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.

Effects of rumen-undegradable protein on intake, performance, and mammary gland development in prepubertal and pubertal dairy heifers.

The objective of this study was to evaluate the influence of different amounts of rumen-undegradable protein (RUP) on intake, N balance, performance, mammary gland development, carcass traits, and hormonal status of Holstein heifers at different physiological stages (PS). Sixteen prepubertal (PRE) heifers (initial BW = 106 ± 7.6 kg; age = 4.3 ± 0.46 mo) and 16 pubertal (PUB) heifers (initial BW = 224 ± 7.9 kg; age = 12.6 ± 0.45 mo) were used in an experiment over a period of 84 d. Four diets with increasing RUP contents (38, 44, 51, and 57% of dietary crude protein) and heifers at 2 PS (PRE or PUB) were used in a 4 × 2 factorial arrangement of treatments in a completely randomized design. Throughout the experiment, 2 digestibility trials were performed over 5 consecutive days (starting at d 36 and 78) involving feed and ort sampling and spot collections of feces and urine. At d 0 and 83, body ultrasound images were obtained for real-time carcass trait evaluation. The mammary gland was ultrasonically scanned at d 0 and every 3 wk during the experiment. Blood samples were taken at d 0 and 84 to determine serum concentrations of progesterone, estrogen, insulin-like growth factor I (IGF-I), and insulin. No interaction between PS and the level of RUP was found for any trait. Apparent digestibility of dry matter, organic matter, and neutral detergent fiber corrected for ash and protein was not affected by RUP level but was lower for PRE compared with PUB heifers. Sorting against neutral detergent fiber corrected for ash and protein (tendency only) and for crude protein was greater for PUB than PRE heifers. Pubertal heifers had greater average daily gain (905 vs. 505 g/d) and N retention (25.9 vs. 12.5 g/d) than PRE heifers. In addition, average daily gain and N retention were greatest at 51% RUP of dietary protein. Mammary ultrasonography indicated no effects of RUP amounts on mammary gland composition, whereas PRE heifers had greater pixel values than PUB, indicating higher contents of fat rather than protein in the mammary glands of PRE heifers. Serum progesterone and IGF-I concentration was affected only by PS, and PRE heifers had greater values of progesterone and IGF-I concentrations than PUB heifers. Serum insulin concentration was unaffected by PS but tended to be higher at 51% of RUP. In conclusion, an RUP level of 51% increases body weight, average daily gain, feed efficiency, and N retention in heifers regardless of the PS. In addition, PRE heifers have a lower sorting ability and reduced intake, total-tract digestibility, and N retention. They also have higher amounts of fat in their mammary glands, even at moderate growth rates.

Comparative analysis of laparoscopic and ultrasound-guided biopsy methods for gene expression analysis in transgenic goats.

The present study aimed to compare laparoscopic (LP) and ultrasound-guided (US) biopsy methods to obtain either liver or splenic tissue samples for ectopic gene expression analysis in transgenic goats. Tissue samples were collected from human granulocyte colony stimulating factor (hG-CSF)-transgenic bucks and submitted to real-time PCR for the endogenous genes (Sp1, Baff, and Gapdh) and the transgene (hG-CSF). Both LP and US biopsy methods were successful in obtaining liver and splenic samples that could be analyzed by PCR (i.e., sufficient sample sizes and RNA yield were obtained). Although the number of attempts made to obtain the tissue samples was similar (P > 0.05), LP procedures took considerably longer than the US method (P = 0.03). Finally, transgene transcripts were not detected in spleen or liver samples. Thus, for the phenotypic characterization of a transgenic goat line, investigation of ectopic gene expression can be made successfully by LP or US biopsy, avoiding the traditional approach of euthanasia.

Anxiolytic-like effects of standardized extract of Justicia pectoralis (SEJP) in mice: Involvement of GABA/benzodiazepine in receptor.

Justicia pectoralis (Acanthaceae) is used as an antiinflammatory, antimicrobial and bronchodilator, and its extract exerts an anxiolytic-like effect profile in animal models. This work presents the behavioral effects of an aqueous standardized extract of Justicia pectoralis (SEJP) in animal models, such as the elevated plus maze (EPM), light/dark, open field, rota rod and pentobarbital sleep time. The extract was administered intragastrically to male mice at single doses of 50, 100 and 200 mg/kg, while diazepam 1 or 2 mg/kg was used as a standard drug and flumazenil 2.5 mg/kg was used to evaluate the participation of benzodiazepinic receptors. The results showed that, similar to diazepam (1 mg/kg), SEJP significantly modified all the observed parameters in the EPM test, without altering the general motor activity in the open field, rota rod and pentobarbital sleep time tests. Flumazenil reversed not only the diazepam effect but also the SEJP effect. In the same way, all doses of SEJP increased the time of permanence in the light box in the light/dark test. The results showed that SEJP presented an anxiolytic-like effect, disproving sedative effects.

Effects of free and dipeptide forms of methionine supplementation on oxidative metabolism of broilers under high temperature.

Our previous studies have shown that methionine supplementation could help to attenuate the effects of heat stress on the metabolism of broiler chickens. Here we investigated for the first time the effects of methionine supplementation in the form of DL-methionyl-DL-methionine on broilers subjected to heat stress during the growth phase. Broilers were divided into two groups; one group was reared under thermoneutral conditions and the other under continuous heat stress (30 ±â€¯1 °C, 60% relative humidity). Both groups were subdivided into three dietary treatments: a methionine-deficient (MD) diet, a diet supplemented with free methionine (DL-M), and a diet supplemented with methionine dipeptide (DL-MM). Broilers raised under chronic heat stress had lower feed intake and weight gain than broilers raised under thermoneutral conditions (P < 0.05). There were no differences in animal performance between methionine-supplemented diets (DL-M and DL-MM). Heat-stressed birds had significantly higher heterophil/lymphocyte (H/L) ratio than thermoneutral birds. Under heat stress, broilers fed DL-M and DL-MM diets had lower H/L ratio than birds fed the MD diet. Higher concentrations of carbonylated proteins and lower concentration of reduced glutathione were observed in broilers raised under heat stress. In comparing heat-stressed broilers, we found that birds fed the DL-M diet had lower concentrations of thiobarbituric acid-reactive substances and carbonylated proteins than those fed the MD diet (P < 0.05). Higher expression of glutathione peroxidase (GPX) and glutathione synthetase (GSS) genes was observed in heat-stressed broilers (P < 0.05). Under heat stress, the MD diet increased GPX expression compared with other diets. Under thermoneutral conditions, the DL-M diet resulted in the highest GSS expression. There was a negative correlation between DNA methylation and GPX and GSS expression. Our results showed that supplementation of broiler diets with free methionine or methionine dipeptide may help attenuate the effects of heat stress through enhanced activation of genes related to the glutathione antioxidant system. Methionine effects were found for gene regulation, gene expression, and post-translational processing.

Implications of efavirenz for neuropsychiatry: a review.

Antiretroviral therapy has revolutionized the treatment of the human immunodeficiency virus because it has improved the clinical outcomes of patients. It is essential that these drugs cross the blood-brain barrier, since the virus is present in the central nervous system (CNS). Efavirenz passes through this barrier satisfactorily and can reduce the deleterious central effects of the human immunodeficiency virus. However, patients treated with efavirenz have been observed to experience psychiatric symptoms such as mania, depression, suicidal thoughts, psychosis, and hallucinations. The aim of this review is to describe the pharmacokinetic and pharmacodynamic properties of efavirenz and its major neuropsychiatric symptoms and the neurochemical pathways associated with these changes in the CNS. The databases Medline and Lilacs were used to search for review articles and preclinical and clinical research articles published from January 1996 to 2010. The search terms used were efavirenz, central nervous system, neuropsychiatry, neurotransmitters, adverse effects, and neurochemistry. Subject categories considered included effects on viral replication, pharmacokinetic and pharmacodynamic properties of efavirenz, and neuropsychiatric adverse effects including time course, duration, and probable mechanisms involved. The mechanisms involved in these changes include interference with cytochrome P450 enzymes, cytokines, tryptophan-2-3-dioxygenase, and brain creatine kinase.

Involvement of monoaminergic targets in the antidepressant- and anxiolytic-like effects of the synthetic alkamide riparin IV: Elucidation of further mechanisms through pharmacological, neurochemistry and computational approaches.

Despite recent advances, current antidepressants have considerable limitations: late onset of action and the high profile of refractoriness. Biomedical research with natural products has gained growing interest in the last years, and had provide useful candidates for new antidepressants. Riparins are a group of natural alkamides obtained from Aniba riparia, which had marked neuroactive effects, mainly as antidepressant and antinociceptive agents. We made modifications of the basic structure of riparins, originating a synthetic alkamide, also known as riparin IV (RipIV). RipIV demonstrated a superior analgesic effect than its congeners and a marked antidepressant-like effect. However, the basic mechanism for the central effects of RipIV remains unknown. Here, we aimed to investigate the participation of monoaminergic neurotransmission targets in the antidepressant-like effects of RipIV. To do this, we applied a combined approach of experimental (classical pharmacology and neurochemistry) and computer-aided techniques. Our results demonstrated that RipIV presented antidepressant- and anxiolytic-like effects without modifying locomotion and motor coordination of mice. Also, RipIV increased brain monoamines and their metabolite levels. At the higher dose (100 mg/kg), RipIV increased serotonin concentrations in all studied brain areas, while at the lower one (50 mg/kg), it increased mainly dopamine and noradrenaline levels. When tested with selective receptor antagonists, RipIV antidepressant effect showed dependence of the activation of multiple targets, including D1 and D2 dopamine receptors, 5-HT2A/2, 5-HT3 receptors and α2 adrenergic receptors. Molecular docking demonstrated favorable binding conformation and affinity of RipIV to monoamine oxidase B (MAO-B), serotonin transporter (SERT), α1 receptor, D2 receptor, dopamine transporter (DAT) and at some extent GABA-A receptor. RipIV also presented a computationally predicted favorable pharmacokinetic profile. Therefore, this study demonstrated the involvement of monoaminergic targets in the mechanism of RipIV antidepressant-like action, and provide evidence of it as a promising new antidepressant.

Antinociceptive effect of topiramate in models of acute pain and diabetic neuropathy in rodents.

This study assesses the antinociceptive effect induced by different dosages of topiramate (TP), an anticonvulsant drug that is orally administered in models of neuropathic pain and acute pain in rats and mice, respectively. Orally administered TP (80 mg/Kg) in mice causes antinociception in the first and second phases of a formalin test, while in doses of 20 and 40 mg/Kg it was only effective in the second phase. TP (80 mg/Kg, p.o) also exhibited antinociceptive action in the hot plate test, however, it did not have an effect in the capsaicin test in mice, nor in the model of neuropathic pain in diabetic rats. The antinociceptive effect caused by TP (80 mg/Kg, p.o) in the formalin test was reversed by prior treatment with naloxone (opioid antagonist), but not with glibenclamide (antagonist of the potassium channel), ondansetron (antagonist of the serotonin 5HT3 receptor) or cyproheptadine (antagonist of the serotonin 5HT2A receptor).The data show that TP has an important antinociceptive effect in the models of nociception induced by chemical (formalin) or thermal (hot plate) stimuli, and that the opioid system plays a part in the antinociceptive effect, as shown by formalin.

Effects of cottonseed oil and ferrous sulfate on the performance and expression of antioxidant enzymes in broilers.

Aiming to reduce feed costs, cottonseed oil (CSO) has been used as an alternative component in diets for broilers. However, this oil contains gossypol, an antinutritional agent that impacts the use of mineral elements, inhibits glucose uptake, and has a direct inhibitory action on intestinal enzymes. Nevertheless, toxic effects of gossypol can be prevented by the addition of iron salts, such as ferrous sulfate (FS), to the diet. This work was conducted to evaluate performance and gene expression of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the intestines of 21- and 42-day-old broilers fed 0, 2, 4, or 6% concentrations of CSO, with or without FS. All CSO diets led to weight gain (WG) at 21 D. At 42 D, an increase in WG and a decrease in feed conversion (FCR) in the diets containing FS were observed. In 21-day-old birds supplemented with 4% CSO and FS, an increase in GPx gene expression was observed when compared to the 6% level. Animals (42 day old) supplemented with 6% CSO and FS presented greater expression of SOD gene when compared to 2% CSO and FS. In addition, a higher GPx expression in broilers supplemented with 6% CSO and FS compared to 6% CSO without FS was achieved. In conclusion, including CSO in the diets of broiler favors WG in animals at 21 D of age, independent of the presence or absence of FS; and including 4% CSO and FS in the diet of these animals alters the expression of the GPx gene in the intestine, so it is not necessary to add FS at 21 D. On the other hand, in 42-day-old broilers, the addition of FS is indicated, due to increases WG, decreased FCR and at the 6% CSO level without FS increase in the expression of the SOD and GPx genes.

Acetylcholinesterase activities in hippocampus, frontal cortex and striatum of Wistar rats after pilocarpine-induced status epilepticus.

Experimental manipulations suggest that in vivo administration of cholinergic agonists or inhibitors of acetylcholinesterase (AChE) increases the concentration of acetylcholine. Biochemical studies have proposed a role for AChE in brain mechanisms responsible by development to status epilepticus (SE) induced by pilocarpine. The present study was aimed at investigating the changes in AChE activities in hippocampus, striatum and frontal cortex of adult rats after pilocarpine-induced SE. The control group was treated with 0.9% saline (s.c., control group) and another group received pilocarpine (400 mg/kg, s.c.). Both groups were sacrificed 1 h after treatment. The results have shown that pilocarpine administration and resulting SE produced a significant decrease in the AChE activity in the hippocampus (63%), striatum (35%) and frontal cortex (27%) of adult rats. Our results demonstrated a direct evidence of a decrease in the activity of the AChE in rat brain regions during seizure activity that could be responsible by regulation of acetylcholine levels during the establishment of SE induced by pilocarpine.

Effect of gabaergic, glutamatergic, antipsychotic and antidepressant drugs on pilocarpine-induced seizures and status epilepticus.

This work was designed to study the influence of drugs during seizures and status epilepticus (SE) induced by pilocarpine and mortality in adult rats. Fluoxetine (10 and 20 mg/kg), NMDA (N-methyl-D-aspartate, 10 and 20 mg/kg), amitriptyline (25 and 50 mg/kg), ketamine (0.5 and 1.0 mg/kg), gabapentin (100 and 150 mg/kg) and pimozide (10 and 20 mg/kg) were administered intraperitoneally, 30 min prior to pilocarpine (400mg/kg, s.c.). The animals were observed (24h) to determine: number of peripheral cholinergic signs, tremors, stereotyped movements, seizures, SE, latency to first seizure and number of deaths after pilocarpine treatment. Fluoxetine, amitriptyline, NMDA, and pimozide had proconvulsant effects in both doses tested. Smaller and higher doses of these drugs no protected and increased pilocarpine-induced seizures and/or mortality. Gabapentin and ketamine protected against seizures and reduced the latency to first seizure. Thus, these results suggest that caution should be taken in the selection of pharmacotherapy and dosages for patients with epilepsy because of the possibility of potentiating convulsive process toxicity.

Pharmacological studies of the opioids, mood stabilizer and dopaminergic drugs on pilocarpine-induced seizures and status epilepticus.

This work was designed to study the influence of drugs during seizures and status epilepticus (SE) induced by pilocarpine and mortality in adult rats. Morphine (0.1 and 0.2 mg/kg), SCH 23390 (0.1 and 0.2 mg/kg), haloperidol (5 and 10mg/kg) and lithium (30 and 60 mg/kg) were administered intraperitoneally (i.p.), 30 min before to pilocarpine (400 mg/kg, s.c.). The animals were observed (24 h) to determine: number of peripheral cholinergic signs, tremors, stereotyped movements, seizures, SE, latency to first seizure and number of deaths after pilocarpine treatment. Morphine and haloperidol had proconvulsant effects in both doses tested. Smaller and higher doses of these drugs no protected and increased pilocarpine-induced seizures, SE and/or mortality. SCH 23390 protected against seizures, increased the latency to first seizure and reduced the mortality of the animals treated with pilocarpine Theses results suggest that dopamine receptor system receptor subtypes exert opposite functions on the regulation of convulsive activity. The morphine is proconvulsant in lower doses. The opioids in high doses tested exert an action proconvulsant during the establishment of epileptic activity induce by pilocarpine. The lithium no protected the animals against seizures induced by pilocarpine and is used which a model of epilepsy associated with lower doses of pilocarpine in several studies, suggesting absence of the effect anticonvulsants in rodents.

Anatomical description of the skulls of peccaries (Tayassu tajacu, Linnaeus 1758) by computed tomography / [Descrição anatômica de crânio de catetos (Tayassu tajacu, Linnaeus, 1758) por tomografia computadorizada]

The aim of this study was to evaluate the anatomical structures of the skulls of peccaries to establish the basis for their clinical study and future preclinical research. Ten skulls of adult peccaries were subjected to tomographic examination. The data obtained were processed via three-dimensional image reconstruction software (3D images). The reconstructions obtained from the neurocranium of the studied specimens allowed the identification and description of the following structures: nasal bone, frontal bone, parietal bones, incisor bone, maxillary bone, zygomatic bone, temporal bone, palatal bone, occipital bone, vomer bone, pterygoid bone, sphenoid bone, paranasal sinuses and orbit. Computed tomography proved to be an important diagnostic tool in the investigation of the skull of this species, allowing the acquisition of anatomical values not yet documented for the species in the literature.(AU)

O objetivo deste estudo foi avaliar as estruturas anatômicas dos crânios de catetos, a fim de se estabelecerem as bases para seu estudo clínico e futuras pesquisas pré-clínicas. Dez crânios de catetos adultos foram submetidos a exame tomográfico. Os dados obtidos foram introduzidos em um software de reconstrução de imagens tridimensionais (imagens em 3D). As reconstruções obtidas do neurocrânio dos espécimes estudados permitiram a identificação e a descrição das seguintes estruturas: osso nasal, osso frontal, ossos parietais, osso incisivo, osso maxilar, osso zigomático, osso temporal, osso palatino, osso occipital, osso vômer, osso pterigoide, osso esfenoide, seios paranasais e órbita. A tomografia computadorizada mostrou-se como uma ferramenta diagnóstica importante na investigação do crânio dessa espécie, permitindo a aquisição de valores anatômicos ainda não documentados para a espécie na literatura.(AU)

B-mode and Doppler ultrasonography of abdominal structures of the peccary (Tayassu tajacu, Linnaeus 1758) / [Ultrassonografias Doppler e modo-B das estruturas abdominais de catetos (Tayassu tajacu Linnaeus, 1758)]

This study used B-mode and Doppler ultrasonography to characterize the abdominal structures of healthy peccaries raised in captivity. Fifteen peccaries were used for this study. The urinary vesicle appeared as an ovoid structure, located in the abdominal and pelvic transition, with a hyperechogenic, thin, smooth, and regular wall. The kidneys presented retroperitoneal topography and had similar sizes. The kidney/aorta ratio had an average value of 10.53±15cm (right) and 10.23±0.12 (left). The right adrenal gland had a length of 1.93±0.34cm and diameter of 0.56±0.16cm. The left adrenal gland had a length of 1.85±0.42cm and diameter of 0.52±0.11cm. The spleen had a diameter of 1.13±0.18cm. The hepatic vein demonstrated polyphasic flow in pulsed Doppler, with two retrograde peaks and an anterograde peak with a flow velocity of 25.7±0.83cm/s. The abdominal aorta had a diameter of 0.58±0.05cm and a flow velocity of 115.17±5.32cm/s. The morphological and hemodynamic study of the abdominal structures of the peccary, observed through B-mode and Doppler ultrasonography, aided in identifying the size, shape, position, echogenicity, and echotexture of the abdominal organs and in making inferences about the normal parameters for these structures in this species.(AU)

Este estudo teve como objetivo utilizar as ultrassonografias de modo-B e Doppler para caracterizar as estruturas abdominais de um cateto sadio criado em cativeiro. Quinze catetos foram utilizados para este estudo. A vesícula urinária apareceu como uma estrutura ovoide, localizada na transição entre as partes abdominal e pélvica, com uma parede hiperecogênica, fina, lisa e regular. Os rins apresentaram topografia retroperitoneal e tamanhos semelhantes. A relação rim/aorta teve um valor médio de 10,53 ± 15cm (direita) e 10,23 ± 0,12cm (esquerda). A glândula adrenal direita tinha um comprimento de 1,93 ± 0,34cm e um diâmetro de 0,56 ± 0,16cm. A glândula suprarrenal esquerda tinha um comprimento de 1,85 ± 0,42cm e um diâmetro de 0,52 ± 0,11cm. O baço tinha um diâmetro de 1,13 ± 0,18cm. A veia hepática demonstrou fluxo polifásico no Doppler pulsátil, com dois picos retrógrados e um pico anterógrado com velocidade de fluxo de 25,7±0,83cm/s. A aorta abdominal tinha um diâmetro de 0,58 ± 0,05cm e uma velocidade de fluxo de 115,17±5,32cm/s. Os estudos morfológico e hemodinâmico das estruturas abdominais do queixada, observadas por meio das ultrassonografias modo-B e Doppler, auxiliaram na identificação do tamanho, da forma, da posição, da ecogenicidade e da ecotextura dos órgãos abdominais e na realização de inferências sobre os parâmetros de normalidade para as estruturas nas espécies.(AU)

Pilocarpine-induced status epilepticus: monoamine level, muscarinic and dopaminergic receptors alterations in striatum of young rats.

Behavioural changes, muscarinic and dopaminergic receptors density and levels of monoamines were measured in striatum of rats after pilocarpine-induced status epilepticus (SE). Wistar rats at the age of 21 days were treated with pilocarpine (400mg/kg; subcutaneously) whilst the control group was treated with 0.9% saline (s.c.). Both groups were sacrificed 1h following the treatment. SE induced a muscarinic receptor downregulation of 64% in pilocarpine group. This effect was also observed to be 57% in D(1) and 32% in D(2). In the dissociation constant (K(d)) values in muscarinic and D(1) receptor no alterations were verified. On the other hand, the K(d) value for D(2) was observed to increase 41%. High performance liquid chromatography determinations showed 63, 35, 77 and 64% decreases in dopamine, 3-methoxy-phenylacetic acid, serotonin and 5-hydroxyindoleacetic acid contents, respectively. The homovanilic acid level was verified to increase 119%. The noradrenaline content was unaltered. A direct evidence of monoamine levels alterations can be verified during seizure activity and receptor density changes appear to occur in an accentuated way in immature brain during the estabilishment of SE induced by pilocarpine.

Evaluation of levetiracetam effects on pilocarpine-induced seizures: cholinergic muscarinic system involvement.

Levetiracetam (LEV) is a new antiepileptic drug effective as adjunctive therapy for partial seizures. It displays a unique pharmacological profile against experimental models of seizures, including pilocarpine-induced seizures in rodents. Aiming to clarify if anticonvulsant activity of LEV occurs due to cholinergic alterations, adult male mice received LEV injections before cholinergic agonists' administration. Pretreatment with LEV (30-200 mg/kg, i.p.) increased the latencies of seizures, but decreased status epilepticus and death on the seizure model induced by pilocarpine, 400 mg/kg, s.c. (P400). LEV (LEV200, 200 mg/kg, i.p.) pretreatment also reduced the intensity of tremors induced by oxotremorine (0.5 mg/kg, i.p). [3H]-N-methylscopolamine-binding assays in mice hippocampus showed that LEV200 pretreatment reverts the downregulation on muscarinic acetylcholine receptors (mAChR), induced by P400 administration, bringing back these density values to control ones (0.9% NaCl, i.p.). However, subtype-specific-binding assays revealed that P400- and LEV-alone treatments result in M1 and M2 subtypes decrease, respectively. The agonist-like behavior of LEV on the inhibitory M2 mAChR subtype, observed in this work, could contribute to explain the reduction on oxotremorine-induced tremors and the delay on pilocarpine-induced seizures, by an increase in the attenuation of neuronal activity mediated by the M1 receptors.

Antidepressant-like effect of Hoodia gordonii in a forced swimming test in mice: evidence for involvement of the monoaminergic system.

Hoodia gordonii is a plant species used traditionally in southern Africa to suppress appetite. Recently, it has been associated with a significant increase in blood pressure and pulse rate in women, suggesting sympathomimetic activity. The present study investigated the possible antidepressant-like effects of acute and repeated (15 days) administration of H. gordonii extract (25 and 50 mg/kg, po) to mice exposed to a forced swimming test (FST). Neurochemical analysis of brain monoamines was also carried out to determine the involvement of the monoaminergic system on these effects. Acute administration of H. gordonii decreased the immobility of mice in the FST without accompanying changes in general activity in the open-field test during acute treatment, suggesting an antidepressant-like effect. The anti-immobility effect of H. gordonii was prevented by pretreatment of mice with PCPA [an inhibitor of serotonin (5-HT) synthesis], NAN-190 (a 5-HT1A antagonist), ritanserin (a 5-HT2A/2C antagonist), ondansetron (a 5-HT3A antagonist), prazosin (an α1-adrenoceptor antagonist), SCH23390 (a D1 receptor antagonist), yohimbine (an α2-adrenoceptor antagonist), and sulpiride (a D2 receptor antagonist). A significant increase in 5-HT levels in the striatum was detected after acute administration, while 5-HT, norepinephrine and dopamine were significantly elevated after chronic treatment. Results indicated that H. gordonii possesses antidepressant-like activity in the FST by altering the dopaminergic, serotonergic, and noradrenergic systems.

Effects of lithium, alone or associated with pilocarpine, on muscarinic and dopaminergic receptors and on phosphoinositide metabolism in rat hippocampus and striatum.

The mechanism of action of lithium (Li) alone or with pilocarpine (Pilo), focusing on muscarinic and dopaminergic systems and also on phosphoinositide metabolism was studied. Li (3 mEq/kg) administered to rats once (1 d) or daily for 7 days (7 d), 24 h before Pilo (15 mg/kg), exacerbated cholinergic signs, leading to tremors. convulsions and brain lesions. Increases in muscarinic receptors (MR) of 29 and 49% were observed in the hippocampus after atropine (Atro) and Li-Atro-Pilo treatments, respectively, as compared to controls (Atro) and the Li-Pilo group (Li-Atro-Pilo). In the striatum, except for the 37% increase in the Li-Atro (50 mg/kg)-Pilo group as compared to the Li-Pilo one, no other changes were observed in MR. A decrease of 32% on average in D2-like receptors (D2R) was detected in the hippocampus in the group Li-7d. On the contrary, in the striatum an increase (25%) in the Li-7d group was observed and this effect was blocked by Li-Pilo. As far as inositol phosphates (IP) and phosphatidylinositol-4,5-biphosphate (PIP2) metabolism is concerned, Li caused a decrease (28%) and an increase (60%) in IP and PIP2 accumulations, respectively, in hippocampus slices while Pilo only altered IP accumulation (32% decrease). In this area the association of Li-Atro (10 mg/kg)-Pilo also caused a decrease (36%) in PIP2 as compared to the Li-Pilo group. In striatal slices, except for the Li, Atro (10 mg/kg) and Li-Atro (10 mg/kg)-Pilo groups which showed a decrease (33 40%) in IP accumulation, no other alteration was detected. The potentiation of the effect of Pilo by Li does not seem to depend on the PI metabolism, but instead on its involvement with muscarinic and dopaminergic systems.

Different times of withdrawal from cocaine administration cause changes in muscarinic and dopaminergic receptors in rat premotor cortex.

The present work studied neurochemical changes in rat premotor cortex 30 min, 1 and 5 days after withdrawal from cocaine repeated administration (20 and 30 mg/kg, intraperitoneally, daily for 7 days). Binding assays were performed in 10% homogenates, and ligands used were [(3)H]-N-methylscopolamine, [(3)H]-SCH 23390, and [(3)H]-spiroperidol for muscarinic, D(1)- and D(2)-like receptors, respectively. Levels of cyclic AMP (cAMP) and cyclic guanosine monophosphate (cGMP) were determined using a commercial kit. Scatchard analyses of muscarinic receptors showed an upregulation after 1 and 5 days withdrawal. While D(2)-like receptors were upregulated at all withdrawal periods, D(1)-like receptors were upregulated only at the 30 min withdrawal, and returned to normal levels after 1 day of the last injection. In relation to cAMP levels, the repeated cocaine administration, 1 day after the last injection produced a decrease (around 26%) with both doses, while a 67% increase was seen in cGMP levels with the 30 mg/kg dose. These findings indicate lasting neurochemical changes in premotor cortex caused by cocaine which remained after different withdrawal periods.