The injection of vasoconstrictors together with a local anaesthetic will prolong the duration of spinal anaesthesia. We use phenylephrine ((-)-l-(mhydroxyphenyl>2-methyl-aminoethanol HQ), which has been reported to double the duration of anaesthesia (Moore and Bridenbaugh, 1966). These authors found no systemic response to the added phenylephrine in a retrospective study of 1911 spinal anaesthe...

A patient with papillary muscle disease caused by myocardial infarction was studied before and after injection of phenylephrine. The pulmonary wedge pressure was normal at rest. However, pressures and murmur changes, occurring spontaneously and after injection of phenylephrine, suggested that intermittent severe mitral regurgitation contributed significantly to the recurrent episodes of acute l...

The neuromodulatory interaction of sex steroids with the opioid system may involve in sex differences in pain sensitivity. Also, sex steroids undergo fluctuations during estrus cycle. On the other hand, adrenergic system can influence pain sensitivity. Thus, the aim of the present study was to investigate the effect of phenylephrine and prazocin on pain sensitivity during estrus cycle. For this...

AIMS A systematic literature review comparing the efficacy of ephedrine and phenylephrine for the management of spinal anesthesia-induced hypotension during Cesarean sections (C-sections) was published in 2002. A number of well-designed trials with controversial results have been published afterward. Therefore, an updated meta-analysis was necessary. METHODS The MEDLINE, EMBASE, and the Cochr...

We have previously found that the vascular responsiveness to α1-adrenergic agonists is reduced in pregnant rats and enhanced in a rat model of pregnancy-induced hypertension produced by chronic treatment of pregnant rats with the nitric oxide (NO) synthase inhibitor N G-nitro-l-arginine methyl ester (l-NAME). The purpose of this study was to investigate whether the observed changes in vascular ...

Objective: The effect of an a-adrenergic agonist, phenylephrine, on the NarCa exchange current in rat ventricular myocytes was investigated. Methods: The NarCa exchange current was measured at room temperature in rat ventricular myocytes as the whole-cell current induced by addition of extracellular Na and Ca, while blocking Na current by setting the holding potential at y30 mV, K currents by i...

OBJECTIVE The effect of an alpha-adrenergic agonist, phenylephrine, on the Na+/Ca2+ exchange current in rat ventricular myocytes was investigated. METHODS The Na+/Ca2+ exchange current was measured at room temperature in rat ventricular myocytes as the whole-cell current induced by addition of extracellular Na+ and Ca2+, while blocking Na+ current by setting the holding potential at -30 mV, K...

OBJECTIVE The duration of extracellular signal-regulated kinase (ERK) activation and the ERK-dependency of hypertrophic growth differ between stimulation of alpha-adrenoceptors or angiotensin II receptors. As both receptor systems activate different protein kinase C (PKC) isoforms, we hypothesized that PKC isoforms contribute to the specific effect of alpha-adrenoceptor stimulation. METHODS I...

Small mesenteric arteries of spontaneously hypertensive (SHR) and Wistar-Kyoto rats (WKY) were compared for the production of 20-HETE and the effects of 20-HETE and N-methylsulfonyl-12,12-dibromododec-11-enamide (DDMS, 30 micromol/L), a 20-HETE synthesis inhibitor, on contractile responsiveness to phenylephrine (0.1 to 50.0 micromol/L). 20-HETE production was higher in vessels of SHR compared w...