Nivalin®
NIVALIN AND THE ADRENALS
Effect of
Nivalin on the adrenal medulla
Nivalin stimulates acetylcholine-mediated neurotransmission in the
splanchnic nerve to the receptors of adrenal medulla chromaffin cells. The
stimulating effect is also exhibited via the blood. The result is release
of medullar epinephrine.
Effect of
Nivalin on adrenal cortex
Experimental data indicate that subcutaneously administered Nivalin
increases significantly plasma 17-oxycorticosteroid concentrations [6].
This effect is realized via the pituitary-adrenal system and stimulation
of peripheral cholinergic structures, and ACTH is suggested to play a key
role [7].
Nivalin and
electrophysiology of afferent nerve activity
Low doses of Nivalin cause accelerated rate of fast potentials and
appearance of slow potentials. In higher dose the effect of Nivalin
develops in two phases: inhibition, followed by stimulation.
Nivalin and the
cardiovascular system
Nivalin potentiates acetylcholine-mediated effects in the heart, expressed
in moderate negative inotropism occurring at concentrations of 10-6
to 10-3 g/ml. Higher doses produce a biphasic change in heart
rhythm: initially slows down and then becomes faster. This is reflected in
moderate PQ-interval elongation and higher T-wave voltage in the
electrocardiogram.
Nivalin exhibits moderate hypotensive effects at low and medium doses,
potentiating the cardiac and peripheral vascular effects of acetylcholine.
At higher doses the effect is byphasic: an initial drop in arterial blood
pressure is followed by raised blood pressure, which is explained by the
effects of Nivalin on central nervous system, adrenal medulla, sympathetic
ganglia and postganglionic parasympathetic conduction in the heart muscle.
Nivalin has no cardiotoxic effect within a broad dosage range. Any adverse
effects can be rapidly neutralized by atropine.
Nivalin and the
central nervous system
Nivalin crosses the blood-brain barrier due to the presence of tertiary
nitrogen atom. This enables it to exhibit its anticholinesterase activity
at all levels in the central nervous system where acetylcholine-mediated
neurotransmission takes place.
Effect of
Nivalin on the spinal cord and medulla oblongata
Nivalin increases the bio-electrical activity of the spinal cord and
medulla. The frequency and amplitude biopotentials in postganglionic
fibers increase. Nivalin intensifies efferent activity in the motor
nerves.
Nivalin stimulates all monosynaptic and polysynaptic reflexes in the
spinal cord. The effects of Nivalin on spinal cord and brain medulla have
dual realization - through action and through descending reflex control
from central brain structures.
Effect of
Nivalin on the brain
Conditioned reflexes, as a classical model of higher nervous activity, are
influenced by Nivalin. Nivalin shortens the latency period and the
reaction time for conditional reflexes.
Nivalin abolishes disturbances in the conditional reflex caused by
cholinolytics. Animal studies have demonstrated that Nivalin normalizes
disturbed function on several levels of higher nervous activity, induced
by psychopharmacological agents [8].
Electroencephalographic (ECG) registration of brain bioelectrical activity
has shown that Nivalin acts on the ascending activating reticular
formation in brain stem and ventral and dorsal hippocamp. Histologic
changes were found in the neuronal cells of these structures, which
confirms Nivalin interference in their metabolic activity [9].
Nivalin and its
effects on phagocytosis
Experimental data show that Nivalin activates phagocytosis and thus
improves cell-mediated immunity. This mechanism is thought to be triggered
by the effect of Nivalin on central and autonomic nervous system through
acetylcholine and other mediators [10].
|
|