scholarly journals Dynamics of Proteo- and Fibrinolytic Activity in Brain Structures of Rats with Diabetes Mellitus Complicated by Carotid Ischemia-Reperfusion

2018 ◽  
Vol 25 (1) ◽  
Author(s):  
O. Tkachuk ◽  
M. Povar

The imbalance in the protease-antiprotease system is an integral part of the pathogenesis of acute disorder of cerebrovascular circulation and diabetes mellitus (DM), but its manifestations in the complication of diabetes by ischemia-reperfusion of the brain have not been investigated yet.The objective of the work – is to study the dynamics of carotid ischemia-reperfusion effect on the proteo- and fibrinolytic activity in brain structures of rats with experimental DM.Rats with the four-month streptozotocin DM were modeled bilateral carotene ischemia during 20 minutes. In homogenates of brain structures, indicators of proteo- fibrinolytic activity were determined after 1 hour from the beginning of reperfusion and during the 12th day of the post-ischemic period.In the absence of DM, the proteolytic activity of all or individual indicators is increased in both periods of the post-ischemic period in the cortex of the frontal and occipital lobes, the fields of hippocampus CA2 and CA3, and during the 12th day in the field CA1. In rats with diabetes, in all brain structures, there are no changes in the lysis of azo-albumin and azo-casein in both terms of observation and lysis of collagen progressively decreases.In rats without DM in the cortex of the studied particles, fields of the hippocampus CA1 and CA2, all or separate indices of fibrinolytic activity are increased in both periods of the post-ischemic period, in the field CA3 – all indices at the 12th day. In the presence of diabetes in the cortex of both studied lobes and the field CA1, the fibrinolytic activity decreases in the late post-ischemic period, in the fields of CA2 and CA3 – during both observation periods.Conclusion. In the brain structures under investigation at both time intervals, the DM eliminates the reaction of low and high molecular weight proteins to the ischemia-reperfusion and suppresses fibrinolytic activity. 

2021 ◽  
Vol 11 (7) ◽  
pp. 288-297
Author(s):  
S. Tkachuk ◽  
O. Tkachuk ◽  
M. Povar ◽  
O. Yasinska ◽  
O. Denysenko

Introduction. The imbalance in the protease-antiprotease system is an integral part of the pathogenesis of acute disorder of cerebrovascular circulation and diabetes mellitus (DM), but its manifestations in the complication of diabetes by ischemia-reperfusion of the brain have not been investigated yet. The objective of the work – to study the dynamics of carotid ischemia-reperfusion effect on the proteo- and fibrinolytic activity in brain structures of rats with experimental DM. Rats with the four-month streptozotocin DM were modeled bilateral carotene ischemia during 20 minutes. In homogenates of brain structures, indicators of proteo- fibrinolytic activity were determined after 1 hour from the beginning of reperfusion and during the 12th day of the post-ischemic period. In the absence of DM, the proteolytic activity of all or individual indicators il increased in both periods of the post-ischemic period in the cortex of the frontal and occipital lobes, the fields of hippocampus CA2 and CA3, and during the 12th day in the field CA1. Results. In rats with diabetes, in all brain structures, there are no changes in the lysis of azo-albumin and azo-casein in both terms of observation and lysis of collagen progressively decreases. In rats without DM in the cortex of the studied particles, fields of the hippocampus CA1 and CA2, all or separate indices of fibrinolytic activity are increased in both periods of the post-ischemic period, in the field CA3 – all indices at the 12th day. In the presence of diabetes in the cortex of both studied lobes and the field CA1, the fibrinolytic activity decreases in the late post-ischemic period, in the fields of CA2 and CA3 – during both observation periods. Conclusion. In the brain structures under investigation at both time intervals, the DM eliminates the reaction of low and high molecular weight proteins to the ischemia-reperfusion and suppresses fibrinolytic activity.


2021 ◽  
Vol 9 (1) ◽  
pp. 101-106
Author(s):  
O.M. Nika ◽  
O.V. Zaliavska ◽  
O.V. Kaushanska

The role of the transcription factor Hif-1α in pathogenesis of hypoxic lesions and diabetes mellitus (DM) has been confirmed, though molecular mechanisms underlying dysfunctions of the factor in the association of DM with ischemic-reperfusion lesion of the brain remain unknown. Objective: the investigation of Hif-1α protein content in the neurons of the hippocampus fields of rats with experimental DM in the dynamics of ischemic-reperfusion lesion of the brain. The study was conducted on 60 6-month rats with DM simulated at the age of 2 months by means of a single administration of streptozotocin (60 mg/kg of the body weight) (Sigma, USA). Disorders of the cerebral circulation were simulated by means of occlusion of both carotid arteries for 20 minutes. The content of Hif1-α protein was determined by means of fluoroimmunoassay after 20-minute ischemia with one hour reperfusion, and on the 12th day of the post-ischemic period in the hippocampus fields: СА1, СА2, СА3, СА4. In rats without DM 20-minute ischemia with one hour reperfusion increases the content of Hif-1α protein in all the hippocampus fields. On the 12th day of ischemic-reperfusion period in СА2-СА4 hippocampus fields the values of certain examined activity indices of the transcription factor Hif-1α continue to increase, and in СА1 field they are normalized or come closer to the values of animals from the control group. In rats with DM at the early post-ischemic period changes of Hif-1α protein content are lacking in СА1 field, the signs of its reduced activity are found in СА2 field, in СА3 field they are limited by the response of one index, and in СА4 field they are similar to those of the control rats under the experimental conditions. On the 12th day of ischemic-reperfusion period all the activity indices of the transcription factor Hif-1α increase in СА1 filed. They are higher than the corresponding indices in animals from the control group by absolute values under similar experimental conditions; changes of the examined parameters are limited in СА2 and СА3 fields in comparison with those from the control group; the parameters, which increased in the control group of animals, decreased in СА4 field. DM restricts Hif-1α protein response to ischemia-reperfusion in the neurons of СА1-СА3 field at the early ischemic-reperfusion period and in the neurons of СА2-СА4 fields — on the 12th day of the observation.


1969 ◽  
Vol 21 (02) ◽  
pp. 294-303 ◽  
Author(s):  
H Mihara ◽  
T Fujii ◽  
S Okamoto

SummaryBlood was injected into the brains of dogs to produce artificial haematomas, and paraffin injected to produce intracerebral paraffin masses. Cerebrospinal fluid (CSF) and peripheral blood samples were withdrawn at regular intervals and their fibrinolytic activities estimated by the fibrin plate method. Trans-form aminomethylcyclohexane-carboxylic acid (t-AMCHA) was administered to some individuals. Genera] relationships were found between changes in CSF fibrinolytic activity, area of tissue damage and survival time. t-AMCHA was clearly beneficial to those animals given a programme of administration. Tissue activator was extracted from the brain tissue after death or sacrifice for haematoma examination. The possible role of tissue activator in relation to haematoma development, and clinical implications of the results, are discussed.


1984 ◽  
Vol 52 (02) ◽  
pp. 138-143 ◽  
Author(s):  
M Christe ◽  
J Fritschi ◽  
B Lämmle ◽  
T H Tran ◽  
G A Marbet ◽  
...  

SummaryFifteen haemostasis parameters have been measured in 48 normal persons, 36 diabetics without and 44 with complications and 27 with peripheral arterial disease. Since the patients groups are older than normals, part of the differences are due to age. However, the differences are significant between normals and patients. They become highly significant for the diabetics with complications and nephropathy (Table 7). In diabetics without complications factor VIII functions, fibrinogen and thrombin time are related to age whereas there is a negative correlation for the fibrinolytic activity and antithrombin III. The diabetic complications shade off the correlations, which subsist only for VIIIR: CoF, VIIIR: Ag, ATIII and lysis before stasis. With Hbalc as dependent variable VIIIR:CoF is the only significant predictor variable in diabetics (Table 9).


Author(s):  
Amteshwar Singh Jaggi

Aim: The aim of the present study is to explore the neuroprotective effects of remote ischemic preconditioning in long term cognitive impairment after global cerebral ischemia induced-vascular dementia in mice. Material and methods: The mice were subjected to global cerebral ischemia by occluding the bilateral common carotid arteries for 12 minutes followed by the 24 hours of the reperfusion. The remote ischemic preconditioning stimulus was delivered in the form of 4 cycles of ischemia/reperfusion for 5 minutes each. The cerebral ischemic injury induced-long term cognitive impairment-related learning and memory alterations was assessed using morris water maze, the motor performances of the animals were evaluated using rota-rod test and neurological severity score. The cerebral infract size of the brain were quantified using triphenyltetrazolium chloride staining. Results: Global cerebral ischemia causes long term memory impairment, decreases motor performances and increases the brain infract size in animals. The delivery of remote ischemic preconditioning stimulus significantly abolished the long-term cognitive impairment and ameliorates the motor performances as well as cerebral infract size in brain. Conclusion: The remote ischemic preconditioning mediates neuro protection against global cerebral ischemic injury induced long-term cognitive impairment.


2019 ◽  
Vol 25 (23) ◽  
pp. 2555-2568 ◽  
Author(s):  
Rajeev Taliyan ◽  
Sarathlal K. Chandran ◽  
Violina Kakoty

Neurodegenerative disorders are the most devastating disorder of the nervous system. The pathological basis of neurodegeneration is linked with dysfunctional protein trafficking, mitochondrial stress, environmental factors and aging. With the identification of insulin and insulin receptors in some parts of the brain, it has become evident that certain metabolic conditions associated with insulin dysfunction like Type 2 diabetes mellitus (T2DM), dyslipidemia, obesity etc., are also known to contribute to neurodegeneration mainly Alzheimer’s Disease (AD). Recently, a member of the fibroblast growth factor (FGF) superfamily, FGF21 has proved tremendous efficacy in diseases like diabetes mellitus, obesity and insulin resistance (IR). Increased levels of FGF21 have been reported to exert multiple beneficial effects in metabolic syndrome. FGF21 receptors are present in certain areas of the brain involved in learning and memory. However, despite extensive research, its function as a neuroprotectant in AD remains elusive. FGF21 is a circulating endocrine hormone which is mainly secreted by the liver primarily in fasting conditions. FGF21 exerts its effects after binding to FGFR1 and co-receptor, β-klotho (KLB). It is involved in regulating energy via glucose and lipid metabolism. It is believed that aberrant FGF21 signalling might account for various anomalies like neurodegeneration, cancer, metabolic dysfunction etc. Hence, this review will majorly focus on FGF21 role as a neuroprotectant and potential metabolic regulator. Moreover, we will also review its potential as an emerging candidate for combating metabolic stress induced neurodegenerative abnormalities.


Author(s):  
Shengyuan Wang ◽  
Chuanling Wang ◽  
Lihua Wang ◽  
Zhiyou Cai

Background: Mammalian target of rapamycin (mTOR) has been evidenced as a multimodal therapy in the path-ophysiological process of acute ischemic stroke (AIS). However, the pathway that minocycline targets mTOR signaling is not fully defined in the AIS pathogenesis. This study is to aim at the effects of minocycline on the mTOR signaling in the AIS process and further discover the underlying mechanisms of minocycline involved in the following change of mTOR signaling-autophagy. Methods: Cerebral ischemia/reperfusion (CIR) rat animal models were established with the transient suture occlusion into middle cerebral artery. Minocycline (50mg/kg) was given by intragastric administration. The Morris water maze was used to test the cognitive function of animals. Immunohistochemistry and immunofluorescence were introduced for testing the lev-els of synaptophysin and PSD-95. Western blot was conducted for investigating the levels of mTOR, p-mTOR (Ser2448), p70S6, p-p70S6 (Thr389), eEF2k, p-eEF2k (Ser366), p-eIF4B (Ser406), LC3, p62, synaptophysin and PSD-95. Results: Minocycline prevents cognitive decline of the MCAO stroke rats. Minocycline limits the expression of p-mTOR (Ser2448) and the downstream targets of mTOR [p70S6, p-p70S6 (Thr389), eEF2k, p-eEF2k (Ser366) and p-eIF4B (Ser406)] (P<0.01), while minocycline has no influence on mTOR. LC3-II abundance and the LC3-II/I ratio were upregu-lated in the hippocampus of the MCAO stroke rats by the minocycline therapy (P<0.01). p62 was downregulated in the hippocampus from the MCAO stroke rats administrated with minocycline therapy(P<0.01). The levels of SYP and PSD-95 were up-regulated in the brain of the MCAO stroke rats administrated with minocycline therapy. Conclusion: Minocycline prevents cognitive deficits via inhibiting mTOR signaling and enhancing autophagy process, and promoting the expression of pre-and postsynaptic proteins (synaptophysin and PSD-95) in the brain of the MCAO stroke rats. The potential neuroprotective role of minocycline in the process of cerebral ischemia may be related to mitigating is-chemia-induced synapse injury via inhibiting activation of mTOR signaling.


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