Apelin effects on lipopolysaccharide-increased pulmonary permeability in rats.

Material And Method: Pretreatment with apelin-13 (AP-13, 2 mg/kg, i.p.), sodium butyrate (BUT, 200 mg/kg, s.

Adenosine involvement on bronchial reactivity modulation by diesel exhaust.

Unlabelled: In recent decades, epidemiologic investigations have suggested a strong relationship between air pollution and an increase in the prevalence of allergic rhinitis and asthma.

Aim: To investigate the possible involvement of adenosine (AD) in bronchomotor effects of diesel exhaust (DE).

Material And Method: Isolated bronchi from ovalbumin (OVA) sensitized rats were challenged in presence or absence of diesel exhaust extract (DEE).

Adipokines involvement in lung function.

The last two decades brings many data about white adipose tissue capacity to secrete hormones, named adipokines, which could mediate the relationship between obesity and lung diseases. In this paper we presented some data about adipokines involvement on pulmonary function, with special emphasis on leptin, adiponectin, tumor necrosis factor alpha, vascular endothelial growth factor, resistin, hepatocyte growth factor, interleukin-6, angiotensinogen and apelin.

Relaxation and polarization of precontracted rat aortic smooth muscle by sodium nitrite and an L-type channel blocker.

Unlabelled: Membrane potential (MP) is essential for smooth muscle (SM) contraction, mainly by determining the activity of L-type Ca2+ channels (Ca(L)). Although a widely used SM model, there are few electrophysiology studies in rat aorta.

Aim: We investigated the mechanism of SM relaxation induced by NaNO2 in comparison with a Ca(L) blocker.

Interactions between angiotensin II and phenylephrine on isolated rat renal arteries and veins.

It is know that not only decreased blood flow to the kidney but also obstruction of renal outflow may, in some instances, be a cause of hypertension. In this view were compared angiotensin (Ang) II responses and investigated interactions between Ang II and phenylephrine (Phe) on renal vessels. Studies were performed on renal artery and vein rings without endothelium obtained from young (4 months) and old (12 month of age) male Wistar rats.

Interactions between angiotensin I and acetylcholine on rat left main bronchial rings.

Angiotensin (Ang) II is known to amplified bronchoconstriction induced by acetylcholine (ACh). On the other hand all the components of renin angiotensin system were located on lungs. Contractile effects of Ang I (the precursor of Ang II) and interactions between Ang I and ACh on rat bronchial rings were characterize using angiotensin II type 1 (AT1) receptor antagonist (losartan), angiotensin converting enzyme (ACE) inhibitors (captopril and teprotide) and chymase inhibitor (chymostatin).

Interactions between extracellular and intracellular administered angiotensin II in isolated rat portal vein rings.

It is already demonstrated that intracellular angiotensin II (Ang II) stimulates smooth muscle contraction and cell growth. We studied the contractile effects of Ang II intracellular delivered by the means of liposomes (LAngII) and also the interactions between intracellular and extracellular administered Ang II on the rat portal vein rings without endothelium. The results were expressed as the percentages of the control contraction (K+ 40 mM; mean +/- S.

[L-type calcium channels involvement in aortic smooth muscle contraction as revealed by membrane potential and active force dynamics].

Membrane potential (MP) is essential in smooth muscle (SM) contractile activity, mainly by its effect upon L-type Ca2+ channels. We simultaneously recorded SM isometric tension and MP in de-endothelised rat aorta rings and examined their submaximal activation by K+, norepinephrine (NE) or phenylephrine (PHE) and the influence of methoxyverapamil (D600). K+ -induced contraction strictly correlated with depolarization, while faster contractions induced by NE or PHE started and peaked with a less depolarized membrane.

Pepstatin A is inducing contractile effects on isolated rat aorta rings.

In a series of experiments dealing with the effects of angiotensin I (AI) and angiotensinogen on isolated rat aorta we observed that pepstatin A was able to induce contractile effects by itself. The endothelin pathway was excluded by the inhibitory effects of captopril, chymostatin and amastatin. In addition, few preliminary experiments showed that the contractile effects of pepstatin A were inhibited by the pretreatment with losartan, an antagonist of AT1 angiotensin receptors.

[Cytosolic calcium dynamics and smooth muscle contraction(II): Reticular calcium fluxes].

The contractile status of smooth muscle depends upon cytosolic Ca2+, the Ca(2+)-sensitivity of actin-myosin interaction and various calcium-independent mechanisms. This second part of our overview is devoted to the complex involvement of endoplasmic reticulum in the cytosolic Ca2+ signals related to smooth muscle contractile activity, with a focus on the functional structure of reticular membrane proteins that ensure the respective Ca2+ fluxes. Ca2+ release is activated by cytosolic Ca2+, involving reticular channels called inositol triphosphate receptors and ryanodine receptors.

[Alternative pathways for the activation of the renin-angiotensin system].

The knowledge of the structure and function of the components of the renin-angiotensin system (RAS) is rapidly increasing. The classic pathway of angiotensin (Ang) II generation includes a reaction catalyzed by angiotensin-converting enzyme (ACE). We actually discuss the alternative pathways for the generation of Ang-II and other angiotensin peptides (Ang III, Ang IV, Ang (1-9), Ang (1-7), des-Asp-Ang I) and the responsible enzymes (tonins, cathepsins, chymases, aminopeptidases, dipeptidyl aminopeptidases, neutral endopeptidases, carboxypeptidases, ACE2 etc.

[Interactions between angiotensin-(1-7)and angiotensin II in isolated rat portal vein].

Our preliminary data show for the first time the interaction between angiotensin-(1-7) (Ang-(1-7)) and angiotensin II (Ang II, 10 nM) in isolated rat portal vein. Very low concentrations (10 nM) of Ang-(1-7) have marked functional antagonizing effects on Ang II-induced contractions. High concentrations of Ang-(1-7) (1-10 mM) do not affect the effects of Ang II.

[Polyamines antagonizing angiotensin II contractile effects in isolated rat aorta].

Our study showed that the administration in pre-treatment of some polyamines (especially spermine and spermidine and almost null agmatine, putrescine and cadaverine) reduced the contractile effects of angiotensin II (Ang II) in isolated rat aorta. These effects might not be associated to the interference of clathrin coated vesicles (coated pits) formation or caveolae interaction (and thus to Ang II internalization through AT1 receptors). In contrast, these effects seem to be due to the interaction with voltage-gated membrane Ca2+ channels.

[Cytosolic calcium dynamics and smooth muscle contraction.III Plasmalemmal calcium fluxes].

Smooth muscle contractile activity depends upon cytosolic Ca2+, the Ca(2+)-sensitivity of actin-myosin interaction and several auxiliary mechanisms. This section presents the plasmalemmal Ca2+ fluxes in relation with the functional structure of their supportive proteins and the contractile impact. Summaries of classical data are accompanied by examples of recent advances.

[Effects of polyamine-loaded liposomes on liver mitochondrial permeability transition].

The objective of the present study was represented by the effects of polyamineloaded liposomes on hepatic mitochondrial permeability transition (MPT). MPT was appreciated through the swelling of the isolated guinea-pig liver mithocondria induced by Ca2+, at 540 nm, using a diode-array 8452 UV-VIS spectrophotometer and a General Purpose software (Hewlett-Packard). Polyamines encapsulated in liposomes might inhibit the appearance of MPT induced by Ca2+, directly proportional to electrical charge: spermine > spermidine > putrescine > cadaverine.

Evidence for the involvement of cerebral renin-angiotensin system (RAS) in stress analgesia.

Studies concerning variations of the central renin-angiotensin system (RAS) during immobilization stress in rats have shown a significant increase in renin-like activity in the hypothalamus and fronto-parietal cortex, together with a definite decrease in the hypophysis and pineal gland. The resultant stress analgesia is blocked by the previous administration of naloxone and saralasin (angiotensin II antagonist). The intracerebral administration of renin and angiotensin II produces an increase in latencies to thermoalgesic stimuli; this is reduced, as is immobilization stress, by naloxone and saralasin.

Some neural effects of adenosin.

The possible neural effects of adenosine were investigated by using electrophysiological techniques at the level of some central and peripheral synapses. The evoked potentials in the somatosensorial cerebral cortex are influenced according to both the type of administration and the level of the electrical stimulation. While the local application does not induce significant alterations, the intrathalamic injections and the perfusion of the IIIrd cerebral ventricle do change the distribution of activated units at the level of different cortical layers especially during the peripheral stimulation.

[Hemorrhagic syndrome in newborn infants during a hospital infection with Pseudomonas aeruginosa].

In a department for neonates 21 of the 34 children contracted infections with various clinical manifestations within a relatively short interval (approximately two weeks). Three of the children died and pathoanatomic examination revealed aspects characteristic of vascularitis and diffuse hemorrhage in most organs accompanied by infiltration and oedema. From the lethal cases, part of the sick and healthy children and personnel the same bacterium was isolated--Pseudomonas aeruginosa, suggesting an in-hospital epidemic.

[Cerebral renin-like activity in different functional conditions (author's transl)].

Using the Boucher micromethod of determining renin activity in the frontoparietal cortex, brain stem, hypothalamus, hypophysis, and epiphysis rat tissue in different functional conditions, we have observed the following: 1 In rats previously treated with an I. V., injection of 1-1.