Medicine, Tanta University, Tanta, Egypt
AUTHOR
Noha
Shafik
3
Department of Biochemistry,Faculty of Medicine, Tanta University, Tanta, Egypt
AUTHOR
ORIGINAL_ARTICLE
The impact of postnatal iron administration on memory and levels of serotonin and gaba in hippocampus of adult male rats
Objectives Excess iron in the brain has been implicated in the pathogenesis of neurodegenerative disorders. The present study was designed to investigate the effect of postnatal iron administration on memory, hippocampal serotonin (5HT) and γ-aminobutyric acid (GABA) levels and oxidative stress markers in adult male rats. Methods Thirty pups at age of 7 days weighting 50-52 grams were randomly divided equally into two groups : control (normal pups) and iron overload group treated with ferrous sulphate (3 mg/kg/day,intraperitoneally) for consecutive 21 days. Spatial and avoidance memories were tested using radial arm maze and passive avoidance tests. Hippocamapl levels of 5HT, GABA, serum total antioxidant capacity (TAC), and total peroxide (TP) were determined. Histopathological studies using H&E and Prussian blue stains were done. Results Iron overloaded rats showed impaired working memory in radial arm maze and impaired avoidance learning in passive avoidance test compared to the controls. Iron overload induced a significant decrease in the hippocampal levels of both 5HT and GABA. Levels of TAC were decreased and total peroxide was increased in iron overload group as compared to control group. Moreover, in contrast to the control group, positive iron depositions in the form of blue particles were detected in different areas of the hippocampus of iron overload group. Conclusion postnatal iron administration resulted in memory impairment possibly through alternation in hippocampal 5HT and GABA levels and oxidative stress
https://besps.journals.ekb.eg/article_34401_ef2271843163527bfe14e05ab5287878.pdf
2014-06-01
57
68
10.21608/besps.2014.34401
iron overload
serotonin
GABA
memory
Marwa
Ahmed
mar_az_ahmed@yahoo.com
1
Departments of Medical Physiology, Faculty of Medicine, Assiut University, Assiut, Egypt
LEAD_AUTHOR
Eman
Abd Allah
eman_sayyed2@yahoo.com
2
Departments of Medical Physiology, Faculty of Medicine, Assiut University, Assiut, Egypt
AUTHOR
Asmaa
Abdel Mola
3
Departments of Histology, Faculty of Medicine, Assiut University, Assiut, Egypt
AUTHOR
ORIGINAL_ARTICLE
The role of endocannabinoid system in the obesity induced atherogenesis : what are the possible mechanism/s involved ?
Objectives: The present work was designed to studythe role of endocannabinoid system in the obesity associated atherogenesis and trying to clarify its possible mechanism/s of action. Methods: Thirty adult male wistar albino rats were utilized in the present experiment. They were divided into three equal groups (10 rats each); Group 1: Lean control group, which were fed normal laboratory chow diet and gavaged once daily by dimethyl sulfoxide in a dose of 0.6ml/kg /day for 10 weeks. Group 2: Atherogenic diet group which were fed high fat diet and gavaged once daily by dimethyl sulfoxide as group 1. Group 3: Atherogenic diet treated group which were fed high fat diet and gavaged once daily by NIDA-41020 (a selective cannabinoid receptor 1 blocker) in a dose of 10mg/ kg /day for 10 weeks. Then body mass index (BMI), bleeding time, and total clotting time were assessed. After that, the animals were sacrificed and lipid profile, atherogenic index, bleeding time, platelet aggregation percentage, clot retractions, clotting time, prothrombin time (PT), activated partial thromboplastin time (aPTT), total & differential leukocytic counts and serum adiponectin levels were assessed in all groups. The aorta was obtained from each animal dissected and stained by haematoxylin/eosin and oil Red O staining for histological examination and detection of aortic thickness and foam cells deposition. Results: The laboratory investigations and histological examination revealed, significant increases in BMI, lipid profile, atherogenic index, platelet aggregation%, peripheral monocytic count, and aortic thickness in the high fat diet received group versus lean controls which were otherwise associated with significant decreases in total clotting time, PT, aPTT, serum HDL & adiponectin levels. These changes were significantly and profoundly inhibited by the administration of the cannabinoid receptor antagonist. Conclusion: The endocannabinoid system is involved in the atherogenic changes associated with obesity. These effects were attributed to interference with serum adiponectin level, dyslipidemia, hypercoagulability, increased platelet activation & peripheral as well as endothelial recruitment of monocytes. These effects were found to be via activation of cannabinoid 1 receptor.
https://besps.journals.ekb.eg/article_34408_3d4b4d0bba5b008953ffdaed2fc9b564.pdf
2014-06-01
69
87
10.21608/besps.2014.34408
adiponectin
Endocannabinoids
Platelet aggregation
Shereen
Bdeer
1
Physiology Department, Faculty of Medicine, Zagazig University
LEAD_AUTHOR
Nawal
Gerges
2
Physiology Department, Faculty of Medicine, Zagazig University
AUTHOR
El-Sayed
Kamel
3
Clinical pharmacology Department, Faculty of Medicine, Zagazig University
AUTHOR
ORIGINAL_ARTICLE
Effect of testosterone on the cereble cortex Bcl-2 expression and oxidative stress in a rat model of vascular dementia
Objectives to investigate the effect of testosterone on the cerebral cortex Bcl-2 expression and oxidative stress in a rat model of vascular dementia (VD). Methods Forty-eight Sprague-Dawley adult male rats were divided into four groups (n=12, each) as follows (i) untreated control, (ii) rats exposed to surgical permanent bilateral occlusion of the common carotid arteries (BCCAO) leading to chronic cerebral hypoperfusion, (iii) rats exposed to BCCAO then received testosterone (0.5 mg/ kg S.C., three times/ week, S.C.) (BCCAO + Tes) for 4 weeks and (iv) rats exposed to BCCAO then received donepezil (3 mg/kg/ day; i.p.) (BCCAO + DON) for 4 weeks. Levels of acetylcholine and norepinephrine in the cerebral cortex were measured. Furthermore, the expression of Bcl-2 in the cerebral cortex and malondialdehyde (MDA), non-enzymatic (reduced glutathione, GSH) and enzymatic [superoxide dismutase (SOD) and catalase (CAT)] anti-oxidants were determined. Histopathological studies of the cerebral cortex were performed. Results BCCAO decreased the expression of Bcl-2 as well as the central level of acetylcholine and norepinephrine as compared to control rats. Also, increased the cerebral cortex level of MDA and decreased the enzymatic and non-enzymatic antioxidant. Treatment with testosterone and donepezil increased acetylcholine and norepinephrine significantly when compared with BCCAO rats. Testosterone significantly increased the expression of Bcl-2 and antioxidant system with significant reduction in MDA. Conclusion Testosterone might employ neuroprotective effects through increasing the expression of Bcl-2 as well as ameliorating the oxidative stress induced by BCCAO in rat model of DA.
https://besps.journals.ekb.eg/article_34412_14754929dd26a12b6c4a351fb79680e4.pdf
2014-06-01
88
103
10.21608/besps.2014.34412
Acetylcholine
Bcl-2
Donepezil
testosterone
Vascular dementia
Oxidative Stress
Hussein
Sakr
sakr_doctor@yahoo.com
1
Medical Physiology Department1, Mansoura Faculty of Medicine, Egypt, Medical Physiology Department2, College of Medicine, King Khalid University, KSA
AUTHOR
Abd El-Aziz
Hussein
2
Medical Physiology Department, Mansoura Faculty of Medicine, Egypt,
LEAD_AUTHOR
Khaled
Khalil
3
Medical Physiology Department, Mansoura Faculty of Medicine, Egypt,
AUTHOR
Amr
Abbas
4
Medical Physiology Department, Mansoura Faculty of Medicine, Egypt,
AUTHOR
ORIGINAL_ARTICLE
Role of melatonin on immobilization induced effects in rat soleus muscle
Objectives: Immobilization results in dramatic losses of skeletal muscle mass. Several reports have strongly implicated oxidative stress as partially causative of disuse atrophy. So, the aim of this study was to investigate the deleterious effects of immobilization upon rat skeletal muscle and to detect the possible protective role of melatonin on these effects. Methods: male Wister albino rats were subjected to immobilization procedure, then divided into (C) control group, and three treated groups with melatonin either once daily at morning (M1) group or at night (M2) group or twice daily (M3) group. Soleus muscle was used to detect myosin heavy chain (MHC) distribution, gene expression and histological examination. Results: The study demonstrated that treatment with melatonin once at night and twice per day prevented the deleterious effects of immobilization by increasing the total antioxidant capacity, decreasing the muscle atrophy F-box (MAFbx) and muscle-specific RING finger-1 (MuRF-1) and increasing in insulin-like growth factor 1 receptors (IGF-1R) gene expression. Conclusions: The results of this study provide evidence that melatonin administration reduces the deleterious effects of immobilization on skeletal muscle. SO, exogenous melatonin may be a possible candidate for hormonal therapy in immobilization-induced muscle atrophy.
https://besps.journals.ekb.eg/article_34414_85204bdeced014ca621759559ffe7c54.pdf
2014-06-01
104
120
10.21608/besps.2014.34414
Abeer
Mostafa
1
Medical Physiology Department, Mansoura Faculty of Medicine, Egypt
LEAD_AUTHOR
Shereen
Samir
2
Medical Physiology Department, Mansoura Faculty of Medicine, Egypt
AUTHOR
ORIGINAL_ARTICLE
Role of Hemeoxygenase-1 on Ischemia Induced Preeclampsia-Like Syndrome in Rats
Background: Placental hypoxia/ischemia has been implicated as a central corn in the development of preeclampsia. One particularly useful model to study the impact of placental ischemia is the reduced uterine perfusion pressure model as it induces preeclampsia - like syndrome. Aim: This study aimed to demonstrate the effect of hemeoxygenase-1 on placental hypoperfusion in reduced uterine perfusion pressure model. Methods: The study was carried out on 50 timed pregnant female wistar rats divided into 5 equal groups; normal pregnant, reduced uterine perfusion pressure, reduced uterine perfusion pressure + Cobalt (III) Protoporphyrin IX Chloride, reduced uterine perfusion pressure + Cobalt (III) Protoporphyrin IX Chloride + tin-protoporphyrin IX and reduced uterine perfusion pressure + tin-protoporphyrin IX. In all these groups, number and weight of pups and maternal mean arterial blood pressure were measured. Then, blood, urine and placental samples were collected for measurement of microalbumin creatinine ratio, soluble fms-like tyrosine kinase, vascular endothelial growth factor, tumor necrosis factor- α, super oxide dismutase and lactic dehydrogenase. Histopatholgoical examination of placentas of all groups was also done. Results and Conclusion: Reduced uterine perfusion pressure produced preeclampsia -like syndrome (hypertention, proteinuria and endothelial dysfunction). All biochemical parameters and histopathological pictures have been significantly improved by hemeoxygenase-1induction. So, hemeoxygenase-1 can be considered as a potential therapeutic target in the treatment of preeclampsia in the near future.
https://besps.journals.ekb.eg/article_34416_cf3452bb3f8e6b06097ce80341d8f76d.pdf
2014-06-01
121
135
10.21608/besps.2014.34416
Hemeoxygenase-1
ischemia
placenta
preeclampsia
Nahid
Tahoon
1
Departments of Medical Physiology, Faculty of Medicine, Tanta University, El-Gharbia, Egypt
LEAD_AUTHOR
Doaa
Zineldeen
2
Department of MedicalBiochemistry, Faculty of Medicine, Tanta University, El-Gharbia, Egypt
AUTHOR
Karima
El-Desuky
3
Departments of Molecular Biology and Pathology, Faculty of Medicine, Tanta University, El-Gharbia, Egypt
AUTHOR
ORIGINAL_ARTICLE
The effect of heparin on cerulein - induced pancreaities in albino rats
The present work aimed to investigate the effect of heparin on cerulein–induced acute pancreatitis model in albino rats. Methods: Thirty male albino rats were used in the study. They were divided into 3 groups: Control group, AP (Acute pancreatitis) group, and heparin–treated group. AP was induced by subcutaneous injection of cerulein (20μg/kg) four times at one hour intervals. At the end of experiment, the animals were sacrificed and blood samples were collected for determination of plasma amylase, lipase levels, tumor necrosis factor–alpha (TNF-α), interleukin-6 (IL-6), APTT (Activated partial thromboplastin time). Hematocrit levels were measured. Pancreatic tissue was evaluated histopathologically. Results: Compared with control group, plasma amylase, lipase, TNF-α, IL-6 and hematocrit levels in AP group were significantly increased (P<0.05). After heparin treatment, plasma amylase, lipase, TNF-α, IL-6 and hematocrit levels were significantly decreased (P<0.05). APTT was significantly prolonged in AP group as compared to control group, but was significantly decreased after heparin treatment. Conclusions: Treatment with heparin improved the biochemical and histopathological findings in a rat model of experimental pancreatitis. Although, our findings suggest that heparin might be considered an effective agent for the treatment of acute pancreatitis, this notion should be supported with further clinical investigations
https://besps.journals.ekb.eg/article_34417_4d7ad830e493b5efcca044e662663748.pdf
2014-06-01
135
147
10.21608/besps.2014.34417
Acute pancreatitis
Cerulein
Heparin
Interleukin-6
Activated partial thromboplastin time
Nermin
Madi
1
Medical Physiology Department, Faculty of Medicine, Tanta University, El-Gharbia, Egypt
LEAD_AUTHOR
Mervat
El-Saka
2
Medical Physiology Department, Faculty of Medicine, Tanta University, El-Gharbia, Egypt
AUTHOR