Altered energy status of primary cerebellar granule neuronal cultures from rats exposed to lead in the pre- and neonatal period

This paper examines the effect of pre- and neonatal exposure of rats to lead (0.1% lead acetate in drinking water, resulting in rat offspring whole blood lead concentration (Pb-B) 4μg/dL) on the energy status of neuronal mitochondria by measuring changes in ATP, ADP, AMP, adenosine, TAN concentration, adenylate energy charge value (AEC) and mitochondrial membrane potential in primary cerebellar granule neurons (CGC) in dissociated cultures. Fluorescence studies were performed to imaging and evaluate mitochondria mass, mitochondrial membrane potential, intracellular and mitochondrial reactive oxygen species (ROS) production. The Na(+)/K(+) ATPase activity in intact CGC was measured spectrophotometrically. Our data shows that pre- and neonatal exposure of rats to Pb, even below the threshold of whole blood Pb value considered safe for people, affects the energy status of cultured primary cerebellar granule neurons through a decrease in ATP and TAN concentrations and AEC value, inhibition of Na(+)/K(+) ATPase, and increase in intracellular and mitochondrial ROS concentration. These observations suggest that even these low levels of Pb are likely to induce important alterations in neuronal function that could play a role in neurodegeneration.

The influence of ACEA--a selective cannabinoid CB1 receptor agonist on whole blood and platelet-poor plasma serotonin concentrations

Through the CB1 receptor cannabinoids modulate serotonin (5-hydroxytryptamine, 5-HT) release in the central nervous system which is connected with some of their pharmacological effects, especially antidepressant activity. 5-HT has many important physiological functions also in the periphery, particularly in the circulatory system and digestive tract. 5-HT dysfunction may be involved in some diseases pathogenesis including hypertension, migraine, cardiac disorders, cerebral ischemia or peripheral vascular diseases. Cannabinoids possible influence on 5-HT release in peripheral tissues may be clinically significant. The aim of the present study was to investigate the influence of ACEA (arachidonyl-2-chloroethylamide), a selective cannabinoid CB1 receptor agonist on whole blood (WB) and platelet-poor plasma (PPP) 5-HT levels. The experiments were carried out on male and female Wistar rats. ACEA (3 mg/kg i.p.) was given alone and in combination with a selective CB1 receptor antagonist AM 251 (3 mg/kg i.p.). Concentrations of 5-HT in WB and PPP were determined by enzyme-linked immunosorbent assay (Serotonin ELISA). ACEA significantly decreased concentration of 5-HT in WB (to 61%, p < 0.02) and its effect was blocked by AM 251. ACEA also reduced of 5-HT in PPP (to 62%) however, the difference was statistically insignificant. Research results reveal that due to CB1 receptor stimulation, ACEA reduces 5-HT contents in bloodstream. This effect is probably the result of inhibition of 5-HT release from gastrointestinal tract.

Involvement of nitric oxide in the gastroprotective effect of ACEA, a selective cannabinoid CB1 receptor agonist, on aspirin-induced gastric ulceration

The involvement of nitric oxide in the gastroprotective effect of ACEA (arachidonyl-2-chloroethylamide), a selective cannabinoid CB1 receptor agonist, on aspirin-induced gastric ulceration was studied in rats. ACEA (3 mg/kg i.p.) significantly reduced gastric ulcer formation. The gastroprotection of ACEA was attenuated by pretreatment with L-NAME (25 and 50 mg/kg i.p.), a nitric oxide synthase inhibitor. The combination of L-arginine (300 mg/kg i.v.), a precursor of nitric oxide with L-NAME (50 mg/kg i.p.) reversed the protective activity of ACEA (3 mg/kg i.p.). These results suggest that endogenous nitric oxide may be involved in the protective effect of ACEA.

Synthesis and anxiolytic activity of 1-phenyl-2-(4-aryl-1,3,4,5-tetrahydropyrido[2,3-b][1 ,4]diazepin-2-ylidene)-ethanone

A two-step, general synthesis of 1-phenyl-2-(4-aryl-1,3,4,5-tetrahydropyrido[2,3-b][1,4]diazepin-2-ylidene)-ethanones 3-9 is presented. This synthesis employs a condensation of 2,3-diaminopyridine with benzoylacetone followed by a basic-activated cyclization reaction with substituted benzaldehydes for final closure of the seven-membered ring. Molecular diversity is fixed by appropriate aldehydes: 2-chloro-, 4-chloro-, 2-bromo-, 4-bromo-, 4-fluoro-, 4-trifluoro- and 3-bromo-4,5-dimethoxybenzaldehyde. Compounds 4, 6, 8, 9 and 10 were examined for their anxiolytic activity. The most active was the compound with the chlorophenyl substituent i.e. 1-phenyl-2-{4-(4-chlorophenyl)-1,3,4,5-tetrahydropyrido[2,3-b][1,4]diazepin-2-ylidene}-ethanone (4).

ACEA (arachidonyl-2-chloroethylamide), the selective cannabinoid CB1 receptor agonist, protects against aspirin-induced gastric ulceration

The effect of a selective cannabinoid CB1 receptor agonist, ACEA (arachidonyl-2-chloroethylamide) in an aspirin-induced ulcer model was studied in rats. ACEA (1.25-5 mg/kg i.p.) significantly reduced gastric ulcer formation to 24, 21 and 0.6% respectively. These results confirm the cytoprotective effect of CB1 receptor agonists and suggest that the endocannabinoid system might be the target for a novel class of anti-ulcer drugs.

Effects of cannabinoids on the anxiety-like response in mice

Several pieces of anatomical, biochemical and pharmacological evidence indicate that the endocannabinoid system via CB1 receptors is implicated in the control of emotional behavior. However, previous studies have reported unclear and contradictory results concerning the role of cannabinoids in anxiety. The aim of the present study was to examine the influence of the cannabinoid agonist WIN 55,212-2 (1 and 5 mg/kg), the CB1 antagonist AM 281 (1, 2 and 4 mg/kg), the inhibitor of anandamide hydrolysis AACOCF3 (1 and 4 mg/kg) and the inhibitor of anandamide transporter AM404 (1 and 4 mg/kg) on the anxiety-like response in mice in the light/dark box test. WIN 55,212-2 (5 mg/kg) induced the anxiogenic-like effect accompanied by motor inhibition, AACOCF3 (4 mg/kg) induced the selective anxiolytic-like effect, whereas AM404 and AM281 were without effect. Pretreatment with AM281 (2 mg/kg) blocked the anxiogenic-like and sedative responses induced by WIN 55, 212-2, as well as the anxiolytic-like effect of AACOCF3. These results support the hypothesis that the endocannabinoid system is involved in the regulation of anxiety-like behavior, and also suggest that the inhibitors of anandamide hydrolysis might be potential anxiolytic drugs.

[Comparison of the early response to natural and synthetic surfactant in premature babies with respiratory distress syndrome]

OBJECTIVES

To compare the early response to natural and synthetic surfactant in premature babies with respiratory distress syndrome (RDS).

METHODS

This is a prospective study of 21 newborns with respiratory distress syndrome treated with natural or synthetic surfactant. The response rapidity after administration of natural or synthetic surfactant was compared by parameters of mechanical ventilation (FiO2, Pmax, IO) in the first 6 hours and during the following 7 days of life. The frequency of respiratory complications, presence of patent ductus arteriosus (PDA) and its treatment and causes of death were evaluated.

RESULTS

Definitely quicker decrease in ventilation parameters was observed after the administration of natural surfactant as compared to the synthetic one. Statistically significant differences were observed during 72 hours and then they decreased.

CONCLUSION

The response after the administration of natural surfactants in premature babies with RDS within the first six hours of treatment was significantly quicker than after synthetic surfactant. This improves the parameters of mechanical ventilation much quicker and prevents complications. Longitudinal studies of the development of children treated with both kinds of surfactant are necessary in order to evaluate the effects of the treatment in the neonatal period.

[Changes in the clinical picture of bronchopulmonary dysplasia]

The mortality of very preterm infants has significantly improved after introducing into clinical practice the antenatal use of glucocorticoid steroids prior to premature births and postnatal treatment with pulmonary surfactant which effectively decreases the tendency of the alveoli to collapse. The period of necessary mechanical ventilation was shortened. Reducing the concentration of inspired oxygen and inflation pressures became possible. In spite of this, long-term damage of lung tissue in immature infants is still a major clinical problem. However, its origin seems to be slightly different. A new form of bronchopulmonary dysplasia (BPD) has been recently evaluated. The most important factors in the pathogenesis of the "new" BPD are: lung tissue immaturity, infections initiating a cascade of events caused by formation of free oxygen radicals and cytokines and the presence of persistent patent ductus arteriosus. Primary prevention of BPD is possible by reducing the rates of prematurity and intrauterine infections. Secondary prevention includes antenatal steroids administration and postnatal surfactant treatment according to the accepted known standards. When protracted mechanical ventilation is necessary, low and subsequently reduced doses of i.v. glucocorticoid steroids in the second and third week of life are administrated, together with diuretics, bronchodilators and suitably high calorie feeding.

The effect of am 251, a cannabinoid CB1 receptor antagonist, on food intake in rats

The anorectic effect of AM 251 (N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-di-chlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide), a CB1 receptor antagonist, was studied in rats. AM 251 (0.5-2.0 mg/kg i.p.) significantly and dose-dependently reduced food intake in both free-feeding and food-deprived rats. The obtained results support the anorectic activity of CB1 receptors antagonists.

Antidepressant--like properties of ACEA (arachidonyl-2-chloroethylamide), the selective agonist of CB1 receptors

The antidepressant effect of ACEA (arachidonyl-2-chloroethylamide), a selective agonist of CB1 receptors, and its interaction with fluoxetine were studied in mice. ACEA (1.0 and 2.0 mg/kg i.p.) reduced the immobility time in the forced swimming test and attenuated the head - twitch response to L-5-HTP. The concomitant administration of ACEA (1.0 mg/kg i.p.) and fluoxetine (20 mg/kg i.p.) resulted in the strongest shortening of immobility time, significant in comparison with both ACEA and fluoxetine given alone. The obtained results indicate that ACEA may have antidepressant efficacy and shows a synergistic effect when given with fluoxetine in the forced swimming test.

Influence of nifedipine, nitrendipine and verapamil at low concentration on antipyrine metabolism examined by extracorporeal rat liver perfusion

An increase in calcium ion concentration in the cytoplasm due to the influence of various toxic agents causes disturbances in the structure and function of hepatocytes, leading to their damage and even death. Calcium ions enter the cell mostly through calcium channels, therefore, it has been suggested that calcium channel inhibitors (CCI) could protect hepatocytes from the action of toxic substances. The present study investigated the effect of the selected CCI (nifedipine, nitrendipine and verapamil) on liver function, measured by the efficiency of oxidation reaction, in this case by determination of the rate of antipyrine metabolism. The experiment was carried out using the method of extracorporeal liver perfusion (ELP). None of the studied CCI applied at a concentration of 50 micromol/l increased the rate of antipyrine metabolism over the whole period of ELP. However, supplementation of perfusion fluid with nifedipine, nitrendipine or verapamil at a concentration of 20 micromol/l considerably improved metabolic liver efficiency during the second hour of perfusion, i.e. at the time, when large number of hepatocytes started to perish, which could indicate protective action of the tested CCI. However, the CCI-induced acceleration of antipyrine metabolism was not a result of their influence on calcium channels, since these drugs block calcium channels, when given at the concentrations as high as 100-400 micromol/l. Moreover, it seems that facilitation of antipyrine metabolism during ELP was not due to their action on microsomal enzymes because CCI were administered at very low concentrations, besides, they are metabolic inhibitors, and not inducers. The present experiment suggests that low concentrations of CCI can exert hepatoprotective effect. However, confirmation of this conclusion requires further studies using other experimental methods.

The secretion of prostaglandin E2 and interleukin 1-beta in women with periodontal diseases and preterm low-birth-weight

Prematurity is of one of the main causes of neonatal morbidity and mortality. Clinical observations show, that periodontitis in pregnant women can be a direct risk factor for preterm labor, with a greater influence rate compared to other risk factors. The aim of the study was to asses the relationship between periodontal diseases and PLBW in the population of women from the Lower Silesian Region (Poland), and the evaluation of prostaglandin E2 (PGE2), interleukin-1 beta (IL-1 beta) levels in gingival cervicular (GCF) and blood serum in women with PLBW and women giving birth on time as well as secretion of these proinflammatory mediators in whole blood after bacterial lipopolysaccharide stimulation. The study group consisted of 84 women with PLBW (39.2% primiparous), aged 17-41 (mean 27.57). The controls were 44 women (47.7% primiparous) aged 16-38 (mean 26.36) who gave birth on time to a normal birthweight baby. PGE2 and IL-1 beta concentrations in serum and GCF were determined by means of immunoenzymatic method (EIA). In the studied population women over 28 years and exposed to medical risk factors had more frequent PLBW occurrence probability. In primiparous over 28 there is 4 times greater probability of preterm labor, and in case of the severe and generalized periodontitis presence there is 3.9 times higher possibility of PLBW compared to women with healthy periodontium. In all women with PLBW there is a significantly higher PGE2 and IL-1 beta concentration in GCF, and in primiparous also PGE2 level in blood serum, compared to controls.

Anorectic activity of 2H-4,6-dimethyl-2-[(4-phenylpiperazin-1- yl)methyl]-3-oxo-2,3-dihydroisothiazolo[5,4-b]pyridine

The effect of 2H-4,5-dimethyl-2-[(4-phenylpiperazin-1-yl)methyl]-3- oxo-2,3-dihydroisothiazolo[5,4-b]pyridine on feeding in rats was investigated. The tested compound decreased food intake in food-deprived rats and in rats receiving palatable-diet.