Vasoactive intestinal polypeptide (VIP) is a neuropeptide with potent circulatory effects in the adult animal and human. Little is known about its effects or mechanism of action in the immature animal. These series of experiments evaluated the effects and possible mechanism of action ofVIP on the developing canine cardiovascular system. In all three series, measurements of mean heart rate and b...

complex regional pain syndrome (crps) is a variety of painful conditions following injury which appears regionally having a distal predominance of abnormal findings. this study, evaluate the use of phentolamine for sympathetic block and regional anesthesia in treatment of crps related pain. in this study, 68 patients with crps who were referred to pain clinics of imam hossein and akhtar hospita...

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...

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...

Mitochondria are morphologically dynamic organelles which undergo fission and fusion processes. Our previous study found that arterial constriction was always accompanied by increased mitochondrial fission in smooth muscle cells, whereas inhibition of mitochondrial fission in smooth muscle cells was associated with arterial relaxation. Here, we used the typical vasorelaxants, verapamil and phen...

Healthy subjects exposed to 20 min of hypoxia increase ventilation and muscle sympathetic nerve activity (MSNA). After return to normoxia, although ventilation returns to baseline, MSNA remains elevated for up to an hour. Because forearm vascular resistance is not elevated after hypoxic exposure, we speculated that the increased MSNA might be a compensatory response to sustained release of endo...

1. Systemic and regional vascular changes were measured in conscious rabbits after intravenous sodium meclofenamate, captopril and phentolamine. These drugs were used respectively to inhibit prostaglandin synthesis and angiotensin-converting enzyme, and to block alpha-adrenoceptors. 2. Meclofenamate reduced renal and adrenal blood flow by 11 and 28% respectively, and doubled hepatic artery flow...

The contribution of the sympathetic nervous system (SNS) to pain, mechanical allodynia (MA), and hyperalgesia in humans is controversial. A clearer understanding is crucial to guide therapeutic use of sympatholytic surgery, blocks, and drug treatments. In rats, capsaicin-evoked MA, and to some extent, pinprick hyperalgesia (PPH), can be blocked with alpha-adrenoreceptor antagonists. In this stu...

Metabolic syndrome (MS) is a combination of medical disorders that increase the risk of developing cardiovascular disease and diabetes. MS is associated with obesity, increased blood pressure, hyperlipidemia, and hyperglycemia. This study was designed to investigate the pharmacological profile of phentolamine, a nonselective α adrenergic receptor antagonist, in the prevention of increased blood...

1. Although alpha-adrenoceptor antagonists have been shown to induce core hypothermia in animals, it is unclear whether the primary mechanism is increased heat loss or decreased heat production. Furthermore, studies have not been performed in humans to determine the role of alpha-adrenoceptors in the maintenance of core temperature. 2. alpha-Adrenoceptor blockade was achieved with three doses o...