“We have found that cocaine’s effects on the cardiovascular system can be reversed by the use of a drug called dexmedetomidine, which is currently approved by the Food and Drug Administration for anesthetic purposes in operating rooms or intensive care units,” said Dr. Wanpen Vongpatanasin, associate professor of internal medicine and senior author of a study appearing in the Aug. 14 issue of the Journal of the American College of Cardiology.
Researchers used dexmedetomidine to test whether cocaine’s effect on the cardiovascular system could be muted. They found that the drug was effective in reversing the actions of cocaine on heart rate, blood pressure and vascular resistance in the skin by interfering with the ability of cocaine to increase nerve activity.
“Typically, patients with cocaine overdoses in the emergency room are treated with nitroglycerin, sedatives such as Valium, and some blood-pressure medications such as calcium channel blockers and some beta blockers,” Dr. Vongpatanasin said. “However, the standard treatments don’t alleviate all of the adverse effects of cocaine on the heart, blood pressure and central nervous system.”
The study examined results from 22 healthy adults who reported to have never used cocaine. The investigators administered a small, medically approved dose of cocaine nose drops to the study participants, which doubled their sympathetic nerve activity, part of the body’s “automatic” response system that becomes more active during times of stress. Participants experienced increases in several cardiovascular parameters including heart rate, blood pressure and resistance to blood flow in the skin.
Microelectrodes, similar to acupuncture needles, were used to record sympathetic nerve activity following doses of intranasal cocaine.
Research subjects who were treated with dexmedetomidine had a decrease in sympathetic nerve activity as well as in all three cardiovascular parameters, which returned to baseline levels measured before administration of cocaine. Dexmedetomidine proved to be more effective than intravenous saline, which was used as a placebo in another group of study participants.
Cocaine abuse in the U.S. is widespread, with nearly 35 million Americans reporting having ever tried cocaine and an estimated 7.3 million users, including 15 percent of young adults ages 18 to 25, according to the National Institute on Drug Abuse. Life-threatening emergencies related to cocaine use include sudden cardiac death, high blood pressure, stroke and acute myocardial infarctions.
“We also found that dexmedetomidine was equally effective in counteracting effects of cocaine in subjects with a rare genetic mutation thought to disrupt the effects of dexmedetomidine,” said Dr. Ronald Victor, professor of internal medicine and co-author of the study. “Because this particular mutation is more common in African-Americans than in Caucasians, our study results are applicable to a more diverse, multiethnic population.” Further research is needed, study authors said, to determine whether the treatment would be effective for acute cocaine overdose in the emergency room and to gauge whether it would be effective in reversing cocaine-induced constriction of the coronary vessels to the same degree it does in skin vessels.
Katherine Morales | EurekAlert!
Rainbow colors reveal cell history: Uncovering β-cell heterogeneity
22.09.2017 | DFG-Forschungszentrum für Regenerative Therapien TU Dresden
The pyrenoid is a carbon-fixing liquid droplet
22.09.2017 | Max-Planck-Institut für Biochemie
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!
When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...
For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.
Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...
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