a1_Both divisions of the autonomic nervous system are involved in regulation of urinary bladder function. Several substances, other than noradrenaline and acetylcholine, seem to play important roles in physiology and pathophysiology of lower urinary tract. In the current study, we aimed to examine if there exist interplays between nitric oxide (NO) and autonomic transmitters and if such interactions vary in different parts of the urinary bladder in healthy and cyclophosphamide (CYP)-induced cystitic rats; when administered to the animals (100 mg/kg; i.p.), the cytotoxic CYP metabolite acrolein induces bladder inflammation. In the current study a series of in vitro functional studies were performed on detrusor muscle strip preparations. Stimulation with electrical field stimulation (EFS), methacholine, adenosine 5´-triphosphate (ATP), and adrenaline evoked contractile responses in isolated bladder preparations that were significantly reduced in cyclophosphamide (CYP)-treated rats. While the nitric oxide synthase inhibitor N ω -nitro-L-arginine (L-NNA; 10-4 M) did not affect contractile responses in normal, healthy strip preparations, it significantly increased the contractile responses to EFS, methacholine and adrenaline, but not to ATP, in the bladders from the CYP-treated rats. In the CYP-treated rats, the ATP-evoked relaxatory part of its dual response (an initial contraction followed by a relaxation) was 6-fold increased in comparison with that of normal preparations, whereas the isoprenaline relaxation was halved in the CYP-treated. While L-NNA (10-4 M) had no effect on the isoprenaline-evoked relaxations, it reduced the ATP-evoked relaxations in strip preparations from the bladder body of CYP-treated rats., a2_Stimulation of β2- and β3-adrenoceptors evoked relaxations and both responses were reduced in cystitis, the latter to a larger extent. In the trigone, the reduced ATP-evoked contractile response in the inflamed strips was increased by L-NNA, while L-NNA had no effect on the ATP-evoked relaxations, neither on the relaxations in healthy nor on the larger relaxations in the inflamed trigone. The study shows that both contractile and relaxatory functions are altered in the state of inflammation. The parasympathetic nerve-mediated contractions of the body of the bladder, evoked by the release of ATP and acetylcholine, were substantially reduced in cystitis. The relaxations to β-adrenoceptor and purinoceptor stimulation were also reduced but only the ATPevoked relaxation involved NO., R. Veselá ... [et al.]., and Obsahuje seznam literatury
Hypertension is one of the major risk factor of cardiovascular diseases, but after a century of clinical and basic research, the discrete etiology of this disease is still not fully understood. One reason is that blood pressure is a quantitative trait with multifactorial determination. Numerous genes, environmental factors as well as epigenetic factors should be considered. There is no doubt that although the full manifestation of hypertension and other cardiovascular diseases usually occurs predominantly in adulthood and/or senescence, the roots can be traced back to early ontogeny. The detailed knowledge of the ontogenetic changes occurring in the cardiovascular system of experimental animals during particular critical periods (developmental windows) could help to solve this problem in humans and might facilitate the age-specific prevention of human hypertension. We thus believe that this approach might contribute to the reduction of cardiovascular morbidity among susceptible individuals in the future., J. Kuneš, ... [et al.]., and Obsahuje seznam literatury
Curcumin, a component of the spice turmeric, was shown to have a protective effect on acute kidney injury markers following ischemia-reperfusion injury (IRI). However, its effect on glomerular and tubular renal functions following IRI is not known and this data is probably of more clinical relevance. In this study, curcumin was tested for its effect on renal functional parameters following two different periods of warm IRI in the rat. Groups V-30 (n=10) and C-30 (n=10) underwent ischemia for 30 minutes whereas groups V-45 (n=8) and C-45 (n=8) underwent ischemia for 45 minutes. C-30 and C-45 received oral curcumin (200 mg/kg/day) whereas V-30 and V-45 received a vehicle. The left renal artery blood flow was measured by a flowmeter before and 15 minutes after reperfusion. Serum TNF-α was measured before and 2 days after ischemia. The function of both kidneys was measured 2 days following ischemia using clearance technique. IRI caused significant increase in TNF-α in all groups. Curcumin significantly ameliorated the ischemiainduced alterations in serum TNF-α and associated histological changes but did not affect the alterations in renal artery blood flow, glomerular (glomerular filtration rate, renal blood flow) or tubular (urinary volume, urinary sodium and fractional excretion of sodium) functions following 30 or 45 min of IRI., F.T. Hammad, S. Al-Salam, L. Lubbad., and Obsahuje seznam literatury
The use of the herbicide paraquat (1,1'-dimethyl-4,4'-bipyridylium dichloride; PQ) which is widely used in agriculture is known to cause dopaminergic neurotoxicity. However, the mechanisms underlying this effect are not fully understood. This present study investigated the behavioral manifestations, motor coordination, and dopaminergic neurodegeneration following exposure to PQ. Male rats were injected with PQ (10 mg/kg i.p.) daily for three weeks. Rotarod systems were used for measuring locomotor activity and motor coordination. The effects of PQ on dorsiflexor, electrophysiologically-induced muscle contraction were studied. Dopamine concentrations in the ventral mesencephalon were measured by high performance liquid chromatography and the number of dopaminergic neurons in substantia nigra pars compacta was estimated by tyrosine hydroxylase immunohistochemistry. PQ induced difficulty in movement and significant reduction in motor activity and twitch tension at the dorsiflexor skeletal muscle. The number of tyrosine hydroxylase positive neurons was significantly less in the substantia nigra pars compacta and nigral dopamine level was significantly reduced in PQ treated animals (20.4±3.4 pg/mg) when compared with control animals (55.0±2.4 pg/mg wet tissue). Daily treatment of PQ for three weeks induces selective dopaminergic neuronal loss in the substantia nigra and significant behavioral and peripheral motor deficit effects., M. A. Fahim, ... [et al.]., and Obsahuje seznam literatury
Matriptase-2, a membrane protein encoded by the Tmprss6 gene, is a negative regulator of hepcidin expression. Although matriptase-2 has been proposed to cleave membrane hemojuvelin, we have recently found decreased hemojuvelin protein levels in Tmprss6 -/- mice. The purpose of this study was to confirm this observation by determining hemojuvelin protein levels in another strain of mice with disrupted Tmprss6 gene, and to determine the effect of matriptase-2 deficiency on the expression of other membrane proteins participating in the bone morphogenetic protein signal transduction. Mask mice, which lack the proteolytic domain of matriptase-2, displayed decreased liver hemojuvelin protein content, while Id1 mRNA level, an indicator of hemojuvelin-dependent signal transduction, was increased. Protein levels of bone morphogenetic protein receptors Alk3 and Acvr2a were unchanged, and tran sferrin receptor 2 and neogenin protein levels were slightly decreased. The results confirm that the loss of matriptase-2 increases bone morphogenetic protein- dependent signaling, while pa radoxically decreasing liver hemojuvelin protein content. The regulation of transferrin receptor 2 protein levels by transferrin saturation was not affected in mask mice. How the loss of matriptase-2 proteolytic activity leads to decreased hemojuvelin protein levels is at present unclear., J. Frýdlová, ... [et al.]., and Obsahuje seznam literatury
All secretory anterior pituitary cells fire action potentials spontaneously and exhibit a high resting cation conductance, but the channels involved in the background permeability have not been identified. In cultured lactotrophs and immortalized GH3 cells, replacement of extracellular Na+ with large organic cations, but not blockade of voltage-gated Na+ influx, led to an instantaneous hyperpolarization of cell membranes that was associated with a cessation of spontaneous firing. When cells were clamped at –50 mV, which was close to the resting membrane potential in these cells, replacement of bath Na+ with organic cations resulted in an outward-like current, reflecting an inhibition of the inward holding membrane current and indicating loss of a background-depolarizing conductance. Quantitative RTPCR analysis revealed the high expression of mRNA transcripts for TRPC1 and much lower expression of TRPC6 in both lactotrophs and GH3 cells. Very low expression of TRPC3, TRPC4, and TRPC5 mRNA transcripts were also present in pituitary but not GH3 cells. 2-APB and SKF-96365, relatively selective blockers of TRPC channels, inhibited electrical activity, Ca2+ influx and prolactin release in a concentration-dependent manner. Gd3+, a common Ca2+ channel blocker, and flufenamic acid, an inhibitor of non-selective cation channels, also inhibited electrical activity, Ca2+ influx and prolactin release. These results indicate that nonselective cation channels, presumably belonging to the TRPC family, contribute to the background depolarizing conductance and firing of action potentials with consequent contribution to Ca2+ influx and hormone release in lactotrophs and GH3 cells., M. Kučka ... [et al.]., and Obsahuje seznam literatury
Cardiovascular disease is a major cause of morbidity and mortality in young adults with end-stage renal disease (ESRD), but its basis is still not well understood. We therefore evaluated the determinants of atherosclerosis in children with ESRD. A total of 37 children with ESRD (with 31 who had undergone transplantation) were examined and compared to a control group comprising 22 healthy children. The common carotid intimamedia thickness (CIMT) was measured by ultrasound as a marker of preclinical atherosclerosis. The association of CIMT with anthropometrical data, blood pressure, plasma lipid levels, and other biochemical parameters potentially related to cardiovascular disease was evaluated. Children with ESRD had significantly higher CIMT, blood pressure, and levels of lipoprotein (a), urea, creatinine, ferritin, homocysteine, and serum uric acid as well as significantly lower values of apolipoprotein A. The atherogenic index of plasma (log(triglycerides/HDL cholesterol)) was also higher in patients with ESRD; however, this difference reached only borderline significance. In addition, a negative correlation was found between CIMT and serum albumin and bilirubin in the ESRD group, and this correlation was independent of age and body mass index. In the control group, a significant positive correlation was observed between CIMT and ferritin levels. Factors other than traditional cardiovascular properties, such as the antioxidative capacity of circulating blood, may be of importance during the early stages of atherosclerosis in children with endstage renal disease., H. M. Dvořáková ... [et al.]., and Obsahuje seznam literatury
The aim of this study was to examine whether threshold to heat stimuli, and expression of transient receptor potential vanilloid1 (TRPV1) and nerve growth factor (NGF) in dorsal root ganglion (DRG) altered under conditions of long-term limb immobilization. A plastic cast was wrapped around the right limb from the forearm to the forepaw to keep wrist joint at 90° of flexion for 5 weeks. Heat hyperalgesia was tested using the plantar test at 6 h after removing cast. The rats were perfused transcardially with 4 % paraformaldehyde and DRGs were excised at 24 h after removing cast. For size distributions of the TRPV1-IR and NGF-IR neuronal profile, the DRG area measurements over 1000 DRG neurons per animal were measured in each side, on both the immobilized (ipsilateral) and contralateral sides. Ipsilateral withdrawal latency was significantly shorter than contralateral sides. Ipsilateral percentage of immunoreactive neurons in the total DRG neurons was significantly higher than contralateral sides in TRPV1-IR and NGF-IR. Long-term casting induced heat hyperalgesia, and up-regulation and phenotypic change of TRPV1-IR and NGF-IR in DRGs on the immobilized side. These DRG alterations may involve heat hyperalgesia after long-term limb immobilization., T. Nishigami, ... [et al.]., and Obsahuje seznam literatury
The hypothalamic supraoptic and paraventricular nuclei consist of oxytocin and arginine vasopressin synthesizing neurons that send projections to the neurohypophysis. A growing body of evidence in adult animals and young animals at near term confirmed the structure and function in the vasopressinergic and oxytocinergic network. However, whether those distinctive neural networks are formed before near term is largely unknown. This study determined the special patterns in location and distribution of oxytocin- and vasopressin-neurons in the paraventricular and supraoptic nuclei from preterm to term in the ovine fetuses. The results showed that oxytocin- and vasopressin-neurons were present in both nuclei at the three gestational time periods (preterm, near term, and term). In the paraventricular nuclei, vasopressin-cells concentrated mainly in the core of the middle magnocellular paraventricular nuclei, and oxytocin-cells were scattered surrounding the core. In the supraoptic nuclei, vasopressin-cells mostly located in the ventral part, and oxytocincells in the dorsal part. The data demonstrated that the special distributed patterns of vasopressin- and oxytocin-neuron network have formed in those two nuclei at least from preterm. Intracerebroventricular injection of angiotensin II significantly increased fetal plasma oxytocin and vasopressin levels at preterm, which was associated with an increase of oxytocin- and vasopressin-neuron activity marked with c-fos expression. The data provided new evidence for the structural and functional development of the oxytocin- and vasopressin-network before birth., L. Shi, Y. Fan, Z. Xu., and Obsahuje seznam literatury
Opening of the mitochondrial membrane permeability transition pore (MPTP) is an important factor in the activation of apoptotic and necrotic processes in mammalian cells. In a previous paper we have shown that cardiac mitochondria from neonatal rats are more resistant to calcium load than mitochondria from adult animals. In this study we have analyzed the ontogenetic development of this parameter both in heart and in liver mitochondria. We found that the high resistance of heart mitochondria decreases from day 14 to adulthood. On the other hand, we did not observe a similar age-dependent sensitivity in liver mitochondria, particularly in the neonatal period. Some significant but relatively smaller increase could be observed only after day 30. When compared with liver mitochondria cardiac mitochondria were more resistant also to the peroxide activating effect on calcium-induced mitochondrial swelling. These data thus indicate that the MPTP of heart mitochondria is better protected against damaging effects of the calcium load and oxidative stress. We can only speculate that the lower sensitivity to calcium-induced swelling may be related to the higher ischemic tolerance of the neonatal heart., Z. Drahota, ... [et al.]., and Obsahuje seznam literatury