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Background: Mediterranean and low-fat diets are effective in the primary prevention of cardiovascular disease. We did a long-term randomised trial to compare the effects of these two diets in secondary prevention of cardiovascular disease. Methods: The CORDIOPREV study was a single-centre, randomised clinical trial done at the Reina Sofia University Hospital in Córdoba, Spain. Patients with established coronary heart disease (aged 20–75 years) were randomly assigned in a 1:1 ratio by the Andalusian School of Public Health to receive a Mediterranean diet or a low-fat diet intervention, with a follow-up of 7 years. Clinical investigators (physicians, investigators, and clinical endpoint committee members) were masked to treatment assignment; participants were not. A team of dietitians did the dietary interventions. The primary outcome (assessed by intention to treat) was a composite of major cardiovascular events, including myocardial infarction, revascularisation, ischaemic stroke, peripheral artery disease, and cardiovascular death. This study is registered with ClinicalTrials.gov, NCT00924937. Findings: From Oct 1, 2009, to Feb 28, 2012, a total of 1002 patients were enrolled, 500 (49·9%) in the low-fat diet group and 502 (50·1%) in the Mediterranean diet group. The mean age was 59·5 years (SD 8·7) and 827 (82·5%) of 1002 patients were men. The primary endpoint occurred in 198 participants: 87 in the Mediterranean diet group and 111 in the low-fat group (crude rate per 1000 person-years: 28·1 [95% CI 27·9–28·3] in the Mediterranean diet group vs 37·7 [37·5–37·9] in the low-fat group, log-rank p=0·039). Multivariable-adjusted hazard ratios (HRs) of the different models ranged from 0·719 (95% CI 0·541–0·957) to 0·753 (0·568–0·998) in favour of the Mediterranean diet. These effects were more evident in men, with primary endpoints occurring in 67 (16·2%) of 414 men in the Mediterranean diet group versus 94 (22·8%) of 413 men in the low-fat diet group (multiadjusted HR 0·669 [95% CI 0·489–0·915], log-rank p=0·013), than in 175 women for whom no difference was found between groups. Interpretation: In secondary prevention, the Mediterranean diet was superior to the low-fat diet in preventing major cardiovascular events. Our results are relevant to clinical practice, supporting the use of the Mediterranean diet in secondary prevention. Funding: Fundacion Patrimonio Comunal Olivarero; Fundacion Centro para la Excelencia en Investigacion sobre Aceite de Oliva y Salud; local, regional, and national Spanish Governments; European Union. © 2022 Elsevier Ltd

En condiciones de cambio climático, el uso óptimo del recurso hídrico y adecuado manejo agronómico, tienen como propósito incrementar el rendimiento y calidad de las cosechas, en tal sentido, el objetivo del ensayo fue evaluar el efecto de tres caudales hídricos suministrados por goteo (C1-1,6 LH-1; C2-1,4LH-1 y C3-1,2 LH-1); en el rendimiento y contenido de antocianinas en cultivares de maíz morado (V1:PMV-581; V2:MMMejorado y V3:MMComun) . Se utilizó el DBCA con factorial. Los resultados para diámetro de mazorcas reportaron que las interacciones C1xV2 y C1xV1, registraron promedios de 4,83 y 4,77 cm respectivamente; para peso de mazorcas por área neta con la interacción C1xV1 se obtuvo el mayor promedio de 4,78 kg, y asimismo un rendimiento equivalente a 11 950 kg.ha-1 .Mayor contenido de antocianinas se obtuvo con la interacción C1xV1 con 88,71 mg.L-1; y con la C2xV1 se obtuvo 74,95 mg.L-1. Se concluye que la interacción C1V1 denoto el mayor rendimiento por hectárea así como el mayor contenido de antocianinas.

From an evolutionary perspective, deiodinases may be considered pivotal players in the emergence and functional diversification of both thyroidal systems (TS) and their iodinated messengers. To better understand the evolutionary pathway and the concomitant functional diversification of vertebrate deiodinases, in the present review we summarized the highlights of the available information regarding this ubiquitous enzymatic component that represents the final, common physiological link of TS. The information reviewed here suggests that deiodination of tyrosine metabolites is an ancient feature of all chordates studied to date and consequently, that it precedes the integration of the TS that characterize vertebrates. Phylogenetic analysis presented here points to D1 as the oldest vertebrate deiodinase and to D2 as the most recent deiodinase gene, a hypothesis that agrees with the notion that D2 is the most specialized and finely regulated member of the family and plays a key role in vertebrate neurogenesis. Thus, deiodinases seem to be major participants in the evolution and functional expansion of the complex regulatory network of TS found in vertebrates.

SUMMARY The physiological role played by thyroid hormones (TH) in hydro-osmotic homeostasis in fish remains a controversial issue. Previous studies have shown that in Fundulus heteroclitus (killifish) hypo-osmotic stress increases liver iodothyronine deiodinase type 2 (D2) mRNA and D2 activity. In this study we identified two conserved osmotic response element (ORE) motifs in the promoter region of the killifish D2 gene (FhDio2) and examined their possible role in the transcriptional regulation of FhDio2during hypo-osmotic stress. As assessed by the electrophoretic mobility shift assay, results from in vivo and in vitro experiments demonstrate that exposure to an abrupt hyposmotic challenge triggers in the liver of killifish a strong nuclear recruitment of a putative osmotic response element binding protein (OREBP). This protein–DNA binding is time-dependent, attains a maximum within 2–8 h after the osmotic stress,and is followed by a significant increase in D2 activity. Furthermore,protein–DNA binding and the subsequent elevation in enzyme activity were blocked by the tyrosine kinase inhibitor genistein. Thus, during hypo-osmotic stress, a putative OREBP kinase-activated pathway stimulates FhDio2transcription and enzymatic activity. These data and the fact that D2 is the major enzyme providing local intracellular T3 suggest that TH plays a direct role in osmoregulation in fish, possibly by participating in hepatic ammonia metabolism. This study provides important insight into the physiological role of TH in hydro-osmotic homeostasis in fish.

An accurate assessment of the animal’s requirements is of utmost importance for a balanced nutrition of farm animals. In this review we describe the results from a series of experiments, performed during the last years by our research group, aiming at assessing the utilization of dietary protein by the Iberian pig throughout the different stages of its productive cycle. Nutritional doseresponse studies involving several isoenergetic treatments differing in proteinconcentration -all with similar aminoacid profile following the ideal proteinconcept- along with comparative growth and metabolic studies with conventional breeds have been performed. Our observations reveal that the capacity of this breed for protein accretion is rather limited compared to that of conventional or lean breeds at similar stages of growth. They also suggest the need for reducing the concentration of protein in the diet of the Iberian pig to comply with the metabolic profile of this native pig breed. We summarise all the information gathered during the last fifteen year sand provide recommendations on the level and composition of dietary protein in the diet for pure breed animals during the different phases of growth. An adequate nutritional management, particularly dietary protein provision, improves the efficiency of utilization of dietary protein and results in relevant economic, environmental and animal welfare benefits.

Introduction: RECIPE study was designed to assess the impact of dietary supplementation with fermented milk enriched with plant sterols (FMPS) on the nutritional behavior, lifestyle and the joint therapeutic responsibility of hypercholesterolemic patients. Methods: Observational, prospective, multicenter, international study, was conducted to assess dietary habits and other lifestyle components in hypercholesterolemic patients in whom the general practitioner indicated FMPS supplementation. Nutritional, lifestyle and clinical data were collected at the initial visit and after a 4 months follow-up. The biochemical and anthropometric data were retrieved from medical records obtained at baseline and 4 months. Results: We report the results of Spain. Two hundred and one physicians who provided valid data of 1044 patients participated. The addition of FMPS was associated with improved overall nutritional index, being adequate initially in 28.2% of patients, and increasing up to 75.2% at the end of the study (P< 001). This nutritional change was associated with an improvement in the lipid profile and anthropometric data. Patients more adherent to therapy generally achieved a better result in all parameters compared to non-compliant ones. Conclusions: The addition of FMPS to a diet designed to reduce the LDL enhances the patient's attitude regarding changes in lifestyle, leading to better overall control of dyslipidemia and anthropometric improvement. © 2012 Elsevier España, S.L. and SEA.

Objetivos: Estimar la prevalencia de sífilis y VIH e identificar los comportamientos de riesgo asociados en personas privadas de libertad (PPL). Materiales y métodos: Estudio transversal realizado durante el año 1999 en 22 establecimientos penitenciarios peruanos. Se realizó RPR para la detección de sífilis (datos ligados) y ELISA para tamizaje de VIH (datos no ligados), confirmándose con IFI o Western Blot. Se realizó una encuesta estructurada y se analizaron los datos mediante los programas SPSS 9,0 y AMOS 4. Resultados: Participaron 6963 PPL. La prevalencia de VIH fue 1,1% y de sífilis 4,1%. Los comportamientos de riesgo asociados a VIH más significativos fueron: consumo de drogas (OR:2,7), infecciones de transmisión sexual (OR: 2,3), relaciones sexuales entre hombres (OR: 2,2), uso de cocaína (OR: 2,1), úlcera genital (OR: 2,1), haber sido encarcelado previamente (OR: 2) y tener tatuajes (OR: 1,99). Mientras los asociados a sífilis fueron: tener relaciones sexuales entre hombres OR: (2,8), infecciones de transmisión sexual (OR: 2,4), úlcera genital (OR:1,8), haber tenido relaciones sexuales con trabajadora sexual (OR: 1,5) y tener más de dos parejas sexuales (OR: 1,5). Utilizando un modelo de ecuaciones estructurales se asoció VIH con el reporte de tener tatuaje, más de dos parejas sexuales, más de un encarcelamiento previo y úlcera genital. Conclusiones: Se encontraron importantes valores de prevalencia de VIH y sífilis en este grupo de personas, siendo necesario continuar realizando estudios similares que nos permitan conocer las tendencias (vigilancia de segunda generación) y conocer el impacto de posibles intervenciones. Objective: To determine HIV and syphilis prevalence and to identify behavioral risk factors in jail prisoners. Materials and methods: Cross-sectional study conducted during 1999 in 22 Peruvian jails. RPR was used to detect syphilis (linked results) and ELISA to screen HIV (non-linked results). Positive results were confirmed with IFI and Western Blot. A structured survey was carried out, resulting data was analized with SPSS 9,0 and AMOS 4. Results: 6 963 PPL participated. HIV and syphilis seroprevalence were 1,1 % and 4,1% respectively.The most significant HIV risks factors were: drug abuse (OR: 2,7), sexually transmitted diseases (OR: 2,3), sexual intercourse between males (OR: 2,2), cocaine use (OR: 2,1), genital ulcer (OR: 2,1), previus incarcelation (OR:2), and having a tattoo (OR: 1,99). The most significant syphilis risks factors were, sexual intercourse between males (OR: 2,8), sexually transmitted diseases (OR: 2,4), genital ulcer (OR: 1,8), sexual intercourse with sex workers (OR: 1,5) and having more than two sexual partners (OR: 1,5). An association between HIV infection and having a tattoo, having more than two sexual partners, more than one previous imprisonment and genital ulcer, was found using a structural equation model. Conclusions: Important rates of HIV and Syphilis prevalence were found among this group, thus making necessary the performace of similar research that may allow the knowledge of new trends (second generation surveillance) and to assess the impact of possible interventions.

Mammary deiodinase type I (M-D1) is present only during lactation and exhibits a clear direct correlation with lactation intensity (size of litters). The present work shows that M-D1 is suckling dependent and that intervals between suckling periods no longer than 12 h are essential to maintain this activity. Moreover, we find that with only 15 min of resuckling in 12-h nonsuckled mothers, the 50% decrease in both M-D1 messenger RNA and enzymatic activity could be restored to control values. This restorative effect by suckling may involve pre- and posttranscriptional mechanisms in which norepinephrine and PRL play important roles. Norepinephrine elicits a potent stimulatory effect on M-D1 messenger RNA and enzyme activities, whereas PRL only increases M-D 1 activity and may modulate the enzyme response to norepinephrine. Oxytocin and GH had no effect. These data suggest that the adrenergic nervous system and PRL could directly participate in mammary energetic expenditure, regulating the local T3 supply.

Lactating rat mammary gland expresses a deiodinating activity that, on the basis of kinetic characteristics, corresponds to the socalled 59-deiodinase type I (D1). In the present study we amplified and sequenced several D1 complementary DNA (cDNA) fragments from rat lactating mammary gland. The mammary cDNA was found to be identical to the previously reported rat liver cDNA in the coding region, but 465 nucleotides shorter on its 39-untranslated region, suggesting that the D1 is the same in both tissues. D1 messenger RNA (mRNA) was also detected by reverse transcriptase-PCR in mammary glands from puberal and late pregnant rats, but not in virgin animals. Densitometric analysis showed a close and direct correlation between mRNA content and enzyme specific activity in mammary gland. Our results also show that rat liver contains both D1 mRNA forms and that the large form may respond to the thyroid status. These data suggest a differential and organ-specific expression of these mRNA forms, which could play a role in the functional regulation of D1 activity. (Endocrinology 138: 4248 ‐ 4254, 1997)

Recent molecular cloning studies in mammals and amphibians have demonstrated that the types I, II, and III deiodinases constitute a family of selenoproteins of critical importance in metabolizing T4 to active (i.e. T3) and inactive (i.e. rT3) metabolites. In several tissues of teleost fish, various deiodinase processes have been described, but the structural and functional characteristics of these enzymes and their relationship to the deiodinases present in higher vertebrates remains uncertain. Using a complementary DNA library derived from the liver of the teleost Fundulus heteroclitus, we have identified a complementary DNA that codes for a deiodinase with functional characteristics virtually identical to those of the mammalian and amphibian type II deiodinase. Sequence analysis demonstrates a high degree of homology at both the nucleotide and predicted amino acid levels between the Fundulus clone and these previously characterized type II enzymes, including the presence of an in-frame TGA codon that codes for selenocysteine. These findings demonstrate that the deiodinase family of selenoproteins has been highly conserved during vertebrate evolution and underscores their importance in the regulation of thyroid hormone action.

Deiodinases are major determinants of thyroid hormone tissue availability and disposal. The knowledge of the expression of these enzymes in lower species is important to understand evolutionary and ontogenetic aspects of thyroid hormone action and metabolism. Here we have studied outer ring deiodination in the trout liver using both reverse T3 (rT3) and T4 as substrates. The use of rT3 disclosed two enzymatic components with the characteristics of mammalian types I and II 5′-deiodinases. The high rT3-Km type I 5′-deiodinase activity (180 nm) has a low cofactor requirement (5 mm dithiothreitol) and is relatively sensitive to propylthiouracil inhibition, whereas the low rT3-Km activity was akin to the outer ring deiodination of T4 in these regards. The use of T4 exhibited only a single type of activity with a low Km (0.63 nm), a relatively high cofactor requirement (25 mm dithiothreitol), and propylthiouracil-resistance. Teleosts constitute a unique example of type II activity expression in the liver of an ...

Recent studies in our laboratory have shown that in some teleosts, 3,5-di-iodothyronine (T2 or 3,5-T2) is as bioactive as 3,5,3′-tri-iodothyronine (T3) and that its effects are in part mediated by a TRβ1 (THRB) isoform that contains a 9-amino acid insert in its ligand-binding domain (long TRβ1 (L-TRβ1)), whereas T3 binds preferentially to a short TRβ1 (S-TRβ1) isoform that lacks this insert. To further understand the functional relevance of T2 bioactivity and its mechanism of action, we used in vivo and ex vivo (organotypic liver cultures) approaches and analyzed whether T3 and T2 differentially regulate the S-TRβ1 and L-TRβ1s during a physiological demand such as growth. In vivo, T3 and T2 treatment induced body weight gain in tilapia. The expression of L-TRβ1 and S-TRβ1 was specifically regulated by T2 and T3 respectively both in vivo and ex vivo. The TR antagonist 1–850 effectively blocked thyroid hormone-dependent gene expression; however, T3 or T2 reversed 1–850 effects only on S-TRβ1 or L-TRβ1 expression, respectively. Together, our results support the notion that both T3 and T2 participate in the growth process; however, their effects are mediated by different, specific TRβ1 isoforms.

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26th European Photovoltaic Solar Energy Conference and Exhibition; 3835-3839, A refined life-cycle assessment of polymer solar cells is presented with a focus on critical components, i.e. the transparent conductive ITO layer and the encapsulation components. This present analysis gives a comprehensive sketch of the full environmental potential of polymer-OPV in comparison with other PV technologies. It is shown that on a m2 basis the environmental characteristics of polymer-OPV are highly beneficial, while on a watt-peak and on a kWh basis, these benefits are – at the current level of the development - still (over-)compensated by low module efficiency and limited lifetime expectancy. The findings of this study underscore that, from an environmental and sustainability point of view, the replacement of the ITO layer and the optimization of encapsulation concepts should be in the spotlight of any near-term R&D efforts of the OPV community. Solutions to both of these technological issues are actively pursued. Some of these are discussed as examples in this paper.

Iodide is a trace element and a key component of thyroid hormones (TH). The availability of this halogen is the rate-limiting step for TH synthesis; therefore, thyroidal iodide uptake and recycling during TH synthesis are of major importance in maintaining an adequate supply. In the rat, the thyroid gland co-expresses a distinctive pair of intrathyroidal deiodinating enzymes: the thyroid iodotyrosine dehalogenase (tDh) and the iodothyronine deiodinase type 1 (ID1). In the present work, we studied the activity of these two dehalogenases in conditions of hypo- and hyperthyroidism as well as during acute and chronic iodide administration in both intact and hypophysectomized (HPX) rats. In order to confirm our observations, we also measured the mRNA levels for both dehalogenases and for the sodium/iodide symporter, the protein responsible for thyroidal iodide uptake. Our results show that triiodothyronine differentially regulates tDh and ID1 enzymatic activities, and that both acute and chronic iodide administration significantly decreases rat tDh and ID1 activities and mRNA levels. Conversely, both enzymatic activities increase when intrathyroidal iodide is pharmacologically depleted in TSH-replaced HPX rats. These results show a regulatory effect by iodide on the intrathyroidal dehalogenating enzymes and suggest that they contribute to the iodide-induced autoregulatory processes involved in the Wolff-Chaikoff effect.

El objetivo fue analizar el pedigrí de cuatro ganaderías mexicanas (Los Encinos=ENC, Montecristo=MCR, Fernando de la Mora=FMO y San José=SJO) a través de estimaciones de parámetros poblacionales tales como el tamaño de población base, tamaño efectivo, número de ancestros, aportaciones porcentuales e intervalos generacionales. Además se analizó el efecto de la consanguinidad sobre el comportamiento de los animales (tienta y lidia al caballo y al torero) con un modelo animal que consideró como efectos fijos a grupo contemporáneo (año-época de nacimiento-sexo, el efecto de sexo sólo en tienta) y las covariables lineales de edad y consanguinidad del individuo; los efectos aleatorios fueron el valor genético del individuo y el error. Los pedigríes incluyeron de 3246 a 8279 animales nacidos entre 1904 y 2006; la información de comportamiento data de 1978 a 2006, variando de 202 a 2776 observaciones. Las consanguinidades promedio variaron entre 2,4% y 12,9%, con máximos individuales de 47,7% en MCR y de alrededor de 40% en las otras ganaderías. El número de ancestros como proporción de la población de referencia en MCR fue 12,3%, mientras que en FMO, ENC y SJO representaron 17,7%, 27,8% y 34,0%, respectivamente. Tres animales explicaron 50% del pedigrí en MCR y 13 o menos en las otras ganaderías. Los tres ancestros de MCR explicaron 22,6% y 20,2% del pedigrí de SJO y ENC, respectivamente. Las ganaderías MCR, SJO y ENC tienen un origen común. Las tendencias anuales de consanguinidad fueron negativas en ENC y SJO (-0,13±0,02 y -0,25±0,02, respectivamente; p

Five genetic evaluation models of registered Brahman cattle in Mexico were compared for birth weight (PN), weaning (PD), yearling (PA) and final weight at 550 days (PF), and their effect on genetic parameter estimation and EPD ordering were also assessed. Models differed on number of random factors; D, model with direct genetic effect (σ2d), DM, model like D plus maternal genetic effect (σ2m) and genetic covariance between genetic effects equal to zero (σdm = 0), DP, D like model plus maternal permanent effect (σ2p), DMC, DM like model plus covariance between genetic effects (σdm ≠ 0), and DMCP as the complete model, equal to DMC plus (σ2p). Models included the fixed effect of contemporary grouping (herd, sex, year and season of birth), and age of dam as linear and quadratic covariable. A likelihood ratio test (PRV) was performed for model comparison, and EPD reordering was quantified by Spearman rank correlation analysis. The PRV showed DMC as the best model for all variables, except in PD. For PD the best model was DP. A negative genetic correlation rdm (rdm = σdm2) was observed for PN, PA and PF (-0,86, -0,84 and -0,52, respectively) reducing the magnitude of total heritability estimates. For PD, DMC and DMCP did not converge. Correlation between selected models and the other compared models, suggested that there might be important and substantial changes on 10% of superior animals. Structure of data may modify the genetic parameter estimation if adjusting complex models; hence the model selection could be crucial before performing any genetic evaluation. Considerations were made concerning selective recording. &nbsp, Se realizó una comparación de modelos para la evaluación genética de variables de crecimiento, en los pesos al nacimiento (PN), destete (PD), año (PA) y 550 días (PF) de ganado Brahman de registro de México; con el propósito de cuantificar su efecto en la estimación de parámetros genéticos y la jerarquización de las diferencias esperadas de progenie estimadas (DEPs). Los modelos comparados diferían en componentes aleatorios y fueron, D con el efecto directo (σ2d); DM, igual a D pero incluyendo el efecto materno (σ2m) y con la covarianza entre los efectos de σ2dy σ2m(σdm) = 0; DP, como D más el efecto materno de ambiente permanente (σ2p); DMC, como DM pero con σdm≠ 0; y el modelo completo, DMCP, igual a DMC más σ2p. Además, incluyeron el efecto fijo de grupo contemporáneo (hato-sexo-año-época) y la covariable de edad de la madre (lineal y cuadrática). La comparación entre modelos se realizó mediante la prueba de proporción de verosimilitudes (PRV). Las DEPs de los modelos, se compararon por correlación (rango de Spearman). Según la PRV, en todas las variables, excepto PD, el mejor modelo de ajuste fue DMC. Para PD, el mejor modelo fue DP. En PN, PA y PF, se observó una rdm(rdm= σdm) negativa (–0,86, –0,84 y –0,52, respectivamente); lo que disminuyó la magnitud de los estimadores de índice de herencia total. Para PD, los modelos DMC y DMCP no alcanzaron la convergencia. La estimación de las correlaciones de rango entre los valores genéticos directos y maternos de los modelos seleccionados con respecto a los otros modelos comparados, indicó que puede existir cambio sustantivo en la jerarquización del 10% de la población con valores superiores. Se concluye que la estructura de los datos analizados puede afectar la estimación de parámetros genéticos en modelos complejos, por lo que es importante escoger el modelo apropiado antes de llevar al cabo una evaluación genética. Existen algunas consideraciones con respecto al registro selectivo que deben tomarse con reserva sobre todo en evaluaciones nacionales. &nbsp

Se evaluó el efecto de factores ambientales en la producción de leche ajustada a 305 días (PLT), la producción (PP) y los días al pico (DPP) de lactancia, y la persistencia (PER) en vacas Holstein de agroempresas familiares con diferente nivel tecnológico (NT) en el estado de Jalisco, México. La información analizada (n= 4323 mediciones de producción diaria de leche de 537 lactancias) provino de 16 hatos. Las agroempresas se tipificaron como de bajo, medio o alto NT. El modelo mixto incluyó los efectos fijos de NT, número, año y estación de parto. La PLT en el NT bajo fue similar (P>0,05) entre épocas; sin embargo, en el NT medio la PLT en lluvias fue 11% mayor que en secas; mientras que en el NT alto la situación se invirtió, observándose una interacción similar para PP. Las vacas en bajo o alto NT presentaron más tarde (P0,05) entre épocas; no entanto, no NT médio a PLT nos períodos de chuva foi 11% maior que nos de seca; enquanto que no NT alto a situação se inverteu, observando-se uma interação similar para PP. As vacas em baixo ou alto NT apresentaram mais tarde (P

Until recently, 3,5-diiodothyronine (3,5-T2) has been considered an inactive by-product of triiodothyronine (T3) deiodination. However, studies from several laboratories have shown that 3,5-T2has specific, nongenomic effects on mitochondrial oxidative capacity and respiration rate that are distinct from those due to T3. Nevertheless, little is known about the putative genomic effects of 3,5-T2. We have previously shown that hyperthyroidism induced by supraphysiological doses of 3,5-T2inhibits hepatic iodothyronine deiodinase type 2 (D2) activity and lowers mRNA levels in the killifish in the same manner as T3and T4, suggesting a pretranslational effect of 3,5-T2(Garcia-G C, Jeziorski MC, Valverde-R C, Orozco A. Gen Comp Endocrinol 135: 201–209, 2004). The question remains as to whether 3,5-T2would have effects under conditions similar to those that are physiological for T3. To this end, intact killifish were rendered hypothyroid by administering methimazole. Groups of hypothyroid animals simultaneously received 30 nM of either T3, reverse T3, or 3,5-T2. Under these conditions, we expected that, if it were bioactive, 3,5-T2would mimic T3and thus reverse the compensatory upregulation of D2 and tyroid receptor β1 and downregulation of growth hormone that characterize hypothyroidism. Our results demonstrate that 3,5-T2is indeed bioactive, reversing both hepatic D2 and growth hormone responses during a hypothyroidal state. Furthermore, we observed that 3,5-T2and T3recruit two distinct populations of transcription factors to typical palindromic and DR4 thyroid hormone response elements. Taken together, these results add further evidence to support the notion that 3,5-T2is a bioactive iodothyronine.