blockade
[blok-ād´] 1. in pharmacology, the blocking of the effect of a neurotransmitter or hormone by a drug.
2. in histochemistry, a chemical reaction that modifies certain chemical groups and blocks a specific staining method.
adrenergic blockade selective inhibition of the response to sympathetic impulses transmitted by
epinephrine or
norepinephrine at alpha or beta receptor sites of an effector organ or postganglionic adrenergic neuron. See also
adrenergic blocking agent.
cholinergic blockade selective inhibition of cholinergic nerve impulses at autonomic ganglionic synapses, postganglionic parasympathetic effectors, or neuromuscular junctions. See also cholinergic blocking agent.
ganglionic blockade inhibition by drugs of nerve impulse transmission at autonomic ganglionic synapses; see also ganglionic blocking agent.
narcotic blockade inhibition of the euphoric effects of narcotic drugs by the use of other drugs, such as
methadone, in the treatment of addiction.
neuromuscular blockade a failure in neuromuscular transmission that can be induced pharmacologically or result from any of various disturbances at the
myoneural junction. See also neuromuscular blocking
agent.
sympathetic blockade block of nerve impulse transmission between a preganglionic sympathetic fiber and the ganglion cell.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.