Summary: The effects of an alpha2 adrenoceptor blocker, yohimbine, and an alpha1 adrenoceptor blocker, phenoxybenzamine, and the central alpha2 adrenoceptor agonist, clonidine, on changes in arterial blood pressure and heart rate were studied during fatiguing muscular contractions to determine whether an adrenergic-opioidergic system might be involved in the mediation of cardiovascular function. Fatiguing contractions of the gastrocnemius and plantaris muscles of cats caused an increase in mean arterial blood pressure to 150-170 mmHg from resting values of 110-120 mmHg. Injection of clonidine into the cerebral aqueduct eliminated the increase in blood pressure; this effect was dose dependent. Naloxone antagonised the effects of the highest dose of clonidine (5 μg). Injections of yohimbine (1 μg) into the cerebral aqueduct had no significant effect on this pressor response. Yohimbine (1 μg) effectively counteracted the antipressor effects of clonidine when the two drugs were injected together until higher doses of clonidine (2-5 μg) were used. Phenoxybenzamine had no effect on the pressor response itself but unlike yohimbine was able to attenuate the effects of clonidine only when injected together. These data suggest that activation of muscle ergoreceptor afferent nerve fibres (group III and IV fibres) during muscular contractions may cause an increase in arterial blood pressure by interfering with an inhibitory adrenergic-endorphinergic pathway in the medullary region of the brainstem.

Tikslas: Išanalizuoti kvėpavimo sulaikymo įtaka blauzdos raumenų arterinei kraujotakai. Uždaviniai: 1. Nustatyti sportuojančių ir nesportuojančių merginų blauzdos raumenų arterinės kraujotakos kaitą sulaikius kvėpavimą iki negalėjimo. 2. Nustatyti arterinio kraujo spaudimo dažnių rodiklių kaita sulaikius kvėpavimą. Tyrimo metodai: Arterinio kraujo spaudimo (AKS) matavimai Korotkovo metodu ir arterinės kraujotakos registracija – veninės okliuzinės pletizmografijos metodu. Tyrimo organizavimas: Tyrime dalyvavo dešimt sportuojančių (adaptuotų greitumo – jėgos fiziniams krūviams) ir aštuoniolika nesportuojančių merginų. Arterinė kraujotaka blauzdos raumenyse ir AKS buvo registruojami po 20 min adaptacijos ramybės būsenoje, bei sulaikius kvėpavimą ir atsigavimo metu. Buvo atliekami du kvėpavimo sulaikymai iki negalėjimo. Rezultatai. Pirmojo kvėpavimo sulaikymo metu sportuojančių merginų kraujotaka mažėjo ir pabaigoje ji sumažėjo iki 1,5±0,3ml/100 ml/min. Atsigavimo metu kraujotakos intensyvumas pirmąją minutę didėjo ir prieš antrąjį sulaikymą beveik pasiekė pradinį lygį. Arterinės kraujotakos intensyvumas antrojo kvėpavimo sulaikymo metu didėjo, tačiau praėjus 45sek pradėjo nežymiai mažėti. Atsigavimo metu kraujotakos intensyvumas sumažėjo analogiškai, kaip ir po pirmo sulaikymo. Atsigavimo pabaigoje pradėjo didėti link pradinio lygio. Nesportuojančių merginų pirmojo kvėpavimo sulaikymo metu kraujotaka mažėjo ir pabaigoje ji sumažėjo iki 1,6±0,38ml/100 ml/min (p<0.05)... [toliau žr. visą tekstą] / Research aim - is to assess influence of arterial blood flow changes in the calf muscles during breathing stop. Research tasks – 1. Establish changes in the calf muscle blood flow before, during and after breathing stop for athletic and non-athletic girls. 2. Establish changes in arterial blood pressure before, during and after breathing stop for athletic and non-athletic girls. Research methods – arterial blood flow changes using venous occlusive plethysmography method, arterial blood pressure using Korotkoff sounds method. Research organization – The study involved 10 athletic (adapted to speed - strength exercise) and 18 non-athletic girls. The examinations were conducted at a room temperature of 18–20O C with the patient in a sitting position. Each girl was introduced with instruction of the research and explained to them, how everything will work. Arterial blood flow in the calf muscle and arterial blood pressure was recorded after 20 min of adaptation at rest, during breathing stop and at recovery time. Research was made of two breathing stop. Recovery from breathing stop was recorded 5min. The blood flow in the calf was determined by venous occlusion plethysmography. Research results – Athletic girls arterial blood flow during first breathing going down and in the end of first breathing stop was stop 1,5±0,3ml/100 ml/min. For non-athletic girls it was similar 1,6±0,38ml/100 ml/min. But during second breathing stop for athletic girls arterial blood flow was 2,4±0,7... [to full text]

Physical activity has versatile impact on female body and strengthens it in addition to improved physiological powers, more active performance of all systems and guaranteed normal course of pregnancy period. As a result, the cardiovascular condition is improved; placental circulation is more active, oxygen transopration and metabolism of the foetus is improved. The death-rate in pregnant women resulting from hypertension is the second after embolism. Preeclampsia is one of the hypertension-related failures, which affects 3 to 5 % of the pregnant women. The present research was targeted to women suffering from preeclampsia. The aim of the research was to investigate the impact of physical activity on manifestation of preeclampsia in pregnant women within 20-35 week of pregnancy. Tasks: 1. to assess arterial blood pressure (ABP) fluctuation of both groups of women (physically passive and physically active within 20-35 weeks of pregnancy; 2. to assess body weight index fluctuation of both groups of women (physically passive and physically active within 20-35 weeks of pregnancy; 3. to assess fluctuation of protein content in urine of both groups of women (physically passive and physically active within 20-35 weeks of pregnancy; 4. to assess life quality (sleep, headache, sight, right underrib pains, physical and physiological fatigue) of both groups of women (physically passive and physically active within 20-35 weeks of pregnancy. Hypothesis. Physical activity in pregnant women... [to full text]

Nėštumas tai fiziologinė sveikos moters būsena. Fizinio aktyvumo stoka nėštumo metu įtakoja nėščiosios savijautą. Nėščiųjų, kurios neatlieka fizinių pratimų kūno masė būna didesnė, negu reguliariai dariusios mankštą nėštumo metu. Fiziškai neaktyvių nėščiųjų širdies susitraukimų dažnis (ŠSD) būna didesnis, nei sportuojančių moterų. Pagal PSO 25 % nėščiųjų skundžiasi nugaros skausmais, susijusius su atramos judamojo aparato pokyčiais nėštumo metu. Daug dėmesio skiriama nėščiųjų sveikatingumui, tačiau nepakankamai pabrėžiama kineziterapijos nauda nėščiosios savijautai, gimdymo eigai. Literatūroje yra nemažai duomenų apie fizinių pratimų teigiamą poveikį moters organizmui, tame tarpe ir nėščiųjų, tačiau kaip taikant fizinius pratimus vandenyje keičiasi nėščiosios riebalinės raukšlės, arterinis kraujo spaudimas ir širdies susitraukimų dažnis nėra žinoma Šio tyrimo tikslas – įvertinti fizinių pratimų vandenyje poveikį nėščiosios savijautai ir kai kuriems fiziologiniams rodikliams. Tyrimo tikslui pasiekti buvo naudojami šie tyrimo metodai: 1. Anketinė apklausa; 2.Riebalinių raukšlių matavimas (kaliperiu); 3.Arterinio kraujospūdžio (mmHg) ir pulso matavimas; 4.Rufjė testas; 5. Matematinė statistika. Tyrimas buvo atliekamas Vilniaus Lietuvos vaikų jaunimo centre (LVJC). Ištirta 20 nėščiųjų, kurios lankė reguliariai užsiėmimus baseine du kartus savaitėje. Antroji grupė, kontrolinė, sudarė taip pat 20 nenėščių moterų, atsitiktinių, panašaus amžiaus, kaip ir nėščiosios. Abiems grupėms... [toliau žr. visą tekstą] / Pregnancy is a physiological appearance of a healthy woman. The lack of physical activities affects the health of pregnant woman. Those women, who do not have any physical activities, have bigger body mass, than those, who exercise regularly. Physically inactive pregnant women have bigger heart systole rate (HSR), than active once. According to PSAO 25 % of pregnant woman complain about back pains, related to changes of abutment during the period of pregnancy. A lot of attention is spared to the health of pregnant women. Unfortunately, the importance of kinezitherapy to pregnant women health is not enough emphasize. There is a lot of information in the literature about the positive effect of physical exercise to women’s´ body, including pregnant once. But, when using kinezitherapy in the water the relative body fat – body muscle mass is changing and the heart systole rate (HSR) are unknown. The importance of this research is to evaluate the effect of physical exercises in the water to a pregnant woman and some physiological indexes. The methods of this research are: 1. Questionnaires; 2. Measurement of oil wrinkles; 3. Measurement of Arterial blood pressure (mmHg) and measurement of pulse; 4.Rufje test; 5. Mathematical statistics. The research was done in Vilnius Lithuanian children and junior centre. There were examined 20 pregnant women (analyzed group) who took part in water activities 2 times a week. In the second group, (control group) there were 20 not pregnant women... [to full text]

Darbo problema – vis dar lieka neaiškus PRR efektyvumas ir jos sąsajos su amžiumi, lytimi, išsilavinimu, IŠL forma, subjektyvia savijauta, subjektyviu sveikatos vertinimu bei organizmo raumenų įtampa, sergantiems IŠL. Todėl šio tyrimo tikslas - nustatyti progresuojančios raumenų relaksacijos taikymo efektyvumą AKS reguliavimui, atsižvelgiant į lytį, amžių, ligos formą, subjektyvų sveikatos vertinimą, išsilavinimą, raumenų įtampą ir subjektyvią savijautos įtampą, sergantiems IŠL, stacionarinės reabilitacijos etape. Tyrime buvo pakviesti dalyvauti 204 Abromiškių reabilitacinės ligoninės, kardiologinio skyriaus pacientai, tačiau į 1 užsiėmimą atėjo 53 (48,18 %) vyrai ir 40 (42,55 %) moterų, į 2 – 20 (18,18 %) vyrų ir 14 (14,89 %) moterų, į 3 – 15 (13,63 %) vyrų ir 12 (12,76 %) moterų ir į 4 – 12 (10,9 %) vyrų ir 8 (8,51 %) moterys. Tiriamieji dalyvavo 4 vienos valandos užsiėmimuose, kurie vyko 4 kartus per savaitę. Siekiant įvertinti PRR efektyvumą AKS mažinimui ir efektyvumo sąsajas su prieš tai išvardintais faktoriais, tiriamiesiems buvo pateikiamos anketos, vedami relaksaciniai užsiėmimai. Kiekvieno užsiėmimo pradžioje ir pabaigoje buvo matuojamas AKS ir duodamas užpildyti manekenas (raumenų įtampai įvertinti) bei subjektyvios savijautos skalė. Tyrimo rezultatai parodė, kad po relaksacijos AKS statistiškai reikšmingi sumažėjimai buvo tik vyrų tarpe, taip pat tarp jaunesnių pacientų, žmonėms sergantiems lengvesne IŠL forma, pacientams su aukštuoju išsilavinimu ir blogesniu... [toliau žr. visą tekstą] / It is still unclear if effectiveness of PMR is related with age, gender, education, IHD form, subjective health status, subjective tension and muscle tension for ischemic heart disease patients. So the aim of this survey is to analize how effectiveness of progressive muscle relaxation in blood pressure regulation is related with these factors for ischemic heart disease in-patients at their rehabilitation period. 204 patients from Abromiškės rehabilitation hospital, cardiac department were invited to participate in relaxation groups, but in the first group participated only 53 (48,18%) men and 40 (42,55%) women, in the second - 20 (18,18%) men and 14 (14,89%) women, in the third - 15 (13,63%) men and 12 (12,76%) women and in fourth - 12 (10,9%) men and 8 (8,51%) women. Participants attended in four hourly relaxation groups which were four times per week. With the purpose to evaluate PMR effectiveness for blood pressure regulation and its’ relation with factors, participants were given questionnaires also relaxation groups were provided. At the beginning and at the end of each session blood pressure was measured also muscle tension was evaluated with the given model and 10 score scale was given for subjective feeling evaluation. The results of this study showed that the statistically significant reductions of blood pressure were only for men also for younger patients and patients with higher education, for patients with easier IHD form and for patients with worse... [to full text]

Tikslas: Išanalizuoti griaučių raumenų arterinės kraujotakos ir fizinio darbingumo kaita atliekant 120 mm Hg slėgio okliuzines treniruotes Uždaviniai: 1. Nustatyti arterinio kraujo spaudimo ir blauzdos raumenų arterinės kraujotakos intensyvumą ramybės būsenoje be okliuzijos ir su 120 mm Hg okliuzija. 2. Nustatyti arterinio kraujo spaudimo ir blauzdos raumenų darbingumo kaitą be okliuzijos ir su 120 mm Hg slėgio okliuzija. 3. Nustatyti arterinio kraujo spaudimo ir blauzdos raumenų arterinės kraujotakos ir darbingumo kaitą atliekant treniruotes, be okliuzijos ir su 120 mm Hg okliuzija. Tyrimo metodai: Dinamometrija, ergometrija, veninė okliuzinė pletizmografija, pulsometrija, arterinio kraujo spaudimo (AKS) matavimai. Tyrimų organizavimas: Pirmo etapo tyrimo, kontrolinėje grupėje – registruojama kraujotaka ir AKS ramybėje ir 15 min be okliuzijos, o eksperimentinėje – su 15 min okliuzija. Antro etapo tyrimo kontrolinėje grupėje registruojama arterinė kraujotaka ir AKS ramybėje ir po 75 % MVJ fizinio darbo kilnojant svarmenį iki visiško nuovargio. Eksperimentinėje grupėje tarp dviejų fizinių krūvių atliekama 15 min okliuzija. Trečio etapo tyrimo kontrolinėje grupėje registruojama arterinė kraujotaka, AKS, ŠSD, bei atliko vienos savaitės treniruočių ciklą. Analogiškai tyrimas buvo atliktas ir eksperimentinėje grupėje, tik buvo atliekama okliuzija. Rezultatai. Pirmo etapo tyrimo eksperimentinės grupės okliuzja 120 mm Hg mažina arterinę kraujotaką. Antro etapo kontrolinėje grupėje... [toliau žr. visą tekstą] / Objective: To analyze the skeletal muscle of arterial blood flow and changes in physical working capacity 120 mm Hg pressure occlusive workouts Goals: 1. Set of arterial blood pressure and arterial calf muscle blood flow at rest without occlusion and 120 mm Hg occlusion. Second Set of arterial blood pressure and calf muscle work change without occlusion and 120 mm Hg pressure occlusion. 3rd Set of arterial blood pressure and calf muscle blood flow and arterial capacity change during workouts without occlusion and 120 mm Hg occlusion. The research methods: Dynamometry, ergometry, venous occlusive plesthysmography, heart rate, arterial blood pressure (BP) measurements. Research Organization: The first phase of the study, the control group - keeping the blood flow and blood pressure at rest and 15 min without occlusion, and experimental - to 15-minute occlusion. The second phase of the study in the control group recorded arterial blood flow and blood pressure at rest and 75% MVC physical work lifting a weight up to full weariness. In the experimental group between two physical workloads performed 15 min occlusion. The third phase of the study in the control group recorded arterial blood flow, blood pressure, heart rate, and performed a one-week training cycle. Similarly, the study was conducted, and the experimental group, but occlusion was performed. Results. The first phase of the study the experimental group okliuzja 120 mm Hg reduces arterial blood flow. The second phase of... [to full text]

Whereas the effects of a long-term activity of head-down tilt (HDT) in the angle between 3ř and 12ř were examined in details in cosmic medicine as the model of a state of weightlessness, literature concerning effect of HDT on cardiovascular control in the angle over 30ř is scarce. The aim of the thesis is to examine acute reaction of systolic, diastolic, mean arterial blood pressure and heart rate during three minutes of 30ř, 50ř and 70ř HDT, realized on a tilt (inversion) table with fixed legs. For the combination of HDT and head-up tilt (HUT), the following protocol was chosen: 5 minutes lying in a horizontal position (HOR), 3 minutes of 70ř HUT, 3 minutes of 30ř HDT, 3 minutes of HOR, 3 minutes of 50ř HDT, 3 minutes HOR, 3 minutes of 70ř HDT, 3 minutes HOR and 3 minutes of 70ř HUT. A non-invasive continuous Peňáz method, using Finapres Ohmeda, was used to monitor beat-by-beat blood pressure and heart rate. Blood pressure was also measured by sphygmomanometer each minute for calibration. In the angle of 30ř HDT, there was a significant decline of heart frequency (p < 0,01). During the 50ř HDT, there was a significant rise of systolic blood pressure in the third minute, of diastolic and mean arterial pressure each minute and the heart rate dropped significantly (all p < 0.05). In the 70ř HDT,...

Tyrimo tikslas – nustatyti sergančių išemine širdies liga asmenų emocijų ir arterinio kraujo spaudimo kitimus taikant ekspresyvaus rašymo metodą psichosocialinės reabilitacijos metu. Tyrime dalyvavo 164 kardiologiniame skyriuje besigydantys pacientai. Keturių užsiėmimų kursą baigė 126 pacientai: 58 vyrai ir 68 moterys. Tiriamieji dalyvavo keturiuose 30 minučių trukmės užsiėmimuose. Užsiėmimai vyko keturias dienas iš eilės. Buvo siekiama įvertinti ekspresyvaus rašymo metodo veiksmingumą pacientų emocinės būsenos ir arterinio kraujo spaudimo kitimams. Buvo sudarytos trys tyrimo dalyvių grupės: a) ekspresyvaus rašymo grupė, kurios dalyviai rašė savo išgyvenimus susijusius su liga; b) neutralaus rašymo grupė, kurios dalyviai rašė apie kasdienę veiklą; c) lyginamoji grupė. Kiekvieno užsiėmimo pradžioje ir pabaigoje buvo matuojamas kraujo spaudimas. Pirmojo ir paskutiniojo užsiėmimų metu tiriamųjų buvo prašoma įvertinti savo emocinę būseną. Tyrimo rezultatai parodė, kad ekspresyvaus rašymo grupės dalyvių neigiamų emocijų pokytis buvo didesnis lyginant su neutralaus ir lyginamąja grupėmis. Ekspresyvaus rašymo grupėje „linksmumo“ pokyčiai didesni lyginant su lyginamąja grupe. Kitos teigiamos emocijos nesiskyrė tarp trijų tyrimo dalyvių grupių. Ekspresyvaus rašymo grupėje sistolinio AKS pokyčiai nėra didesni lyginant su neutralaus rašymo grupe, bet didesni lyginant su lyginamąja grupe. Diastolinio AKS pokyčiai nesiskyrė tarp trijų tyrimo dalyvių grupių. AKS mažėjimą nepaaiškina... [toliau žr. visą tekstą] / The aim of research – to determine the changes of emotions and arterial blood pressure of the patients with ischemic heart disease by applying the method of expressive writing during psychosocial rehabilitation. 164 patients of cardiology department participated in the survey. 126 patients ( 58 men and 68 women) completed the course of four session. The patients attended four 30 min meetings four days in a row. The goal was to evaluate the efficiency of expressive writing for the changes of emotions and arterial blood pressure. The patients were divided into three groups: a) a group of expressive writing, the participants of which wrote their experiences related to the disease b) neutral writing group, where the participants wrote about everyday activities; c) control group. At the beginning and at the end of each meeting their blood pressure was measured. The participants had to evaluate their emotional state during the first and the last meetings. The survey results showed that the change of negative emotions was higher in the participants of expressive writing than in the groups of neutral or control. The changes of „happiness“ were higher in expressive writing group than in control group. Other positive emotions did not differentiate among the groups. The changes of systolic blood pressure in expressive writing group were not higher than in the neutral group, but higher in comparison with control group. The changes of diastolic blood pressure did not differ among the... [to full text]

Perioperative hypotension corresponds to critically low blood pressure events during the pre, intra and postoperative periods. It is a common side effect of general anaesthesia and is strongly associated with an increased risk of postoperative complications, such as acute kidney injury, myocardial injury and in the worst case death. Early treatment of hypotension, preferably even before onset, is crucial in order to reduce the risk and severity of its associated complications. This work explores methods for predicting the onset of hypotension which could serve as a warning mechanism for clinicians managing the patient’s hemodynamics. More specifically, we present methods using only the arterial blood pressure curve to predict two different definitions of hypotension. The presented methods are based on a Convolutional Neural Network (CNN) trained on data from patients undergoing high-risk surgery. The experimental results show that our network can predict hypotension with 70% sensitivity and 80% specificity 5 minutes before onset. The prediction performance is then quickly reduced for longer prediction times, resulting in 60% sensitivity and 80% specificity 15 minutes before onset. / Perioperativ hypotension motsvarar perioder av kritiskt lågt blodtryck före, under och efter operation. Det är en vanlig bieffekt av generell anestesi och är starkt associerad med ökat risk av postoperativa komplikationer, så som akut leverskada, myokardskada och i värsta fall dödsfall. Tidig behandling av hypotension, helst innan perioden börjar, är avgörande för att minska risken och allvarlighetsgraden av postoperativa komplikationer. Det här arbetet utforskar metoder för att förutspå perioder av hypotension, vilket skulle kunna används för att varna vårdpersonal som ansvarar för patientens hemodynamiska övervakning. Mer specifikt så presenteras metoder som endast använder artärblodtryck för att förutspå två olika definitioner av hypotension. Metoderna som presenteras är baserade på ett Convolutional Neural Network (CNN) som tränats på data från patienter som genomgår högriskoperation. De experementella resultaten visar att våran modell kan förutspå hypotension med 70% sensitivitet och 80% specificitet 5 minuter i förväg. Förmågan att förutspå hypotension avtar sedan snabbt för längre prediktionstider, vilket resulterar i 60% sensitivitet och 80% specificitet 15 minuter i förväg.

Toxinas que atuam em canais para Na+ operados por voltagem são as principais responsáveis pelos efeitos tóxicos do envenenamento escorpiônico e podem ser divididas em duas classes: a- e b-neurotoxinas. TsTX-V e TsTX-I da peçonha de Tityus serrulatus (TsV) são, respectivamente, exemplos destas toxinas. Neste trabalho, foram avaliados os efeitos da TsV e destas toxinas sobre a pressão arterial média (PAM) e liberação de catecolaminas em ratos conscientes e não imobilizados, previamente cateterizados, bem como a captação de GABA, dopamina (DA) e glutamato (Glu) em sinaptosomas isolados de cérebro de ratos e a concentração citoplasmática de Ca+2 ([Ca+2 ]C) em células de músculo liso vascular de aorta de ratos. As toxinas foram isoladas por cromatografia de troca iônica (TsTX-I) seguida por CLAE de fase reversa (TsTX-V). As toxinas (15 e 30 g/kg) e TsV (50 e 100 g/kg) foram injetadas intravenosamente. A PAM foi monitorada continuamente através do cateter femoral. Os níveis plasmáticos de adrenalina (ADR) e noradrenalina (NA) foram determinados por CLAE de fase reversa com detector eletroquímico, em 10 min antes e 2,5, 30 e 90 min após os tratamentos. Efeitos pressores máximos foram observados em 2,5?3,5 min. TsV induziu um intenso aumento de longa duração na PAM, bem como a TsTX-I. A TsTX-V mostrou efeitos pressores menores. TsV mostrou os maiores efeitos sobre a liberação de catecolaminas, seguido pela TsTX-I e TsTX-V com um efeito máximo em 2,5 min, seguido por uma gradual redução, permanecendo, todavia, maior que os controles. Embora ambas as classes de toxinas atuem em canais para Na+, TsTX-I mostrou efeitos mais significantes e intensos sobre a liberação de catecolaminas e pressão arterial que a TsTX-V. Parece que a toxicidade da TsTX-V não está somente relacionada à sua capacidade de liberar catecolaminas, indicando que outros neutrotransmissores podem estar envolvidos em sua toxicidade. Nem a TsV ou suas toxinas foram capazes de afetar a captação de 3H-Glu. TsTXI inibiu somente a captação de 3H-DA (IC50 = 28,41 nM). Por outro lado, TsV (0,43ng/mL) inibiu a captação de 3H-GABA e 3H-DA (~50%). TsTX-V mostrou IC50 = 9,37 nM e 22,2 nM para a captação de 3H-GABA e 3HDA, respectivamente. Esses efeitos foram abolidos pelo pré-tratamento com TTX, indicando o envolvimento de canais para Na+ neste processo. Na ausência de Ca+2 e em baixas concentrações de toxinas, a redução não é tão singnificante como na presença de Ca+2. TsTX-V não reduziu a captação de 3H-GABA em células COS-7 expressando os transportadores de GABA, GAT-1 e GAT-3, sugerindo que esta toxina reduz indiretamente o transporte. A redução da captação de 3H-GABA pelos sinaptosomas pode ser devido a rápida e intensa despolarização celular, como revelado por microscopia confocal em células de glioma C6. Assim, TsTX-V causou redução da captação de 3H-GABA e 3H-DA de uma maneira independente de Ca+2, não afetando diretamente os transportadores de GABA, mas em consequencia da despolarização, envolvendo canais para Na+ operados por voltagem. TsV e suas toxinas foram capazes de aumentar a ([Ca2+ ]C , provavelmente por interargir com canais para Na+. Quando comparado aos efeitos despolarizantes do KCl 60 mM (100 %), TsV (100 e 500 g/mL) exibiu um aumento de 49,60 ± 2,58 % e 103,66 ± 5,17 %, respectivamente, enquanto que a TsTX-I e TsTX-V (50 e 100 g/mL de cada) exibiu 43,92 ± 3,06 % e 121,8 ± 8,9 %; 52,56 ± 8,33 % e 79,5 ± 6,1 % de aumento, respectivamente. TsTX-I (100 g/mL) mostrou-se mais potente nesta preparação, visto que uma dose de 100 g/mL causou efeito muito mais intenso do que a TsTX-V na mesma concentração. É possível que as diferenças observadas sobre os efeitos induzidos pela TsTX-I e TsTX-V sejam conseqüência de alterações estruturais entre canais para Na+ presentes em vários tipos de tecidos e inervações. / Voltage-gated Na+ channel toxins are mainly responsible for the toxic effects of scorpion envenoming and can be classified into two classes: a- and b-neurotoxins. TsTX-V and TsTX-I from Tityus serrulatus venom (TsV) are, respectively, examples of these toxins. In this work, were evaluate the effects of TsV and its toxins on mean arterial pressure (MAP) and catecholamines release in conscious unrestrained rats previously catheterized, as well as GABA, dopamine (DA) and glutamate (Glu) uptake in isolated rat brain synaptosomes and cytosolic Ca2+ concentration ([Ca2+ ]C) in vascular smooth muscle cells from rat aorta. Toxins were isolated by ion exchange chromatography (TsTX-I) followed by RP-HPLC (TsTX-V). The toxins (15 and 30 g/kg) and TsV (50 and 100 g/kg) were injected intravenously. MAP was continuously monitored through femoral catheter. Epinephrine (E) and norepinephrine (NE) plasma levels were determined by RP-HPLC with electrochemical detection, at 10 min before and 2.5, 30 and 90 min after treatments. Maximal pressor effects were observed at 2.5 3.5 min. TsV induced intense long lasting increase in MAP, as did TsTX-I. TsTX-V showed the lowest pressor effects. TsV showed the highest effects on catecholamines release, followed by TsTX-I and TsTX-V with maximal effect at 2.5 min, followed by a gradual reduction, however remaining higher than controls. Although both toxins act on Na+ channels, TsTX-I displayed significant and more intense effects on catecholamines release and blood pressure than TsTX-V. It seems that the toxicity of TsTX-V is not related only with its ability to release catecholamines, indicating that other neurotransmitters, may be involved in its toxicity. Neither the TsV or its toxins was capable to affect the 3H-Glu uptake. TsTX-I inhibited only 3H-DA uptake (IC50 = 28.41 nM). On the other hand, TsV (0.43ng/mL) inhibited both 3H-GABA and 3H-DA uptake (~50%). TsTX-V showed IC50 = 9.37 nM and 22.2 nM for 3H-GABA and 3H-DA uptake, respectively. These effects were abolished by pre-treatment with TTX, indicating the involvement of Na+ channels in this process. In the absence of Ca2+ and at low concentrations of toxin, the reduction is not as significant as in the presence of Ca2+. TsTX-V did not reduce 3H-GABA uptake in COS-7 cells expressing GABA transporters GAT-1 and GAT-3, suggesting that this toxin indirectly reduces the transport. The reduced 3H-GABA uptake by synaptosomes could be due to fast and intense cell depolarization as revealed by confocal microscopy of C6 glioma cells. Thus, TsTX-V causes reduction on 3H-GABA and 3H-DA uptake in a Ca2+-independent manner, not affecting directly GABA transporters, but, in consequence of depolarization, involving voltage-gated Na+ channels. TsV and its toxins were able to increase the ([Ca2+ ]C , probably by interact with Na+ channels. When compared to KCl 60 mM depolarizing effect (100 %), TsV (100 and 500 ?g/mL), showed an increase of 49.60 ± 2.58 % and 103.66 ± 5.17 %, respectively, whereas TsTX-I and TsTX-V (50 and 100?g/mL of each) showed 43.92 ± 3.06 % and 121.8 ± 8.9 %; 52.56 ± 8.33 % and 79.5 ± 6.1 %, respectively. TsTX-I (100 ?g/mL) showed most potent effects in this type of preparation, since induced most intense effect that TsTX-V in the same concentration. Thus, it is possible that the differences observed on the effects induced by both toxins are consequence of structural changes among Na+ channels present in several types of tissues and innervations .