Astrocytes elicit bidirectional control of microvascular diameter in acutely isolated brain slices through vasoconstriction and vasodilation pathways that can be differentially recruited via the free Ca2+ concentration endfeet and/or metabolic status tissue. However, Ca2+-level hypothesis has not been tested using direct manipulation. To overcome this, we used Ca2+-clamp whole-cell patching per...

Vasopressors and inotropes are often administered to critically ill patients in intensive care unit for the management treatment of haemodynamic impairment, heart failure, septic cardiogenic shock, trauma among certain other diseases. In with vasopressors used induce vasoconstriction or enhance cardiac contractility. induces vasoconstriction, which causes systemic vascular resistance, leading i...

We determined whether a 3-minute period of intense cardiac sympathetic stimulation, which is known to release neuropeptide Y (NPY), elicits a sustained poststimulatory coronary vasoconstriction in anesthetized dogs that had received propranolol. We also periodically measured the cardiac chronotropic responses to test vagal stimulations; these responses served as an index of the neuronal release...

Reversible cerebral vasoconstriction syndrome (RCVS) is an under-recognised condition. It is characterised by sudden and severe headaches (of "thunderclap" type) associated with multifocal reversible narrowing of the intracranial arteries on neuroradiology. The diagnosis is often established with the resolution of headaches and vasoconstriction. We report two patients with RCVS and review the a...

Reversible cerebral vasoconstriction syndromes (RCVS) are a group of disorders that have in common an acute presentation with headache, reversible vasoconstriction of cerebral arteries, with or without neurological signs and symptoms. In contrast to primary central nervous system vasculitis, they have a relatively benign course. We describe here a patient who was diagnosed with RCVS.

Masuki, Shizue, Frank A. Dinenno, Michael J. Joyner, and John H. Eisenach. Selective 2-adrenergic properties of dexmedetomidine over clonidine in the human forearm. J Appl Physiol 99: 587–592, 2005. First published March 31, 2005; doi:10.1152/japplphysiol.00147.2005.— We tested the hypothesis that dexmedetomidine (Dex) has greater 2vs. 1 selectivity than clonidine and causes more 2-selective va...

Acetylcholine (ACh) elicits vasodilation by releasing a number of endothelium-derived relaxing factors (EDRFs). We used the isolated perfused hydronephrotic rat kidney to examine the characteristics of ACh-induced vasodilation of renal afferent arterioles during different types of underlying vasoconstriction. Basal arteriolar tone was increased by either elevating perfusion pressure to 180 mm H...

BACKGROUND Experimental studies have demonstrated that intracoronary platelet aggregation and thrombus formation may induce marked vasoconstriction of epicardial arteries with endothelial injury. METHODS AND RESULTS To examine the effects of intracoronary thrombus formation on coronary vasomotor tone of human epicardial arteries in vivo, we studied 15 patients who developed intracoronary thro...

We used the insulin-perfused human forearm model to assess the effects of vasoconstriction induced with norepinephrine on the extraction of glucose in the forearm in two groups of healthy young volunteers. The norepinephrine findings were compared with a previously studied group in which vasoconstriction has been caused by reflex activation of the sympathetic nervous system. The aim of the stud...

Numerous observational studies have reported an association between serum urate and elevated blood pressure in adult populations (1). These observations, together with experimental vivo studies, generated substantial interest the role of hyperuricaemia as a mediator pressure, various postulated mechanisms, including activation renin-angiotensin system, oxidative stress, reduced endothelial nitr...