High fat diet reduces the expression of miRNA-29b in heart and increases susceptibility of myocardium to ischemia/reperfusion injury.

Several studies have shown the role of microRNAs (miRNAs) in myocardial dysfunction in response to ischemia/reperfusion (I/R). In this study, we investigated the impact of high fat (HF) diet in the myocardial susceptibility to I/R injury, as well as in the expression of miRNA-29b. Isolated heart experiments using the ex vivo Langendorff perfusion model were used to induce cardiac I/R injury. HF diet-induced cardiac hypertrophy and impaired cardiac functional recovery after I/R. miRNA-29b, which targets Col1, was reduced in the heart of HF diet-fed mice, whereas the cardiac expression of Col1 was increased. In addition, hypoxia-reoxygenation (H/R) reduced the expression of miRNA-29b in cardiomyoblasts cultures. However, the overexpression of miRNA-29b in cardiomyoblasts reduced p53 mRNA levels and H/R injury, suggesting that downregulation of miRNA-29b may be involved in I/R injury. Together, our findings suggest that the reduced expression of miRNA-29b may be involved in the deteriorated cardiac functional recovery following I/R in obese mice.

Cardioprotection induced by a brief exposure to acetaldehyde: role of aldehyde dehydrogenase 2.

Aims: We previously demonstrated that acute ethanol administration protects the heart from ischaemia/reperfusion (I/R) injury thorough activation of aldehyde dehydrogenase 2 (ALDH2). Here, we characterized the role of acetaldehyde, an intermediate product from ethanol metabolism, and its metabolizing enzyme, ALDH2, in an ex vivo model of cardiac I/R injury. Methods and results: We used a combination of homozygous knock-in mice (ALDH2*2), carrying the human inactivating point mutation ALDH2 (E487K), and a direct activator of ALDH2, Alda-1, to investigate the cardiac effect of acetaldehyde. The ALDH2*2 mice have impaired acetaldehyde clearance, recapitulating the human phenotype. Yet, we found a similar infarct size in wild type (WT) and ALDH2*2 mice. Similar to ethanol-induced preconditioning, pre-treatment with 50 µM acetaldehyde increased ALDH2 activity and reduced cardiac injury in hearts of WT mice without affecting cardiac acetaldehyde levels. However, acetaldehyde pre-treatment of hearts of ALDH2*2 mice resulted in a three-fold increase in cardiac acetaldehyde levels and exacerbated I/R injury. Therefore, exogenous acetaldehyde appears to have a bimodal effect in I/R, depending on the ALDH2 genotype. Further supporting an ALDH2 role in cardiac preconditioning, pharmacological ALDH2 inhibition abolished ethanol-induced cardioprotection in hearts of WT mice, whereas a selective activator, Alda-1, protected ALDH2*2 against ethanol-induced cardiotoxicity. Finally, either genetic or pharmacological inhibition of ALDH2 mitigated ischaemic preconditioning. Conclusion: Taken together, our findings suggest that low levels of acetaldehyde are cardioprotective whereas high levels are damaging in an ex vivo model of I/R injury and that ALDH2 is a major, but not the only, regulator of cardiac acetaldehyde levels and protection from I/R.

Distribution of mesenteric cranial artery in the small intestine ofProcyon cancrivorus ( Cuvier, 1798 ) ( Mammalia, Procyonidae ) / Comportamento da artéria mesentérica cranial no intestino delgado de mão-pelada Procyon cancrivorus (Cuvier, 1798) (Mammalia, Procyonidae)

The mesenteric artery is a high caliber vessel dependent on the abdominalartery, right below the emergence of the vessels destined for the liver and stomach. Thepresent study aimed to describe the behavior of the arterial vessel in the small intestine ofthe crab-eating raccoon (Procyon cancrivorus). The animals were collected on highways(roadkill). Cannulation of the abdominal aorta, perfusion with warmed water (40ºC) andstained latex injection (Neoprene 450, Dupont do Brasil and Sulvinil stain, Glassuret S.A)were performed, followed by formaldehyde fixation (10%). The dissection andphotographic documents (Sony Cyber-shot, 8.1 megapixels) made it possible to systemizethe arteries and define the vascular patterns of the viscera. It was verified that the mesentericcranial artery supports the entire jejune and the mesenteric portion of the ileum. Next tothe mesenteric border, it becomes an anastomosis forming vascular arches from wherestraight arteries leave, supplying the mesenteric portion and sometimes also the jejunal antimesentericportion. The artery that irrigates the ileum comes up as a branch of the cranialmesenteric artery. Anatomic knowledge of the vascular pattern of the crab-eating raccoon(Procyon cancrivorus) is of fundamental importance for researches regarding the arterialdistribution of the intestine considering anatomic variances.

A artéria mesentérica é um vaso de grande calibre dependente da artéria aorta abdominal, imediatamente abaixo da emergência dos vasos destinados ao fígado e estômago. O objetivo do presente estudo foi descrever o comportamento dos vasos arteriais do intestino delgado em mão-pelada (Procyon cancrivorus). Os animais são procedentes de coleta em rodovias (mortos por acidente). Realizou-se a canulação da aorta abdominal, perfusão com água aquecida (40ºC) e injeção de látex corado (Neoprene 450, Dupont do Brasil e Sulvinil Corante, Glassuret S.A), seguido de fixação em formaldeído (10%). As dissecações e documentação fotográfica (Câmera Sony Cyber-shot, 8.1 megapixels) permitiram sistematizar as artérias e definir os padrões vasculares da víscera. Verificamos que a artéria mesentérica cranial supre todo o jejuno e a face mesentérica do íleo. Próximo à borda mesentérica, anastomosa-se formando as arcadas vasculares e desta partem as artérias retas, que suprem à face mesentérica e, às vezes, a face antimesentérica do jejuno. A artéria que irriga o íleo surge como último ramo da artéria mesentérica cranial. O conhecimento anatômico do padrão vascular de mão-pelada (Procyon cancrivorus) é de fundamental importância em pesquisas que se referem à distribuição arterial do intestino, levando-se em consideração as variações anatômicas.

Estudo morfológico dos músculos do antebraço de mão-pelada, Procyon cancrivorus Cuvier, 1798 / Morphological study of the muscles of the forearm of crab eating raccoon Procyon cancrivorus Cuvier, 1798

O Procyon cancrivorus (mão-pelada) é um carnívoro amplamente encontrado no território brasileiro, porém com escassas informações literárias ao seu respeito. Portanto, justifica-se a escolha deste animal para estudo, tendo como base aspectos morfológicos, que é fundamental para o conhecimento biológico das espécies. Foram utilizados cinco animais mortos por acidente, procedentes de coleta em rodovias. Os músculos pronador redondo, flexor radial do carpo, flexor superficial dos dedos, flexor ulnar do carpo, braquiorradial, palmar longo, flexor profundo dos dedos, pronador quadrado, extensor radial do carpo, extensor comum dos dedos, extensor lateral dos dedos, extensor ulnar do carpo e abdutor longo, foram dissecados e observados macroscopicamente as inserções proximais e distais. Os músculos flexores são inervados pelo nervo mediano, e irrigados por ramos das artérias mediana e ulnar, enquanto os extensores são irrigados pela artéria radial e seus ramos, sendo inervado pelo nervo radial. Para efeito comparativo, o modelo deste carnívoro silvestre foi comparado com a morfologia de carnívoros domésticos (cão e gato), amplamente descritos na literatura. Observou-se então a grande similaridade entre eles.

The Procyon cancrivorus is a carnivorous widely found in Brazil, but with few literary information to them. So why is the choice of species for study, based on morphology, which is fundamental to the understanding of biological species. We used five animals killed by accident, from collection on highways. The muscles round pronator, the radial carpal flexor, superficial flexor of fingers, ulnar flexor of the carpus, brachioradial, long palmar, deep flexor of fingers, square pronator, radial extensor of the carpus, common finger extensor, lateral extensor of toes, ulnar extensor of the carpus and long abductor were dissected and observed macroscopically the proximal and distal insertions. The flexor muscles are innervated by the median nerve and irrigated by branches artery of the median and ulnar the same name, while the extensor muscles are irrigated by the radial artery and its branches, is innervated by the radial nerve. For comparison purposes, the model of wild carnivore was compared with the morphology of domestic carnivores (dogs and cats), widely described in literature. There was then a great similarity between them.