Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
Future Sci OA ; 10(1): FSO910, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38817372

RESUMO

Aim: This study assessed the acute and sub-chronic toxicity of a novel polyherbal formulation tablet in Wistar rats Materials & methods: Acute toxicity and sub-chronic toxicity was assessed following OECD (Organisation for the Economic Co-operation and Development) guidelines based on 423 and 408. Results & conclusion: No mortality and toxicity showed in rats during acute toxicity. The LD50 of the extract was at 2000 mg/kg. In sub-chronic study, both sex rats were orally administered at 250, 500,1000 and 2000 mg/kg for 90 days and revealed no significant difference (p < 0.05) in hematological and other parameters compared with the control. Histopathology study did not reveal morphological alteration. The No observed adverse effect level of the tablet was observed until 2000 mg/kg.


Non-alcoholic fatty liver disease (NAFLD) affects around 25% of individuals globally and has become the most common long-term liver problem. The reasons why people get this disease can be different for each person. By studying natural substances, scientists have discovered that some compounds help treat the disease some of these substances can also be harmful. By studying natural substances, scientists have discovered that some compounds help treat the disease some of these substances can also be harmful. People are also trying out traditional medicines more and more, and we need to make sure they're safe. To determine whether a medication is secure, we conducted experiments in accordance with the OECD guidelines. One test examines whether a high dose of the drug is lethal. The goal is to determine the optimal dose, which is neither too low nor too excessive. Another test investigated what happens if these rats take the medicine every day for a long time. Variables such as blood tests and tissue samples are collected to make sure the medicine does not make the rats sick. In this case, we tested a medicine called a 'PHF tablet' for 90 days, and it didn't make the animals sick. They found that you can take a relatively high dose without any adverse effects.

2.
Environ Toxicol Pharmacol ; 79: 103410, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32422279

RESUMO

Soil and sludge are major reservoirs of organic compounds such as fluoroquinolones (FQs) which are broad-spectrum antibacterial agents. Hence, we monitored three major FQs, namely, ciprofloxacin (CIP), norfloxacin (NOR), and ofloxacin (OFL), in surface soil from two major dumpsites and dry and wet sludge from sewage treatment plants in Chennai city. The mean concentration of FQs in soil and sludge samples were 20 µg/g and 26 µg/g, respectively. Nearly 50% of the total FQs in dumpsite soil was contributed by CIP followed by NOR (32%) and OFL (13%). Similarly, CIP was the major contributor in sludge samples followed by NOR and OFL. The concentration of FQs was two folds higher in wet sludge than dry sludge most likely indicating that water solubility of these compounds might play an important role for elevated level of FQs in wet sludge. Solid waste from pharmaceutical industries, households, and sludge from wastewater treatment plants were expected to be the major source of FQs in dumpsite soil. Predicted risk assessment using soil to water migration concentrations via surface run off indicated high risk to aquatic organisms. However, risk quotient (RQ) was found less to earthworm in most of the soil samples. The findings from this study might help in future policies on disposal of household antibiotics in the solid waste stream.


Assuntos
Antibacterianos/análise , Ciprofloxacina/análise , Norfloxacino/análise , Ofloxacino/análise , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Animais , Cidades , Monitoramento Ambiental , Índia , Medição de Risco , Esgotos/análise , Instalações de Eliminação de Resíduos
3.
J Neurosci Methods ; 320: 16-25, 2019 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-30871986

RESUMO

BACKGROUND: Motor and non-motor behavior analyses are increasingly utilizied in drug discovery and screening, detection of neurobehavioral disorders and chemical toxicology. The emergence of computational approaches has helped to develop different tools to analyse complex behaviors. Analysis of locomotor behavior helps in understanding the motor neuron disorders like Parkinson's Disease. Although many animal models are available to study the locomotion, adult zebrafish has emerged as a simple and efficient model to study this behavior. An inexpensive and easily customizable tool is required to replace the licensed and expensive set-up to analyse the locomotor behavior. NEW METHOD: In this study we have optimized the ImageJ plugin wrMTrck to analyse motor and non-motor behaviors in adult zebrafish. We have generated a macro to simplify the preprocessing and tracking. Subsequently, we have developed a data analysis sheet to analyse various behavioral end points. RESULTS: We have successfully developed an inexpensive video acquisition set-up and optimized wrMTrck for adult zebrafish. In order to demonstrate the efficacy of this method, adult zebrafish were injected with MPTP and motor and non-motor behaviors were analysed. Expectedly, MPTP injected fish showed decrease in dopamine level and dat expression level, which subsequently led to locomotor behavioral defects as well as anxiety, a non-motor symptom of PD. COMPARISON WITH EXISTING METHOD(S): Further, the obtained results were validated by another ImageJ macro developed by Pelkowski et al. (2011) and we observed identical trajectories. CONCLUSIONS: The usefulness of popular ImageJ plugin wrMTrck and this extended protocol will be helpful to quantify motor and non-motor behavioral parameters.


Assuntos
Comportamento Animal/fisiologia , Pesquisa Comportamental , Locomoção/fisiologia , Neurociências , Transtornos Parkinsonianos/fisiopatologia , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Pesquisa Comportamental/instrumentação , Pesquisa Comportamental/métodos , Pesquisa Comportamental/normas , Modelos Animais de Doenças , Dopaminérgicos/farmacologia , Locomoção/efeitos dos fármacos , Intoxicação por MPTP/induzido quimicamente , Intoxicação por MPTP/fisiopatologia , Neurociências/instrumentação , Neurociências/métodos , Neurociências/normas , Transtornos Parkinsonianos/induzido quimicamente , Peixe-Zebra
4.
Biomed Pharmacother ; 97: 1046-1052, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29136783

RESUMO

OBJECTIVE: Alzheimer's disease (AD) is the most common cause of dementia yet treatment options are extremely limited. The disease is associated with cognitive impairment as well as structural irregularities, accumulation of plaques and neurofibrillary tangles, diminished levels of acetylcholine, oxidative stress, and inflammation in the brain. We have previously reported on the positive effects of a united states patented (US 7,273,626 B2) poly herbal test formulation, consisting of Bacopa monnieri, Hippophae rhamnoides and Dioscorea bulbifera extracts, on cognitive deficits in AD patients. The present study was conducted to investigate the mechanism(s) of action of the formulation using scopolamine treated rats as an AD model. METHOD: The formulation was administered daily along with scopolamine for a period of 14days following which the elevated plus maze, passive avoidance, and Morris water maze tests were performed to assess learning and memory. Rats treated with scopolamine or vehicle only were also included in the experiment. Acetylcholine levels and activities of acetylcholinesterase (AChE) and anti-oxidant enzymes in the brain were also measured at the end of the treatment period. RESULTS: The study demonstrate that scopolamine treatment resulted in learning and memory deficits which were partially and significantly ameliorated by the formulation. The formulation also counteracted scopolamine-induced decreases in acetylcholine levels, increases in AChE activity, and decreases in activities of the antioxidant enzymes. CONCLUSION: The study demonstrates the ability of the test formulation to reverse scopolamine-induced learning and memory deficits in rats which may at least partially be explained by the reversal of scopolamine-induced reductions in brain acetylcholine levels and antioxidant activities by the test formulation.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Transtornos Cognitivos/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/farmacologia , Acetilcolinesterase/metabolismo , Doença de Alzheimer/fisiopatologia , Animais , Antioxidantes/metabolismo , Aprendizagem da Esquiva/efeitos dos fármacos , Bacopa/química , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Transtornos Cognitivos/fisiopatologia , Dioscorea/química , Modelos Animais de Doenças , Hippophae/química , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Memória/efeitos dos fármacos , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/fisiopatologia , Estresse Oxidativo/efeitos dos fármacos , Patentes como Assunto , Ratos , Ratos Wistar , Escopolamina/toxicidade , Estados Unidos
6.
Saudi J Biol Sci ; 22(5): 645-50, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26288571

RESUMO

AIM AND OBJECTIVE: Hippophae rhamnoides is an edible, nutrient rich plant found in the northern regions of India. It belongs to the family Elaeagnaceae and is well known for its traditional pharmacological activities. The present study was aimed to investigate the antioxidant and neuroprotective activities of H. rhamnoides. METHODOLOGY: The hydroalcoholic extract of H. rhamnoides was evaluated for free radical scavenging activity using DPPH, hydroxyl radical scavenging and ferric thiocyanate assays. In vitro neuroprotective activity was assessed on human neuroblastoma cell line-IMR32 against hydrogen peroxide (H2O2) induced cytotoxicity. The neuroprotective effect was determined by measuring the cell viability through tetrazolium dye MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) reducing assay and propidium iodide (PI) staining. Also the intracellular reactive oxygen species (ROS) activity was assessed using dichloro-dihydro-fluorescein diacetate (DCFDA) assay by flowcytometer. RESULTS: The results of the study demonstrated that H. rhamnoides extract possesses potential free radical scavenging activity. The IC50 value for DPPH and OH radical scavenging assay was 70.92 µg/ml and 0.463 mg/ml, also the extract was also found to have considerable level of lipid peroxidation activity. The neuroprotective effect of H. rhamnoides was confirmed by its cell viability enhancing capacity against hydrogen peroxide induced cell cytotoxicity. The extract acted on IMR32 cells in a dose dependent manner as observed through PI and MTT assays. The percentage intracellular ROS activity was reduced by 60-70% in treated cells compared to H2O2 control. CONCLUSION: Thus the outcome of the study suggests that H. rhamnoides acts as a neuroprotectant against oxidative stress induced neurodegeneration.

7.
Complement Ther Med ; 23(2): 157-64, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25847553

RESUMO

OBJECTIVE: Obesity and overweight are the fifth most fatal diseases leading to an increased rate of morbidity and mortality in global population, with its incidence increasing drastically. Taking this into consideration we have conducted the present study in order to explore the efficacy of plant based formulation in the management of adolescent obesity and its associated biomarkers. DESIGN: Randomized, double blind, placebo controlled trial was conducted in 130 obese adolescent of both sexes, with BMI above 25kg/m(2). The subjects were randomly assigned into test formulation group (TFG) and placebo group (PG). TFG received two 500mg capsule containing test formulation whereas, the PG received two 500mg of cellulose powder containing capsule daily for 3 months. The parameters such as blood pressure, inflammatory cytokines, adipokines and lipid profile were assessed in all subjects pre and post treatment. RESULTS: There was a considerable improvement in the levels of lipid profile, inflammatory cytokines, adipokines and blood pressure after treatment in TFG compared to PG. The statistical difference obtained between the groups after three months of treatment for the various biomarkers are given as mean with 95% CI for BMI (-1.4±0.6 (-2.5 to -0.7)), total cholesterol mg/dl (-20.9±5.0 (-30.8 to -11.0)), triglyceride mg/dl (-12.9±5.7 (-23.9 to -1.2)), HDL-c mg/dl (7.2±0.8 (5.6-8.8)), IL-6 (-0.7±0.1 (-0.9 to -0.6)), hs C-reactive protein (CRP) mg/l(-1.0±0.01 (-1.2 to -0.8)), adiponectin µg/ml(4.9±0.4 (4.2-5.7)), leptin ng/ml (-8.0±1.4 (-10.7 to -5.3)), diastolic blood pressure (DBP) mmHg (-10.4±0.8 (-12.0 to -8.7)) and systolic blood pressure (SBP) mmHg (-6.7±0.7 (-8.1 to -5.3)). Also, there was a statistical significance within group TFG. CONCLUSION: The study concludes that the test formulation may prevent the future cardio vascular risk incidence in obese adolescents by reducing inflammation, overweight, lipid profile and by regulating adipokines. Thus it may help to improve the health pattern in obese patients with least side effects.


Assuntos
Biomarcadores/sangue , Obesidade Infantil/sangue , Obesidade Infantil/tratamento farmacológico , Extratos Vegetais/uso terapêutico , Adolescente , Criança , Método Duplo-Cego , Ingestão de Alimentos/efeitos dos fármacos , Feminino , Humanos , Masculino , Extratos Vegetais/farmacologia
8.
Behav Brain Res ; 283: 139-44, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25601573

RESUMO

Elevated plasma homocysteine (hcy) levels, also known as hyperhomocysteinemia (hhcy), have been associated with cognitive impairment and neurodegenerative disorders. Hhcy has been attributed to deficiency of B vitamins which can adversely affect the brain and result in memory loss and poor attention power. Monitoring hcy levels and the use of vitamin supplementation to treat hhcy may therefore prove advantageous for the prevention and management of cognitive impairment. With this in consideration, we measured plasma hcy, folate and vitamin B12 levels in 639 subjects from different age groups in two sub-regions of India. Cognitive function was also measured using attention span and immediate and delayed memory recall tests. Depression scores were obtained using the Beck Depression Inventory-II and functional impairment was assessed using the functional activities questionnaire (FAQ) score. As hhcy has also been linked to inflammation, plasma levels of high sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) were also measured. The results demonstrated significant negative correlations between hcy levels and folic acid levels, vitamin B12 levels and cognitive performance (attention span and delayed but not immediate memory recall) along with significant positive correlations between hcy levels and depression scores and hsCRP (but not IL-6) levels. A positive correlation was also observed between hcy levels and FAQ scores, however this was not found to be significant. Based on these results, folic acid and vitamin B12 intervention in people with elevated hcy levels in India could prove to be effective in lowering hcy levels and help maintain or improve cognitive function.


Assuntos
Envelhecimento/sangue , Envelhecimento/psicologia , Cognição/fisiologia , Homocisteína/sangue , Adolescente , Adulto , Idoso , Atenção/fisiologia , Proteína C-Reativa/metabolismo , Depressão/sangue , Feminino , Ácido Fólico/sangue , Humanos , Índia , Interleucina-6/sangue , Masculino , Rememoração Mental/fisiologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Escalas de Graduação Psiquiátrica , Inquéritos e Questionários , Vitamina B 12/sangue , Adulto Jovem
9.
Nat Prod Res ; 27(16): 1463-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22928548

RESUMO

This study was carried out to evaluate the anti-nociceptive and anti-inflammatory activities of carbon tetrachloride extract (CTCE) of Azadirachta indica fruit skin and its isolated constituent azadiradione at two different dose levels (50 and 100 mg kg⁻¹ body weight). Anti-nociceptive screening by writhing test and hot-plate technique supported both peripheral and central mechanisms, respectively. Anti-inflammatory activity was observed using carrageenan-induced paw oedema model. The results concluded that the animals treated with 100 mg kg⁻¹ dose of CTCE and azadiradione exhibited significant anti-nociceptive and anti-inflammatory activities. This study had rationalised the ethnomedicinal use of the plant for wound, burns and injury by tribal people.


Assuntos
Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Azadirachta/química , Edema/tratamento farmacológico , Frutas/química , Limoninas/química , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Animais , Tetracloreto de Carbono/química , Carragenina/toxicidade , Edema/induzido quimicamente , Limoninas/uso terapêutico , Camundongos
10.
J Young Pharm ; 4(1): 33-7, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22523458

RESUMO

1,3,4-Oxadizoles form a biologically important group of compounds having activities like analgesic, anti-inflammatory, bactericidal, antifungal, anticonvulsant, psychotropic, plant growth regulating and mono amino oxidase inhibition. This research has focused on the incorporation of the oxadiazole moiety into isoniazid because of their versatile biological action, to get 2-aryl-5-(4-pyridyl)-1,3,4-oxadiazole to explore the possibilities of some altered biological action. 1,3,4-Oxadiazole derivatives were synthesized by microwave-assisted synthesis and screened for their analgesic, anti-inflammatory activities. The synthesized compounds were characterized by Melting point, Thin layer chromatographyInfra red, Nuclear magnetic resonance spectroscopy, etc. Almost all the synthesized compounds possessed good activity as compared to the standard.

11.
Eur Rev Med Pharmacol Sci ; 14(1): 57-62, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20184090

RESUMO

Methanol leaf extracts of two Ethiopian traditional medicinal plants viz., Lomisar [vernacular name (local native language, Amharic); Cymbopogon citratus (DC) Stapf. (Poaceae)] and Bisana [vernacular name (local native language, Amharic); Croton macrostachyus Del. (Euphorbiaceae)] were screened for larvicidal activity against late third instar larvae of Anopheles arabiensis Patton, a potent malaria vector in Ethiopia. The larval mortality was observed 24 h of post treatment. Both plant extracts demonstrated varying degrees of larvicidal activity against Anopheles arabiensis. Cymbopogon citratus extract has exhibited potent larvicidal activity than Croton macrostachyus at lower concentrations. The LC50 and LC90 values of Cymbopogon citratus were 74.02 and 158.20 ppm, respectively. From this data, a chi-square value 2.760 is significant at the P < 0.05 level. While, the LC50 and LC90 values of Croton macrostachyus were 89.25 and 224.98 ppm, respectively and the chi-square value 1.035 is significant at the P < 0.05 level. The present investigation establishes that these plant extracts could serve as potent mosquito larvicidal agents against Anopheles arabiensis. However, their mode of actions and larvicidal efficiency under the field conditions should be scrutinized and determined in the near future.


Assuntos
Anopheles/fisiologia , Croton/química , Cymbopogon/química , Insetos Vetores/fisiologia , Inseticidas/toxicidade , Malária/transmissão , Animais , Etiópia , Humanos , Larva/fisiologia , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Folhas de Planta/química
12.
J Med Entomol ; 47(1): 1-15, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20180302

RESUMO

The taxonomic status of the sand fly Phlebotomus (Euphlebotomus) argentipes Annandale & Brunette 1908, which transmits Leishmania (Leishmania) donovani (Laveran & Mesnil 1903) in southern Asia, is reassessed, because variation in morphology, behavior, and distribution suggests it to be a complex of sibling species. The putative complex is composed of the nominotypical member Phlebotomus argentipes sensu stricto, Phlebotomus annandalei Sinton 1923 status revived and Phlebotomus glaucus Mitra & Roy 1953 new status. An allolectotype is designated for the female of P. argentipes as well as neotypes for the males of P. annandalei and P. glaucus. Morphological descriptions, illustrations, and keys are presented to allow identification of adult males and females. Based on female morphological characters, P. argentipes s.s., P. annandalei and P. glaucus can be distinguished from each other using principal component analysis. P. glaucus is widespread in India, occurring sympatrically with P. argentipes s.s. in L. donovani-endemic foci, whereas P. annandeli is peripatric to the type species in Chennai, southern India. "In copula" is a process of postcopulatory sexual selection occurring as correlated coevolution of male and female reproductive traits, which drives species isolation. This pattern has been implicated in reproductive isolation among the members of the P. argentipes complex. Further research on adult behavior and larval biology of the P. argentipes complex is needed to understand the epidemiology and control of visceral leishmaniasis.


Assuntos
Phlebotomus/classificação , Animais , Tamanho Corporal , Ecossistema , Feminino , Geografia , Índia , Masculino , Phlebotomus/anatomia & histologia , Phlebotomus/crescimento & desenvolvimento , Psychodidae/anatomia & histologia , Psychodidae/classificação , Caracteres Sexuais
13.
Anc Sci Life ; 28(4): 3-6, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22557323

RESUMO

Asthmatic patients are more subjected to continuous oxidative stress. Roosting the antioxidant defenses of asthma patient could be beneficial as it may help thwart symptoms of the lung disease and asthma. Considering these facts different plant extracts and phytoconstituents with proven anti asthmatic property had been subjected to antioxidant study at various combinations using Diphenyl Vicryl Hydrazyl radical scavenging method, Hydrogen Peroxide radical scavenging method, Nitric oxide radical inhibition method, ABTS radical scavenging method and Lipid peroxidation assay method.All the selected herbal based constituents and extracts at different combination showed a potent antioxidant activiy by Nitric oxide radical inhibition activiy method followed by ABTS method. The present finding suggests that the selected plant based anti asthmatic constituents namely Coleus extract (10% Forskolin), Piper longum extract (20% Piperine), CurcuminC3Complex (60% Curcumin), Vasaka (30% Vasicinone), Forskolin (95%), Pperine (98%), Curcumin C3 Complex (98.5%) and Vasicinone (75%) could be utilised in alternate anti asthmatic therapy, since they play a vital role in scavenging Nitric oxide which could prevent the bronchial inflammation in asthmatic patients.

16.
Fitoterapia ; 76(7-8): 715-7, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16246499

RESUMO

The hexane extract and ethyl acetate soluble fraction of methanolic extract of the fruit pulp of Momordica dioica exhibited moderate and concentration dependent antifeedant activity against Spodoptera litura.


Assuntos
Comportamento Alimentar/efeitos dos fármacos , Momordica , Extratos Vegetais/farmacologia , Spodoptera/efeitos dos fármacos , Animais , Frutas , Larva
18.
J Biosci ; 30(5): 711-31, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16388145

RESUMO

Females of phlebotomine sandflies (Diptera: Psychodidae) possess highly variable spermathecae that present several important taxonomic characters. The cause of this diversity remains a neglected field of sandfly biology, but may possibly be due to female post-mating sexual selection. To understand this diversity, a detailed study of the structure and function of the spermathecal complex in at least one of the species was a prerequisite. Using scanning and transmission electron microscopy, described here is ultrastructure of the spermathecal complex in the sand fly, Phlebotomus papatasi Scopoli. The spermathecal complexes are paired; each consists of a long spermathecal duct, a cylindrical spermathecal body, and a spherical spermathecal gland. Muscle fibres, nerves, tracheoles, and vascular sinuses connect the spermathecal body and duct through the epithelial layers. Spermathecal gland is formed by a typical insect epidermis and consisting of an epithelial layer of class-1 epidermal cells and elaborate glandular cells of class-3 epidermal cells, each having both receiving and conducting ductules (i.e. "end apparatus") and a "cytological apodeme", which is a newly described cell structure. The spermathecal body and duct are lined by class-1 epidermal cells and a cuticle, and are enveloped by a super-contracting visceral muscular system. The cuticle consists of rubber-like resilin, and its fibrillar arrangement and chemical nature are described. A well-developed neuromuscular junction exists between the spermathecal gland and the spermathecal body, which are connected to each other by a nerve and a muscle. The spermathecal complexes of the sandfly are compared with those of other insect species. The physiological role and possible evolutionary significance of the different parts of spermathecal complex in the sandfly are inferred from the morphology and behaviour. Post-mating sexual selection may be responsible for the structural uniqueness of the spermathecal complex in phlebotomine sandflies.


Assuntos
Phlebotomus/anatomia & histologia , Estruturas Animais/anatomia & histologia , Estruturas Animais/ultraestrutura , Animais , Feminino , Genitália Feminina/anatomia & histologia , Genitália Feminina/citologia , Genitália Feminina/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Microscopia de Contraste de Fase , Músculos/ultraestrutura , Phlebotomus/ultraestrutura
19.
J Biosci ; 30(5): 733-47, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16388146

RESUMO

The spermathecal complex of Phlebotomus papatasi Scopoli (Diptera: Psychodidae) undergoes histological and physiological changes during its gonotropic cycle. The present histochemical study revealed a mucopolysaccharide secretory mass in the spermathecae of the newly emerged sandfly. Sperm competition occurs when two or more males compete to fertilize an ovum in the female reproductive tract. In this study, spermatophores of two or more competing males were deposited at the base of the spermathecal ducts, which originate from the female bursa copulatrix. This suggests that females play a role in sperm displacement, which is defined as any situation in which the last male to mate with a female fertilizes maximum number her eggs. A blood meal ingested by the female for ovary development and egg laying stimulates the release of sperm from the spermatophore. The spermatozoa then migrate to the lumen of the spermatheca. The ultrastructure of spermatozoa comprises a head with double-layered acrosomal perforatorium, an elongate nucleus, and the axoneme with a 9 + 9 + 0 flagellar pattern. This axomene differs from the flagellate axoneme of other Psychodinae. Morphological changes, such as the casting off of the acrosomal membrane, and histological changes in the spermatophore are also described. Mating plugs that have been described previously in sandflies appear to be artefacts. Females of P. papatasi may be inseminated more than once during each gonotrophic cycle, and additional inseminations may be necessary for each cycle. The relationships between the volumes of the sperm and the spermatheca were calculated to determine sperm utilization and fecundity of P. papatasi. As the females of P. papatasi mate polyandrously, the anatomical and physiological complexity of the spermathecal complex may be related to post-copulatory sexual selection.


Assuntos
Phlebotomus/anatomia & histologia , Phlebotomus/fisiologia , Estruturas Animais/anatomia & histologia , Estruturas Animais/ultraestrutura , Animais , Copulação , Ingestão de Alimentos , Feminino , Fertilidade , Genitália Feminina/anatomia & histologia , Genitália Feminina/citologia , Genitália Feminina/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Oviposição , Reprodução , Espermatogônias , Espermatozoides
20.
J Med Entomol ; 37(5): 653-9, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11004775

RESUMO

The morphology of insect genitalia is often highly species-specific, and its variation has been suggested as an important impetus for evolution. Structural variation of the male genitalia and the female spermathecae in Phlebotomine sand flies is unique among the blood sucking Diptera. We describe the fine structures involved in mating for Phlebotomus papatasi (Scopoli). Relationships among the length of the spermathecal duct and aedeagal filament were studied in 26 species of Old World phelebotomine sand flies comprising 12 subgenera. In most taxa the aedeagal filaments were very long allowing direct insemination into the spermathecae, indicating that intrasexual competition among males occurs as sperm precedence. There was a positive correlation between the lengths of the spermathecal ducts and aedeagal filaments, indicating that an evolutionary "arms race" occurs between males and females over the control of fertilization. The pattern of genitalia variation in phlebotomine sand flies also indicated that differences in the lengths of the spermathecal ducts and aedeagal filaments are distributed unevenly among closely related species. Genital differences do not seem to occur in populations of the Phlebotomus argentipes Annandale & Brunetti complex, whereas differences showed strongly in closely related Phlebotomus papatasi and P. bergeroti Parrot, and in sympatric Phlebotomus martini Parrot and P. celiae Minter.


Assuntos
Evolução Biológica , Genitália Feminina/anatomia & histologia , Genitália Masculina/anatomia & histologia , Psychodidae/anatomia & histologia , Psychodidae/classificação , Animais , Vetores de Doenças/classificação , Feminino , Masculino , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...