Circulatory and respiratory consequences of massive hemorrhage are reversed by protoveratrines

In a rat model of severe hypotension and respiratory depression induced by step-wise bleeding, protoveratrines cause a prompt and sustained improvement of cardiovascular and respiratory functions, both in anesthetized and in conscious animals, seemingly through a magnification of the reflex response originated by the chemoreceptors of aortic and carotid bodies. The restoration of cardiovascular function is attributable to an increase both in total peripheral resistance and cardiac output. The finding could provide the basis for a new approach to the first-aid management of massive blood losses.     

Control of the cardiovascular system of Aplysia by identified neurons.

The neural network that controls the cardiovascular system of Aplysia adapts cardiovascular function to a variety of different physiological and behavioral situations. It (1) coordinates the cardiovascular system with the renal and respiratory systems; (2) modifies both systemic and regional blood flow during food-elicited arousal and feeding; and (3) changes the tension of longitudinal vascular muscle to adapt the arterial tree to changes in body shape. Indirect evidence suggests that the cardiovascular control circuit may also play a role in maintaining homeostasis during egg laying. Several putative neurotransmitters, including acetylcholine, serotonin, R15 alpha 1 and R15 alpha 2 peptides, have been localized to identified neurons in this circuit.     

Control of the cardiovascular system ofAplysia by identified neurons

The neural network that controls the cardiovascular system ofAplysia adapts cardiovascular function to a variety of different physiological and behavioral situations. It (1) coordinates the cardiovascular system with the renal and respiratory systems; (2) modifies both systemic and regional blood flow during food-elicited arousal and feeding; and (3) changes the tension of longitudinal vascular muscle to adapt the arterial tree to changes in body shape. Indirect evidence suggests that the cardiovascular control circuit may also play a role in maintaining homeostasis during egg laying. Several putative neurotransmitters, including acetylcholine, serotonin, R151 and R152 peptides, have been localized to identified neurons in this circuit.     

Acute physiological responses during blood substitution with colloidal gelatin in conscious rats

Summary The effects of exchange-transfusion with a proprietary gelatin-based plasma volume expander, Haemaccel, have been investigated in conscious, chronically-catheterized rats. No adverse changes in basic cardiovascular or respiratory functions occurred during the procedure although an increase in intravascular fluid sodium but not potassium concentration was observed.     

Acute physiological responses during blood substitution with colloidal gelatin in conscious rats

The effects of exchange-transfusion with a proprietary gelatin-based plasma volume expander, Haemaccel, have been investigated in conscious, chronically-catheterized rats. No adverse changes in basic cardiovascular or respiratory functions occurred during the procedure although an increase in intravascular fluid sodium but not potassium concentration was observed.     

Geochemistry,soils and cardiovascular diseases

Summary The hypothesis is presented that deficiencies or excesses in the content or availability of trace elements in rocks and soils, or in water flowing through them, may be a possible cause of certain chronic diseases, including cardiovascular ones. The geographic distribution of cardiovascular diseases is often associated with geochemical differences. This trend is particulalry evident in the United States and in Europe, with higher rates for cardiovascular mortality in areas underlain by soils that are poor in most essential trace elements. Confirmation of this trends is found in connection with the degree of mineralization of local water supplies. Areas that are served by soft waters usually show higher rates of cardiovascular mortality and other forms of cardiovascular pathology, compared with the areas that are served by hard waters. Such a negative association between water hardness and cardiovascular pathology is evident in many countries, both industrialized and developing ones.     

Geochemistry, soils and cardiovascular diseases

The hypothesis is presented that deficiencies or excesses in the content or availability of trace elements in rocks and soils, or in water flowing through them, may be a possible cause of certain chronic diseases, including cardiovascular ones. The geographic distribution of cardiovascular diseases is often associated with geochemical differences. This trend is particularly evident in the United States and in Europe, with higher rates for cardiovascular mortality in areas underlain by soils that are poor in most essential trace elements. Confirmation of this trend is found in connection with the degree of mineralization of local water supplies. Areas that are served by soft waters usually show higher rates of cardiovascular mortality and other forms of cardiovascular pathology, compared with the areas that are served by hard waters. Such a negative association between water hardness and cardiovascular pathology is evident in many countries, both industrialized and developing ones.     

Melatonin,mitochondria and hypertension

Melatonin, due to its multiple means and mechanisms of action, plays a fundamental role in the regulation of the organismal physiology by fine tunning several functions. The cardiovascular system is an important site of action as melatonin regulates blood pressure both by central and peripheral interventions, in addition to its relation with the renin–angiotensin system. Besides, the systemic management of several processes, melatonin acts on mitochondria regulation to maintain a healthy cardiovascular system. Hypertension affects target organs in different ways and cellular energy metabolism is frequently involved due to mitochondrial alterations that include a rise in reactive oxygen species production and an ATP synthesis decrease. The discussion that follows shows the role played by melatonin in the regulation of mitochondrial physiology in several levels of the cardiovascular system, including brain, heart, kidney, blood vessels and, particularly, regulating the renin–angiotensin system. This discussion shows the putative importance of using melatonin as a therapeutic tool involving its antioxidant potential and its action on mitochondrial physiology in the cardiovascular system.     

Respiratory inhibition and reversible fusion of frog blastomeres.

Rotenone and high doses of chloramphenicol, both of which specifically inhibit electron transport between NADH and flavoprotein in the respiratory chain, caused fully separated Rana pipiens blastomeres to refuse, as shown by syncytium counts on embryos reconstructed from serial sections. With chloramphenicol, the effect was completely reversible: re-cleavage and normal development followed drug removal. The blastomere fusion effect was not produced by the succinic dehydrogenase-specific respiratory inhibitor, thenoyltrifluoroacetone, nor by a non-mitochondrial protein synthesis inhibitor, cycloheximide, both of which instead produced simple arrest of cleavage.     

Cardiac design in lower vertebrates: what can phylogeny reveal about ontogeny?

In very few instances can the cardiovascular systems of adult 'lower' vertebrates serve as direct models for development in 'higher' vertebrates, primarily because numerous evolutionary specializations for preferential distribution of cardiac output between systemic tissues and gas exchange organs occur in the highly derived circulation of most extant lower vertebrates. Yet, the extensive literature on the cardiovascular anatomy and physiology of aquatic and air breathing fishes, amphibians and reptiles offers important conceptual insights into both patterns and mechanisms of development in birds and mammals. The primary contribution of such studies to the student of developing bird and mammal circulations is the clear demonstration that surprisingly complex hemodynamic function can develop from supposedly 'simple' cardiovascular systems typified by incompletely divided heart chambers. Thus, the hemodynamics of embryonic bird and mammal circulations should be determined by measurement, rather than inferred from structure.     

Role of p21-activated kinases in cardiovascular development and function

p21-activated kinases (Paks) are a group of six serine/threonine kinases (Pak1-6) that are involved in a variety of biological processes. Recently, Paks, more specifically Pak1, -2, and -4, have been shown to play important roles in cardiovascular development and function in a range of model organisms including zebrafish and mice. These functions include proper morphogenesis and conductance of the heart, cardiac contractility, and development and integrity of the vasculature. The mechanisms underlying these effects are not fully known, but they likely differ among the various Pak isoforms and include both kinase-dependent and -independent functions. In this review, we discuss aspects of Pak function relevant to cardiovascular biology as well as potential therapeutic implications of small-molecule Pak inhibitors in cardiovascular disease.     

前列腺素E2受体生化性质及功能的研究进展

前列腺素E2受体(EP)是一类G蛋白偶联受体,主要与前列腺素E2(PGE2)结合,在多种疾病的发生中发挥作用.研究发现EP在机体几乎所有系统,如心血管系统、呼吸系统、生殖系统、神经系统等的病理反应中发挥重要作用,甚至与肿瘤的发生也有关联.研究并掌握EP相关性质对于临床疾病的治疗有着重要的意义,在国际上已成为研究和报道的热点.本文简要综述了关于EP前沿的研究成果,以期为广大研究者提供借鉴,为进一步阐释EP作用机制以及相关研究乃至临床治疗提供新的思路.     

Regulation of sodium and body fluid homeostasis during development: Implications for the pathogenesis of hypertension

The spontaneously hypertensive rat (SHR) is an important animal model of human essential hypertension. During the first month of life, increased retention of sodium is present in the SHR which appears to be mediated by the renin-angiotensin system. The present review will discuss the role that increased activity of the renin-angiotensin system plays in sodium/body fluid regulation during early development. It is hypothesized that disordered regulation of sodium/body fluid homeostasis during this stage leads to pathological cardiovascular regulation in adulthood. Through an understanding of the relationship between sodium/body fluid balance in the young and cardiovascular function in the adult insights may be gained into both the pathological state of hypertension and the critical role played by early development in shaping homeostatic mechanisms in adulthood.     

Regulation of sodium and body fluid homeostasis during development: implications for the pathogenesis of hypertension.

The spontaneously hypertensive rat (SHR) is an important animal model of human essential hypertension. During the first month of life, increased retention of sodium is present in the SHR which appears to be mediated by the renin-angiotensin system. The present review will discuss the role that increased activity of the renin-angiotensin system plays in sodium/body fluid regulation during early development. It is hypothesized that disordered regulation of sodium/body fluid homeostasis during this stage leads to pathological cardiovascular regulation in adulthood. Through an understanding of the relationship between sodium/body fluid balance in the young and cardiovascular function in the adult insights may be gained into both the pathological state of hypertension and the critical role played by early development in shaping homeostatic mechanisms in adulthood.     

The COVID-19 pandemic and global environmental change: Emerging research needs

The outbreak of COVID-19 raised numerous questions on the interactions between the occurrence of new infections, the environment, climate and health. The European Union requested the H2020 HERA project which aims at setting priorities in research on environment, climate and health, to identify relevant research needs regarding Covid-19. The emergence and spread of SARS-CoV-2 appears to be related to urbanization, habitat destruction, live animal trade, intensive livestock farming and global travel. The contribution of climate and air pollution requires additional studies. Importantly, the severity of COVID-19 depends on the interactions between the viral infection, ageing and chronic diseases such as metabolic, respiratory and cardiovascular diseases and obesity which are themselves influenced by environmental stressors. The mechanisms of these interactions deserve additional scrutiny. Both the pandemic and the social response to the disease have elicited an array of behavioural and societal changes that may remain long after the pandemic and that may have long term health effects including on mental health. Recovery plans are currently being discussed or implemented and the environmental and health impacts of those plans are not clearly foreseen. Clearly, COVID-19 will have a long-lasting impact on the environmental health field and will open new research perspectives and policy needs.     

The COVID-19 pandemic and global environmental change: Emerging research needs

The outbreak of COVID-19 raised numerous questions on the interactions between the occurrence of new infections, the environment, climate and health. The European Union requested the H2020 HERA project which aims at setting priorities in research on environment, climate and health, to identify relevant research needs regarding Covid-19. The emergence and spread of SARS-CoV-2 appears to be related to urbanization, habitat destruction, live animal trade, intensive livestock farming and global travel. The contribution of climate and air pollution requires additional studies. Importantly, the severity of COVID-19 depends on the interactions between the viral infection, ageing and chronic diseases such as metabolic, respiratory and cardiovascular diseases and obesity which are themselves influenced by environmental stressors. The mechanisms of these interactions deserve additional scrutiny. Both the pandemic and the social response to the disease have elicited an array of behavioural and societal changes that may remain long after the pandemic and that may have long term health effects including on mental health. Recovery plans are currently being discussed or implemented and the environmental and health impacts of those plans are not clearly foreseen. Clearly, COVID-19 will have a long-lasting impact on the environmental health field and will open new research perspectives and policy needs.     

Interaction of BW755C, a potent inhibitor of lipoxygenase and cyclo-oxygenase, with mitochondrial cytochrome oxidase

The interaction between BW755C (3-amino-1-[m-(trifluoromethyl)phenyl]-2-pyrazoline), a potent inhibitor of both lipoxygenase and cyclo-oxygenase, and respiratory chain in mitochondria and electron transport particles (ETP) from rat livers was examined. BW755C accelerated the oxygen uptake by mitochondria without the addition of substrate for the respiratory chain. Spectrophotometric study revealed that BW755C was quickly oxidized by cytochrome oxidase in mitochondria to a compound possessing an absorption maximum at 524 nm. p-Phenylenediamine (p-diaminobenzene, PPDA), which, like BW755C, serves as an electron donor to cytochrome oxidase, was shown to inhibit the generation of active oxygen in macrophages; the inhibition was stronger than that of BW755C. These results strongly suggest that the oxidative conversion of BW755C by mitochondrial cytochrome oxidase is associated with its potentially inhibitory action on the active oxygen-generating system in phagocytes.     

Angiotensin-converting enzyme 2 in acute respiratory distress syndrome

Angiotensin-converting enzyme (ACE) and ACE2 are highly homologous metalloproteases that provide essential catalytic functions in the renin-angiotensin system (RAS). Angiotensin II is one key effector peptide of the RAS, inducing vasoconstriction and exerting multiple biological functions. ACE cleaves angiotensin I to generate angiotensin II, whereas ACE2 reduces angiotensin II levels. Accumulating evidence has demonstrated a physiological and pathological role of ACE2 in the cardiovascular systems. Intriguingly, the SARS coronavirus, the cause of severe acute respiratory syndrome (SARS), utilizes ACE2 as an essential receptor for cell fusion and in vivo infections. Moreover, recent studies have demonstrated that ACE2 protects murine lungs from acute lung injury as well as SARS-Spike protein-mediated lung injury, suggesting a dual role of ACE2 in SARS infections and protection from ARDS. Received 18 May 2006; received after revision 12 March 2007; accepted 24 April 2007