RESUMEN
The A1 adenosine receptor is the most widely expressed P1 receptor in vertebrates, performing inhibitory tone of the nervous system. Increased levels of adenosine are crucial to promote tissue protection in threatening situations, such as convulsion and hypoxia. Zebrafish is an established model organism for studies on health and disease. In this study, we evaluated the functionality of A1 adenosine receptor through development of zebrafish (6-7-day-, 3-, 8-, and 24-month-old), assessing: (I) the effects of the agonist N6-cyclopenthyladenosine (CPA) over locomotor parameters, (II) the anticonvulsant properties of CPA and adenosine per se in the pentylenetetrazol-induced seizure, and (III) the gene expression of adora1b through development. CPA promoted decreased distance traveled in the highest concentrations/doses tested (larvae: 75 to 500 µM; adults: 20 mg.kg-1), altered mean velocity (larvae: 50-500 µM; adults: 20 mg.kg-1) and time in the bottom zone of apparatus (adults: decrease in 20 mg.kg-1). Adenosine increased the latency of the larvae to reach stage II at 5 and 10 µM. CPA anticonvulsant effect against convulsive stage II was reached at 75 µM, although it decreased basal locomotor activity in larvae. For adults, CPA 10 mg.kg-1 was effective as anticonvulsant without locomotory effects. Adenosine had minor anticonvulsant effects in the concentration tested (larvae: 5 and 10 µM). The level of gene expression of adora1b was stable in brain from adult animals (8- and 24-month-old animals). These results suggest that zebrafish has similar responses to CPA as mammals. To avoid confounding factors, such as locomotor effects, during any brain function investigation using A1 adenosine receptor as a target, the concentration below 75 µM or below the dose of 20 mg.kg-1 of CPA is ideal for zebrafish at larval and adult stages, respectively.
Asunto(s)
Anticonvulsivantes , Pez Cebra , Animales , Pez Cebra/genética , Adenosina/farmacología , Receptores Purinérgicos P1/genética , Expresión Génica , MamíferosRESUMEN
Alcohol (ethanol) dependence and related disorders are life-threatening conditions and source of suffering for the user, family members and society. Alcohol withdrawal syndrome (AWS) is a little-known dynamic process associated with a high frequency of relapses. A state of hyperglutamatergic neurotransmission and imbalanced GABAergic function is related to an increased susceptibility to seizures during alcohol withdrawal. Adenosine signaling display an important role in endogenous response to decrease seizure and related damages. Here, an intermittent alcohol exposure regimen (1 h daily of 0.5% ethanol solution) for 16 days or 8 days of the same ethanol exposure regimen followed by 1 or 8 days of ethanol withdrawal was used to assess adenosine signaling in the context of seizure susceptibility using adult zebrafish. In both abstainer groups, a sub-convulsant dose of pentylenetetrazol (2.5 mM) was able to increase the frequency of animals reaching a clonic seizure-like state, while continuous-treated animals had no seizure, as did control animals. The total brain mRNA expression of A1 adenosine receptor was decreased in animals with 1 day of ethanol withdrawal. The agonism of A1 adenosine receptor induced an anticonvulsant effect in animals with 1 day of ethanol withdrawal after the injection of the specific agonist (N6-cyclopentyladenosine, 10 mg.Kg- 1; i.p.). These findings reinforce A1 adenosine receptor as a key target in acute alcohol withdrawal syndrome and zebrafish as an excellent platform to study biological mechanism of AWS.
Asunto(s)
Alcoholismo , Síndrome de Abstinencia a Sustancias , Animales , Síndrome de Abstinencia a Sustancias/tratamiento farmacológico , Alcoholismo/tratamiento farmacológico , Adenosina/farmacología , Pez Cebra/metabolismo , Anticonvulsivantes/uso terapéutico , Etanol/toxicidad , Convulsiones/inducido químicamente , Convulsiones/tratamiento farmacológico , Receptores Purinérgicos P1RESUMEN
Abstract Objective: To investigate the prevalence and factors associated with no intention to exclusively breastfeed for the first 6 months of life in a sample of women in the first 24 h postpartum during the hospital stay. Methods: Cross-sectional study with data from screening phase of a birth cohort. The proportion of mothers who did not intend to breastfeed exclusively for 6 months (primary outcome) derived from a negative response to the question "Would you be willing to try to breastfeed exclusively for the first 6 months?", in an interview conducted by previously trained interviewers. Crude and adjusted prevalence ratios (PR) with 95% confidence intervals were obtained by Poisson regression with robust variance. Results: A total of 2964 postpartum women were interviewed. The overall prevalence of mothers who did not intend to breastfeed exclusively for 6 months was 17.8% (16.4-19.1%). After adjusting for maternal age and type of pregnancy (singleton or multiple), no intention to exclusively breastfeed was higher in mothers with a monthly household income < 3 minimum wages (PR, 1.64; 1.35-1.98) and in those who intended to smoke 4-7 days/week after delivery (PR, 1.42; 1.11-1.83). The presence of significant newborn morbidity (PR, 0.32; 0.19-0.54) and intention to breastfeed up to 12 months (PR, 0.46; 0.38-0.55) had a protective effect against not intending to breastfeed exclusively for 6 months. Conclusions: Approximately 1 in every 5 mothers did not intend to breastfeed exclusively for 6 months. Strategies aimed at promoting exclusive breastfeeding should focus attention on mothers from lower economic strata and smokers.
Asunto(s)
Humanos , Femenino , Embarazo , Recién Nacido , Lactancia Materna , Intención , Prevalencia , Estudios Transversales , MadresRESUMEN
OBJECTIVE: To investigate the prevalence and factors associated with no intention to exclusively breastfeed for the first 6 months of life in a sample of women in the first 24â¯h postpartum during the hospital stay. METHODS: Cross-sectional study with data from screening phase of a birth cohort. The proportion of mothers who did not intend to breastfeed exclusively for 6 months (primary outcome) derived from a negative response to the question "Would you be willing to try to breastfeed exclusively for the first 6 months?", in an interview conducted by previously trained interviewers. Crude and adjusted prevalence ratios (PR) with 95% confidence intervals were obtained by Poisson regression with robust variance. RESULTS: A total of 2964 postpartum women were interviewed. The overall prevalence of mothers who did not intend to breastfeed exclusively for 6 months was 17.8% (16.4-19.1%). After adjusting for maternal age and type of pregnancy (singleton or multiple), no intention to exclusively breastfeed was higher in mothers with a monthly household income < 3 minimum wages (PR, 1.64; 1.35-1.98) and in those who intended to smoke 4-7 days/week after delivery (PR, 1.42; 1.11-1.83). The presence of significant newborn morbidity (PR, 0.32; 0.19-0.54) and intention to breastfeed up to 12 months (PR, 0.46; 0.38-0.55) had a protective effect against not intending to breastfeed exclusively for 6 months. CONCLUSIONS: Approximately 1 in every 5 mothers did not intend to breastfeed exclusively for 6 months. Strategies aimed at promoting exclusive breastfeeding should focus attention on mothers from lower economic strata and smokers.