Disturbances of thyroid function are often accompanied by cognitive and affective disorders. Assessment of cognitive status in the patients with subclinical hypothyroidism represents a possibility for early diagnostics of cognitive impairment and timely introduction of necessary pharmacotherapy treatment. The aim of this study was to quantify whether there are P3 event related potential (ERP) deviations as electrophysiological markers of cognitive activity in patients with subclinical hypothyroidism. P300 potentials were examined in thirty patients with subclinical hypothyroidism and in 30 healthy subjects of the control group. P300 was recorded using the classic auditory oddball paradigm, with 20% of target and 80% of non-target stimuli. The results analysis showed a significantly longer latency P300 and reduced amplitude P300 in subjects with subclinical hypothyroidism compared to euthyroid subjects. There is also a statistically significant negative correlation between the results of a mini mental state examination and the P300 latency at Fz electrode (r= -0.47, p <0.01) and Cz electrode (r= -0.43, p =0.017). P300 ERP is important in the evaluation of patients with subclinical hypothyroidism, due to the sensitivity in the detection cognitive disorders.

One of the best-studied responses of cognitive evoked potentials is a so-called “P300”, the late positive wave complex that occurs about 300-500 ms after the stimulus. It is obtained when the subject’s attention is focused on a signal that is rare, especially if the signal has a motivational or emotional meaning. In the study of P300 potential, we followed the variations of potential amplitude and latency, so the objective was to examine whether there is a difference in Fz and Cz amplitudes of auditory induced cognitive evoked P300 potential depending on the performance of oddball tasks, both in male and female subjects. The study included 60 subjects (30 female respondents and 30 male respondents). P300 potential is induced by the auditory "oddball" paradigm with 80% of non-target and 20% of target stimuli that are presented to the patient through headphones. The target tones are high tones of 2000 Hz. The standard, 1000 Hz tones the respondent should ignore but when he hears the target tones the respondent should press the button on the special handle. The value of Fz and Cz amplitudes both in male and female subjects obtained in the classical "oddball" paradigm when the subject reacted to the signal by pressing the key with the dominant (right) arm were statistically significantly lower (p>0,05) than the values of Fz and Cz amplitudes obtained when the key was pressed by the non-dominant hand. Based on this experiment it can be concluded that both in male and female subjects the performance of oddball tasks does not affect the amplitude of P300 cognitive evoked potentials.

Uloge endotelina u kardiovaskularnoj fiziologiji i patofiziologiji od njegovog otkrića do danas su neosporne. U srcu endotelini su značajni za procese razvoja, rasta i remodelovanja kao i za kontrolu kontraktilnosti i ritmičnosti. Srčane endotelne ćelije u endokardu i miokardnim kapilarima predstavljaju glavni izvor endotelina, a kardiomiociti su njihova primarna meta. Endotelin-1 je jedna od najpotentnijih poznatih supstanci sa pozitivnim inotropnim efektom, stoga endotelini imaju ključnu ulogu u srčanoj endotelno-miokardnoj interakciji. Endotelini su familija peptida od 21 amino kiseline koju čine endotelin-1, endotelin-2 i endotelin-3. Ostvaruju svoje efekte aktivacijom endotelinskih receptora, ETA i ETB, koji pripadaju familiji receptora vezanih za G proteine. ETA i ETB receptori su gusto distribuirani na kardiomiocitima, ćelijama provodnog sistema srca, koronarno vaskularnim i endokardno endotelnim ćelijama. U fiziološkim uslovima mesto sinteze endotelina su endotelne ćelije ali u patofiziološkim uslovima i veliki broj neendotelnih ćelija u srcu. Endotelin-1 ima pozitivno hronotropno i inotropno dejstvo. Administracija ET-1 uzrokuje koronarnu vazokonstrikciju, dovodi do ishemije miokarda i letalne ventrikularne aritmije. U akutnom infarktu miokarda ET-1 povećava miokardnu nekrozu i aritmije ali ima povoljan efekat na oporavak srca nakon infarkta u početnoj fazi remodelovanja srca. ET-1 preokreće acidozom indukovan negativan inotropan i luzitropan efekat, bez povećanja intracelularnog kalcijuma. Endotelin može da se suprotstavi aritmogenim efektima kateholamina. Tako, male koncentracije endotelina imaju protektivni efekat na srce. Osnovne indikacije za primenu antagonista endotelina jesu srčana insuficijencija, plućna hipertenzija i rezistentna arterijska hipertenzija. Dobro i pažljivo dizajnirane kliničke studije su potrebne za verifikaciju terapeutskih potencijala novih klasa lekova u kardiovaskularnoj medicini.

Scientific researches considering the effects of glucagon on cardiovascular system show that glucagon has a certain cardiostimulative potential. The fact that glucagon accomplishes its cardiostimulative effects by activating its own, highly specific glucagonic receptors is of most importance. That's the reason why we've wanted to give more details about the effects that glucagon has on cardiovascular system in terms of having more precise image of its effects on hemodynamics and changes which can be seen on electrocardiogram. The experiment included six dogs treated with intravenous glucagon injection. Electrocardiograph and hemodynamic parameters (middle arterial pressure, central venous pressure and heart st nd rd th th th th th frequency) have been recorded in 1 , 2 , 3 , 5 , 10 , 20 , 30 and 40 minute. Electrocardiograph and heart frequency have been recorded by continuous monitoring. Middle arterial pressure has been recorded through catheter placed into a. femoralis while central venous pressure has been recorded through central venous catheter placed into v. femoralis. Having received the intravenous injection, glucagon shows extremely positive chronotropic effect, followed by ephemeral increase of middle arterial pressure, while central venous pressure has a significant decrease. Having received intravenous injection, P-R, Q-Tand T-Pinterval have been significantly shorten.

Alpha lipoic acid is the most efficient of all known antioxidants for its lipo and hydrosolubility which enable easy penetrability in cytoplasm making its protection of free reactive radicals, energetic metabolism, regulation of genetic expresion etc. It has wide application in prevention and in therapy of diabetic angiopathy, neuropathy, cardiovascular, cerebrovascular, neurodegenerative disease, lesion, (insufficiency) of liver, HIV, intoxication with hard metals, mycotoxins etc. An important proprety of lipoic acid is its possibility to prevent or remove lesions which are caused by application aminogycosides and haloperidol (ototoxicity, nephrotoxicity) according to its wide application. R isomer of lipoic acid is physiological substance presented in organism which synthesize in in liver enabling its its application in relatively high dose for a longer period of time.

L-carnitine is assorted with non-vitamin nutritives (metavitamines) on the grounds of importance to the living process, while itb similar to aminoacids in terms of structure. It has multistructural role in functioning of an organism while one of the most important and best investigated roles is the sphere of energizing metabolism because it is needed for the transport of the longchain fatty acids into the mitochondria where they are subject to a β oxidation. It has widespread clinical application in prevention and therapy of: genetic and secondarycarnithine deficiency, cardiovascular disease, lipid metabolism disorder, carbohydrate metabolism disorder, aciduria of organic acids, renal and liver insuficiency, neuropathy, miopathy, as well as the means for improvent of fitness capacites of sportsmen. L-carnitine is crucial part of organism of mamals, therefore it can be applied in relatively big doses whereby it requires no detoxication in liver, on the contrary, it significaty increases its detoxication capacites. Key words: L-carnitine, Physiology, Prevention , Therapy. L-carnitine is assorted with non-vitamin nutritives (metavitamines) on the grounds of importance to the living process, while itb similar to aminoacids in terms of structure. It has multistructural role in functioning of an organism while one of the most important and best investigated rol condarycarnithine deficiency, cardiovascular disease, lipid metabolism disorder, carbohydrate metabolism disorder, aciduria of organic acids, renal and liver insuficiency, neuropathy, miopathy, as well as the means for improvent of fitness capacites of sportsmen. L-carnitine is crucial part of organism of mamals, therefore it can be applied in relatively big doses whereby it requires no detoxication in liver, on the contrary, it significaty increases its detoxication capacites.

The most important characteristic of calcium channels is a selective regulation of a slow incoming current of calcium into the tissue cells with tendency of a slow growth of the action potential. Such tissues include smooth muscles of the blood vessels, cardiocities and hearth noduses (AVand SAnode). Different calcium antagonists have different influences on the mentioned tissues, because they also have different chemical components. Verapamil, Nifedipin and Diltiazem have the most common usage. Verapamil is a product of papaverine, nifedipin is a product of dehydroperidine while diltiazem is a product of benzodiazepine. Their common characteristic is blocking the calcium channels which cause blood vessels vasodilatation, negative inotropic and negative chronotropic influence. By blocking calcium to enter through channels spores of miofibrile smooth muscles, calcium antagonists are reducing the amount of available calcium for contraction, which causes vasodilatation. One of the best-known and the commonest calcium antagonist is verapamil. In electrophysiological terms, it inhibits action potential of the heart noduses (especially AV node), where the most important thing for depolarisation, is a slow entrance of calcium. By extending the refractory period of SA node, it reduces the frequency of impulse generation (heart frequency), while by extending the refractory period of AVnode, it slows down the work of chambers in cases of flater and atrium fibrillation. Taking into consideration the fact that verapamil shows cardiodepresive effects, the aim of our work is to study closely its effects on electrocardiogram and hemodynamic parameters. The experiment was conducted on six adult, healthy dogs which were, after 10 minutes 0,9% NaCl infusion, treated with i.v. bolus verapamil injections on every 5 minutes until the appearance of intoxication signs, which causes bradycardia, heart rhythm disorder and the fall of arterial blood pressure. The average verapamil dose was 4 mg per kilogram. After i.v. verapamil administration, heart frequency and middle arterial pressure have a significant fall, while central venous pressure has a significant rise. Larger verapamil doses nd rd can significantly extend T-P and P-R interval with the appearance of AV-block (2 and 3 grade), while the Q-T interval doesn't show any significant change.

Artrial hypertension is a very serious social-medical probleme as such has an epidemic characteristics according to high prevalence at incidence frequency disease of young, a high death rate, there is also a somewhat difficult erly diagnosis at the early stages of illnes due to unspecified clinical examination in majority of diseased. On the basis of etiology, arterial hypertension is divived into: primary (essential) and secondary (symptomatologic). According to the current criteria, primary arterial hypertension is considered to be all the cases where etiology cannot identify only the cause or a specific structural change in a organ. It instead causes a larger number of etiological factors by their group actions which are called risk factors.Including the secondary hypertension all cases at arterial hypertension are classified und there can be seen a specific structural change in an organ and disorder of it's function. The aim of our work was to determinate which were the familiar risk factors in development of arterial hypertension and it's domination to inhabitants of Zubin Potok considering high prevalence of arterial hypertension out of 6500 inhabitants in the infirmary of Zubin Potok, 2450 patients are registrated with arterial hypertension. Examination is performed to 100 patients with primary arterial hypertension by prospectus analysis which are registrated consecutively in the interval of two months by biochemicals parametars, a height of systolic and dyastolic arterial pressure and BMI. By means of questionnaire the rest of risk factors are gathered with a piece of data smoking, alchoholism and stress. During the examination we determined that the most typics risk factor is disorder of metabolism of lypoproteins, and important pathothysiological mechanism in development of arterial hypertension is reduction of HDLcholesterol, which can be one of indirect indentifier of oxidative stress.

Nowdays, reaction time is most often used in data processing as a quantitative method and technique for information step and speed processing. The aim of this investigation was to examine everyday work pressure on reaction time nd among students. An examination included 30 students of 2 year of Medicine Faculty 15 males and 15 females. Audible and visual simple reaction time as well as choice reaction time for 2, 4 and 6 stimuli was used for reaction time measurement. Measurements were done three times a day. Achieved results acknowledge statistically significant improvement of reaction time at noon compared to reaction time in the morning in all samples except for visual simple reaction time for male students. For all kinds of stimuli, reaction time were significantly prolonged in the evening in both groups. Therefore, we have concluded that morning activities had positive impact on students functional condition but afternoon activities acted like an additional stress that altered students latent fatigue to clearly observable acute fatigue.

Systematic and programmed physical exercise, called training, play a significant role in human health and ability improvement. A moderate physical exercise is considered as a very efficient method of increasing general physical ability and reaching the top results in sport, and simultaneously contributes to health quality of persons having sedentary professions. In active sportspersons, ability of cardiovascular, respiratory and bone-muscle systems are determined by training quality itself. Sportspersons show characteristically better adaptability of neurohumoral system to effort, as well as a higher activity of intracellular enzyme systems. Well-dosed physical exercise has an exceptional influence on human health, above all by regulating cholesterol blood level and electrolyte level of serum, whose minimal change can directly affect human health. This study was aimed to establish quantity and quality of organism response to physical exercise, in regard to level of daily training, by determining lipid fractions level in serum and electrolyte composition of serum. The study involved 50 healthy men in age between 20 and 25, divided into two groups. The first group was composed by physically untrained men, chosen by the random sample method. The other group of subjects was composed by 35 active sportsmen, chosen by direct selection for the best-trained ones among them. In order to reach a submaximal exertion, we used Astrand's test of submaximal exertion on the bicycle-ergometer. Blood samples were taken immediately before and after testing. The following parameters were determined in blood serum: high-density lipoproteins (HDL), low-density lipoproteins (LDL), triglyceride + + 2+ 2+ - content, as well as concentration of sodium (Na ), potassium (K ), calcium (Ca ), magnesium (Mg ) and chlorine (Cl) ions. On the base of our research we concluded that physical exercise of submaximal intensity did not lead to any quantitative and qualitative change of lipid fractions in blood serum of untrained persons. Physically inactive persons had higher serum concentrations of triglycerides and total cholesterol in regard to the investigated sportsmen. At the same time, sportsmen showed a higher HDL content of serum. Physical exertion in sportsmen led to a significant rise of triglycerides and highdensity lipoproteins content of serum, and the levels of total cholesterol and low-density lipoproteins did not changed + ++ significantly. Physical exertion of submaximal intensity in both studied groups caused a significant increase of Na , Ca and ++ + - Mg ion concentration, while concentration of K and Cl ions did not changed significantly. Numerous clinical studies showed that moderate aerobe exercise amplifies endothelial function and reduces cardiovascular risk