Identification of reference genes for studies of quantitative gene expression in male and female quail tissues.

In industrial poultry, quail production has gained increasing prominence over the years. It is known that the intensification of genetic studies has contributed greatly to this growth, through techniques, such as analysis of gene expression by PCR, for example. This study aimed to evaluate stability and recommend reference genes for quantitative real-time PCR in different tissues from male and female broiler quails. The stability of 10 housekeeping genes (GAPDH, RPL5, MRPS27, MRPS30, TFRC, HMBS, EEF1, LDHA, B2M, and UBC) by means Bestkeeper, NormFinder, GeNorm softwares with ΔCq method. The tissues analyzed were: heart, thigh muscle, brain, and spleen, considering that they are tissues commonly used in nutrigenomic, immunological, and poultry performance research. As expected, the reference genes tested showed varying stability depending on the tissue evaluated. According to the present study, the most stable housekeeping genes were MRPS30, TFRC, and HMBS in heart; MRPS30, EEF1, and HMBS in thigh muscle; B2M, GAPDH, and UBC in brain; and EEF1, LDHA, and HMBS in spleen. Therefore, it is recommended to be used as reference genes for gene expression studies of male and female quails.

FTIR study of secondary structure changes in Epidermal Growth Factor by gold nanoparticle conjugation.

Conformation of protein is vital to its function, but may get affected when processing to manufacture products. It is therefore important to understand structural changes during each step of production. In this study, we investigate secondary structure changes in the targeting protein Epidermal Growth Factor (EGF) during synthesis of theranostic bifunctional nanoparticle, devised for Photodynamic therapy of breast cancer. We acquired FTIR spectra of EGF; unconjugated, post treatment with α-lipoic acid, attached to gold nanoparticle, and bound to the bifunctional nanoprobe. We observed decreasing disordered structures and turns, and increasing loops, as the synthesis process progressed. There was an overall increase in ß-sheets in final product compared to pure EGF, but this increase was not linear and fluctuated. Previous crystal structure studies on EGF-EGFR complex have shown loops and ß-sheets to be important in the binding interaction. Since our study found increase in these structures in the final product, no adverse effect on binding function of EGF was expected. This was confirmed by functional assays. Such studies may help modify synthesis procedures, and thus secondary structures of proteins, enabling increased functionality and optimum results.

Calcium chloride-enriched calcium aluminate cement promotes in vitro osteogenesis.

AIM: To evaluate the effects of 2.8% or 10% calcium chloride (CaCl2 ) in calcium aluminate cement (CAC) with either bismuth oxide (Bi2 O3 ) or zinc oxide (ZnO) as radiopacifiers on the progression of osteogenic cell cultures. METHODOLOGY: Rat calvaria-derived cells were grown on Thermanox® coverslips for 24 h and exposed to samples of (i) CACb: with 2.8% CaCl2 and 25% Bi2 O3 ; (ii) CACb+: with 10% CaCl2 and 25% Bi2 O3 ; (iii) CACz: with 2.8% CaCl2 and 25% ZnO; or (iv) CACz+: with 10% CaCl2 and 25% ZnO, placed on inserts. Nonexposed cultures served as the control. Calcium and phosphorus contents in culture media were quantified. The effects of the cements on cell apoptosis, cell viability and acquisition of the osteogenic cell phenotype were evaluated. Data were compared by Kruskal-Wallis test (α = 5%). RESULTS: CACb+ promoted the highest levels of calcium in the culture media; CACz+, the lowest levels of phosphorus (P < 0.05). CACz+ and CACb increased cell apoptosis (P < 0.05). CACb reduced cell viability (P < 0.05) and the expression of the osteoblastic phenotype. CACz+ and CACb+ promoted greater cell differentiation and matrix mineralization compared to CACz and CACb (P < 0.05). CONCLUSION: For CAC with the lower CaCl2 content, the use of Bi2 O3 was detrimental for osteoblastic cell survival and differentiation compared to ZnO, while CAC with the higher CaCl2 content supported the acquisition of the osteogenic cell phenotype in vitro regardless of the radiopacifier used. Thus, CAC with 10% CaCl2 would potentially promote bone repair in the context of endodontic therapies.

Influence of early mineral deposits of silicate- and aluminate-based cements on push-out bond strength to root dentine.

AIM: To evaluate mineral trioxide aggregate (MTA), Biodentine and several formulations of calcium aluminate cements (CACb) in terms of their ability to release calcium ions (Ca2+ ) and form apatite-like precipitates after short-term immersion in phosphate-buffered saline (PBS) and its influence on the bond strength to the root-end cavity. METHODOLOGY: Ten samples of MTA, Biodentine, CACb and calcium-enriched aluminate cement (CACb+) were placed in contact with PBS or deionized water for 14 days. The cement surfaces were analysed using SEM, EDS-X and FTIR. Eighty standardized root-end cavities filled with the cements (ten samples of each cement) were immersed in PBS or deionized water for 14 days, and the bond strengths were measured. Data from the push-out test were analysed using two-way ANOVA and Tukey's tests (α = 0.05). RESULTS: A gradual decrease was observed in Ca2+ concentrations and pH of all solutions. FTIR bands of different phases of hydroxyapatite were identified. Crystalline formation was observed on the surface of all cements after immersion in PBS. No significant difference was observed in the bond strength of the test materials (P > 0.05); however, all cements without contact with the solution revealed significantly lower bond strength values than those in contact with the solution (P < 0.05). CONCLUSION: MTA, Biodentine, CACb e CACb+ were associated with precipitation of crystals after being in contact with PBS for 14 days, indicated by different phases of hydroxyapatite crystalline formation, which also increased dislodgment resistance of the material from root-end cavities. The CACb+ had similar bond strengths and precipitation of crystals to existing materials.

Osteogenic cell response to calcium aluminate-based cement.

AIM: To evaluate the effect of a calcium aluminate-based cement (CAC+) on the development of the osteogenic phenotype in vitro. METHODOLOGY: Rat calvaria-derived cells were grown on Thermanox® coverslips for 24 h and then exposed to either samples (4-h set) of CAC+ or mineral trioxide aggregate (MTA) placed on Transwell® inserts for periods of up to 14 days. Nonexposed cultures were used as the controls. The comparisons were made using the nonparametric Kruskal-Wallis test, followed by the Student-Newman-Keuls post hoc test when appropriate. RESULTS: The results showed that proximity to MTA or CAC+ samples inhibited cell growth, whereas at a distance, viable and proliferative cells adhered to and spread on the Thermanox® , expressing osteoblast differentiation markers prior to mineralization of the extracellular matrix. Compared with MTA, the osteogenic cell cultures exposed to CAC+ exhibited significantly greater cell viability, alkaline phosphatase (ALP) activity and expression of runt-related transcription factor 2, osterix, ALP, bone sialoprotein and osteocalcin (P < 0.05 for all). For the osteogenic cell cultures exposed to CAC+, the quantification of matrix mineralization was not altered (P > 0.05). CONCLUSIONS: CAC+ supported the acquisition of the osteogenic cell phenotype in vitro, rendering this novel material a potential alternative to MTA in endodontic procedures. Further in vivo studies are needed to verify if the beneficial in vitro effects of CAC+ on osteoblastic cells correspond to an increase and/or acceleration of bone repair in the periapical region.

Effects of blood and root-dentin cleaning on the porosity and bond strength of a collagen bioceramic material.

To assess the effect of cleaning protocols on dentin contaminated with blood in reparative endodontic materials, bovine root samples were divided: no contamination (N); contamination (P); contamination and cleaning with saline (S), 2.5% NaOCl+saline (Na) or 2.5% NaOCl+17% EDTA+saline (NaE) and filled with: mineral trioxide aggregate (MTA), calcium-aluminate-cement (C), or C+collagen (Ccol) (n=13). The samples were evaluated for porosity, chemical composition, and bond strength. MTA porosity was lower than C (p=0.02) and higher than Ccol (p<0.001). P and NaE were similar (p=1.00), but higher than the other groups (p<0.001). MTA bond strength was similar to Ccol (p=0.777) and lower than C (p=0.028). P presented lower bond strength than the N (p<0.001); S and Na were similar to each other (p=0.969), but higher than P and lower than N (p<0.001). It was observed a predominance of mixed and cohesive failures. None of the samples showed Ca/P ratio values similar to human hydroxyapatite. This study showed that contamination with blood increased the materials porosity, but dentin cleaning with 2.5% NaOCl reduced this effect, and the collagen additive reduced the material porosity. Furthermore, blood contamination reduced the materials bond strength, and cleaning with saline or 2.5% NaOCl diminished this effect.

Comparison of different glycerol and egg yolk concentrations added to tris-based extender for the collared peccaries (Tayassu tajacu) semen freezing.

This study aimed to evaluate various concentrations of egg yolk (5, 10, or 20%) in combination with different concentrations of glycerol (3% or 6%) added to a Tris-based extender on the post-thaw characteristics of sperm obtained from Tayassu tajacu. For this purpose, semen from 10 sexually male mature collared peccaries was collected by electroejaculation and evaluated for sperm motility, vigour, viability, morphology and functional membrane integrity. The ejaculates were initially extended in Tris-fructose plus egg yolk (5%, 10% or 20%). After cooling, the semen was added to Tris-egg yolk plus glycerol (6% or 12%), resulting in a final concentration of 3% or 6% glycerol of the extender. Straws were frozen using liquid nitrogen and thawed in a water bath at 37°C for 30 s. The frozen-thawed semen was evaluated as reported for fresh semen. After thawing, a significant decrease was verified for sperm motility and vigour, for all the samples in comparison with fresh semen. However, no differences were evidenced among treatments for any sperm characteristics evaluated (p > 0.05), except for the combination between 10% egg yolk and 6% glycerol, which provided the worst preservation of functional membrane integrity (p < 0.05). The interactions between higher concentrations of egg yolk (20%) and glycerol (6%) and also between lower concentrations of the same substances (5% egg yolk and 3% glycerol) added to the Tris-based extender negatively affected the preservation of the normal sperm morphology after thawing (p < 0.05). In conclusion, the use of Tris-based extender added to 10% or 20% egg yolk plus 3% glycerol is recommended for effective sperm cryopreservation in collared peccaries.

Efficacy of the trial-based thought record, a new cognitive therapy strategy designed to change core beliefs, in social phobia.

WHAT IS KNOWN AND BACKGROUND: Social anxiety disorder (SAD) often follows a chronic course and is associated with substantial impairment in functioning. Although results from clinical trials clearly establish evidence for efficacy of cognitive behavioural therapy in treating this disorder, up to 50% of patients with SAD show little or no improvement. Thus, new approaches that have promised in improving the efficacy of treatment for SAD are needed. One such approach is the trial-based thought record (TBTR), which targets the restructuring of patients' core beliefs. OBJECTIVE: To determine whether patients receiving TBTR would report fewer symptoms of social anxiety and general psychiatric distress following treatment, relative to conventional cognitive therapy (CCT). METHODS: A two-arm randomized trial comparing TBTR (n = 17) with a set of CCT techniques (n = 19), which included the standard seven-column dysfunctional thought record and the positive data log in SAD patients according to DSM-IV. RESULTS: Scores on many outcome measures decreased significantly across the course of treatment in both groups (P < 0·001), including the Liebowitz Social Anxiety Scale, Fear of Negative Evaluation Scale (FNE), Social Avoidance and Distress Scale (SADS), Beck Anxiety Inventory, and Clinical Global Impression - Improvement. In addition, a one-way ancova, taking baseline values as covariates, showed that TBTR was significantly more efficacious than CCT in reducing the scores of FNE (P = 0·01 at mid-treatment and P = 0·004 at post-treatment), and SADS (P = 0·03 at post-treatment). WHAT IS NEW AND CONCLUSION: This study provides preliminary evidence that TBTR is at least as efficacious as CCT in reducing symptoms of SAD, pointing to the need for additional studies of TBTR in SAD and other psychiatric disorders.

Effect of centrifugation and sugar supplementation on the semen cryopreservation of captive collared peccaries (Tayassu tajacu).

The present study is aimed at evaluating the effect of centrifugation for seminal plasma removal and the supplementation of fructose or glucose to the Tris-based extender on the kinematic patterns of the motility parameters of frozen-thawed semen obtained from captive collared peccaries (Tayassu tajacu). Semen samples (n = 14) were collected from 10 sexually mature male collared peccaries by electroejaculation. These samples were further evaluated for parameters such as motility, vigor, sperm viability, membrane integrity, and sperm morphology. The samples were divided into four aliquots, and only two of these aliquots were centrifuged. The semen aliquots (centrifuged and raw semen samples) were diluted in Tris-based extenders supplemented with fructose or glucose. Egg yolk (20%) and glycerol (3%) were added to all the samples which were cryopreserved in liquid nitrogen and thawed at 37 °C/1 min. The frozen-thawed semen was evaluated for the same parameters described for the fresh semen. On the other hand, the kinematic motility patterns were evaluated by a computer-aided system. After thawing, it was observed that the values for the total sperm motility were around 30% for all the samples. A negative effect of centrifugation was verified for parameters such as sperm morphology, linearity, straightness, and beat cross frequency (P < 0.05). However, no differences between fructose and glucose were verified for any semen end point (P > 0.05). In conclusion, it is not recommended to centrifuge the ejaculates from collared peccaries prior to conducting the cryopreservative procedures using a Tris-based extender supplemented with fructose or glucose.

Chemical, physical and mechanical properties of a novel calcium aluminate endodontic cement.

AIM: To evaluate the influence of additives on several physical and chemical properties of a novel endodontic cement based on calcium aluminate in comparison with mineral trioxide aggregate (MTA). METHODOLOGY: Manipulation tests, measurements of temperature, pH, ionic conductivity, compressive strength, apparent porosity, and pore size distribution were carried out on Gray-MTA (Angelus) and calcium aluminate cement (Secar-71, Kerneos) with and without various additives: a polymeric dispersant, CaCl(2) as plasticizer, and ZnO as radiopacifier. RESULTS: The calcium aluminate cement without additives had a setting time of approximately 60min, and when combined with Li(2) CO(3) it decreased to 10min. The material also released Ca(2+) ions and alkalinized the medium. Moreover, the addition of additives (dispersant, plasticizer, and radiopacifier) improved its properties resulting in a material with a viscosity of 57mPas, enhanced handling properties, a mechanical strength of 81MPa, a porosity of 4% and pores with small diameter (0.25µm). MTA had no temperature increase (that indicates setting) up to 400min, a mechanical strength of 34MPa, and porosity of 28% with pores 2.5µm in diameter. CONCLUSION: The novel cement set more rapidly, had better fluidity, improved handling properties, higher mechanical strength, and reduced porosity with lower pore size compared to Gray-MTA Angelus.

Effects of blood and root-dentin cleaning on the porosity and bond strength of a collagen bioceramic material

Abstract To assess the effect of cleaning protocols on dentin contaminated with blood in reparative endodontic materials, bovine root samples were divided: no contamination (N); contamination (P); contamination and cleaning with saline (S), 2.5% NaOCl+saline (Na) or 2.5% NaOCl+17% EDTA+saline (NaE) and filled with: mineral trioxide aggregate (MTA), calcium-aluminate-cement (C), or C+collagen (Ccol) (n=13). The samples were evaluated for porosity, chemical composition, and bond strength. MTA porosity was lower than C (p=0.02) and higher than Ccol (p<0.001). P and NaE were similar (p=1.00), but higher than the other groups (p<0.001). MTA bond strength was similar to Ccol (p=0.777) and lower than C (p=0.028). P presented lower bond strength than the N (p<0.001); S and Na were similar to each other (p=0.969), but higher than P and lower than N (p<0.001). It was observed a predominance of mixed and cohesive failures. None of the samples showed Ca/P ratio values similar to human hydroxyapatite. This study showed that contamination with blood increased the materials porosity, but dentin cleaning with 2.5% NaOCl reduced this effect, and the collagen additive reduced the material porosity. Furthermore, blood contamination reduced the materials bond strength, and cleaning with saline or 2.5% NaOCl diminished this effect.

Resumo As amostras de raízes bovinas foram divididas em: sem contaminação (N); contaminação sanguínea (P); contaminação sanguínea e limpeza com soro fisiológico (S), 2,5% NaOCl+soro fisiológico (Na) ou 2,5% NaOCl+17%EDTA+soro fisiológico (NaE) e preenchido com: agregado de trióxido mineral (MTA), cimento de aluminato de cálcio (C), ou C+colágeno (Ccol) (n=13). A porosidade do MTA foi menor que C (p=0,02) e maior que Ccol (p<0,001). P e NaE foram semelhantes (p=1,00), mas superiores aos demais grupos (p<0,001). A resistência de união do MTA foi semelhante ao Ccol (p=0,777) e inferior ao C (p=0,028). P apresentou menor resistência de união que o N (p<0,001); S e Na foram semelhantes entre si (p=0,969), porém maiores que P e menores que N (p<0,001). Este estudo mostrou que a contaminação com sangue aumentou a porosidade dos cimentos, mas a limpeza da dentina com NaOCl 2,5% reduziu esse efeito, e o aditivo de colágeno reduziu a porosidade dos cimentos. Além disso, a contaminação sanguínea reduziu a resistência de união dos cimentos e a limpeza com solução salina ou NaOCl 2,5% diminuiu esse efeito.

Bioactivity and Toxicity of Senna cana and Senna pendula Extracts.

This work investigated the content of total polyphenolic compounds and flavonoids as well as their toxicity and larvicidal and acetylcholinesterase inhibitory activities. The antioxidant activities of two medicinal Senna species extracts (Senna cana and Senna pendula) were also investigated. The ethanol extract of the leaves of S. cana and the ethanol extract of the branches of S. pendula presented the best performance in the DPPH/FRAP and ABTS/ORAC assays, respectively. For the inhibition of acetylcholinesterase, the hexane extract of the flowers of S. pendula presented the lowest IC50 value among the ethanol extracts of the leaves of S. cana and showed the best performance in some assays. The hexane extract of the leaves of S. pendula and the hexane extract of the branches of S. cana were moderate to Artemia salina Leach. In the quantification of phenols and flavonoids, the ethanol extract of the leaves of S. cana presented the best results. The ethanol extracts of the leaves of S. cana were found to be rich in antioxidants, phenolic compounds, and flavonoids. These results indicate the antioxidant potential of the extracts of Senna species and can be responsible for some of the therapeutic uses of these plants.

Sperm cryopreservation of lane snapper Lutjanus synagris (Linnaeus, 1758).

This study aims developing and evaluate a protocol of semen cryopreservation of the lane snapper Lutjanus synagris. Firstly, sperm motility rate, motility time, density and spermatocrit were appraised to characterize the sperm quality of the lane snapper. The effect of three extenders with distinct ionic compositions and pH values combined with seven concentrations of cryoprotector dimethylsulfoxide (0; 2.5; 5.0; 7.5; 10.0; 12.5 e 15.0%), five cooling rates (110, 90, 60, 45 e 30°C -min), nine equilibration time (1; 2,5; 5; 10; 15; 20; 25; 30 e 60 minutes) e five dilutions ratio (1:1; 1:3; 1:6; 1:10 e 1:20) on the sperm motility rate and motility time were analyzed. Fertilization test was accomplished to evaluate the viability of the cryopreserved sperm. The higher sperm motility rate and motility time (P<0.05) was achieved by combining extender with pH 8.2 with 10% concentration of dimethylsulfoxide and cooling rate 60°C -min, 1 minute of equilibration time and 1:3 (v/v) dilution ratio. The use of cryopreserved sperm presented fertilization rates >60% validating the present protocol for lane snapper. The cryoconserved sperm of lane snapper is a viable alternative, being possible to maintain appropriate sperm viability.

Relative distribution of gastrin-, CCK-8-, NPY- and CGRP-immunoreactive cells in the digestive tract of dorado (Salminus brasiliensis).

The endocrine cells (ECs) of the gastrointestinal mucosa form the largest endocrine system in the body, not only in terms of cell numbers but also in terms of the different produced substances. Data describing the association between the relative distributions of the peptide-specific ECs in relation to feeding habits can be useful tools that enable the creation of a general expected pattern of EC distribution. We aimed to investigate the distribution of ECs immunoreactive for the peptides gastrin (GAS), cholecystokinin (CCK-8), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP) in different segments of the digestive tract of carnivorous fish dorado (Salminus brasiliensis) by using immunohistochemistry procedures. The distribution of endocrine cells immunoreactive for gastrin (GAS), cholecystokinin (CCK-8), neuropeptide Y (NPY), and calcitonin gene-related peptide (CGRP) in digestive tract of dorado S. brasiliensis was examined by immunohistochemistry. The results describe the association between the distribution of the peptide-specific endocrine cells and feeding habits in different carnivorous fish. The largest number of endocrine cells immunoreactive for GAS, CCK-8, and CGRP were found in the pyloric stomach region and the pyloric caeca. However, NPY-immunoreactive endocrine cells were markedly restricted to the midgut. The distribution pattern of endocrine cells identified in S. brasiliensis is similar to that found in other carnivorous fishes.

Role of the spleen on the pathogenesis of schistosomal periportal (pipestem) fibrosis of the liver: an experimental approach.

Splenectomized and sham-operated mice with chronic Schistosoma mansoni infection were compared for the development of periportal fibrosis (pipestem fibrosis). Although this lesion appeared less frequently in splenectomized mice, it also developed in the absence of the spleen. The time of splenectomy, spleen weight, presence of anti-idiotypic antibodies, the number of eggs in the liver, and the type and size of periovular granulomas in the liver as evaluated by computerized morphometry did not show statistically significant differences between the two groups. It is concluded that the role of the spleen in the development of pipestem fibrosis seems ancillary and that multifactorial influences, including worm burden, hepatic vascular adjustment, and factors associated with the biology of extracellular matrix of the liver, probably play a more significant role.

Binding of lactoferrin and free secretory component to enterotoxigenic Escherichia coli.

The ability of two glycoproteins of human milk, lactoferrin and free secretory component, to bind to Escherichia coli colonization factors (CFAs) was investigated using immunocytochemistry assays of enriched fimbrial extracts. The results revealed that lactoferrin binds to fimbrial CFA I adhesin but not to CFA II adhesin (CS1 and CS3), while free secretory component interacts with both CFA I and CFA II adhesins. Our data indicate that lactoferrin and free secretory component, which are very abundant proteins of human milk, could play an important role against infant enteric disease by blocking bacterial adhesion.

Is there a relationship between antipsychotic blood levels and their clinical efficacy? An analysis of studies design and methodology.

There are now more than 50 studies concerning neuroleptic blood levels and clinical outcome relationships. Haloperidol, the most studied, is the only antipsychotic permitting some conclusions. A number of authors suggest that the striking lack of agreement between different studies results from heterogeneity of their quality. Here, we have used a scoring system for assessing the quality of those studies. According to this system, none (0/14) of the studies having a score < 0.60 was able to show a therapeutic window, as compared to 53% (10/19) of those having a score > or = 0.60 (p = 0.002, Fisher exact test). Also, the studies able to identify the presence of a therapeutic window during haloperidol treatment were those having sample size > 20 (p = 0.06) and those whose patients were treated with fixed doses (p = 0.02). The diagnosis of schizophrenia in the studies seems not to be an exclusive condition, as compared with those also including schizophreniform and schizoaffective disorders (p = 0.12). Our qualitative analysis of haloperidol blood level publications seem to indicate that an upper limit may exist for haloperidol efficacy; values above this limit seem not to provide any supplementary clinical improvement and may even reduce therapeutic effect.

Central lead administration induces natriuretic and kaliuretic effects in rats.

The aim of the present experiments was to discern whether central acute lead injections affect brain control of renal function. Adult Wistar male rats received third-ventricle injections of lead acetate in three different doses (0.03, 0.3, and 3.0 nmol/rat). Lead acetate induced a significant increase in renal excretion of sodium and potassium. Pretreatment with losartan, a selective angiotensin II AT1 receptor antagonist (10.8 nmol/rat into the third ventricle 10 min before central lead injection), inhibits lead-induced natriuretic and kaliuretic effects. In addition, pretreatment with gadolinium, a calcium-channel blocker (0.3 nmol/rat into the third ventricle 20 min before central lead administration), reversed the increase in renal excretion of sodium and potassium provoked by central lead administration. Taken together, the data presented here suggest that lead injected into the third ventricle increases renal excretion of sodium and potassium by a mechanism that depends on the functional integrity of central angiotensin II AT1 receptors and calcium channels.

Effect of third ventricle administration of L-694,247, a selective 5-HT1D receptor agonist, on water intake in rats.

L-694,247, a selective 5-HT1D receptor agonist, injected directly into the third ventricle (2.5, 5.0, and 10.0 micrograms/rat) of dehydrated rats induced a dose-dependent partial blockade of water intake. Injected in this way, the compound abolishes drinking behavior induced by third ventricle administration of carbachol (2 micrograms/rat), angiotensin II (5 ng/rat), and isoproterenol (40 micrograms/rat). In addition, intraventricular injections of L-694,247 did not modify water intake in normohydrated rats. The effects of L-694,247 are due to a specific interaction with 5-HT1D receptors, because its inhibitory effect on water intake in dehydrated rats is blocked by the previous administration of a 5-HT1D antagonist, GR 127935 (5 micrograms/rat), directly into the third ventricle. It is concluded that central 5-HT1D receptor activation disrupts the functional integrity of central pathways related to drinking behavior.

Central 5-HT(4) receptors and drinking behavior.

The aim of the present study was to investigate the effect of acute third ventricle injections of two different 5-HT(4) receptor antagonists, GR 113808 and SB 204070, on water intake in different situations. Injections of 80 nmol/rat of both GR 113808 and SB 204070 were unable to modify water intake in normohydrated rats. Pretreatment with GR 113808 (40 and 80 nmol/rat) and SB 204070 (80 and 160 nmol/rat) blunted water intake after third ventricle injections of angiotensin II (9.6 pmol/rat) compared to saline-pretreated controls. Pretreatment with 80 nmol/rat of both antagonists potentiated drinking induced by third ventricle injections of carbachol (11.0 nmol/rat) compared to saline-pretreated control. In all doses employed, none of the compounds was able to modify water intake in dehydrated rats. A separate control test using one-bottle taste aversion paradigm indicated that the reduction in water intake observed in some of the present experiments could not be attributed to a drug-induced malaise. It is suggested that central 5-HT(4) receptors exert a dualistic role on the control of water intake potentiating angiotensin II-induced drinking and inhibiting thirst induced by central cholinergic activation