Arrhythmogenic Interaction Between Sympathetic Tone and Mechanical Stretch in Rat Pulmonary Vein Myocardium.

Rapid firing from pulmonary veins (PVs) frequently initiates atrial fibrillation, which is a common comorbidity associated with hypertension, heart failure, and valvular disease, i.e., conditions that pathologically increase cardiomyocyte stretch.

Characteristics of renal sympathetic nerve single units in rabbits with angiotensin-induced hypertension.

We examined the effect of chronic angiotensin (Ang II)-induced hypertension on activity of postganglionic renal sympathetic units to determine whether altered whole renal nerve activity is due to recruitment or changes in firing frequency. Rabbits were treated with a low (20 ng kg(-1) min(-1), 8 weeks) or high dose (50 ng kg(-1) min(-1), 4 weeks) of Ang II before the experiment under chloralose-urethane anaesthesia. Spontaneously active units were detected from multiunit recordings using an algorithm that separated units by action potential shape using templates that matched spikes within a prescribed standard deviation.

Neuropeptide FF2 receptor distribution in the human brain. An immunohistochemical study.

Human neuropeptide FF2 (hFF2) receptor has been postulated to mediate central autonomic regulation by virtue of its ability to bind with high affinity to many amidated neuropeptides. In the present immunohistochemical study, we identified hFF2 positive neurons in the forebrain and medulla oblongata of individuals, who died suddenly of mechanical trauma or hypothermia. Morphologically, these neurons demonstrated features identified with both projection neurons and interneurons.

Experimental antioxidant biotherapy for protection of the vascular wall by modified forms of superoxide dismutase and catalase.

The antithrombotic activities of superoxide dismutase and catalase are determined by their effects on reactive oxygen species. Modification of these enzymes with chondroitin sulphate enhances the effect due to accumulation of the derivatives on the surface of the vascular wall cells. We have shown that the effects of covalently modified biocatalysts exceed those of native enzymes, free chondroitin sulphate and their mixtures.

Distribution of the neuropeptide FF1 receptor (hFF1) in the human hypothalamus and surrounding basal forebrain structures: immunohistochemical study.

Neuropeptides with C-terminal RFamide and their receptors NPFF1 (FF1) and NPFF2 (FF2) have been implicated in a wide variety of functions, including nociception and autonomic and neuroendocrine regulation. Recent studies indicate that the FF1, but not FF2, mRNA is highly expressed in the human hypothalamus. In the present study, localization of FF1 in the human hypothalamus and surrounding regions was studied immunohistochemically by using an antibody against human FF1 (hFF1).

[Expression of T-cadherin in the rat carotid artery wall after balloon injury and in different rat organs].

T-cadherin is an unusual glycosilphosphatidylinositol (GPI)-anchored member of the cadherin family of cell adhesion proteins. In contrast to classical cadherins, tissue distribution of T-cadherin so far remained unknown. We examined tissue distribution of T-cadherin in rats using Western blotting and immunohistochemical method.

[Differences in phorbol-dependent phosphorylation of regulatory proteins and contraction of phasic and tonic smooth muscle].

Smooth muscles are divided into slowly contracting tonic and relatively fast phasic muscles. In both cases Ca2+ is a key mediator of the contractile response. However, the appearance of a tonic component during sphincter or arterial muscle contraction and its absence in contracting visceral smooth muscle is characteristic of their difference.

[Functional properties and intracellular localization of high molecular weight isoforms of ligh chain myosin kinase].

The vertebrate genetic locus, coding for a Ca2+/calmodulin-dependent enzyme myosin light chain kinase (MLCK), the key regulator of smooth muscle contraction and cell motility, reveals a complex organization. Two MLCK isoforms are encoded by the MLCK genetic locus. Recently identified M(r) 210 kDa MLCK contains a sequence of smooth muscle/non-muscle M(r) 108 kDa MLCK and has an additional N-terminal sequence (Watterson et al.

[Fatty acid transport in the blood by lipoproteins as macromolecules: facts and a hypothesis].

We develop a hypothesis of lipid transport in blood which differs significantly from commonly used one. In any organism hydrophobic substances transport in aqueous medium functions on the base of the some principles. Hence: (a) lipoproteins transport mainly fatty acids; (b) lopoprotein structure are based on the protein chemistry principles; (c) all lipiproteins are build up according to a single principle and are bilayers--protein: lipid; (d) apolipoprotein is a protein which binds one lipid class, determines the peculiarities of structure and function of transporting macromolecule and disturbs fatty acids transport in blood at inherent synthesis absence or change of apoprotein primary structure; (e) only fatty acids and all their derivatives are lipids.

[Antithrombotic activity of complexes of superoxide dismutase with chondroitin sulfate in arterial damage in rats].

The comparative antithrombotic activity of superoxide dismutase and chondroitin sulfate in the form of covalent or noncovalent complexes was studied on the rat arterial thrombosis induced by treatment of vessel with ferrous chloride solution. The covalent conjugate between superoxide dismutase and chondroitin sulfate has been shown to exert the highest antithrombotic effect. The higher antithrombotic activity of covalent conjugate is stipulated by its coupling on the glycocalyx of vascular wall and by the stability of the covalent bond between superoxide dismutase subunits and chondroitin sulfate.

[Interaction of the beta1-subunit of G-proteins with the actin cytoskeleton].

Using immunoblotting with specific antibodies, we have identified beta 1- and beta 2-subunits of Gi-proteins in membrane and cytosolic fractions of pig lung. It has been shown that beta 1-subunit is present both in membrane and cytosolic fractions, whereas beta 2-subunit is associated only with membranes. Activation of membrane-bound G proteins with non-hydrolysable GTP analogues have led to partial release from membrane of beta 1-, but not beta 2-subunits.

Location and functional characterization of myosin contact sites in smooth muscle caldesmon.

Caldesmon interaction with smooth muscle myosin and its ability to cross-link actin filaments to myosin were investigated by the use of several bacterially expressed myosin-binding fragments of caldesmon. We have confirmed the presence of two functionally different myosin-binding sites located in domains 1 and 3/4a of caldesmon. The binding of the C-terminal site is highly sensitive to ionic strength and hardly participates in acto-myosin cross-linking, while the N-terminal binding site is relatively independent of ionic strength and apparently contains two separate myosin contact regions within residues 1-28 and 29-128 of chicken gizzard caldesmon.

Kinase-related protein: a smooth muscle myosin-binding protein.

Kinase-related protein (telokin) is a small myosin-binding protein which has recently been discovered in smooth muscle. The KRP messenger RNA is transcribed from within the myosin light chain kinase (MLCK) gene, a rare example in vertebrates of two proteins coded for by a single gene. Owing to a separate transcription unit and a common reading frame, kinase-related protein is expressed as an independent protein which consists of the C-terminal 156 amino acids of the kinase.