Sub-0.1 degree phase locking of a single-photon interferometer.

We report a single-photon Mach-Zehnder interferometer stabilized to a phase precision of 0.05 degrees over 15 hours. To lock the phase, we employ an auxiliary reference light at a different wavelength than the quantum signal. The developed phase locking operates continuously, with negligible crosstalk, and for an arbitrary phase of the quantum signal. Moreover, its performance is independent of intensity fluctuations of the reference. Since the presented method can be used in a vast majority of quantum interferometric networks it can significantly improve phase-sensitive applications in quantum communication and quantum metrology.

Microbial Contamination of Photographic and Cinematographic Materials in Archival Funds in the Czech Republic.

In this study we investigated the microbial contamination of 126 samples of photographic and cinematographic materials from 10 archival funds in the Czech Republic. Microorganisms were isolated from the light-sensitive layer by swabbing it with a polyurethane sponge. Microbial isolates were identified by MALDI-TOF MS (bacteria) or by phenotype testing and microscopy (fungi). Bacterial contamination was more abundant and more diverse than fungal contamination, and both were significantly associated with archives. The most frequently isolated fungal genera were Cladosporium, Eurotium, Penicillium, Aspergillus and Alternaria. The most frequently isolated bacteria were Gram-positive genera such as Staphylococcus, Micrococcus, Kocuria, Streptococcus and Bacillus. This bacterial and fungal diversity suggests that air is the main vehicle of contamination. We also analysed the impact of the type of material used for the carrier (paper, baryta paper, cellulose acetate and nitrate or glass) or the light-sensitive layer (albumen, gelatine, collodion and other) on the level and diversity of microbial contamination. Carriers such as polyester and cellulose nitrate may have a negative impact on bacterial contamination, while paper and baryta paper may have a partially positive impact on both fungal and bacterial contamination.

Feedforward-enhanced Fock state conversion with linear optics.

Engineering quantum states of light represents a crucial task in the vast majority of photonic quantum technology applications. Direct manipulation of the number of photons in the light signal, such as single-photon subtraction and addition, proved to be an efficient strategy for the task. Here we propose an adaptive multi-photon subtraction scheme where a particular subtraction task is conditioned by all previous subtraction events in order to maximize the probability of successful subtraction. We theoretically illustrate this technique on the model example of conversion of Fock states via photon subtraction. We also experimentally demonstrate the core building block of the proposal by implementing a feedforward-assisted conversion of two-photon state to a single-photon state. Our experiment combines two elementary photon subtraction blocks where the splitting ratio of the second subtraction beam splitter is affected by the measurement result from the first subtraction block in real time using an ultra-fast feedforward loop. The reported optimized photon subtraction scheme applies to a broad range of photonic states, including highly nonclassical Fock states and squeezed light, advancing the photonic quantum toolbox.

Fully tunable and switchable coupler for photonic routing in quantum detection and modulation.

Photonic routing is a key building block of many optical applications challenging its development. We report a $2\times 2$2×2 photonic coupler with a splitting ratio switchable by a low-voltage electronic signal with 10 GHz bandwidth and tens of nanoseconds latency. The coupler can operate at any splitting ratio ranging from 0:100 to 100:0 with the extinction ratio of 26 dB in optical bandwidth of 1.3 THz. We show sub-nanosecond switching between arbitrary coupling regimes including a balanced 50:50 beam splitter, 0:100 switch, and a photonic tap. The core of the device is based on a Mach-Zehnder interferometer in a dual-wavelength configuration allowing real-time phase lock with long-term sub-degree stability at single-photon level. Using the reported coupler, we demonstrate for the first time, to the best of our knowledge, a perfectly balanced time-multiplexed device for photon-number-resolving detectors and also the active preparation of a photonic temporal qudit state up to four time bins. Verified long-term stable operation of the coupler at the single-photon level makes it suitable for a wide application range in quantum information processing and quantum optics in general.

Heart ventricles specific stress-induced changes in ß-adrenoceptors and muscarinic receptors.

The left and right ventricles fulfill different role in heart function. Here we compare chamber specific changes in local catecholamine concentrations; gene expression and the receptor protein amount of all three ß-adrenoceptors (ß-AR) in rat right heart ventricles exposed to acute (1 session) and repeated (7 sessions) immobilization stress (IMMO) vs. previously observed changes in left ventricles. Density of muscarinic receptors as main cardio-inhibitive receptors was also measured. In the right ventricles, noradrenaline and adrenaline were increased. No ß1-AR changes were observed, in spite of the increased sympathetic activity. On the other hand, we have found a decrease of ß2-AR gene expression (reduction to 30%) after 7 IMMO and protein (to 59%) after 1 IMMO. ß3-AR gene expression was increased after 7 IMMO. Muscarinic receptor density was not changed. When comparing correlation in left and right ventricles, there was strong correlation between adrenaline and ß2-AR gene expression, protein and ß3-AR gene expression in the left ventricles while only correlation between adrenaline and ß2-AR mRNA and protein in the right ventricles was found. Our results show that maintenance of cardiac homeostasis under stress conditions are to a great extent achieved by a balance between different receptors and also by a balanced receptor changes in left vs. right ventricles. Taken together, decrease of cardio-stimulating ß2-AR represents a new important mechanism by which ß2-AR contributes to the heart physiology.

Characterization of transgenic tobacco plants containing bacterial bphC gene and study of their phytoremediation ability.

Genetically modified plants can serve as an efficient tool for remediation of diverse dangerous pollutants of the environment such as pesticides, heavy metals, explosives and persistent organic compounds. Transgenic lines of Nicotiana tabacum containing bacterial bphC gene from the degradation pathway of polychlorinated biphenyls (PCBs) were tested. The product of the bphC gene - enzyme 2,3-dihydroxybiphenyl-1,2-dioxygenase is responsible for cleaving of the biphenyl ring. The presence of bphC gene in transgenic plants was detected on DNA, RNA and protein level. The expression of the bphC/His gene was verified afterpurification of the enzyme from plants by affinity chromatography followed by a Western blot and immunochemical assay. The enzyme activity of isolated protein was detected. Efficient transformation of 2,3-DHB by transgenic plants was achieved and the lines also exhibited high production of biomass. The transgenic plants were more tolerant to the commercial PCBs mixture Delor 103 than non-transgenic tobacco. And finally, the higher decrease of total PCB content and especially congener 28 in real contaminated soil from a dumpsite was determined after cultivation of transgenic plant in comparison with nontransgenic tobacco. The substrate specificity of transgenic plants was the same as substrate specificity of BphC enzyme.

Repeated immobilization stress increases expression of ß3 -adrenoceptor in the left ventricle and atrium of the rat heart.

Stress is a contributor of many cardiovascular diseases. Positive inotropic and chronotropic effects of catecholamines are regulated via ß-adrenergic receptors (ARs). Many reports exist concerning changes of cardiac ß1 - and ß2 -ARs in stress, but only a few deal with modulation of cardiac ß3 -AR. Our aim was to analyze the expression and binding sites of ß1 -, ß2 - and ß3 -ARs and adenylyl cyclase activity in the left ventricle, and ß3 -AR expression and binding in the left atrium of rats exposed to acute and chronic immobilization stress (IMO). The concentration of noradrenaline in the ventricle decreased, while adrenaline increased, especially after repeated IMO. The mRNA and protein levels, and binding sites of ß3 -subtype significantly rose following chronic IMO, while all parameters for ß2 -AR dropped after single and repeated exposure. Similarly, the mRNA levels and binding sites for ß3 -subtype increased in the left atrium as a consequence of chronic IMO. The rise in ß3 -subtypes and a drop in ß2 -subtypes resulted in inhibition of adenylyl cyclase activity within the left ventricle. Taken together, among other factors, up-regulation of ß3 -AR could represent an adaptation mechanism, which might be related to altered physiological function of the left ventricle and atrium during prolonged emotional stress and might serve cardioprotective function during catecholamine overload.

Distant white-matter diffusion changes caused by tumor growth.

OBJECTIVES: Various reports have suggested that the involvement of normal-looking white matter with tumors is not limited to just signal abnormalities detectable on conventional imaging. Thus, the purpose of this study was to investigate the distant effects of glioblastomas and metastases on white matter using diffusion tensor imaging (DTI). MATERIALS AND METHODS: Data for 21 patients harboring a glioblastoma (n=12) or a metastasis (n=9) located at a distance of smaller or equal to 10mm from a DTI-based reconstruction of the pyramidal tract were analyzed, using regions of interest (ROIs) placed along the pyramidal tracts in the cerebral peduncle distant (>15 mm) from the tumor. RESULTS: For the whole study population, fractional anisotropy (FA) was significantly lower on the side ipsilateral to the tumor (P<0.001), a difference that was also observed in the glioblastoma and metastasis subgroups. The trace value was significantly higher on the ipsilateral side in the whole population and metastasis subgroup, but not in the glioblastoma subgroup. The decrease in FA and the trace value increase were significant in a subgroup of patients with motor deficits, but not in those without such deficits. CONCLUSION: Hemispheric glioblastomas and metastases located close to the pyramidal tract induce diffusion changes in the tract that are observable at a distance of greater than 15 mm from the tumor border in the absence of T2 signal changes. These changes are different in glioblastomas and metastases, and mechanisms other than Wallerian degeneration may be contributing to the observed changes.

Corticotropin-releasing hormone affects short immobilization stress-induced changes in lung cytosolic and membrane glucocorticoid binding sites.

Glucocorticoids act via glucocorticoid receptors (GR), typically localized in the cytosol (cGR). Rapid action is probably mediated via membrane receptors (mGR). In corticotropin-releasing hormone knockouts (CRH-KO), basal plasma glucocorticoid levels do differ from wild type levels (WT), but are approximately ten times lower during exposure to immobilization stress (IMMO) in comparison to WT. We tested the following hypotheses: (1) the mice lung tissue GR basal numbers would not be changed in CRH-KO (because of similar glucocorticoid levels), (2) the number of GR would be changed in WT but not in KO during short (30, 90, and 120 min) IMMO (because of higher increase of glucocorticoid levels in WT). The basal levels of cGR were not changed in CRH-KO (compared to WT), while mGR were significantly lower (62 %) in CRH-KO. In WT, there was the only decrease (to 32 %) in cGR after 120 min when we also found an increase in mGR in WT (to 201 %). In CRH-KO, IMMO caused gradual decrease in cGR (to 52 % after 30 min, to 46 % after 90 min, and to 32 % after 120 min). In CRH-KO, the only increase in mGR appeared already at 30 min of IMMO. These data suggest, on the contrary to our hypotheses, that CRH-KO are more susceptible to GR changes in early phases of stress.

Decrease in heart adrenoceptor gene expression and receptor number as compensatory tool for preserved heart function and biological rhythm in M(2) KO animals.

Muscarinic receptors (MR) are main cardioinhibitory receptors. We investigated the changes in gene expression, receptor number, echocardiography, muscarinic/adrenergic agonist/antagonist changes in heart rate (HR) and HR biorhythm in M(2) KO mice (mice lacking the main cardioinhibitory receptors) in the left ventricle (LV) and right ventricle (RV). We hypothesize that the disruption of M(2) MR, key players in parasympathetic bradycardia, would change the number of receptors with antagonistic effects on the heart (ß(1)- and ß(2)-adrenoceptors, BAR), while the function of the heart would be changed only marginally. We have found changes in LV, but not in RV: decrease in M(3) MR, ß(1)- and ß(2)-adrenoceptor gene expressions that were accompanied by a decrease in MR and BAR receptor binding. No changes were found both in LV systolic and diastolic function as assessed by echocardiography (e.g., similar LV end-systolic and end-diastolic diameter, fractional shortening, mitral flow characteristics, and maximal velocity in LV outflow tract). We have found only marginal changes in specific HR biorhythm parameters. The effects of isoprenaline and propranolol on HR were similar in WT and KO (but with lesser extent). Atropine was not able to increase HR in KO animals. Carbachol decreased the HR in WT but increased HR in KO, suggesting the presence of cardiostimulatory MR. Therefore, we can conclude that although the main cardioinhibitory receptors are not present in the heart, the function is not much affected. As possible mechanisms of almost normal cardiac function, the decreases of both ß(1)- and ß(2)-adrenoceptor gene expression and receptor binding should be considered.

Anatomy of the supraventricular portion of the pyramidal tract.

BACKGROUND: The anatomy and somatotopy of the pyramidal tract during its course in the internal capsule has recently been discussed by many publications. However, the reports on the anatomy of the clinically more important supraventricular portion of the tract are scarce. The objective of this study is to investigate the anatomy and somatotopy of the supraventricular portion of the pyramidal tract. METHODS: In 13 patients undergoing surgery with subcortical electric stimulation for tumors located in the supraventricular white matter close to the pyramidal tract (as depicted by diffusion tensor tracking [DTT]), the relationship between the position of the stimulation point and the motor response in the arm or leg was analyzed. Additionally, the somatotopic organization of the tract was studied using separate tracking of arm and leg fibers in 20 healthy hemispheres. Finally, the course of the tract was studied by dissecting 15 previously frozen human hemispheres. RESULTS: In most cases, subcortical stimulation during the resection of tumors located behind and in front of the pyramidal tract elicited leg and arm movement, respectively. This association of stimulation point position with motor response type was significant. A DTT study of the somatotopy demonstrated a varying degree of rotation of the leg and arm fibers from mediolateral to posteroanterior configuration. Anatomic dissections demonstrated a folding-fan like structure of the pyramidal tract with a similar rotation pattern. CONCLUSION: The pyramidal tract undergoes a large part of its rotation from mediolateral to posteroanterior configuration during its course in the supraventricular white matter, although interindividual differences exist.

The use of diffusion tensor images of the corticospinal tract in intrinsic brain tumor surgery: a comparison with direct subcortical stimulation.

BACKGROUND: Diffusion tensor imaging (DTI) is now widely used in neurosurgery to preoperatively delineate the course of the pyramidal tract. OBJECTIVE: To evaluate the accuracy of the method by comparison with subcortical electrical stimulation and to evaluate the influence of the distance of the pyramidal tract from the tumor on the resection extent and postoperative clinical deficits. METHODS: A diffusion tensor imaging depiction of the pyramidal tract was used in preoperative planning and intraoperative navigation in 72 cases. In 36 cases, subcortical electrical stimulation was used during the resection. The preoperative tumor-to-tract distance was compared with the stimulation result, the extent of resection, and the short-term postoperative course. RESULTS: A significant nonlinear relationship between the tract-to-tumor distance and the probability of a motor response to subcortical stimulation was observed. The largest preoperatively measured tumor-to-tract distance with a positive stimulation result was 8 mm. Moreover, we observed a trend toward transient postoperative motor deterioration in patients with tumors close to the pyramidal tract. Resection extent was not significantly affected by the tumor-to-tract distance. CONCLUSION: Despite methodological obstacles, reasonable accuracy of the diffusion tensor imaging reconstructions of the pyramidal tracts was confirmed by our study. The occurrence of transient postoperative motor deterioration is higher in patients with tumors located close to the pyramidal tract.

Beta3 adrenoceptors substitute the role of M(2) muscarinic receptor in coping with cold stress in the heart: evidence from M(2)KO mice.

We investigated the role of beta3-adrenoceptors (AR) in cold stress (1 or 7 days in cold) in animals lacking main cardioinhibitive receptors-M2 muscarinic receptors (M(2)KO). There was no change in receptor number in the right ventricles. In the left ventricles, there was decrease in binding to all cardiostimulative receptors (beta1-, and beta2-AR) and increase in cardiodepressive receptors (beta3-AR) in unstressed KO in comparison to WT. The cold stress in WT animals resulted in decrease in binding to beta1- and beta2-AR (to 37%/35% after 1 day in cold and to 27%/28% after 7 days in cold) while beta3-AR were increased (to 216% of control) when 7 days cold was applied. MR were reduced to 46% and 58%, respectively. Gene expression of M2 MR in WT was not changed due to stress, while M3 was changed. The reaction of beta1- and beta2-AR (binding) to cold was similar in KO and WT animals, and beta3-AR in stressed KO animals did not change. Adenylyl cyclase activity was affected by beta3-agonist CL316243 in cold stressed WT animals but CL316243 had almost no effects on adenylyl cyclase activity in stressed KO. Nitric oxide activity (NOS) was not affected by BRL37344 (beta3-agonist) both in WT and KO animals. Similarly, the stress had no effects on NOS activity in WT animals and in KO animals. We conclude that the function of M2 MR is substituted by beta3-AR and that these effects are mediated via adenylyl cyclase rather than NOS.

The effect of a gadolinium-based contrast agent on diffusion tensor imaging.

OBJECTIVE: The aim of this study was to investigate in detail the effect of gadolinium contrast on diffusion tensor imaging scans. As the present literature offers conflicting results, we have included a large selection of indices in the analysis. MATERIALS AND METHODS: Sixteen patients harboring an intra-axial contrast enhancing brain tumor were included in this study. Two diffusion tensor imaging scans were performed-one natively, and the second following a gadolinium contrast agent application. Maps of the invariant indices fractional anisotropy (FA), linear, planar, and spherical indices, trace, eigenvalues λ(1), λ(2), λ(3) as well as of the components of the diffusion tensor matrix Dxx, Dyy, Dzz, Dxy, Dxz and Dyz were co-registered and compared statistically with matching ROI pairs in the contrast enhancing areas, peritumoral edema and the normal appearing white matter. RESULTS: We have observed a significant increase in the FA and disproportional decrease of the eigenvalues in the post-contrast scans. In accordance with these findings, the spherical index was decreased and the linear and planar indices were increased. There was a significant decrease of all diagonal components of the diffusion tensor matrix. These changes have been strongest in the contrast enhancing areas, but there were also significant changes in the peritumoral edema and the normal appearing white matter. CONCLUSION: Diffusion tensor imaging scans performed after gadolinium contrast agent administration may display artificially increased FA values due to disproportional changes of the measured eigenvalues. The distortion of the diffusion measurement is strongest in, but not limited to the contrasting areas.

Sexual dimorphism in stress-induced changes in adrenergic and muscarinic receptor densities in the lung of wild type and corticotropin-releasing hormone-knockout mice.

We tested the hypothesis that single and repeated immobilization stress affect densities of alpha(1)-adrenoceptor (alpha(1)-AR) and beta-AR subtypes, muscarinic receptors (MR), adenylyl cyclase activity (AC) and phospholipase C activity (PLC) in lungs of male and female wild type (WT) and corticotropin-releasing hormone gene (CRH-knockout (KO)) disrupted mice. We found sex differences in the basal levels of alpha(1)-AR subtypes (females had 2-3 times higher density of receptors than males) and MR (males had twice the density found in females). In marked contrast, beta-AR subtype densities did not differ between sexes. CRH gene disruption decreased all three studied receptors in intact mice (to 20-50% of WT) in both sexes (except beta(1)-AR in females). Stress induced sexually dimorphic responses, while all alpha(1)-AR subtypes decreased in females (to 30% of control approximately), only alpha(1A)-AR level diminished (about 50%) in males. beta(1)-AR decreased in males (to about 40%) but remained stable in females. beta(2)-AR diminished in females (to about 20-60%) and also in males (to about 30-60%). MR decreased in both sexes (approximately to 50%). AC activity diminished in males (to < 50%) while PLC activity was not changed. In CRH-KO mice, the stress response was severely diminished. Paradoxically, the receptor response to stress was less affected by CRH-KO in males than in females. AC activity did not change in CRH-KO mice. In conclusion, in mice the stress reaction is sexually dimorphic and an intact hypothalamo-pituitary-adrenocortical system is required for the normal reaction of pulmonary adrenergic and MR to stress.

Cloning the bacterial bphC gene into Nicotiana tabacum to improve the efficiency of phytoremediation of polychlorinated biphenyls.

The aim of this work was to construct transgenic plants with increased capabilities to degrade organic pollutants, such as polychlorinated biphenyls. The environmentally important gene of bacterial dioxygenase, the bphC gene, was chosen to clone into a plant of Nicotiana tabacum. The chosen bphC gene encodes 2,3-dihydroxybiphenyl-1,2-dioxygenase, which cleaves the aromatic ring of dihydroxybiphenyl, and we cloned it in fusion with the gene for ß-glucuronidase (GUS), luciferase (LUC) or with a histidine tail. Several genetic constructs were designed and prepared and the possible expression of desired proteins in tobacco plants was studied by transient expression. We used genetic constructs successfully expressing dioxygenase's genes we used for preparation of transgenic tobacco plants by agrobacterial infection. The presence of transgenic DNA , mRNA and protein was determined in parental and the first filial generation of transgenic plants with the bphC gene. Properties of prepared transgenic plants will be further studied.

The detection of the non-M2 muscarinic receptor subtype in the rat heart atria and ventricles.

Mammal heart tissue has long been assumed to be the exclusive domain of the M(2) subtype of muscarinic receptor, but data supporting the presence of other subtypes also exist. We have tested the hypothesis that muscarinic receptors other than the M(2) subtype are present in the heart as minor populations. We used several approaches: a set of competition binding experiments with pirenzepine, AFDX-116, 4-DAMP, PD 102807, p-F-HHSiD, AQ-RA 741, DAU 5884, methoctramine and tripinamide, blockage of M(1) muscarinic receptors using MT7 toxin, subtype-specific immunoprecipitation experiments and determination of phospholipase C activity. We also attempted to block M(1)-M(4) receptors using co-treatment with MT7 and AQ-RA 741. Our results show that only the M(2) subtype is present in the atria. In the ventricles, however, we were able to determine that 20% (on average) of the muscarinic receptors were subtypes other than M(2), with the majority of these belonging to the M(1) subtype. We were also able to detect a marginal fraction (6 +/- 2%) of receptors that, based on other findings, belong mainly to the M(5) muscarinic receptors. Co-treatment with MT7 and AQ-RA 741 was not a suitable tool for blocking of M(1)-M(4) receptors and can not therefore be used as a method for M(5) muscarinic receptor detection in substitution to crude venom. These results provide further evidence of the expression of the M(1) muscarinic receptor subtype in the rat heart and also show that the heart contains at least one other, albeit minor, muscarinic receptor population, which most likely belongs to the M(5) muscarinic receptors but not to that of the M(3) receptors.

Receptor subtype abundance as a tool for effective intracellular signalling.

The regulation of heart function is one of the essentials for the survival of organism. Therefore, the effective mechanisms of regulation can minimize the energy requirements and improve the ability to react to different needs on time and appropriately. Two receptor types, beta-adrenoceptors and muscarinic receptors, with almost antagonistic function, are "basic regulators" of the heart parameters. It is relevant to mention that beside the main adrenoceptors and muscarinic receptors subtypes (beta(1)- and M(2)-subtype), other minor subtypes that regulate heart function, i.e. beta-, beta-adrenoceptors, alpha(1)-adrenoceptors and minor subtypes of muscarinic receptors (M(1), M(3) and M(5)) are present in the heart. In this regard is intriguing that just two catecholamines (adrenaline, noradrenaline) have many "targets"--receptors that differ so much in the functional consequences of their activation: while beta(1)- and beta(2)-adrenoceptors cause cardiostimulation, beta(3)-adrenoceptors are responsible for cardioinhibition and alpha(1)-adrenoceptors contribute to enhanced inotropy. Similarly, some data show that other muscarinic receptors than M(2) muscarinic subtype, are expressed in the heart and these minor subtype(s) can contribute to the heart regulation in similar way as beta(3)-adrenoceptors to the catecholamine action. Taken together, regulation of heart function through different receptor subtypes and using homologous and heterologous regulation can represent an effective tool for coping with permanently changing environmental conditions.

Novel roles for genetically modified plants in environmental protection.

Transgenic plants of environmental benefit typically consist of plants that either reduce the input of agrochemicals into the environment or make the biological remediation of contaminated areas more efficient. Examples include the construction of species that result in reduced pesticide use and of species that contain genes for either the degradation of organics or the increased accumulation of inorganics. Cutting-edge approaches, illustrated by our own work, focus on the applicability of genetically modified (GM) plants that produce insect pheromones or that are specifically tailored to the phytoremediation of cadmium or PCBs. This paper discusses the role that the next generation of GM plants might play in preventing and reducing chemical contamination and in converting contaminated sites into safe agricultural or recreational land.

Regulation of adrenoceptor and muscarinic receptor gene expression after single and repeated stress.

Although stress is tightly connected with elevated levels of catecholamines, stress effects on target structures of catecholamine action--adrenoceptors (ARs)--has not been deeply studied yet. Similarly, very little is known about changes of muscarinic receptors (MRs) during stress. We determined changes in these receptors in the individual parts of the heart (right atria and ventricles) of animals (rats and mice) exposed to a single and repeated immobilization stress. Changes of tissue catecholamines, beta(2)-AR gene expression, protein levels, and binding sites were determined in rat right ventricles, and changes in beta(1)-, beta(2)-, and beta(3)-AR gene expression were followed in murine right atria. Tissue catecholamines were elevated, while beta(2)-AR mRNA levels and beta(2)-AR proteins and binding were decreased, in rat right ventricles. In murine right atria, beta(1)- and beta(2)-AR gene expression was elevated, while beta(3)-AR mRNA levels and M(2)-MR were reduced. Taken together, our data show that interaction of AR and MR is important for the organism coping with stress and that different heart regions reveal distinct reactions to stress.