Insulin-resistance induces cerebrovascular dysfunction and increases the risk for stroke. We investigated whether rosuvastatin (RSV), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, can reverse reduced cerebrovascular responsiveness in insulin-resistant rats. Dilator responses of the basilar artery (BA) were examined after 1-day or 4-wk RSV (2 mg.kg(-1).day(-1)) treatment in anesth...

53 Airway Physiology Following Arousal—Jordan et al. INTRODUCTION The pathogenesis of obstructive sleep apnea (OSA) is only partially understood; in particular, the potential role of arousals from sleep in destabilizing upper airway function is controversial.1 Arousals from sleep commonly occur at the termination of respiratory events in OSA2,3 and have been suggested by some authors to predisp...

Isometric tension changes of the bovine iris dilator muscle were investigated in vitro. Electrical field stimulation (0.03-1 msec duration) produced a relaxation, which was abolished by the addition of tetrodotoxin, thereby suggesting a neuronal origin. Marked relaxation was also initiated in high K solution. Both of these relaxations were potentiated by neostigmine, while atropine abolished th...

A marked functional polarity of endothelial cells as well as an asymmetry of the vascular wall in response to vasoactive compounds is well established. Therefore, we investigated the polarity of endothelium-derived relaxant factor (EDRF) release from native endothelial cells, its diffusion characteristics, and its dilator effects on inner and outer muscle layers of the vascular wall in isolated...

PURPOSE To examine the effect of the posterior location of the dilator on iris anterior curvature during dilation. METHODS An in vivo human study, an ex vivo porcine experiment, and an in silico computational model were performed in parallel. Iris anterior curvature was measured in vivo before and after dilation by time-domain slit lamp optical coherence tomography (SL-OCT). All patients (n =...

Two distinct responses to transmural electrical stimulation of cerebrovascular smooth muscle isolated from dogs and sheep have been identified. Both these responses were blocked with tetrodotoiin and therefore were attributed to stimulation of intramural nerves. A constrictor response to transmural nerve stimulation (TNS) which was blocked with guanethidine was attributed to stimulation of symp...

PURPOSE (1) To use finite element (FE) modelling to estimate local iris stresses (i.e. internal forces) as a result of mechanical pupil expansion; and to (2) compare such stresses as generated from several commercially available expanders (Iris hooks, APX dilator and Malyugin ring) to determine which design and deployment method are most likely to cause iris damage. METHODS We used a biofidel...

Two distinct responses to transmural electrical stimulation of cerebrovascular smooth muscle isolated from dogs and sheep have been identified. Both these responses were blocked with tetrodotoiin and therefore were attributed to stimulation of intramural nerves. A constrictor response to transmural nerve stimulation (TNS) which was blocked with guanethidine was attributed to stimulation of symp...

Secreted frizzled-related proteins (sFRPs) are secreted glycoproteins involved in neoplastic growth. Four hormones synthesized in the heart, namely vessel dilator, atrial natriuretic peptide (ANP), kaliuretic peptide (KP) and long-acting natriuretic peptide (LANP), have anticancer effects both in vitro and in vivo. These heart hormones were evaluated for their ability to inhibit sFRP-3, which i...