trimethaphan-camsylate and Hypotension

To clarify the characteristics of the blood circulation in the cochlea, we investigated the relationship between cochlear blood flow and perilymphatic oxygen tension in guinea pigs with trimetaphan camsilate induced hypotension. Cochlear blood flow was measured by laser Doppler flowmetry, and perilymphatic oxygen tension by a polarographic method. Cochlear blood flow generally paralleled systemic blood pressure, while perilymphatic oxygen tension showed a slower response to the decrease of systemic blood pressure. Although there were individual differences in the changes of systemic blood pressure, cochlear blood flow and perilymphatic oxygen tension, they were found to be dose dependent. Since hypotension induced by trimetaphan camsilate is fairly reproducible in the dose range of this experiment, this drug can be used as a ganglion blocking agent in experiments on cochlear blood flow and perilymphatic oxygen tension during systemic hypotension. The change of perilymphatic oxygen tension with a slower response could be considered to be a factor in the homeostasis in the inner ear fluid.

Topics: Animals; Blood Pressure; Cochlea; Dose-Response Relationship, Drug; Guinea Pigs; Hypotension; Lasers; Oxygen; Perilymph; Regional Blood Flow; Trimethaphan; Vasodilator Agents

The effects of cerebral ischaemia by carotid artery occlusion and of a ganglionic blocking agent (Arfonad) on cardiac output and regional blood flows were studied after 15 min of haemorrhagic hypotension (mean arterial pressure 50 mmHg) in the rat. The microsphere technique was used for blood flow determinations. Animals subjected to haemorrhagic hypotension and simultaneous carotid artery occlusion (group BC) exhibited a stronger immediate vasoconstrictor response than animals subjected to haemorrhagic hypotension only (group B) and more blood had to be withdrawn to achieve stable hypotension at 50 mmHg (2.6 +/- 0.1 vs. 2.2 +/- 0.4 ml per 100 g body weight (body wt); P less than 0.05). However, group B showed the same decrease in cardiac output as group BC, but the blood flows of the kidneys, spleen, intestine, liver and skin were less deranged at the end of the hypotensive period. Groups B and BC exhibited similar intestinal ischaemic mucosal damage, measured as leakage of [125I]albumin. When induction of haemorrhagic hypotension was combined with ganglionic blockade administration (Arfonad) and carotid artery occlusion (group ABC), significantly less blood had to be withdrawn than in groups BC (1.6 +/- 0.2 vs. 2.6 +/- 0.1 ml per 100 g body wt; P less than 0.05). The blood flows of the kidneys, small intestine, liver, spleen and skin were less compromised in group ABC. In addition, group BC had more profound metabolic acidosis and were more haemoconcentrated than group ABC; moreover, group BC, tended to be hypoglycaemic and showed intestinal mucosal damage, whereas neither of these effects occurred in group ABC.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Brain Ischemia; Cardiac Output; Ganglionic Blockers; Hemorrhage; Hypotension; Intestinal Mucosa; Intestine, Small; Male; Rats; Rats, Inbred Strains; Regional Blood Flow; Trimethaphan

In an earlier study [Am. J. Physiol. 232 (Regulatory Integrative Comp. Physiol. 1): R27-R30, 1977], we defined the concept of brain elastic response in vivo as measured by a pressure-depth ratio (G0) derived from a graphic analysis of the elastic response tests. These tests have shown that brain elastic response in vivo is sensitive to changes in the intracranial system and that the response is nonlinear. In this study we identify a second parameter, G0, a second-order pressure-depth ratio that characterizes the nonlinear behavior and, along with G0, can be evaluated from a mathematical relation that models the experimental results obtained from the elastic response test. The equation is a logarithmic function relating the pressure and the subpial insertion depth. From this we obtain G0 and G0 as the slope and curvature of the response function at the subpial position. In animal experiments we correlated the changes in these parameters with those of cerebral hemodynamics during hemorrhagic and drug-induced hypotension. The calculated values of G0 and G0 are reproducible and reflect changes in cerebral blood flow and/or volume.

Topics: Animals; Blood Pressure; Brain; Cerebrovascular Circulation; Dogs; Elasticity; Femoral Artery; Hemorrhage; Hypotension; Intracranial Pressure; Models, Neurological; Nitroprusside; Regional Blood Flow; Trimethaphan; Vascular Resistance; Vasodilator Agents

Topics: Adenosine; Anesthesia, General; Animals; Arteries; Blood Pressure; Dipyridamole; Dogs; Electrolytes; Gases; Heart Rate; Hypotension; Nitroprusside; Trimethaphan

Topics: Blood; Blood Pressure; Dogs; Heart; Hypotension; Lactates; Metabolism; Pharmacology; Physiology; Research; Shock; Shock, Hemorrhagic; Trimethaphan

Topics: Blood Chemical Analysis; Blood Pressure Determination; Dogs; Histamine; Hypotension; Morphine; Pharmacology; Research; Trimethaphan

Topics: Blood Circulation; Hemodynamics; Humans; Hypotension; Hypotension, Controlled; Trimethaphan

Topics: Animals; Disease; Dogs; Hypotension; Hypotension, Controlled; Hypothermia; Hypothermia, Induced; Liver; Portal Vein; Trimethaphan; Vascular Diseases

Topics: Autonomic Agents; Hypotension; Insulin; Trimethaphan

Topics: Autonomic Agents; Brain; Glucose; Hemodynamics; Hemorrhage; Hypotension; Hypotension, Controlled; Metabolism; Oxygen; Trimethaphan

Topics: Autonomic Agents; Hypotension; Hypotension, Controlled; Surgical Procedures, Operative; Trimethaphan; Urinary Tract

Topics: Humans; Hypotension; Hypotension, Controlled; Neurosurgery; Neurosurgical Procedures; Trimethaphan

Topics: Autonomic Agents; Hypotension; Trimethaphan

Topics: Autonomic Agents; Cerebral Cortex; Humans; Hypotension; Oxygen; Trimethaphan

Topics: Anesthesia; Anesthesiology; Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Bloodless Medical and Surgical Procedures; Humans; Hypotension; Sympatholytics; Trimethaphan

Topics: Brain; Hypotension; Neurosurgery; Neurosurgical Procedures; Psychosurgery; Sympatholytics; Trimethaphan

Topics: Aged; Disease; Ductus Arteriosus; Ductus Arteriosus, Patent; Humans; Hypotension; Sympatholytics; Trimethaphan

Topics: Autonomic Agents; Ear; Hypotension; Hypotension, Controlled; Otolaryngology; Otologic Surgical Procedures; Trimethaphan

Topics: Autonomic Agents; Humans; Hypotension; Hypotension, Controlled; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan; Urine

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hypotension; Sympatholytics; Trimethaphan

Topics: Bloodless Medical and Surgical Procedures; Humans; Hypotension; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Aged; Analgesia; Anesthesia; Anesthesia and Analgesia; Humans; Hypotension; Neurosurgery; Pain Management; Sympatholytics; Trimethaphan

Topics: Analgesia; Anesthesia; Anesthesia and Analgesia; Hypotension; Hypotension, Controlled; Neurosurgery; Pain Management; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Otolaryngology; Otorhinolaryngologic Surgical Procedures; Sympatholytics; Trimethaphan

Topics: Hypotension; Sympatholytics; Trimethaphan

Topics: Autonomic Agents; Electrolytes; Hemodynamics; Hexamethonium; Humans; Hypotension; Hypotension, Controlled; Kidney; Muscle Relaxants, Central; Norepinephrine; Sympatholytics; Trimethaphan; Water

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hepatectomy; Hypotension; Liver; Sympatholytics; Trimethaphan

Topics: Child; Hypotension; Hypotension, Controlled; Pediatrics; Specialties, Surgical; Sympatholytics; Trimethaphan

Topics: Brain; Hypotension; Psychosurgery; Split-Brain Procedure; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Specialties, Surgical; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Analgesia; Anesthesia; Anesthesia and Analgesia; Hypotension; Hypotension, Controlled; Neurosurgery; Pain Management; Sympatholytics; Trimethaphan

Topics: Autonomic Agents; Brain; Ganglionic Blockers; Hemodynamics; Hexamethonium; Hypotension; Hypotension, Controlled; Muscle Relaxants, Central; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Anesthesia; Anesthesiology; Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Brain; Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Analgesia; Anesthesia; Anesthesia and Analgesia; Autonomic Agents; Hypotension; Hypotension, Controlled; Neurosurgery; Sympatholytics; Trimethaphan

Topics: Ganglionic Blockers; Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hypotension; Injections, Intravenous; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Sympatholytics; Trimethaphan

Topics: Hypotension; Hypotension, Controlled; Neurosurgery; Neurosurgical Procedures; Sympatholytics; Trimethaphan

Topics: Hypotension; Sympatholytics; Trimethaphan