We examined the hypothesis that impaired endothelium-dependent vasodilation in atherosclerosis is associated with decreased synthesis of nitrogen oxides by the vascular endothelium. The descending thoracic aortae of rabbits fed either normal diet, a high cholesterol diet for 2-5 wk (hypercholesterolemic, HC), or a high cholesterol diet for 6 mo (atherosclerotic, AS) were perfused in a bioassay ...

It has been shown that endothelium-derived relaxing factor (EDRF) may inhibit platelet aggregation in vitro through activation of platelet-soluble guanylate cyclase. To assess whether EDRF may also affect platelet function in vivo, intravascular platelet aggregation was initiated by placing an external constrictor around endothelially injured rabbit carotid arteries. Carotid blood flow velocity...

EDHF Defined It is well established that stimulation of receptors on the endothelium can elicit dilation of arteries and arterioles by initiating the synthesis and release of nitric oxide (NO) and/or metabolites of the cyclooxygenase pathway (most often prostacyclin). Recent evidence now suggests that there is at least one other endothelium-dependent dilator mechanism that does not involve NO o...

Evidence from investigations of brain microcirculation (pial arterioles) reveals at least 3 different endothelium (EC) dependent mechanisms for dilation. Only one of the three can be triggered by acetylcholine (ACh) and in this vascular bed it is only this path that is dependent upon endothelial nitric oxide synthase (NOS) which produces nitric oxide (NO) from arginine. In this vascular bed the...

The word “serendipity” is considered very difficult to define; it may be considered “A talent for making fortunate discoveries while searching for other things”. The history of sexual medicine teaches us the importance of serendipity along with research. Serendipity in the year 1988 was initiated by a slow elevator. Dr. Jacob Rajfer, Professor of Urology, had attended a meeting on the 2 floor o...

The word “serendipity” is considered very difficult to define; it may be considered “A talent for making fortunate discoveries while searching for other things”. The history of sexual medicine teaches us the importance of serendipity along with research. Serendipity in the year 1988 was initiated by a slow elevator. Dr. Jacob Rajfer, Professor of Urology, had attended a meeting on the 2 floor o...