摘要:

Most of the known cardiovascular effects of L-arginine are exerted via its conversion to nitric oxide by nitric oxide synthase. Accumulating evidence indicates that supplemental administration of L-arginine is sufficient to restore endothelium-derived nitric oxide production in many disorders in which endothelium-derived nitric oxide production is altered. L-arginine may enhance nitric oxide production by competing as a substrate with an endogenous antagonist for nitric oxide synthase. In other cases, L-arginine may act by competing with molecular oxygen as a substrate so as to reduce the production of superoxide anion. It is likely that other mechanisms exist by which the nitric oxide synthase pathway can be perturbed. Regardless of the mechanism, a wide array of cardiovascular disorders characterized by endothelial dysfunction are reversible by L-arginine,

ISSN:1062-4821    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

As our understanding of endotnelial function continues to evolve,it hasbecome increasingly clear that the peripheral vasculature exhibits striking regional and segmental heterogeneity in the influence of the endothelial cell layer on vascular tone. This heterogeneity encompasses not only the normal interactions between endothelium-derived factors and vascular smooth muscle, but also: the way in which these interactions can change during juvenile growth or in disease such as hypertension. The underlying causes of this heterogeneity are multifactorial and include intrinsic differences among endothelial cell populations and differences in the endothelial cell microenvironment.

ISSN:1062-4821    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Non-steroidal anti-inflammatory drugs are efficacious treatments for rheumatoid arthritis and osteoarthritis. However, an adverse effect of treatment with non-steroidal anti-inflammatory drugs is: acute renal failure, particularly in a subset of patients that are in a state of effective volume depletion. The frequency of this side-effect in the general treated population is not known, but is probably less than 1% per year. Non-steroidal anti-inflammatory drugs act by inhibiting the synthesis of prostaglandins, which are important mediators of renal function. In the volume-depleted state prostaglandins may counter the vasoconstriction associated with the activation of the renin-angiotensin system. Cyclooxygenase is the rate-limiting enzyme involved in the synthesis of prostaglandins. Cyclooxygenase exists in two forms: a constitutive form (cyclooxygenase-1) and an inducible form (cyclooxygenase-2), which is associated with inflammation. Non-steroidal anti-inflammatory drugs are non-specific inhibitors of both forms of Cyclooxygenase. New data are emerging regarding the role of cyclooxygenase-2 in the control of renal function. In normal rat and dog kidney, cyclooxygenase-2 is sparsely expressed in the macula densa, but expression is upregulated when animals are volume depleted. This review explores the possible role of cyclooxygenase-2 in the maintenance of normal renal function in volume depleted states.

ISSN:1062-4821    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Many important cellular functions are regulated by vascular potassium channels, including the resting membrane potential. Recent evidence suggests that the function of these channels is altered in pathophysiologicaldisorders of the cardiovascular system. Using molecular cloning techniques, considerable effort has been made over the past 5 years to elucidate the structure of various types of potassium channels. Several different potassium channel clones have been identified from neuronal and cardiac tissues, although only a few have so far been identified in smooth muscle.

ISSN:1062-4821    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Several lines of evidence indicate a significant association between insulin and cardiovascular disease. This association might be explained by direct (cardio) vascular effects of insulin. Two hemodynamic actions of insulin are discussed in this review; it induces direct vasodilation in skeletal muscle: and stimulation of the sympathetic nervous system. These closely linked effects normally offset each other. Although more insight has been obtained into responses in insulin-resistant individuals and possible mechanisms, direct evidence to support a causative role for insulin is not yet available.

ISSN:1062-4821    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:1062-4821    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:1062-4821    

出版商:OVID    

年代:1998

数据来源: OVID