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The bed nucleus of the stria terminalis (BNST) is currently widely studied due to its impact in the anxiety-, stress-, and fearrelated behaviours, as well as in addiction. The BNST is highly heterogeneous brain area constituting of set of subnuclei and a variety of neuron populations, properties of which have only partially been revealed by the earlier research. One of the neuron populations, on which only a very little research has been conducted, is the somatostatin (Sst) expressing neurons, highly abundant in the anterodorsal part of the BNST (adBNST), especially in oval and juxtacapsular nuclei of the BNST. This work aims to elucidate the connectivity of this Sst-neuron population, and their role in the behaviours related to BNST activation, particularly the anxiety-, reward-, and drug withdrawal-related behaviours. To specifically study the somatostatin neuron population in the adBNST, I targeted the neurons using stereotaxic delivery of AAV-vectors encoding a myristylated green fluorescent protein (GFP) for neuronal tracing to Sst-Cre-tdTomato reporter line mice (n=2), and Cre-inducible hM3Dq-DREADDs to Sst-IRES-Cre mice (n=21), with Cre-inducible mCherry fluorescent protein as a control (n=20). The mice were treated with activation-inducing 1.0 mg/kg i.p. clozapine-N-oxide (CNO) 30 min prior to the behavioural tests. To assess acute anxiety-like behaviour, I used the elevated-plus maze paradigm and a modified open field test, in which a novel object is introduced to the arena in the middle of the trial. To study the potential effect on reward-associated behaviours, I used the biased conditioned place preference (CPP) test, and for the withdrawal-linked behaviours, we used a method to precipitate the withdrawal symptoms with naltrexone in subchronically morphine-treated mice (n=9 hM3Dq, n=8 control). The neuronal tracing revealed that the adBNST Sst-neurons project to areas known to partake in stress and fear reactions as well as in autonomic and homeostatic control. Namely, projections were seen in medial and central amygdaloidal nuclei, lateral hypothalamus, periaqueductal grey, ventral pallidum, and parabrachial nucleus. In the elevated-plus maze, the CNO-induced activation of the Sst-neurons did not have any effect on the locomotor activity of the mice between the groups. At the same time, Sst activation did not seem to have any significant effect on the time the mice spent in the open arms, nor in the exploratory activities, like the frequency of the head dips or the stretch-attend postures. In line with these results, no effect on the movement between the groups was observed in the open field test. Similarly, no differences in anxiety-related behaviours, like in the time spent in the centre of the arena or in the number of contacts with the novel object during the last phase of the test, were observed. The CPP test failed to show any meaningful rewarding or aversive properties of CNO-induced activation of the Sst-neurons, while the movement rates of the groups during the conditioning trials were not different in statistically significant way. As for the withdrawal symptoms, all the mice showed the predetermined symptoms, but the test failed to show any differences between the study groups. The neuronal tracing revealed connectivity for the adBNST Sst-neurons with brain regions involved in fear- and anxiety behaviour, social encounters, and autonomic control. In spite of this, the CNO-induced chemogenetic activation of the adBNST Sst-neurons failed to show any significant behavioural effects in the chosen paradigms for anxiety-, and reward-related behaviours, and for withdrawal symptoms. Further research is needed to dissect the Sst-subcircuitry of adBNST, both in order to verify the observed output regions, and to elucidate the role these neurons play in modification of behavioural phenotypes.

Extracellular vesicles (EVs) are a very heterogeneous group of cell originated nanoparticles that act as mediators of intercellular communication. Accurate characterization of EVs is essential to enable their wider use and development as possible biomarkers, drug carriers, and vaccines. There is no validated reference material with EV-like properties currently available. A validated reference material would improve the reliability and reproducibility of EV studies. Nanoerythrosomes (NanoE) have been studied as a possible option for biological reference material. We aimed to further characterize and compare properties of NanoEs and erythrocyte-derived EVs (EryEV) and assess their stability concerning concentration and size distribution at most commonly applied storage temperatures, +4°C, -20°C, and -80°C for 12 weeks. Characterization was done using nanoparticle tracking analysis and flow cytometry. In addition, we studied the surface protein expression including CD235a, CD47, and CD41 of NanoEs and EryEV and conducted a preliminary cellular uptake test using PC-3 cells, CFSE-labeled NanoE, and EryEV particles. For both, NanoE and EryEV samples, 20°C was the worst storage condition. NanoEs stay stable at +4°C for a month and at -80°C, there were some drops in concentration during the 12 weeks of the experiment. EryEVs stay stable at +4°C and -80°C for 12 weeks. Both NanoE and EryEV particles seemed to be taken into the PC-3 cells, but due to problems with autofluorescence we conclude that confirming studies with different labeling protocols or another method need to be conducted. Both NanoEs and EryEVs samples had a significant number of CD47-positive particles.

Improvements in drug screening technology have resulted in a situation where more poorly soluble compounds enter the drug development pipeline. Poor aqueous solubility is a major issue especially in preclinical toxicity testing, where the generation of high drug loads is needed. For oral delivery, liquid formulations are often used and suspensions are potential options for poorly soluble drugs. While several different techniques to enhance solubility exist, most of them have method specific disadvantages or are not universal. Solid state modification, and especially the use of the high energy amorphous form, offers an efficient technique to enhance dissolution properties of a wide range of compounds. A problem of the amorphous form, however, is its physical instability. Amorphous drug in aqueous suspension can re-crystallize via solid-solid and/or solution-mediated pathways. To maintain the solubility advantage of amorphous forms for sufficient period of time, stabilization is needed. One way to stabilize the amorphous form is to prepare a solid dispersion, where the amorphous drug is dispersed in a stabilizing hydrophilic carrier matrix. Another way to add stabilizing agents is to dissolve them into the suspension medium prior to the amorphous solids. Solubilizing polymers may elevate the equilibrium solubility and reduce the driving force for solution mediated crystallization. The aims of this study were to stabilize amorphous indomethacin in aqueous suspensions and to understand the mechanisms behind stabilization. Indomethacin (IND) was used as a poorly soluble model drug (BCS class II). Four different polymers (PVP, HPMC, HPMC-AS and Soluplus®) were selected as stabilizing agents. Crystallization of solid amorphous IND and the concentration of dissolved IND in water were studied after adding: i) the pure amorphous IND, ii) solid dispersions (SDs) at 1:1 and 9:1 drug:polymer ratios (w/w), and iii) the pure amorphous IND into aqueous medium containing predissolved polymer at concentrations of 10 mg/ml or 1 mg/ml, total drug and polymer concentrations being equivalent to 1:1 and 9:1 drug:polymer ratios (w/w) in the SDs, respectively. For HPMC-AS only a 1 mg/ml polymer concentration was used due to its limited solubility. Both the solid and solution phases of the suspension were analysed at different time points for up to 24 h or until crystallization had occurred. Phase transformations in the solid phase were analysed using ATR-FT-IR spectroscopy combined with principal component analysis. The concentration of dissolved drug over the time was assessed by UV spectroscopy. In general, all the polymers, either in SDs or pre-dissolved in medium delayed the onset of crystallization of amorphous IND. Higher polymer concentrations inhibited the crystallization longer than lower ones. A general trend was that SDs were superior in stabilization of amorphous solids, but pre-dissolved polymer solutions generated and maintained higher IND concentrations in solution. Of the four polymers studied, Soluplus® showed the most promising results: SD of Soluplus® and IND at 1:1 ratio (w/w) stayed amorphous in aqueous medium for more than 28 days. On the other hand, crystallization was quite rapid (30 min) when the amount of polymer was inadequate (9:1 w/w). Soluplus® solution (10 mg/ml) generated a 20-fold higher IND concentration than the corresponding SD, possibly due to micellisation. Different polymers showed different abilities to inhibit crystallization and enhance the drug concentration in solution. The addition method and the drug-polymer ratio had an influence on the stabilization abilities of the polymer. Stabilization mechanisms may be both thermodynamic (type of polymer) and kinetic(method of addition).

Cholesterol-lowering statins are well-tolerated and effective in prevention of cardiovascular diseases. One of the target groups in treatment of dyslipidaemia is type 2 diabetics, who benefit from reducing cholesterol levels even without a history of cardiovascular disease or high cholesterol levels. Common adverse events associated with statins are myopathy and an increase in liver enzymes. Statins have also been shown to slightly increase the risk of developing type 2 diabetes and increase blood glucose levels. The risk seems to increase with higher doses. Higher doses, however, prevent cardiovascular events more than moderate doses. In this cohort study we assessed the relationship between statins and development of diabetes in a Finnish diabetes prevention study. In addition, we assessed the effects of statins on blood glucose levels. The diabetes risk associated with statins was evaluated by a parametric survival-analysis and the impact on blood glucose levels by a mixture model. The material consisted of the follow-up data from the Diabetes Prevention Study (DPS) from year 1993 to 2009 and along with that statistics on reimbursements for prescription medicines from Kela's reimbursement database. The purpose of DPS was initially to determine if type 2 diabetes can be prevented or delayed by lifestyle intervention. Participants with impaired glucose tolerance were randomly assigned to the intervention group or the control group. The intervention group received intensive and individual counseling on healthy lifestyle while the control group was given general information on health behavior. The study revealed that 36,8 % (n = 182) of the participants had used statins during follow-up. Statin use was more common in the intervention than the control group. Simvastatin was the most used statin and statins had been used for four years on average. Statins were associated with a slight increase in risk of developing diabetes and an increase in fasting plasma glucose and 2 h glucose levels. The risk of diabetes was slighter in the intervention group. Further research is needed to determine the mechanism causing the increase in risk of diabetes, if different statins differ in the extent of risk and if a specific patient group or characteristic is more vulnerable to develop diabetes when exposed to statins. The diabetes risk associated with statins should be taken into account when designing a statin trial. Develoment of diabetes should be a pre-specified endpoint and blood glucose and insulin levels monitored during follow-up.

Heart failure is a disease of major social and economic impact. The disease is most commonly onset by extensive cardiomyocyte death following a myocardial infarction. Five-year mortality of heart failure is higher than some cancers. Loss of cardiac muscle tissue leads to pathological thickening and fibrosis of the left ventricular wall, which eventually further diminish cardiac function. Cardiomyocytes hardly proliferate, which also exacerbates the problem. Several cell signalling pathways are indicated in pathological reprogramming of the heart and the exact significance of these pathways remains to be demonstrated. Treatment strategies based on renewing cardiac muscle, such as direct injection of stem cells into the myocardium, have failed to reach clinically significant effects on heart failure patients. Direct inhibition of pathological cardiac reprogramming by using small molecule modulators remains as an auspicious strategy to treat heart failure. GATA4, or GATA binding protein 4, is a transcription factor expressed mainly in heart, lung, intestine, gonad and liver tissues, which regulates tissue renewal and cell proliferation by controlling protein transcription. GATA4 binds to GATA sequences in DNA with two zinc finger moieties and enables transcription of target genes. Interactions of GATA4 and several other transcription factors are in central role of guiding heart development, hypertrophy and fibrosis. One of these transcription factors is NKX2-5, which synergistically interacts with GATA4. Inhibition of this interaction in rat myocardial infarction model has been shown to protect against development of heart failure. A screening campaign against the transcriptional synergy of GATA4 and NKX2-5 found potent small molecule inhibitors of this interaction, but these compounds are characterised with stem cell toxicity. The aim of the study was to design and synthesise novel derivatives of GATA4-NKX2-5 synergy inhibitor hit molecule with reduced stem cell toxicity. Modifications on the phenyl ring of the hit molecule were designed, which either increase electron density of the ring or possibly alter the torsional angle between the phenyl and isoxazole ring moieties. Activity of the compounds was studied on a luciferase reporter gene system in COS-1 cells and toxicity was analysed on IMR90 human induced pluripotent stem cell line. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) bromide and lactate dehydrogenase (LDH) assays were selected to measure toxicity on stem cells. Stem cell toxicity of several previously synthesised compounds was assayed in parallel with the novel derivatives. Ten novel derivatives were designed, synthesised and assayed. Four of the new compounds, a mono-ortho-methyl, a di-ortho-methyl, a di-meta-methoxy and cyclohexyl derivatives were found to be equipotent inhibitors of reporter gene activity compared to the hit compound. Additionally, the mono-ortho-methyl, di-ortho-methyl and di-meta-methoxy derivatives were less toxic to stem cells than the hit molecule in the MTT assay. Several other derivatives were found to be less toxic, but also non-active in the luciferase assay. None of the studied compounds exhibited notable necrotic toxicity on stem cells, as examined by the LDH assay. According to this study it may be concluded that substituents of the hit molecule phenyl ring may be altered to decrease stem cell toxicity of the compound. Some of the alterations, most notably substituents in the para-position of the phenyl ring and substitution of the phenyl ring with smaller saturated hydrocarbon rings, diminish the activity of the hit compound. Remarkable toleration of ortho-substitution reinforces the hypothesis of phenyl-isoxazole torsional angle significance for toxicity. On the other hand, addition of two methoxy groups to both meta positions most likely lacks any substantial effect on the torsional angle, which implies another mechanism of toxicity avoidance. Activity and improved safety of the novel inhibitors should be confirmed in animal models before any decisive conclusions on the effects of structural modifications on the hit molecule can be made. In addition, other mechanisms of toxicity should be studied with relevant cell-based assays.

Antibiotic resistance is a global crisis causing increasing number of infections that cannot be treated with conventional antibiotics. The main reasons for the resistance crisis include overuse and misuse of antibiotics, use in agriculture, and decreased interest of pharmaceutical companies to discover and develop new antibiotics. Apart from mortality, antibiotic resistance causes large economical costs due to longer hospitalizations and more expensive treatments. Bacteria can acquire resistance via multiple pathways. Main path for spread of resistance in bacterial populations is horizontal gene transfer (HGT) in which bacteria receive genetic material that contain resistance genes. Bacteria can acquire new resistance traits via mutations in their genome. The emergence of resistance is a natural feature of bacteria and therefore many bacteria and bacteria can quickly acquire resistance towards novel antibiotics. The resistance properties of potential new antibiotics should be studied already during drug discovery and development. This study determined resistance properties of diazaborine compounds, which have been shown to have antibacterial activity especially against Gram-negative bacteria. The studied properties were mutant prevention concentration (MPC) and spontaneous mutation frequency. MPC measures the antimicrobial compound concentrations in which single-step resistant mutants arise. MPC values can be compared to minimum inhibitory concentration (MIC) values to determine range of mutant selection window (MSW) in which single-step resistant mutants are selectively amplified. Spontaneous mutation frequency is a feature for bacteria in presence of antimicrobials. Spontaneous mutation frequencies demonstrate the proportion of emerged resistant mutants from a bacterial population in each antimicrobial concentration. Four diazaborine compounds were studied with Escherichia coli ATCC25922 and the results were compared with ciprofloxacin. Ciprofloxacin had the lowest MPC at 16xMIC, diazaborine compounds 1, 2 and 3 at 32xMIC and diazaborine compound 4 at 64xMIC. Spontaneous mutation frequency of E. coli was on a normal level with each compound.

Liposomes are nano-sized vesicles in which the aqueous phase is surrounded by lipid-derived bilayer. They are excellent drug vehicles for example in ocular drug delivery because they can, among other things, increase the bioavailability and stability of the drug molecules and reduce their toxicity. Liposomes are known to be safe to use, because they degrade within a certain period of time and they are biocompatible with the cells and tissues of the body. Owing to its structure, the surface of liposomes can also be easily modified and functionalized. Light-activated ICG liposomes allow drug release in a controlled manner at a given time and specific site. Their function is based on a small molecule called indocyanine green (ICG) which, after being exposed to laser light, absorbs light energy and thereby locally elevates the temperature of the lipid bilayer. As a result, the drug inside is released into the surroundings. The blood circulation time of liposomes has often been prolonged by coating the liposomes with polyethylene glycol (PEG). Although PEG is generally regarded as a safe and biocompatible polymer, it has been found to increase immunological reactions and PEG-specific antibodies upon repeated dosing. Conversely, hyaluronic acid (HA), is an endogenous polysaccharide, which is present in abundance for instance in vitreous. Thus, it could serve as a stealth coating material which extends the otherwise short half-life of liposomes. One of the main objectives of this thesis was to find out whether HA could be used to coat liposomes instead of PEG. In order to prepare HA-coated liposomes, one of the lipid bilayer phospholipids, DSPE, had to be first conjugated with HA. For the conjugation, potential synthesis protocols were sought from the literature. Ultimately two different reductive amination-based protocols were tested. Consequently, the protocol in which the conjugation was achieved via the aldehyde group of HA, proved to be working. Thereafter, HA-coated liposomes were prepared by thin film hydration from the newly synthesised conjugate as well as DPPC, DSPC and 18:0 Lyso PC. Calcein was encapsulated in the liposomes. HA-covered liposomes were then compared with uncoated and PEGylated liposomes by examining their phase transition temperatures, ICG absorbances, sizes, polydispersities, and both light and heat-induced drug releases. The aforementioned tests were also conducted when the effects of the HA and ICG doubling were examined and the possibility to manufacture HA liposomes with small size was assessed. HA-liposomes showed similar results as PEG-coated liposomes. In addition, successful extrusion of HA-liposomes through a 30 nm membrane was also demonstrated in the results. Doubling of HA did not significantly affect the results. In contrast, increasing the molar amount of ICG by double caused spontaneous calcein leakage even before any heat or light exposure. Based on these findings, HA could work as a coating material instead of PEG, yet further studies are required for ensuring this conclusion. The other key objective was to evaluate the stability of four different formulations, named as AL, AL18, AL16 and AL14, in storage and biological conditions. Based on the differences in the formulation phospholipid composition, the assumption was that AL would be the most stable of the group and that the stability would decrease so that AL18 and AL16 would be the next most stable and eventually AL14 would be the least stable formulation. As in the previous study, the liposomes were prepared by thin film hydration with calcein being encapsulated inside the liposomes. In the storage stability test, liposomes were stored in HEPES buffer at either 4 °C or at room temperature for one month. In the test conducted in physiological conditions, the liposomes were added either to porcine vitreous or fetal bovine serum (FBS) and the samples were incubated at 37 ºC for five days. Regardless of the experiment, phase transition temperatures as well as light and heat-induced drug releases were initially measured. As the test progressed, calcein release, ICG absorbance, size, and polydispersity were measured at each time point. The initial measurements confirmed the hypothesis about the stability differences of tested formulations. In the storage stability test, all formulations, except AL14, appeared to be stable throughout the study and no apparent differences between the formulations or temperatures were observed. On the other hand, the stability of liposomes stored in biological matrices varied so that the liposomes were more stable in vitreous than in FBS and the stability decreased in both media as expected.

Nowadays, targetability studies usually require sample modifications and quite often, examination requires the use of directed light in harmful wavelengths. The surface plasmon resonance (SPR) technique does not need either of those actions. With SPR technology, the targetability of biomolecules can be studied in real-time and without any additional labels. The SPR response is received by measuring the change in surface plasmon resonance conditions due to refractive index changes caused by material interactions in the vicinity of a metal sensor surface. In the present study, the targetability of neonatal Fc receptor (FcRn) was studied by SPR. FcRn-mediated targetability studies were performed against protein A and human colorectal adenocarcinoma (Caco-2) immobilized on SPR sensors. The aim of the study was to confirm the FcRn targetability with bare Fc-fragment and Fc-fragment modified nanoparticles (NPs) designed for oral drug delivery. The NPs consisted of a core porous silicon (PSi) particle, entrapped into a lignin capsule, and finally functionalized with the FcRn-targeting ligand. Results confirmed the binding efficacy of bare Fc-fragment with protein A at pH 6.5, which was the critical pH value for preserving the lignin capsule around the PSi NPs. The cell-based SPR response was significantly higher for FcRn-targeted NPs when compared with non-functionalized NPs. According to these results, FcRn-mediated transcytosis emerges with great potential for oral drug delivery via Fc-functionalized NPs.

There are certain characteristics in children’s medication process, such as weight or body surface area-based drug dosing and off-label use of medications, that expose children to medication errors. Small children especially are prone to physical injuries resulting from medication errors. High-alert medications bear a heightened risk of causing significant, even life-threatening harm to a patient when used in error. The aim of this study was to promote children's medication safety by identifying medication errors and contributing factors to errors associated with the use of high-alert medications in pediatric medication process in a hospital environment. The data of this retrospective register study consisted of voluntary medication error reports (HaiPro) made in the pediatric and adolescent units at Helsinki university hospital (HUS). ISMP's (Institute for Safe Medication Practices) list of high-alert medications in acute care settings was used to limit the data. The data was analyzed by using both quantitative and qualitative methods. The aim of the quantitative analysis was to report the frequencies (n) and proportions (%) of high-alert medications and routes of administration and the aim of the qualitative analysis was to identify the types of medication errors and contributing factors in the data. ISMP’s high-alert medications accounted for approximately one-fifth (19.7%) of all medication error reports made in pediatric and adolescent units in 2018–2020. Twelve medications and intravenous route covered approximately 65.0% of all high-alert medications and routes of administration mentioned in the data. Medication errors were mostly identified in medication administration stage (43.3%) and administration errors were often preceded by prescribing errors. Dosing errors (20.5%) and documenting errors (16.8%) were the most common medication error types in the data. Errors associated with dosing and infusion rate were most often involved in severe medication errors. The most frequently identified contributing factors in the data were associated with the work situation and conditions, documenting and information transfer or medications. More detailed risk analysis considering high-alert medications and the intravenous medication process and targeting preventive barriers to identified risk areas are recommended in pediatric and adolescent units in the future. Barriers should be planned to cover the entire medication process. Among different types of medication errors, multiple dosing errors and errors during the programming of infusion rate require special attention in the future.

Chronic heart failure is a major worldwide health problem. It is a complex and severe syndrome caused by different kinds of cardiovascular diseases. Cardiac hypertrophy is frequently caused by hypertension and can lead to abnormality in heart contraction, activation of many neurohumoral mechanism and heart failure. The most important neurohormonal mechanisms of heart failure are activation of sympathetic nervous system and the renin-angiotensin-aldosterone system, insufficiently contracting left ventricle, cardiac remodeling and myocyte loss owing to apoptosis. Antihypertensive drug treatment is often used to prevent or decelerate progression of cardiac hypertrophy. Activation of the renin-angiotensin-aldosterone system plays a major role in heart failure. During the past decades angiotensin converting enzyme inhibitors (ACEIs) have been used as firstline treatment of heart failure. ACEI treatment has been shown to reduce mortality associated with chronic heart failure and improve prognosis of the disease. Angiotensin receptor blockers (ARBs) were expected to replace ACEIs in the treatment of heart failure but for the present they are only an alternative to ACEIs. Beta-blocking agents which reduce activation of sympathetic nervous system have established themself as the second most important treatment of heart failure. Diuretics are widely used as the treatment of heart failure but only aldosterone antagonists has been shown to improve prognosis of the disease. Also digoxin is still used in the treatment of chronic heart failure. In the future renin inhibitors, neutral endopeptidase inhibitors, vasopressin antagonists and molecules that affect inflammatory cytokines could potentially be capable of improving the prognosis of chronic heart failure patients. The major object in the present study was to investigate development of left ventricular hypertrophy induced by abdominal aorta banding in male Wistar rats and prevention of hypertrophy by calcium sensitizer levosimendan and angiotensin II receptor blocker valsartan. Also functionality of abdominal aorta banding as a rodent model of cardiac hypertrophy and heart failure was estimated. Abdominal aorta was constricted above the right renal arteries. That leads to pressure overload and increase in cardiac load. Heart response to pressure overload by hypertrophy in the form of wall thickening. 64 rats were assigned to different groups, each having eight rats. Three of the groups were treated with levosimendan with different daily doses (0,01 mg/kg; 0,10 mg/kg; 1,00 mg/kg) and three of the groups were treated with valsartan with different daily doses (0,10 mg/kg; 1,00 mg/kg; 10,00 mg/kg) via drinking water for eight weeks after the surgery. Sham-operated group underwent the same surgical procedures without constriction of the aorta. All the groups were compared to abdominal aorta banded group without any medical treatment. Cardiovascular parameters such as isovolumic relaxation time (IVRT), left ventricle end-systolic (ESD) and end-diastolic (EDD) dimensions, ejection fraction (EF), fractional shortening (FS), cardiac output (CO), stroke volume (SV), interventricular septum (IVS) and posterior wall (PW) thickness were measured eight weeks after the surgery by using cardiac ultrasound. In the present study levosimendan slightly improved systolic function of the heart. Improvement of the systolic function was seen in a tendency to improve ejection fraction and fractional shortening in abdominal aorta banded rats compared to abdominal aorta banded rats without medical treatment. Neither levosimendan nor valsartan affected diastolic function of heart. Diastolic function was measured by isovolumic relaxation time. Neither levosimendan nor valsartan had significant effect on development of cardiac hypertrophy. Cardiac hypertrophy was estimated by measuring heart weight-to-body weight ratio (HW/BW), left ventricular wall thicknesses and left ventricular internal dimensions in systole and diastole. The present study indicates that outflow constriction by aortic banding is clearly a model of cardiac hypertrophy but not of heart failure.