Role of cholinergic and adrenergic pathways of the medial septal area in the control of water intake and renal excretion in rats

In this study, we investigated an interaction between noradrenergic and cholinergic pathways of the medial septal area (MSA) on the control of water intake and urinary electrolyte excretion by means of injection of their respective agonists. Noradrenaline (a nonspecific α-adrenergic agonist) and clonidine (an α2-adrenergic agonist), but not phenylephrine (an α1-adrenergic agonist), induced natriuresis and kaliuresis. α-Adrenergic activation had no effect on the natriuresis and kaliuresis induced by carbachol (a cholinergic agonist) and it inhibited the antinatriuresis and antikaliuresis induced by isoproterenol (a ß-adrenergic agonist). Interactions related to volume excretion are complex. α-Adrenergic activation induced a mild diuresis and inhibited the antidiuresis induced by isoproterenol, but phenylephrine combined with carbachol induced antidiuresis. The water intake induced by carbachol was inhibited by clonidine and noradrenaline, but not phenylephrine. These results show an asymmetry in the interaction between α-adrenergic and cholinergic receptors concerning water intake and electrolyte excretion. © 1992.

Interaction between the septal area and the subfornical organ in the control of water intake induced by thirst-eliciting procedures

Rats bearing lesions in the septal area followed by lesions in the subfornical organ were submitted to various thirst-eliciting procedures. The rats with hyperdipsia induced by lesions of the septal area drank more water than either during the control period or after lesion of the subfornical organ under the same thirst-eliciting or angiotensin-liberating stimuli (polyethyleneglycol, isoproterenol, water deprivation and ligation of the inferior vena cava). The overdrinking elicited by lesions in the septal area was blocked after lesion of the subfornical organ. Neither hypovolemia, nor hypotension or water deprivation could elicit increased water intake in animals whose subfornical organ had been destroyed. Animals with lesions in the subfornical organ showed decreased water intake after cellular dehydration. The results obtained suggest that the subfornical organ acts as a more important structure than the septal area in the regulation of water intake elicited by angiotensin, with two opposite effects: a direct one facilitating water intake, and an indirect one inhibiting the septal area. The septal area has an inhibitory effect on the subfornical organ and on water intake. © 1980.

Importance of the central nucleus of the amygdala on sodium intake caused by deactivation of lateral parabrachial nucleus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sodium nitrite prevents both reductions in circulating nitric oxide and hypertension in 7-day lead-treated rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development and characterization of a biocompatible soybean oil-based microemulsion for the delivery of poorly water-soluble drugs

The aim of this work was the development and characterization of a biocompatible microemulsion (ME) containing soybean oil (O), phosphatidylcholine/sodium oleate/Eumulgin®HRE40 as the surfactant mixture (S) and water or buffer solution as the aqueous phase (W), for oral delivery of the poorly water-soluble drugs sulfamerazine (SMR) and indomethacin (INM). A wide range of combinations to obtain clear oil-in-water (o/w) ME was observed from pseudo-ternary phase diagrams, which was greater after the incorporation of both drugs, suggesting that they acted as stabilizers. Drug partition studies indicated a lower affinity of the drugs for the oil domain when they were ionized and with increased temperature, explained by the fact that both drugs were introduced inside the oil domain, determined by nuclear magnetic resonance. High concentrations of SMR and INM were able to be incorporated (22.0 and 62.3 mg/mL, respectively). The ME obtained presented an average droplet size of 100 nm and a negative surface charge. A significant increase in the release of SMR was observed with the ME with the highest percentage of O, because of the solubilizing properties of the ME. Also, a small retention effect was observed for INM, which may be explained by the differences in the partitioning properties of the drugs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3535-3543, 2015.

The control of sodium chloride intake: Functional relationship between hypothalamic inhibitory areas and amygdaloid complex stimulating areas

Sodium chloride intake was studied in rats submitted to different neurosurgical procedures. Intake decreased in animals submitted to bilateral destruction of the basolateral amygdaloid complex, and increased after the same animals were submitted to destruction of the anterior lateral hypothalamus, a procedure which is known to cause increased intake in intact rats. In the reverse experiment, where the anterior lateral hypothalamus was destroyed before the basolateral amygdaloid complex, the effect of increased sodium chloride intake induced by destruction of the hypothalamus overcame the decreased expected upon destruction of the amygdaloid complex. These results permit us to conclude that the hypothalamic areas which inhibit sodium chloride intake predominate over the stimulating areas of the amygdaloid complex in the control of sodium chloride intake. © 1981 ANKHO International Inc.

Physico-chemical characterization and analytical development for sodium azumolene, a potential drug designed to fight malignant hyperthermia

Sodium azumolene is a drug designed to fight Malignant Hyperthermia (MH), which is characterized by genetic predisposition and triggered by the use of inhalational anesthetics. This drug is shown as a water-soluble analogue of dantrolene sodium, 30-folds more water soluble, which gives advantages for its emergency use. To our knowledge there is no analytical method for sodium zaumolene raw material or dosage form published so far. The objective of the present investigation was to develop and validate analytical methods to achieve sodium azumolene chemical identification and quantification. The sodium azumolene was characterized regarding its thermal behavior, by differential thermal analysis and thermogravimetric analysis; Visible, UV and infrared absorption. To accurately assess the sodium Azumolene content three different analytical methods (visible and UV spectrophotometry and high performance liquid chromatography) were developed and validated. All methods showed to be linear, accurate, precise and reliable. Azumolene has shown to be equipotent to dantrolene in the treatment and prevention of an MH crisis and the great advantage compared to dantrolene is better water solubility. This study has characterized the sodium azumolene and presents new analytical methods which have not been reported so far.

Validation of analytical methodology for quantification of cefazolin sodium by liquid chromatography

A reversed-phase high performance liquid chromatography method was validated for the determination of cefazolin sodium in lyophilized powder for solution for injection to be applied for quality control in pharmaceutical industry. The liquid chromatography method was conducted on a Zorbax Eclipse Plus C18 column (250 x 4.6 mm, 5 μm), maintained at room temperature. The mobile phase consisted of purified water: acetonitrile (60: 40 v/v), adjusted to pH 8 with triethylamine. The flow rate was of 0.5 mL min-1 and effluents were monitored at 270 nm. The retention time for cefazolin sodium was 3.6 min. The method proved to be linear (r2 =0.9999) over the concentration range of 30-80 µg mL-1. The selectivity of the method was proven through degradation studies. The method demonstrated satisfactory results for precision, accuracy, limits of detection and quantitation. The robustness of this method was evaluated using the Plackett–Burman fractional factorial experimental design with a matrix of 15 experiments and the statistical treatment proposed by Youden and Steiner. Finally, the proposed method could be also an advantageous option for the analysis of cefazolin sodium, contributing to improve the quality control and to assure the therapeutic efficacy

Development and validation of an economic, environmental friendly and stability-indicating analytical method for determination of ampicillin sodium for injection by RP-HPLC

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Development of an innovative, ecological and stability-indicating analytical method for semiquantitative analysis of ampicillin sodium for injection by thin layer chromatography (TLC)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of Sodium Lauryl Sulfate as a Blackbird Wetting Agent

New and improved strategies are needed for managing overabundant blackbird (Icteridae spp.) populations in some areas of the United States. From 2004 to 2007, we evaluated sodium lauryl sulfate (SLS) as a wetting agent during controlled outdoor cage and flight pen tests in Colorado and small-scale field tests at urban blackbird roosts in Missouri. In the outdoor cage tests (ambient temperature -5 to 2° C), mortality of male red-winged blackbirds (Agelaius phoeniceus) sprayed with 1, 2, and 5 ml of SLS on the back feathers only, on the breast feathers only, or on both breast and back feathers ranged from 25% to 100%. A SLS spray on male red-winged blackbirds at 2° C ambient temperature with 1 ml of SLS sprayed on breast feathers and back feathers resulted in 90% mortality in less than 60 minutes. In a flight pen test (-12 to -5° C ambient temperature ), SLS sprayed at 20 l per 3,400 l of water with a single ground-based sprinkler-head system over 35 male red-winged blackbirds roosting in cedar trees (Juniperus virginiana) resulted in 53% mortality. There was no mortality in the control group exposed to the same treatment without the SLS. Small-scale field tests conducted in Missouri at 6 sites with a single ground-based sprinkler-head spray system and at 2 sites with 4 sprinkler-head spray systems resulted in mortality that ranged from 0 to 4,750 and 4,500 to 15,000 blackbirds and starlings, respectively. Spray operations lasted from 28 to 208 minutes. Each spray covered about 200 m2 . At all sites, mortality of blackbirds sprayed with the SLS occurred as soon as 30 minutes post-SLS application. Mortality at two sites where pump problems precluded completing the spray ranged from 0 to 800 birds. Air leaving the system as the system was activated caused birds to flush from the roost trees. Poor water quality and pump durability were problems at some sites.

Interaction of cationic water-soluble meso-tetrakis(4-N-methylpyridiniumyl)porphyrin (TMPyP) with ionic and nonionic micelles: aggregation and binding

The equilibrium of meso-tetrakis(4-N-methylpyridiniumyl)porphyrin (TMPyP) in aqueous solution in the presence of surfactants was studied by optical spectroscopic techniques and SAXS (small angle X-ray scattering). Anionic SDS (sodium dodecyl sulfate), zwitterionic HPS (N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate) and nonionic TRITON X-100 (t-octyl-phenoxypolyethoxyethanol), surfactants were used. TMPyP is characterized by a protonation equilibrium with a pK(a) around 1.0, associated with the diacid-free base transition, and a second pK(a) around 12.0 related with the transition between the free base and the monoanion form. Three independent species were observed for TMPyP at pH 6.0 as a function of SDS concentration: free TMPyP, TMPyP-SDS aggregates and porphyrin monomer bound to micelles. For HPS and TRITON X-100, the equilibrium of TMPyP as a function of pH is quite similar to that obtained in pure aqueous solution: no aggregation was observed, suggesting that electrostatic contribution is the major factor in the interaction between TMPyP and surfactants. SAXS data analysis demonstrated a prolate ellipsoidal shape for SDS micelles; no significant changes in shape and size were observed for SDS-TMPyP co-micelles. Moreover, the ionization coefficient, alpha, decreases with the increase of the porphyrin concentration, suggesting the ""screening"" of the anionic charge of SDS by the cationic porphyrin. These results are consistent with optical absorption, fluorescence and RLS (resonance light scattering) spectroscopies data, allowing to conclude that neutral surfactants present a smaller interaction with the cationic porphyrin as compared with an ionic surfactant. Therefore, the interaction of TMPyP with the ionic and nonionic surfactants is predominantly due to the electrostatic contribution. Copyright (c) 2008 Society of Porphyrins & Phthalocyanines.

Mejillonesite, a new acid sodium, magnesium phosphate mineral, from Mejillones, Antofagasta, Chile

Mejillonesite, ideally NaMg(2)(PO(3)OH)(PO(4))(OH)center dot H(5)O(2), is a new mineral approved by the CNMNC (IMA 2010-068). It occurs as isolated crystal aggregates in thin zones in fine-grained opal-zeolite aggregate on the north slope of Cerro Mejillones, Antofagasta, Chile. Closely associated minerals are bobierrite, opal, clinoptilolite-Na, clinoptilolite-K, and gypsum. Mejillonesite forms orthorhombic, prismatic, and elongated thick tabular crystals up to 6 mm long, usually intergrown in radiating aggregates. The dominant form is pinacoid {100}. Prisms {hk0}, {h0l}, and {0kl} are also observed. The crystals are colorless, their streak is white, and the luster is vitreous. The mineral is transparent. It is non-fluorescent under ultraviolet light. Mohs' hardness is 4, tenacity is brittle. Cleavage is perfect on {100}, good on {010} and {001}, and fracture is stepped. The measured density is 2.36(1) g/cm(3); the calculated density is 2.367 g/cm(3). Mejillonesite is biaxial (-), alpha= 1.507(2), beta= 1.531(2), gamma= 1.531(2), 2V(meas) = 15(10)degrees, 2V(calc) = 0 degrees (589 nm). Orientation is X= a, Z= elongation direction. The mineral is non-pleochroic. Dispersion is r> v, medium. The IR spectrum contains characteristic bands of the Zundel cation (H(5)O(2)(+), or H(+)center dot 2H(2)O) and the groups P-OH and OH(-). The chemical composition is (by EDS, H(2)O by the Alimarin method, wt%): Na(2)O 9.19, MgO 26.82, P(2)O(5) 46.87, H(2)O 19, total 101.88. The empirical formula, based on 11 oxygen atoms, is Na(0.93)Mg(2.08)(PO(3)OH)(1.00) (PO(4)) (OH)(0.86) .0.95H(5)O(2) The strongest eight X-ray powder-diffraction lines [d in angstrom(I)(hkl)] are: 8.095(100)(200), 6.846(9) (210), 6.470(8)(111), 3.317(5)(302), 2.959(5)(132), 2.706(12)(113), 2.157(19)(333), and 2.153(9) (622). The crystal structure was solved on a single crystal (R = 0.055) and gave the following data: orthorhombic, Pbca, a = 16.295(1), b = 13.009(2), c = 8.434(1) angstrom, V= 1787.9(4) angstrom(3), Z = 8. The crystal structure of mejillonesite is based on a sheet (parallel to the b-c plane) formed by two types of MgO(6) octahedra, isolated tetrahedra PO(4) and PO(3)OH whose apical vertices have different orientation with respect to the sheet. The sheets are connected by interlayer, 5-coordinated sodium ions, proton hydration complexes, and hydroxyl groups. The structure of mejillonesite is related to that of angarfite, NaFe(5)(3+)(PO(4))(4)(OH)(4).4H(2)O and bakhchisaraitsevite, Na(2)Mg(5)(PO(4))(4)center dot 7H(2)O.

Variations in Structure Explain the Viscometric Behavior of AOT Microemulsions at Low Water/AOT Molar Ratios

The viscosity of AOT/water/decane water-in-oil microemulsions exhibits a well-known maximum as a function of water/AOT molar ratio, which is usually attributed to increased attractions among nearly spherical droplets. The maximum can be removed by adding salt or by changing the oil to CCl4. Systematic small-angle X-ray scattering (SAXS) measurements have been used to monitor the structure of the microemulsion droplets in the composition regime where the maximum appears. On increasing the droplet concentration, the scattering intensity is found to scale with the inverse of the wavevector, a behavior which is consistent with cylindrical structures. The inverse wavevector scaling is not observed when the molar ratio is changed, moving the system away from the value corresponding to the viscosity maximum. It is also not present in the scattering from systems containing enough added salt to essentially eliminate the viscosity maximum. An asymptotic analysis of the SAXS data, complemented by some quantitative modeling, is consistent with cylindrical growth of droplets as their concentration is increased. Such elongated structures are familiar from related AOT systems in which the sodium counterion has been exchanged for a divalent one. However, the results of this study suggest that the formation of non-spherical aggregates at low molar ratios is an intrinsic property of AOT.

Antihypertensive and antioxidant effects of a single daily dose of sodium nitrite in a model of renovascular hypertension

Dietary nitrite and nitrate have been reported as alternative sources of nitric oxide (NO). In this regard, we reported previously that sodium nitrite added to drinking water was able to exert antihypertensive effects in an experimental model of hypertension in a dose-dependent manner. Taking into consideration that nitrite is continuously converted to nitrate in the bloodstream, here we expanded our previous report and evaluate whether a single daily dose of sodium nitrite could exert antihypertensive effects in 2 kidney-1 clip (2K1C) hypertensive rats. Sham-operated and 2K1C rats were treated with vehicle or sodium nitrite (15 mg/kg/day) for 4 weeks. We evaluated the effects induced by sodium nitrite treatment on systolic blood pressure (SBP) and NO markers such as plasma nitrite, nitrite + nitrate (NOx), cGMP, and blood levels of nitrosyl-hemoglobin. In addition, we also evaluated effects of nitrite on oxidative stress and antioxidant enzymes. Dihydroethidium (DHE) was used to evaluate aortic reactive oxygen species (ROS) production by fluorescence microscopy, and plasma levels of thiobarbituric acid-reactive species (TBARS) were measured in plasma samples from all experimental groups. Red blood cell superoxide dismutase (SOD) and catalase activity were evaluated with commercial kits. Sodium nitrite treatment reduced SBP in 2K1C rats (P < 0.05). We found lower plasma nitrite and NOx levels in 2K1C rats compared with normotensive controls (both P < 0.05). Nitrite treatment restored the lower levels of nitrite and NOx. While no change was found in the blood levels of nitrosyl-hemoglobin (P > 0.05), nitrite treatment increased the plasma levels of cGMP in 2K1C rats (P < 0.05). Higher plasma TBARS levels and aortic ROS levels were found in hypertensive rats compared with controls (P < 0.05), and nitrite blunted these alterations. Lower SOD and catalase activities were found in 2K1C hypertensive rats compared with controls (both P < 0.05). Nitrite treatment restored SOD activity (P < 0.05), whereas catalase was not affected. These data suggest that even a single daily oral dose of sodium nitrite is able to lower SBP and exert antioxidant effects in renovascular hypertension.