ISCHEMIC NECROSIS resultinig from accidental extravasation of levarterenol (Levophed) in patients in shock can be prevented by local injection of 5 or 10 mg. of the anti-adrenergic drug phentolamine (Regitine).'4 This method is not effective when vasoconstriction has existed for several hours and irreversible tissue damage has occurred. Preliminary observatioins suggest that inmediate protectio...

The extent to which sympathetic nerve activity restrains metabolic vasodilation in skeletal muscle remains unclear. We determined forearm blood flow (FBF; ultrasound/Doppler) and vascular conductance (FVC) responses to 10 min of ischemia [reactive hyperemic blood flow (RHBF)] and 10 min of systemic hypoxia (inspired O(2) fraction = 0.1) before and after regional sympathetic blockade with the al...

Spontaneous rhythmic motor output of crayfish thoracic ganglia consists of bursts of activity in antagonistic leg motor neurons (MNs), alternating with a rather slow cycle period (typically > or = 20 s). The most common pattern (77% of preparations) consists of long coxal promotor bursts, the duration of which was correlated strongly with cycle period, and relatively short remotor bursts indepe...

We hypothesized that nitric oxide (NO), in addition to beta-adrenergic effects, may contribute to exercise-induced coronary responses after alpha-adrenergic receptor blockade. Data were analyzed as relationships between coronary sinus (CS) O(2) saturation (CS O(2)sat) or coronary blood flow (CBF) and myocardial O(2) consumption (MVO(2)). As MVO(2) increased, CS O(2)sat fell more (P < 0.05) afte...

THE recognition of the importance of the sympathetic nervous system in the control of the systemic arterial blood pressure has stimulated the search for therapeutically useful sympathoadrenergic blocking agents that may be of use in the diagnosis and treatment of hypertensive vascular disease. Numerous agents of diverse chemical structure have been developed and explored for such therapeutic ef...

PURPOSE To examine prospectively the incidence of digital infarction and phentolamine rescue in a large series of patients in whom local anesthesia with adrenaline was injected electively into the hand and fingers. There continues to be a commonly held belief that epinephrine injection is contraindicated in the finger despite a lack of valid evidence to support this concept in the literature. ...

1. The effects of chlorpromazine on sympathetic neuroeffector transmission have been studied in the rabbit isolated pulmonary artery and aorta. 2. Chlorpromazine (10(-8)-10(-5) M), prazosin (10(-9)-10(-7) M) and phentolamine (3 x 10(-8)-3 x 10(-5) M) decreased the contractions of pulmonary artery evoked by electrical field stimulation (150 pulses; 3 Hz). The rank order of inhibitory potency (ID...

Although the vasodilatory response during mental stress is blunted in heart failure (HF), the mechanisms underlying this phenomenon are not fully understood. We tested the hypothesis that sympathetic activity limits the endothelium-dependent vasodilatation during mental stress in chronic HF patients. Twenty-one HF patients (age 45 +/- 2 yr, functional classes III and IV, New York Heart Associat...

The diagnosis of sympathetically maintained pain (SMP) is typically established by assessment of pain relief during local anesthetic blockade of the sympathetic ganglia that innervate the painful body part. To determine if systemic α-adrenergic blockade with phentolamine can be used to diagnose SMP, we compared the effects on pain of local anesthetic sympathetic ganglion blocks (LASB) and phent...

Oxidative stress and transcriptional pathways of nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor kappa-B (NF-κB) are critically involved in the etiopathology of amebic liver abscess (ALA). In this work, we studied the relationship between the adrenergic nervous system and ALA in the hamster. ALA was visible at 12 h of infection. While 6-hydroxidopamine (6-OHDA) decreased i...