Search results for "wistar"
showing 10 items of 1094 documents
Cytoskeleton mediates negative inotropism and lusitropism of chromogranin A-derived peptides (human vasostatin1-78 and rat CgA(1-64)) in the rat heart
2010
Cytoskeleton scaffold in cardiac myocytes provides structural support and compartmentalization of intracellular components. It is implicated in cardiac pathologies including hypertrophy and failure, playing a key role in the determinism of contractile and diastolic dysfunctions. Chromogranin A (CgA) and its derived peptides have revealed themselves as novel cardiovascular modulators. In humans, normal CgA levels considerably increase in several pathologies, including heart failure. Recent data have shown on the unstimulated rat heart that human recombinant Vasostatin-1 (hrVS-1) and rat chromogranin A 1-64 (rCgA(1-64)) induce negative inotropic and lusitropic effects counteracting the beta-a…
Weaning induces NOS-2 expression through NF-κB modulation in the lactating mammary gland: importance of GSH
2005
Zaragozá, R; Miralles, VJ; Rus, AD; García, C; Carmena, R; García-Trevijano, ER; Barber, T; Pallardó, FV; Torres, L; Viña, JR. At the end of lactation the mammary gland undergoes involution, a process characterized by apoptosis of secretory cells and tissue remodelling. To gain insight into this process, we analysed the gene expression profile by oligonucleotide microarrays during lactation and after forced weaning. Up-regulation of inflammatory mediators and acute-phase response genes during weaning was found. Expression of IκBα (inhibitory κBα), a protein known to modulate NF-κB (nuclear factor-κB) nuclear translocation, was significantly up-regulated. On the other hand, there was a time-…
In vivo antihypertensive mechanism of lactoferrin-derived peptides: Reversion of angiotensin I- and angiotensin II-induced hypertension in Wistar rats
2015
Novel peptides with antihypertensive effects in SHR rats have previously been identified in lactoferrin (LF) hydrolysates. To investigate their in vivo antihypertensive mechanism, we have assessed the blood pressure lowering effects of two of these LF-derived peptides (RPYL and DPYKLRP) in Wistar rats subjected to either angiotensin I- or angiotensin II-induced hypertension. Blood pressure was measured by the tail-cuff method, hypertension was induced by subcutaneous infusion of angiotensins, and then captopril, valsartan or LF-derived peptides orally administered. Angiotensin I- and angiotensin II-induced hypertension were reversed by captopril and valsartan, respectively. RPYL and DPYKLRP…
L-cysteine and glutathione metabolism are impaired in premature infants due to cystathionase deficiency.
1995
There are conflicting reports in the literature as to whether L-cysteine is an essential amino acid in premature infants as the result of the absence of hepatic cystathionase activity. To analyze the physiological importance of the cystathionase deficiency, we studied sulfur amino acid metabolism in human neonates of different gestational ages. Plasma cystathionine concentrations are higher in premature infants < or = 32 wk gestation (group 1) than in premature infants of 33-36 wk gestational age (group 2) or in full-term infants (group 3), whereas plasma cysteine concentrations are much lower in group 1 and 2 premature infants than in mature infants. Furthermore, erythrocytes from group 1 …
An O2-sensitive glomus cell-stem cell synapse induces carotid body growth in chronic hypoxia.
2013
Summary Neural stem cells (NSCs) exist in germinal centers of the adult brain and in the carotid body (CB), an oxygen-sensing organ that grows under chronic hypoxemia. How stem cell lineage differentiation into mature glomus cells is coupled with changes in physiological demand is poorly understood. Here, we show that hypoxia does not affect CB NSC proliferation directly. Rather, mature glomus cells expressing endothelin-1, the O 2 -sensing elements in the CB that secrete neurotransmitters in response to hypoxia, establish abundant synaptic-like contacts with stem cells, which express endothelin receptors, and instruct their growth. Inhibition of glomus cell transmitter release or their sel…
Intervention of two voltage-dependent calcium-entry pathways in the contractile response to acetylcholine and KCl in rat uterus.
1994
The contractile response of rat uterine smooth muscle was investigated. Verapamil and diltiazem concentration-dependently relax the sustained contractions induced by KCl (56 mmol/l) or acetylcholine (10(-4) mol/l). This inhibitory effect was not not freely reversed by washing the tissue and subsequently no contractile response was obtained in depolarized tissue, but a lower biphasic response (phasic and tonic) to acetylcholine was observed. Addition of cumulative concentrations of CaCl2 (1.2-19.2 mmol/l) induced a partial recovery of the contractile response to acetylcholine or KCl, but addition of MgCl2 (1.2-19.2 mmol/l did not. When the channel was reactivated by a third addition of KCl o…
Comparative study of the rat uterine smooth muscle relaxant activity of three bisbenzyltetrahydroisoquinolines with tetrandrine
1993
Abstract The relaxant activity of three bisbenzyltetrahydroisoquinolines—obaberine, popisonine and lindoldhamine—was examined in rat isolated uterus and their inhibitory potencies were compared with that of tetrandrine. All alkaloids tested relaxed KCl-depolarized rat uterus and totally or partially inhibited oxytocin-induced rhythmic contractions. The degree of methylation of the free phenolic hydroxy groups and the loss of one diarylether bridge influence the potency of relaxant action of these alkaloids. Only alkaloids with absolute configuration 1R,1′S or 1R1′R acted intracellularly, promoting relaxation of contractile responses induced by oxytocin or vanadate in a Ca2+-free medium.
Nephrotoxicity of ibandronate and zoledronate in Wistar rats with normal renal function and after unilateral nephrectomy.
2015
A previous animal study compared the nephrotoxic effect of ibandronate (IBN) and zoledronate (ZOL), but interpretation of these study results was limited because of the model of minimal nephrotoxic dosage with a dosage ratio of 1:3. The present study investigated the nephrotoxicity of ibandronate and zoledronate in a 1.5:1 dose ratio, as used in clinical practice and compared the nephrotoxicity in rats with normal and with mildly to moderately impaired renal function. We compared rats with normal renal function (SHAM) and with impaired renal function after unilateral nephrectomy (UNX), treated either with ibandronate 1.5mg/kg, zoledronate 1mg/kg or placebo once (1×) or nine (9×) times. Rena…
Combined pre- and postnatal ethanol exposure in rats disturbs the myelination of optic axons.
2011
Aims: To analyse myelination and outgrowth of the optic axons in relation to the neuro-ophthalmological manifestations of ethanol (EtOH) abuse during pregnancy. Methods: An experimental model of chronic EtOH exposure was developed in rats and their offspring by subjecting the dams to a liquid diet (35% of the daily total calories as either EtOH or maltose-dextrose nutritional controls (Con). Eyeballs and optic nerves were obtained at key developmental stages and processed for morphologic, immunocytochemical and immunoblotting procedures, using alternatively antibodies against myelin basic protein (MBP) or neurofilament (NF) protein, and image analysing. Results: A significant delay in onset…
Inhibitory effects of okadaic acid on rat uterine contractile responses to different spasmogens
1997
In the present study, we examined the effects of okadaic acid, a selective inhibitor of type I and 2A protein phosphatases, on the mechanical responses evoked by oxytocin, K + - and Na + -modified solutions and ouabain in estrogen-primed rat myometrium. Oxytocin elicited a rapid, phasic contraction followed by rhythmic oscillations. The phasic response was partially resistant to the absence of external Ca 2+ . Okadaic acid (1 μM) and the L-type calcium channel blocker nifedipine (1 μM) abolished the oscillatory component and reduced the initial, phasic response to about 80% of the control response. High K + (60 mM) solution, ouabain (1 mM), K + -free medium and low Na + (25 mM) solution ind…