Jasenka Mršić-Pelčić

Hyperbaric oxygen treatment: the influence on the hippocampal superoxide dismutase and Na+,K+-ATPase activities in global cerebral ischemia-exposed rats

The influence of hyperbaric oxygen (HBO) treatment on the activities of superoxide dismutase (SOD) and Na(+),K(+)-ATPase was determined during different time periods of reperfusion in rats exposed to global cerebral ischemia. Ischemic animals were either sacrificed or exposed to the first HBO treatment 2, 24, 48 or 168 h after ischemic insult (for SOD activities measurement) or immediately, 0.5, 1, 2, 6, 24, 48, 72 or 168 h after ischemic procedure (for Na(+),K(+)-ATPase activities measurement). Hyperbaric oxygenation procedure was repeated for seven consecutive days. The results of presented experiments demonstrated the statistically significant increase in the hippocampal SOD activity 24 and 48 h after global cerebral ischemia followed by a decrease in the enzymatic activity 168 h after ischemic insult. In the ischemic rats treated with HBO the level of hippocampal SOD activity was significantly higher after 168 h of reperfusion in comparison to the ischemic, non HBO-treated animals. In addition, it was found that global cerebral ischemia induced a statistically significant decrease of the hippocampal Na(+),K(+)-ATPase activity starting from 1 to 168 h of reperfusion. Maximal enzymatic inhibition was obtained 24 h after the ischemic damage. Decline in Na(+),K(+)-ATPase activity was prevented in the animals exposed to HBO treatment within the first 24 h of reperfusion. Our results suggest that global cerebral ischemia induces significant alterations in the hippocampal SOD and Na(+),K(+)-ATPase activities during different periods of reperfusion. Enhanced SOD activity and preserved Na(+),K(+)-ATPase activity within particular periods of reperfusion, could be indicators of a possible beneficial role of HBO treatment in severe brain ischemia.

The influence of MK-801 on the hippocampal free arachidonic acid level and Na+,K+-ATPase activity in global cerebral ischemia-exposed rats

The influence of 20 min global cerebral ischemia on the free arachidonic acid (FAA) level and Na+,K+-ATPase activity in the rat hippocampus at different time points after ischemia was examined. In addition, the effect of MK-801 on mentioned parameters was studied. Animals were exposed to 20 min global cerebral ischemia and were sacrificed immediately, 0.5, 1, 2, 6, 24, 48, 72, and 168 h after ischemic procedure. The level of the FAA and the Na+,K+-ATPase activity was measured during all reperfusion periods examined. Various doses of MK-801 (0.3, 1.0, 3.0, and 5.0 mg/kg) had been injected 30 min before ischemic procedure started. It was found that 20 min global cerebral ischemia induces a statistically significant increase of the FAA level immediately after ischemia and during the first 0.5 h of reperfusion. After a transient decrease, the level of FAA level increased again after 24 and 168 h of recirculation. Treatment with 3.0 mg/kg of MK-801 significantly prevented the FAA accumulation immediately and 0.5 h after ischemic insult while application of 5.0 mg/kg of MK-801 exerted a protective effect during the first 24 h. Global cerebral ischemia induces the significant decline in the Na+,K+-ATPase activity in the hippocampus starting from 1 to 168 h of reperfusion. Maximal inhibition was obtained 24 h after the ischemic damage. Application of 3.0 mg/kg of MK-801 exerted statistically significant protection during the first 24 h while the treatment with 5.0 mg/kg of MK-801 prevented fall in enzymatic activity during all reperfusion periods examined. Our results suggest that, in spite of different and complex pathophysiological mechanisms involved in the increase of FAA level and the decrease of the Na+,K+-ATPase activity, blockade of NMDA receptor subtype provides a very important strategy for the treatment of the postischemic excitotoxicity.

A single dose of PPARγ agonist pioglitazone reduces cortical oxidative damage and microglial reaction following lateral fluid percussion brain injury in rats

Neuroprotective actions of the peroxisome proliferator-activated receptor-γ (PPARγ) agonists have been observed in various animal models of the brain injuries. In this study we examined the effects of a single dose of pioglitazone on oxidative and inflammatory parameters as well as on neurodegeneration and the edema formation in the rat parietal cortex following traumatic brain injury (TBI) induced by the lateral fluid percussion injury (LFPI) method. Pioglitazone was administered in a dose of 1mg/kg at 10min after the brain trauma. The animals of the control group were sham-operated and injected by vehicle. The rats were decapitated 24h after LFPI and their parietal cortices were analyzed by biochemical and histological methods. Cortical edema was evaluated in rats sacrificed 48h following TBI. Brain trauma caused statistically significant oxidative damage of lipids and proteins, an increase of glutathione peroxidase (GSH-Px) activity, the cyclooxygenase-2 (COX-2) overexpression, reactive astrocytosis, the microglia activation, neurodegeneration, and edema, but it did not influence the superoxide dismutase activity and the expressions of interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha in the rat parietal cortex. Pioglitazone significantly decreased the cortical lipid and protein oxidative damage, increased the GSH-Px activity and reduced microglial reaction. Although a certain degree of the TBI-induced COX-2 overexpression, neurodegeneration and edema decrease was detected in pioglitazone treated rats, it was not significant. In the injured animals, cortical reactive astrocytosis was unchanged by the tested PPARγ agonist. These findings demonstrate that pioglitazone, administered only in a single dose, early following LFPI, reduced cortical oxidative damage, increased antioxidant defense and had limited anti-inflammatory effect, suggesting the need for further studies of this drug in the treatment of TBI.

Temporal and regional changes of superoxide dismutase and glutathione peroxidase activities in rats exposed to focal cerebral ischemia.

Reactive oxygen species are important cause of tissue injury during cerebral ischemia and reperfusion (I/R). Superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px) are intracellular enzymes responsible for endogenous antioxidant defense of tissues affected by I/R. The aim of this study was to examine temporal and regional changes of SOD and GSH‐Px activities in animals exposed to transient focal cerebral ischemia. Male Wistar Hannover rats were subjected to the right middle cerebral artery occlusion for 2 h. The animals were sacrificed immediately, 0·5, 1, 2, 3, 6, 24, 48, 72 or 168 h after ischemic procedure. SOD and GSH‐Px activities were determined spectrophotometrically in the hippocampus and parietal cortex, both unilaterally and contralaterally to the occlusion. Sham‐operated animals were used as the control group. Our results indicated that transient focal cerebral ischemia causes significant changes in SOD activities in the hippocampus and parietal cortex such as in GSH‐Px activities in the parietal cortex, unilaterally and contralaterally to the lesion in rats during different reperfusion periods. Statistically significant activation of GSH‐Px was registered neither in the right nor in the left hippocampus of ischemic animals. Copyright

Characteristics of blood‐pressure control in treated hypertensive patients in Croatia

The aim of our study was to investigate blood pressure (BP) control and different factors with possible influence on BP control in Croatian hypertensive patients. In this cross‐sectional investigation, a representative sample of target populations (primary care physicians and patients) from different parts of Croatia was included according to the study protocol. During December 2003 and January 2004, we included, according to correctly completed questionnaires, 141 physicians and 814 hypertensive patients. A controlled BP (BP<140/90 mmHg) in this hypertensive population treated with antihypertensive drugs was in 23% of patients. The analysis of BP control according to risk factors showed that significantly related with higher levels of systolic or diastolic BP were the age (poorer systolic BP control in patients older than 60 years), left ventricular hypertrophy, changes of the eye retina, smoking and diabetes mellitus. Furthermore, patients from towns closer to the hospital, from urban centers, with higher education and employed had significantly lower average BP. According to our results of hypertension control in Croatia, there is a need and a possibility for the improvement of the quality of hypertension care. The relationship between demographic and cardiovascular risk factors with poor BP control should be taken into account when treating patients.

Sildenafil induced choreoathetosis in men with Parkinson's disease

OBJECTIVE The present report describes a case of choreoathetotic movements which were most probably induced by sildenafil in a patient with Parkinsons disease (PD) treated with levodopa/carbidopa (LD/CD). CASE SUMMARY A 56-year-old retired man was admitted to hospital because of bizarre, involuntary movements and anxiety. Before admission he had taken sildenafil 100 mg. He had a previous history of PD for 5 years and during the last 3 years he was stable with long-acting LD/CD and selegiline. He is in Stage 2 according to Hoehn and Yahr Staging of PD. The patient did not have any problems with erectile function and he took sildenafil 50 minutes after the last daily dose of LD/CD. The patient was discharged from the hospital 12 hours after the admittance without any symptoms of choreoathetosis. CONCLUSION Choreoathetotic dyskinesia is an adverse effect which was provoked by sildenafil administration (drug abuse) in a previously stabile responder to LD therapy, but probably had a lower threshold for dyskinesia. Predisposition for this pharmacokinetic interaction could be a short time interval between LD and sildenafil applied in high dosage.

Antihypertensive Drugs in Croatia: What Changes the Drug Usage Patterns?

PURPOSE Possible factors that could influence changes in patterns of prescribing antihypertensives could be identified by monitoring national trends in hypertension treatment. The choice of pharmacologic treatment in people with hypertension has important therapeutic and financial implications, due to the fact that the financial costs associated with hypertension continue to increase. The aims of our study were to identify and analyze changes in the usage of antihypertensive drugs in Croatia from 2000 to 2016 and to identify the changes in prescribing patterns as well as mean prices per defined daily dose (DDD). METHODS Data on consumption in Croatia were obtained from the International Medical Statistics database. According to the World Health Organizations Collaborating Center for Drugs Statistics Methodology, per-annum volumes of drugs are presented in DDD per 1000 population per day (DDD/1000), while data on financial expenditure are presented in euros. FINDINGS The consumption of drugs for cardiovascular disease in Croatia during the period from 2000 to 2016 increased 150.81%, while financial expenditure in the same period increased 47.32%. The most frequently prescribed subgroup was agents acting on the renin-angiotensin system (RAS). Their share among antihypertensives increased from 39.13% (2000) to 53.39% (2016). The share of diuretics in the same period decreased from 20.16% in 2000 to 12.73% in 2016. IMPLICATIONS The prescribing patterns of antihypertensive drugs in Croatia have changed, which could be a result of a combination of different factors, such as changes in laws, pharmaceutical marketing, and guidelines on hypertension therapy. The most prescribed subgroup in all of the investigated years was agents acting on the RAS, mainly because of the increased prescribing of combinations of RAS agents plus diuretics. The financial implications of legal changes and the introduction of new generic drugs led to decreased cost per DDD of antihypertensives during the investigated period, but the total expenditure on antihypertensives in Croatia increased due to increased consumption.

Decrease in Oxidative Stress Parameters after Post‐Ischaemic Recombinant Human Erythropoietin Administration in the Hippocampus of Rats Exposed to Focal Cerebral Ischaemia

Recombinant human erythropoietin (rhEpo) is a multi‐functional drug with antioxidant potential. However, the underlying molecular mechanisms of its action are still unclear. The purpose of this study was to investigate the effects of rhEpo on the brain infarct volume as well as on the levels of the neuronal damage, oxidative stress parameters and active caspase‐3, nuclear factor erythroid 2‐related factor 2 (Nrf2) and haemeoxygenase‐1 (HO‐1) expressions in the hippocampi of rats exposed to the right middle cerebral artery occlusion (MCAO) for 1 hr. Ischaemic animals received either vehicle or rhEpo (5000 IU/kg, i.p.) immediately or 3 hr after the induction of ischaemia. Sham‐operated, vehicle‐treated animals served as the control group. Rats were killed 24 hr after the onset of the ischaemic or sham experimental procedure. MCAO caused ipsilateral brain infarction within the striatum and cortex. In the CA1 region of the hippocampi, we did not find significant neuronal loss, but a statistically significant rise in the active caspase‐3 and Nrf2 protein expressions was registered. We detected also significant increases in the hippocampal levels of oxidative stress parameters (thiobarbituric acid‐reactive substances, superoxide dismutase, glutathione peroxidase). Post‐ischaemic administration of rhEpo significantly reduced the brain infarct volume, decreased levels of all tested oxidative stress parameters and increased the Nrf2 expression level. These findings suggest that decrease in oxidative stress parameters in the hippocampus could be an early indicator of post‐ischaemic neuroprotective effect of rhEpo in rats exposed to focal cerebral ischaemia and that this effect could be attributable to additional post‐ischaemic activation of Nrf2 endogenous antioxidant system.

Personalized Medicine in Clinical Pharmacology

Clinical pharmacology includes the principles of personalized medicine as tailoring of medical treatment to the individual characteristics of each patient. In this chapter, three different areas of clinical pharmacology that are important in the individualization of the therapy (therapeutic drug monitoring, individualization in patients with renal and liver dysfunction, and pharmacogenetics/pharmacogenomics) have been presented. The main goal of therapeutic drug monitoring is to use drug concentrations to manage a patient’s medication regimen and optimize the outcome of the treatment. Proper dosage adjustment is of utmost importance in patients with liver or kidney dysfunction (main organs involved in the processes of metabolization and elimination of drugs). The recognition that a part of interindividual variability in drug response is inherited, and therefore predictable, created the field of pharmacogenetics/pharmacogenomics. Therefore, it is important to take into consideration all these specific fields, and the result will be adequate dosage for individual patients. This personalized therapy would maximize therapeutic efficacy, minimize drug toxicity, and can have an important economic impact on the health system. We presume, in the future, that personalized medicine will probably lose this adjective “personalized” since it is a unique medicine that uses all the tools we have at disposal in order to use drugs optimally for individual patients. In this approach, clinical pharmacologists certainly have a particularly important place.