Furosemide-induced vasodilation: Importance of the state of hydration and filtration

Furosemide-induced vasodilation: Importance of the state of hydration and filtration. The circumstances under which furose-mide increases renal blood flow was examined in mongrel dogs as it may relate to a tubuloglomerular feedback mechanism. Two maneuvers, desoxycorticosterone (DOCA) plus salt treatment and inhibition of tubular fluid flow, were used in the dogs to evaluate the renal vascular effects of furosemide because these maneuvers have been reported to blunt the tubuloglomerular feedback in micropuncture studies. In addition, we also used two structurally different nonsteroidal antiinflammatory drugs to assess the importance of prostaglandins to achieve furosemide's renal vasodilation. Furosemide (5 mg/kg, i.v.) increased renal blood flow in volume-depleted animals from a baseline flow of 141 ± 28ml/min to a maximum of 176 ± 35ml/min at 6min after furosemide administration. If the animals were pretreated with a high-salt diet and i.m. DOCA for 5 days, furosemide administration produced no renal vascular effects but still caused a large diuresis, and these dogs still had a responsive renal vascular bed to infused prostaglandin E2. In addition, kidneys rendered non-filtering in volume-depleted animals had no renal vascular response to furosemide. Volume-depleted animals, pretreated with either indomethacin or sodium meclofenamate, did not have a renal vascular response to furosemide although they did have a diuretic response and a responsive renal vasculature to prostaglandin E2. From our data, we hypothesize that the renal vascular response to furosemide is secondary to a tubular mechanism mediated by a vasodilatory prostaglandin. Because furosemide has been shown to disrupt the tubuloglomerular feedback mechanism, and the two maneuvers, DOCA plus salt treatment and lack of filtration, blunt the tubuloglomerular feedback response as well as inhibit the renal vascular response to furosemide, we further hypothesize that furosemide-induced renal vasodilation may be secondary to the disruption of an active tubuloglomerular feedback mechanism.Vasodilatation induite par le furosémide: Importance de l'état d'hydratation et de filtration. Les circonstances où le furosémide augmente le débit sanguin rénal ont été étudiées chez des chiens bâtards en fonction d'un mécanisme possible de rétro-contrôle tubulo-glomérulaire. Deux manoeuvres, le traitement par la désoxycorticosterone (DOCA) et le sel et l'inhibition du débit tubulaire, ont été utilisées chez des chiens pour évaluer les effets vasculaires rénaux du furosemide, puisque ces deux manoeuvres sont réputées effacer le rétro-contrôle tubulo-glomérulaire dans les études par microponction. De plus, nous avons employé deux drogues anti-inflammatoires, non stéroïdiennes, de structures différentes pour évaluer l'importance des prostaglandines dans le déterminisme d'une vasodilatation rénale. Le furosemide (5 mg/kg, i.v.) augmente le débit sanguin rénal chez les animaux déshydratés à partir d'une ligne de base de 141 ± 28ml/min jusqu'à un maximum de 176 ± 35ml/min 6 minutes après l'administration de furosémide. Quand les animaux ont été prétraités par une alimentation riche en sel et de la DOCA i.m. pendant 5 jours l'administration de furosémide n'a pas produit d'effets vasculaires rénaux mais a cependant déterminé une diurèse importante et le lit vasculaire rénal de ces chiens pouvait encore répondre à la perfusion de prostaglandines E2. De plus, des reins devenus non filtrants chez des animaux déshydratés n'avaient pas de réponse vasculaire rénale au furosémide. Les animaux déshydratés et pré-traités soit par l'indométhacine, soit par le méclofénamate de sodium, n'avaient pas de réponse vasculaire rénale au furosémide quoiqu'ils avaient une réponse diurétique et une réponse vasculaire rénale à la prostaglandin E2. De ces résultats nous tirons l'hypothèse que la réponse vasculaire rénale au furosémide est secondaire à un mécanisme tubulaire dont la vasodilatation par la prostaglandine est un médiateur. Puisqu'il a été montré que le furosemide supprime le rétro-contrôle tubulo-glomérulaire et que les deux manoeuvres, DOCA et sel, d'une part, absence de filtration, d'autre part, annulent le rétro-contrôle tubulo-glomérulaire de même qu'elles inhibent la réponse vasculaire rénale au furosémide, nous faisons l'hypothèse supplémentaire que la vasodilatation rénale induite par le furosémide peut être secondaire à l'interruption d'un mécanisme actif de rétro-contrôle tubulo-glomérulaire

Do Perceptions of Ballot Secrecy Influence Turnout? Results from a Field Experiment

Although the secret ballot has long been secured as a legal matter in the United States, formal secrecy protections are not equivalent to convincing citizens that they may vote privately and without fear of reprisal. We present survey evidence that those who have not previously voted are particularly likely to voice doubts about the secrecy of the voting process. We then report results from a field experiment where we provided registered voters with information about ballot secrecy protections prior to the 2010 general election. We find that these letters increased turnout for registered citizens without records of previous turnout, but did not appear to influence the behavior of citizens who had previously voted. These results suggest that although the secret ballot is a long-standing institution in the United States, providing basic information about ballot secrecy can affect the decision to participate to an important degree.

Self-interest, beliefs, and policy opinions: understanding how economic beliefs affect immigration policy preferences

Research on how economic factors affect attitudes toward immigration often focuses on labor market effects, concluding that, because workers’ skill levels do not predict opposition to low- versus highly skilled immigration, economic self-interest does not shape policy attitudes. We conduct a new survey to measure beliefs about a range of economic, political, and cultural consequences of immigration. When economic self-interest is broadened to include concerns about the fiscal burdens created by immigration, beliefs about these economic effects strongly correlate with immigration attitudes and explain a significant share of the difference in support for highly versus low-skilled immigration. Although cultural factors are important, our results suggest that previous work underestimates the importance of economic self-interest as a source of immigration policy preferences and attitudes more generally

Ballot secrecy concerns and voter mobilization: new experimental evidence about message source, context, and the duration of mobilization effects

Recent research finds that doubts about the integrity of the secret ballot as an institution persist among the American public. We build on this finding by providing novel field experimental evidence about how information about ballot secrecy protections can increase turnout among registered voters who had not previously voted. First, we show that a private group’s mailing designed to address secrecy concerns modestly increased turnout in the highly contested 2012 Wisconsin gubernatorial recall election. Second, we exploit this and an earlier field experiment conducted in Connecticut during the 2010 congressional midterm election season to identify the persistent effects of such messages from both governmental and non-governmental sources. Together, these results provide new evidence about how message source and campaign context affect efforts to mobilize previous non-voters by addressing secrecy concerns, as well as show that attempting to address these beliefs increases long term participation

Subtle linguistic cues may not affect voter behavior: new evidence

One of the most important recent developments in social psychology is the discovery of minor interventions that have large and enduring effects on behavior. A leading example of this class of results is Bryan et al. (2011), which shows that administering a set of survey items worded so that subjects think of themselves as voters (noun treatment) rather than as voting (verb treatment) substantially increases political participation (voter turnout) among subjects. We revisit these experiments by replicating and extending their research design in a large-scale field experiment. In contrast to the 11 to 14 percentage point greater turnout among those exposed to the noun rather than verb treatment reported in Bryan et al. (2011), we find no statistically significant difference in turnout between the noun and verb treatments (the point estimate of the difference is approximately zero). Further, when we benchmark these treatments against a standard get-outthe- vote message, we find that both are less effective at increasing turnout than a much shorter basic mobilization message. In sum, in our experiments, we find no evidence that describing a subject as a voter rather than as voting has a positive relative or absolute effect on subject behavior. In our conclusion, we detail how our study differs from Bryan et al. (2011) and discuss how our results might be interpreted

Reporting guidelines for experimental research: A report from the experimental research section standards committee.

The standards committee of the Experimental Research section was charged with preparing a set of reporting guidelines for experimental research in political science. The committee defined its task as compiling a set of guidelines sufficient to enable the reader or reviewer to follow what the researcher had done and to assess the validity of the conclusions the researcher had drawn. Although the guidelines do request the reporting of some basic statistics, they do not attempt to weigh in on statistical controversies. Rather, they aim for something more modest but nevertheless crucial: to ensure that scholars clearly describe what it is they did at each step in their research and clearly report what their data show. In this paper, we discuss the rationale for reporting guidelines and the process used to formulate the specific guidelines we endorse. The guidelines themselves are included in Appendix 1

All in the family: partisan disagreement and electoral mobilization in intimate networks—a spillover experiment

We advance the debate about the impact of political disagreement in social networks on electoral participation by addressing issues of causal inference common in network studies, focusing on voters' most important context of interpersonal influence: the household. We leverage a randomly assigned spillover experiment conducted in the United Kingdom, combined with a detailed database of pretreatment party preferences and public turnout records, to identify social influence within heterogeneous and homogeneous partisan households. Our results show that intrahousehold mobilization effects are larger as a result of campaign contact in heterogeneous than in homogeneous partisan households, and larger still when the partisan intensity of the message is exogenously increased, suggesting discussion rather than behavioral contagion as a mechanism. Our results qualify findings from influential observational studies and suggest that within intimate social networks, negative correlations between political heterogeneity and electoral participation are unlikely to result from political disagreement

Can political participation prevent crime? Results from a field experiment about citizenship, participation, and criminality

Democratic theory and prior empirical work support the view that political participation, by promoting social integration and pro-social attitudes, reduces one’s propensity for anti-social behavior, such as committing a crime. Previous investigations examine observational data, which are vulnerable to bias if omitted factors affect both propensity to participate and risk of criminality or their reports.A field experiment encouraging 552,525 subjects aged 18-20 to register and vote confirms previous observational findings of the negative association between participation and subsequent criminality. However, comparing randomly formed treatment and control groups reveals that the intervention increased participation but did not reduce subsequent criminality. Our results suggest that while participation is correlated with criminality, it exerts no causal effect on subsequent criminal behavior