Injection Of Serotonin Research Articles

Reproductive conditioning, spawning induction and early development of the estuarine Caribbean clam, Polymesoda arctata (Deshayes, 1854), under hatchery conditions

Polymesoda arctata is a Caribbean estuarine clam commercially important that currently is considered threatened. The reproductive conditioning, spawning and early development were evaluated under laboratory conditions using organisms collected in the lagoon system of Ciénaga Grande de Santa Marta (Colombian Caribbean) between December 2020 and May 2021. Two reproductive conditioning experiments were conducted over 7 weeks, examining the frequency of mature animals in the natural environment (controls) and in the laboratory under two water temperatures (26 and 29 °C) and different salinity regimes (constant at 5 and 15 ppt, increasing from 5 to 15 ppt, and decreasing from 15 to 5 ppt). One spawning experiment was done, comparing the spawning response of adult clams exposed to various stimuli (changes in water temperature and salinity, flow of seawater irradiated with UV light, addition of a high concentration of food and sperm to the water, as well as injections of serotonin and KCl into the foot and/or adductor muscle). Higher frequencies of mature clams were observed after 2 to 5 weeks of reproductive conditioning at a low temperature (26 °C) and under a constant salinity regime (at 5 or 15 ppt). Higher percentages of spawning and post-stimulation survival as well as spawning response speed were observed in specimens injected in the foot with a low concentration of serotonin (0.4 mL at 20 μM). The time of spawning response onset was shorter in males than in females. The fecundity increased with the live weight of the females, showing an average value of 3.4 × 106 oocytes per female. The early development of the estuarine clam from oocyte to juvenile stage was described in detail. The growth rates of larvae and spat were relatively high but their survival values were low, showing the need for additional research on the larval and post-larval rearing.

Polysaccharide-rich extract of Genipa americana leaves exerts anti-inflammatory effects modulated by platelet mediators

Ethnopharmacological relevanceGenipa americana L. (Rubiaceae) leaves are traditionally used to treat fever, pharyngitis, healing, luxation and bruises. Aim of the studyThis study aimed to investigate the anti-inflammatory effect of the polysaccharide-rich extract of G. americana leaves (PE-Ga) in acute inflammation models and underlying mechanisms associated with platelet activity. Materials and methodsRats received PE-Ga (0.3–3.0 mg/kg; IV) 30 min before injection (IP or SC) of zymosan, serotonin, PGE2, PLA2, PAF or L-arginine, and evaluated in the models of paw edema and acute peritonits. The blockage of plasma serotonin reuptake into platelets was performed with fluoxetine (40 mg/kg; IP). ResultsIn vitro, PE-Ga inhibited ADP-induced platelet aggregation up to 49%. In the edema model, PE-Ga reduced (41%) the time-course of the edema induced by zymosan, mainly the last phase (62%), as well as that induced by PLA2 (32%), PAF (35%), L-arginine (36%), PGE2 (49%) or serotonin (54% AUC); and reversed paw hypernociception induced by PGE2 or serotonin. In the peritonitis model, PE-Ga reversed abdominal hypernociception and reduced leukocyte migration induced by zymosan to blood (38%) and peritoneal cavity (55%), mainly neutrophils (70%). PE-GA also decreased leukocyte rolling (32%) and adhesion (47%), and increased the rolling velocity 2.2-fold. In the peritoneal fluid, PE-Ga reversed P-selectin and reduced total proteins (17%), MDA (40%), NO2−/NO3− (27%), and MPO activity (43%) but increased catalase activity 3.3-fold compared to zymosan. In addition, fluoxetine reversed PE-Ga anti-inflammatory effect on leukocyte migration and adhesion. ConclusionsPE-Ga exerts antiplatelet and anti-inflammatory effects in acute inflammation induced by zymosan, being modulated by P-selectin and platelet serotonin, among other inflammatory mediators.

Alleviation of allergic conjunctivitis by (±)5(6)-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid in mice.

Background: Allergic conjunctivitis (AC) is a common ophthalmologic disorder that causes symptoms that often reduces a patient's quality of life (QOL). We investigated the effects of the eicosapentaenoic acid metabolite (±)5(6)-dihydroxy-8Z,11Z,14Z,17Z-eicosatetraenoic acid ((±)5(6)-DiHETE) on AC using a mouse model. Methods: BALB/c mice were sensitized with two injections of short ragweed pollen in alum, challenged fifth with pollen in eyedrops. The clinical signs and tear volume were evaluated at 15min after the final challenge. Histamine-induced ocular inflammation model was prepared by instilling histamine onto the surface of the eye. Fifteen minutes after histamine application, tear volume was measured using the Schirmer tear test. Miles assay was performed to investigate vascular permeability. To cause scratching behavior 10μg of serotonin was injected in the cheek. Results: Repeated topical application of pollen induced conjunctivitis, accompanied by eyelid edema and tearing in mice. Pollen application typically degranulates mast cells and recruits eosinophils to the conjunctiva. Intraperitoneal administration of 300μg/kg of (±)5(6)-DiHETE significantly inhibited pollen-induced symptoms. The administration of (±)5(6)-DiHETE also attenuated mast cell degranulation and eosinophil infiltration into the conjunctiva. To assess the effects of (±)5(6)-DiHETE on the downstream pathway of mast cell activation in AC, we used a histamine-induced ocular inflammation model. Topical application of 4μg/eye histamine caused eyelid edema and tearing and increased vascular permeability, as indicated by Evans blue dye extravasation. Intraperitoneal administration of 300μg/kg or topical administration of 1 μg/eye (±)5(6)-DiHETE inhibited histamine-induced manifestations. Finally, we assessed the effects of (±)5(6)-DiHETE on itching. An intradermal injection of 10μg serotonin in the cheek caused scratching behavior in mice. Intraperitoneal administration of 300μg/kg (±)5(6)-DiHETE significantly inhibited serotonin-induced scratching. Conclusion: Thus, (±)5(6)-DiHETE treatment broadly suppressed AC pathology and could be a novel treatment option for AC.

The Anterior Insula and its Projection to the Prelimbic Cortex are Involved in the Regulation of 5-HT-Induced Itch

Itch is an unpleasant sensation that urges people and animals to scratch. Neuroimaging studies on itch have yielded extensive correlations with diverse cortical and subcortical regions, including the insular lobe. However, the role and functional specificity of the insular cortex (IC) and its subdivisions in itch mediation remains unclear. Here, we demonstrated by immunohistochemistry and fiber photometry tests, that neurons in both the anterior insular cortex (AIC) and the posterior insular cortex (PIC) are activated during acute itch processes. Pharmacogenetic experiments revealed that nonselective inhibition of global AIC neurons, or selective inhibition of the activity of glutaminergic neurons in the AIC, reduced the scratching behaviors induced by intradermal injection of 5-hydroxytryptamine (5-HT), but not those induced by compound 48/80. However, both nonselective inhibition of global PIC neurons and selective inhibition of glutaminergic neurons in the PIC failed to affect the itching-scratching behaviors induced by either 5-HT or compound 48/80. In addition, pharmacogenetic inhibition of AIC glutaminergic neurons effectively blocked itch-associated conditioned place aversion behavior, and inhibition of AIC glutaminergic neurons projecting to the prelimbic cortex significantly suppressed 5-HT-evoked scratching. These findings provide preliminary evidence that the AIC is involved, at least partially via aversive emotion mediation, in the regulation of 5-HT-, but not compound 48/80-induced itch.

An electrophysiological method for evaluation of topical antipruritic drugs on itch-related neuronal activities in the spinal cord in hairless mice

To evaluate the effects of antipruritic drugs, it is important to determine whether the neural responses induced by physiological itch stimuli are suppressed. Although there are several behavioral assessments for topical antipruritic drugs applied to the skin, there are few established methods at neuronal levels using in vivo electrophysiological recordings for predicting local efficacy of antipruritic drugs for cutaneous application. To establish an assessment of topical antipruritic drugs applied to skin using in vivo extracellular recording from neurons in the superficial dorsal horn, we examined the relationships between itch-related biting behavior and spinal neuronal responses elicited by intradermal injection of pruritogen serotonin (5-HT) in hairless mice. The efficacy of topical occlusive application of local anesthetics was also evaluated by an in vivo electrophysiological method. 5-HT significantly increased the firing frequency in spinal neurons. The spinal firing frequency time course was similar to that of the biting behavior after the 5-HT injections. The 5-HT-induced spinal responses were significantly decreased by topical occlusive application of lidocaine or a Nav 1.7 channel blocker to the calf. The intradermal 5-HT injection-induced spinal neuronal responses appeared to be suppressed by topical occlusive application of lidocaine or a Nav1.7 channel blocker. The electrophysiological method for evaluating topical antipruritic drugs may be beneficial in assessing local effects on the skin.

Serotonin is a gap junction-permeable neuronal tracer in the mouse retina.

Gap junctions are dynamically modulated bridges allowing the transcellular passage of ions and small molecules with a molecular mass of up to 1 kDa, a mechanism utilized for molecular communication purposes by living cells. This same mechanism is also exploited by scientists to reveal the existence of gap junction contacts by the cell-to-cell movement of tracers. However, multiple labeling experiments require the availability of multiple gap junction-permeable tracers. To this end, we utilized the well-known transient OFF alpha retinal ganglion cell (RGC)-coupled array as a model system to study and compare the transjunctional movement of neurobiotin (NB), a commonly used tracer, and serotonin, a recently identified tracer. Although the transjunctional movement of serotonin has been established in cell cultures, here we show, for the first time, that serotonin is also a potent tracer in in vitro tissue. In addition, serotonin is lighter than the classical gap junction-permeable NB, and thus, we expected that tracer movement would be comparable to or better than that of serotonin. We found that intracellular serotonin injections result in the labeling of the coupled transient OFF alpha RGC array very similar to those of the classical NB-labeled arrays. Both serotonin and NB-injected transient OFF alpha RGCs displayed the well-known pattern with coupled RGCs and a cohort of coupled wide-field amacrine cells (ACs). By using morphological characteristics, we confirm that the serotonin and the NB-coupled AC arrays are identical, and thereby confirm that serotonin is a potent gap junction-permeable tracer and can be readily used as an alternative to NB in in vitro tissue. Moreover, serotonin can be utilized in parallel with other dyes or tracers, enabling the use of multiple labels in the same material.

Features of the Effects of Serotonin and Dopamine on Changes in Heart Rate Variability in Non-Linear Rats under Conditions of Acute Stress.

Changes in indicators of heart rate variability after a single injection of serotonin (200 μg/kg) or dopamine (60 μg/kg) were analyzed in male non-linear rats at rest and during acute stress. At rest, administration of serotonin is accompanied by an increase in the role of the vasomotor center in the formation of heart rate variability; administration of dopamine causes a moderate weakening of HF waves. In both cases, no sharp shifts in the sympathetic-parasympathetic relations are seen, but a more variable rhythm is formed under the effect of serotonin. Under conditions of acute stress, the increase in HR after injection of serotonin is half as much as in the control series, a trend towards weakening of the power of VLF- and even LF-waves is observed. After dopamine injection, a sharp increase in HR and strain index and a decrease in the power of waves of all spectral ranges and the centralization index are observed at the beginning of stress, but by the 30th min, tachycardia becomes moderate, the powers of all waves are restored; HF waves dominate in the spectrum, but potentiation of VLF- and LF-waves and growth of the centralization index are not observed in contrast to the control series. In general, serotonin and dopamine exhibit stress-limiting properties and moderate activation of sympathoadrenal influences and the suprasegmental level of regulation under stress conditions, but after dopamine injection we observed increased reactivity at the beginning of stress and less variable HR. Therefore, serotonin has more pronounced stress limiting effects, which can be revealed by heart rate variability analysis.

MPCVD-Grown Nanodiamond Microelectrodes with Oxygen Plasma Activation for Neurochemical Applications.

Nanodiamonds (NDs) are a carbon nanomaterial that has a diamond core with heteroatoms and defects at the surface. The large surface area, defect sites, and functional groups on NDs make them a promising material for electrochemical sensing. Previously, we dip-coated ND onto carbon-fiber microelectrodes (CFMEs) and found increases in sensitivity, but the coating was sparse. Here, we directly grew thin films of ND on niobium wires using microwave plasma chemical vapor deposition (MP-CVD) to provide full surface coverage. ND microelectrodes show a reliable performance in neurotransmitter detection with good antifouling properties. To improve sensitivity, we oxygen plasma etched ND films to activate the surface and intentionally add defects and oxygen surface functional groups. For fast-scan cyclic voltammetry detection of dopamine, oxygen plasma-etching increases the sensitivity from 21 nA/μM to 90 nA/μM after treatment. Fouling was tested by repeated injections of serotonin or tyramine, and both ND and plasma oxidized nanodiamond (NDO) microelectrodes maintain their currents better compared to CFMEs and therefore are more antifouling. A biofouling test in brain slices shows that ND microelectrodes barely have any current drop, while the more hydrophilic NDO microelectrodes decrease more, but still not as much as CFMEs. Overall, grown ND microelectrodes are promising in neurotransmitter detection with excellent fouling resistance, whereas oxygen plasma etching slightly lowers the fouling resistance but dramatically increases sensitivity.

The modulatory effects of biogenic amines on male mating performance in Bactrocera dorsalis.

In insects, the emergence of mating behavior requires the interplay among sex-determination hierarchy mechanisms that regulate sex-specific differentiation, perception and integration of different sensory cues, and precisely patterned behavioral outputs. Biogenic amines, including octopamine (OA), dopamine (DA), tyramine (TA), serotonin and histamine, have been identified and proposed as putative neurotransmitters, neurohormones and/or neuromodulators in the central nervous system of insects to influence multiple physiologies and behaviors. The current study provides the physiological roles and pharmacology of these biogenic amines in the mating performance of Bactrocera dorsalis. Silencing gene expressions coding for biosynthetic enzymes of DA and serotonin in male flies could decrease mating rates, while OA, TA and histamine had no such effects on mating. Furthermore, injection of DA or the DA receptor antagonist chlorpromazine could affect mating rate, as well as injection of serotonin. Pharmacological treatments with other biogenic amines or their receptor antagonists in male flies have no roles in regulating mating performance. We conclude that DA and its receptors are involved in regulating male mating behaviors in B. dorsalis, while changes in serotonin levels in male flies could also affect mating rates. In the current study, the modulatory effects of these biogenic amines on mating performance were investigated, and these results will be helpful in providing a new strategy for controlling B. dorsalis.

Dermal secretion physiology and thermoregulation in the lone star tick, Amblyomma americanum

Ticks are hematophagous ectoparasites that transmit a wide range of pathogens. The lone star tick, Amblyomma americanum, is one of the most widely distributed ticks in the Midwest and Eastern United States. Lone star ticks, as other three-host ixodid ticks, can survive in harsh environments for extended periods without a blood meal. Physiological mechanisms that allow them to survive during hot and dry seasons include thermal tolerance and water homeostasis. Dermal fluid secretions have been described in metastriate ticks including A. americanum. We hypothesized that tick dermal secretion in the unfed tick plays a role in thermoregulation, as described in other hematophagous arthropods during blood feeding. In this study, we found that physical contact with a heat probe at 45 °C or high environmental temperature at ∼50 °C can trigger dermal secretion in A. americanum and other metastriate ticks in the off-host period. We demonstrated that dermal secretion plays a role in evaporative cooling when ticks are exposed to high temperatures. We find that type II dermal glands, having paired two cells and forming large glandular structures, are the source of dermal secretion. The secretion was triggered by an injection of serotonin, and the serotonin-mediated secretion was suppressed by a pretreatment with ouabain, a Na/K-ATPase blocker, implying that the secretion is controlled by serotonin and the downstream Na/K-ATPase.

Противовоспалительное и анальгетическое действие ингибитора индуцируемой синтазы оксида азота в эксперименте

Introduction. Nitric oxide plays a key role in the development of inflammation. In this regard, it is promising to create a drug that reduces the production of nitric oxide in the focus of inflammation. Aim. To study experimentally the anti-inflammatory and analgesic effects of an inducible nitric oxide synthase inhibitor of an aminoguanidine derivative (LIS-M). Materials and methods. The compound LIS-M in 1% aqueous solution of polyvinylpyrrolidone was administered intramuscularly at doses of 5, 10 and 20 mg/kg to 150 male Sprague Dawley rats and 50 male CD-1 mice with experimental models of inflammation and pain. The animals of the comparison group received diclofenac at a dose of 10 mg/kg, the animals of the control group received 1% aqueous solution of polyvinylpyrrolidone in an equivalent volume. The effect of the LIS-M compound on the course of experimental pathology and its analgesic potential ulcerogenic effect were evaluated. Results. In male Sprague Dawley rats, the LIS-M compound reduces acute exudative inflammation caused by injection of carrageenan, histamine or serotonin in plantar aponeurosis, inhibits the proliferation of granulation tissue and exudation around a cotton swab implanted under the skin, does not have an ulcerogenic effect. In male CD-1 mice, it weakens the pain reaction and increases the time before it occurs. Conclusion. The LIS-M compound at doses ranging from of 5 to 20 mg/kg has a pronounced antiexudative, antiproliferative and analgesic effect, not inferior to the action of diclofenac at a dose of 10 mg/kg, and does not have an ulcerogenic effect.

Effect of in ovo injection of serotonin on the behavior and hormone level in laying hens

Feather pecking is a typically abnormal behavior that significantly impacts breeding efficiency and animal welfare in the egg production sector. Serotonin (5-HT) is essential for neuronal development and behavioral regulation. This study evaluated the effects of birds’ behavioral development (including feather pecking) and changes in serum hormones in chickens followed in ovo injection of 5-HT. On day 11, incubated eggs were injected with 5-HT at 0 (saline control), 5 ug (low) or 15 ug (high) (n = 166 per treatment). The hatched female chicks were raised under similar conditions up to 20 weeks of age (n = 60 per treatment). Birds’ behaviors were recorded using a digital video recording system. The time to first vocalize and first move, along with the duration of vocalization and escape attempts during the isolation test, during isolation test were analyzed on day 1, and week 4, 8, 12, 16 and 20. Blood samples were collected followed behavioral tests (n = 5/treatment). The expression of 5-HTR1A genes in the hypothalamus was measured by real-time PCR. Compared to controls, 5-HT administrated pullets had greater body weight (P < 0.05) with an improved feed conversion rate (P < 0.05) as well as higher serum concentrations of norepinephrine (NE) regardless of their doses. In addition, serum dopamine (DA) concentrations were lower in both high- and low-dose pullets at 8 and 12 weeks of age (P < 0.05). Also, a decrease in fearfulness response was observed based on the test to vocalize and duration of vocalization (P < 0.05). Further, this exhibited a lesser frequency of total aggressive behavior compared with the chicks in the control group, especially at 8 weeks of age (P < 0.05), where it is associated with elevated serum 5-HT concentration and upregulated hypothalamic expression of 5-HTR1A (P < 0.05). The changes of these hormone concentrations and gene expressions suggested that 5-HT accumulation in early embryonic stages may alter both the adrenergic and serotonergic systems, which could further regulate the isolation behavior and improve birds' growth performance to a certain extent.

Anxiety induces long-term memory forgetting in the crayfish

When two male crayfish encounter, agonistic bouts are initiated and a winner-loser relationship is established. Larger animals are more likely to win with their physical advantage, but they are frequently beaten by small dominant animals with previous winning experience. This winner effect remains for several days. In mammals, anxiety impairs learning and induces memory forgetting. In this study, dominant crayfish were exposed to electrical shocks two days after their first win, after which they were paired with large or small naive opponents the following day. Our results showed that electrical shock-applied dominant animals were beaten by large naive opponents, but overcame small naive opponents, suggesting that electrical shocks cause animals to forget their previous winner effect. Electrical shocks appeared to elicit serotonin-mediated anxiety since electrical shocks had no effect on mianserin-injected dominant animals. A 0.5µM serotonin injection induced a caused anxiety-like reaction, while a 1.0µM serotonin injection-induced no changes in posture and walking activity. For pairings between dominant and naive animals 1 day after serotonin injection, 0.5µM serotonin caused similar forgetting of the winner effect, but 1.0µM serotonin had no effect. Serotonin of low concentrations mediated anxiety and stimulated forgetting of the winner's memory.

Effects of in ovo injection of serotonin on behavior and hypothalamic genes expression in post hatch-chicks

Serotonin (5-HT) is essential for neuronal development and behavioral regulation. Serotonin, upon in ovo administration, has been previously reported to modulate aggressive behavior in avian species, however it still remains unknown if maternal serotonin affects chick behavior through hypothalamic gene expression. We injected an equal volume of saline (control) and either a 5 μg (low) or a 15 μg (high) dose of 5-HT into embryos on embryonic day 11 (E11). The blood concentration of 5-HT was determined in chicks on post-hatching D3 (Day 3) and D45. The behavioral fear and aggression were analyzed at D10 and D52. In isolation test, the latency to vocalize and walk, the duration of vocalizations and walking were recorded. Hypothalamic expression of genes related to the serotonin pathway and the methylation status of hypothalamic 5-HT 1A receptor (5-HTR1A) were measured at D56. Chicks treated with embryonic 5-HT exhibited a certain decrease in the degree of fear as determined by the duration of vocalizations (p < 0.05) in an isolation test. They also exhibited a significantly less aggressive behavior (p < 0.05) as compared to chicks given saline control. We also noticed that the higher dosage was consequently associated with elevated concentration of 5-HT in blood. Exposure to high dosage of 5-HT significantly down-regulated Monoamine oxidase A (MAO-A) and B (MAO-B). Alternatively, the mRNA expression of Hypothalamic tryptophan hydroxylase 2 (TPH2) was significantly up-regulated (p < 0.05). However, the mRNA levels of Tryptophan hydroxylase 1 (TPH1) and the transporter for 5-HT (5-HTT) remained unchanged. Interestingly, 5-HTR1A was found to be significantly increased in the high-dosage group (p < 0.05). The promoter region of 5-HTR1A gene was significantly hypomethylated (p < 0.05) which correlated negatively with the mRNA expression of 5-HTR1A genes (r=-0.682, p = 0.005). These results indicate that in ovo serotonin injection affects aggressive and fearful behaviors by modifying the expression of genes involved in the serotonergic pathway, through DNA methylation mediated epigenetic mechanisms.

Influences of Serotonin Hydrochloride on Adiponectin, Ghrelin and KiSS1 Genes Expression.

Background: Serotonin and kisspeptin stimulates gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) release while ghrelin and adiponectin inhibit them. In the present experimental study, the effects of central injection of serotonin were investigated on LH concentration, KiSS1, adiponectin, and ghrelin genes expression. Materials and Methods: Fifteen Wistar male rats in three groups received saline or serotonin hydrochloride via the third cerebral ventricle. Blood samples were collected via the tail vein. Serum LH concentration and relative gene expression were evaluated by radioimmunoassay and real-time polymerase chain reaction method, respectively. Results: Serotonin significantly increased the mean serum LH concentration and KiSS1 gene expression levels compared to the saline group. Serotonin significantly decreased the mean ghrelin and adiponectin genes expression levels compared to the saline group. Conclusion: The serotonergic pathway may have stimulatory effects on hypothalamic kisspeptin synthesis, partly via inhibiting hypothalamic ghrelin and adiponectin neural activity.

Influences of Serotonin Hydrochloride on Adiponectin, Ghrelin and KiSS1 Genes Expression

Background: Serotonin and kisspeptin stimulates gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) release while ghrelin and adiponectin inhibit them. In the present experimental study, the effects of central injection of serotonin were investigated on LH concentration, KiSS1, adiponectin, and ghrelin genes expression. Materials and Methods: Fifteen Wistar male rats in three groups received saline or serotonin hydrochloride via the third cerebral ventricle. Blood samples were collected via the tail vein. Serum LH concentration and relative gene expression were evaluated by radioimmunoassay and real-time polymerase chain reaction method, respectively. Results: Serotonin significantly increased the mean serum LH concentration and KiSS1 gene expression levels compared to the saline group. Serotonin significantly decreased the mean ghrelin and adiponectin genes expression levels compared to the saline group. Conclusion: The serotonergic pathway may have stimulatory effects on hypothalamic kisspeptin synthesis, partly via inhibiting hypothalamic ghrelin and adiponectin neural activity.[GMJ.2020;9:e1767]

Anti-inflammatory activity and mechanism of action of ethanolic leaf extract of Morinda lucida Benth

Background and aimMost developing countries resort to medicinal plants for treating diseases, but few of these have scientific backing for their use. The aim of the study was to validate traditional use of Morinda lucida leaves in treating inflammation and determine the mechanism of action. Experimental procedureEffect of hydroethanolic leaf extract of M. lucida (HEML) on localized inflammation was evaluated using rat paw edema presented by sub-planter injections of λ-carrageenan, histamine or serotonin in separate experiments. Systemic inflammation was evaluated by lipopolysaccharide (LPS)-induced hyperthermia. Antioxidant activity of HEML was also evaluated using the free-radical scavenging assay. Results and conclusionNo mortalities were recorded in acute toxicity assay after administering 5000 mg/kg HEML to rats. It showed very good activity against localized and systemic inflammation in inverse dose-dependent manner and caused reduction in nitric oxide and prostaglandin E−2 levels by affecting expression of inducible nitric oxide synthase, but not cyclooxygenases-2 in LPS-activated RAW 264.7 murine macrophages. HEML reduced pro-inflammatory cytokines interleukin (IL)-1β and tumor necrotic factor, but elevated levels of anti-inflammatory cytokine IL-10 in vitro. HEML contains saponins, reducing sugars, polyphenols and flavonoids and showed antioxidant activity with EC50 = 0.6415 ± 0.0027 mg/ml. In conclusion, this study provides evidence that HEML possesses anti-inflammatory activity, possibly through modulation of production of early/late phase inflammation mediators.

Противовоспалительное и анальгетическое действие нового сложноэфирного производного индометацина

Сложный эфир индометацина и ментола (ИМЛ) при введении внутрь в дозе 12,5 мг/кг оказывает профилактическое противовоспалительное действие на моделях острого экссудативного воспаления, вызванного каррагенином, гистамином и серотонином, и хронического пролиферативного воспаления у крыс. При введении за 12 ч до каррагенина антиэкссудативное действие ИМЛ превосходит эффект индометацина на 36 % (p &lt; 0,05), при введении ИМЛ за 8 ч до применения гистамина и серотонина — на 32 % (p &lt; 0,05). Максимальная концентрация индометацина, освобождаемого при гидролизе ИМЛ, создается в плазме крови крыс через (8 ± 0,3) ч, а максимальная концентрация индометацина — через (4 ± 0,5) ч. ИМЛ тормозит развитие грануляционной ткани слабее индометацина на 25,6 % (p &lt; 0,05), подавляет гипералгезию у мышей больше, чем индометацин на 16 % (p &lt; 0,05), не повреждает слизистую оболочку желудка крыс и создает в ней концентрацию индометацина в 3,2 – 5,3 раза более низкую, чем та, которая возникает при применении индометацина (p &lt; 0,05).

Breeding and Larval Rearing of Asian Moon Scallop Amusium pleuronectes in Eastern Samar, Philippines

Asian moon scallop, Amusium pleuronectes, is among the most common commercially harvested scallop in the Philippines. This study investigated suitable conditioning methods, induced spawning, and documented scallop larval development at the Marine Fisheries Research and Development Center (MFRDC) Guiuan, Eastern Samar. Scallops held in tanks with flow-through water system without substrate yielded high survival rate of 48.06 ± 5.95%. Optimum water temperature was 28-29°C for maintaining scallops. Isochrysis galbana and Chaetoceros calcitrans were suitable microalgal feed for A. pleuronectes consumed at 7,388,888 cells min-1 per scallop. These significant results were applied in maintaining scallops at the hatchery. As a result, scallops with an average 19.8 mm shell length (SL) reached 37.5 mm SL within four months with a survival rate of 96.57 ± 2.04%, average daily growth rate (ADGR) of 0.13 ± 0.04 mm.day-1, and specific growth rate (SGR) of 3.92 ± 1.31%.d-1. Natural spawning was successful under controlled conditions while induced spawning trial through thermal stimulation, food shock, sexual stimulation, and serotonin injection resulted unsuccessful release of sperm and eggs. The estimated number of fertilized eggs per spawning ranged from 0.22-1.4 million. Fertilized eggs appeared spherical and dark in color with 54.2-62.57 µm in diameter. After nine hours, the larvae developed into trochophore stage with 59.08-84.4 µm in length. D-veliger with 120.37-157.07µm shell length developed after 24 hours. Development of the early umbone stage was reached on day 5; and on day 7, the umbo larvae become well-developed with shell length of 135.45-173.36 µm. On day 9, pedi-veligers were observed in the culture. Spat grew 312.41-509.48 µm on day 16 and survived until four months with final shell length of 4-10 mm. For the larval rearing, stocking density of A. pleuronectes larvae observed highest survival rate of 0.04 ± 0.03% at 200 larvae/L, while no larvae survived at 800 larvae/L due to contamination of protozoans in the culture medium.

Role of Nitric Oxide in the Antipruritic Effect of WIN 55,212-2, a Cannabinoid Agonist.

Introduction:For centuries, cannabinoids are known to be effective in pain relief. Itch is an unpleasant sensation that provokes a desire to scratch. Since itch and pain are two sensations sharing a lot in common, we aimed to investigate whether the cannabinoid agonist WIN 55,212-2 reduces serotonin-induced scratching behavior and also observe whether modulation of Nitric Oxide (NO) production mediates the antipruritic effect of WIN 55,212-2.Methods:Scratching behavior is induced by intradermal injection of serotonin (50 μg/50 μL/mouse) to BALB/c mice. The cannabinoid agonist WIN 55,212-2 (1, 3, 10 mg/kg, IP) was given 30 min before serotonin injection. To observe the effect of NO modulation on the antipruritic effect of cannabinoids, the endothelial nitric oxide synthase (NOS) inhibitor L-NAME (3 mg/kg, IP), the neuronal NOS inhibitor 7-nitroindazole (3 mg/kg, IP), and the NO precursor L-arginine (100 mg/kg, IP) were administered together with WIN 55,212-2.Results:WIN 55,212-2 reduced serotonin-induced scratches at higher doses (3, 10 mg/ kg; P<0.0001). The endothelial NOS inhibitor L-NAME, the neuronal NOS inhibitor 7-nitroindazole, and the nitric oxide precursor L-arginine did not influence the antipruritic action of WIN 55,212-2. When NO modulators were used alone, only the neuronal NOS inhibitor 7-nitroindazole attenuated serotonin-induced scratches (P<0.0001).Conclusion:Our findings indicate that exogenous cannabinoids may attenuate serotonininduced scratches and NO does not mediate the antipruritic effect of WIN 55,212-2. On the other hand, neuronal NOS inhibition may play a role in the production of serotonin-induced scratches.