Short CommunicationAbstract
The article shows that the current level of physiology does not disclose the biological mechanisms of the organism transition from one range to adapt to a higher with an increase in the regular forces of the stimulus above sub-extreme. A new trend in the physiology of adaptation progredient adaptation, explains the mechanism of increasing the tolerance of the organism, with dependence on Psychoactive Substances (PAS). It is scientifically proved, that dependences of the organism on PAS are the states of progredient adaptation.
Abbreviations: NGF: Nerve Growth Factor; VNS: Vegetative Nervous System; PAS: Psychoactive Substances
Introduction
Urgency of the Issue
It is known, that at the pick of dependence on any psychoactive substance (PAS), a person, for example, an opium (heroin) addict uses doses, which are multiple times, almost 10 times, higher than the lethal dose for an ordinary person [1]. The fact, that the drug user does not die, is explained by the increase in the body’s tolerance in response to the increase in the dose of PAS [2]. Urgent issues of medicine are not only identification of mechanisms for increasing tolerance, but also validation of the physiological process occurring on exposure to increasing doses of a psychoactive substance and the response increase in tolerance of a PAS-dependent organism.
Purpose and Objectives of the Study
Adaptation reactions of the organism with regular exposure to
a sub-extreme stimulus. Lack of adaptive reactions of the organism
already known in physiology to explain the adaptation mechanisms
in response to a further increase in the regular stimulus strength
above the sub-extreme level in PAS dependent patients. The
pronounced reactions by the Vegetative Nervous System (VNS)
in PAS dependent patients indicate the vegetotrophy of most of
these substances. The amount of their influence is closest to the
sub-extreme level. Responsive adaptive reactions of the organism
under regular influence of the external factor of the average to
sub-extreme strength were studied by L. Kh. Garkavi and coauthors
(1977) [3]: Under the influence of sub-extreme stimuli,
an activation reaction with the stages of primary and persistent
activation occurs, indicating a higher activity of protective systems.
The stage of persistent activation is true, active resistance,
stable and long enough - up to six months - in contrast to the
training reaction and in the absence of constant exposure. But in PAS
dependence, the process does not result in the reaction of persistent
activation; the dose to which the adaptation has occurred is habitual and results in no euphorizing effect. To achieve neurophysiological
shift sufficient for euphoria, a larger dose is required. But increase
in the dose of PAS after the activation reaction is stressful for the
organism. Stress in its development has three stages. The first stage
is the “anxiety reaction”, the second one is the stage of tolerance,
when hypertrophy of the adrenal cortex with a steady increase
in the formation and secretion of corticosteroids develops. They
increase the amount of circulating blood and blood pressure,
have an antihistamine effect, enhance gluconeogenesis, normalize
physiological reactions, etc. The tolerance of the organism to the
stimulus increases. Prolonged exposure to the stimulus results in
the stage of exhaustion, and death may occur. Doses of PAS above
the stress level are lethal [1].
L Kh Garkavi and co-authors showed that: “the reactivity of
the organism is represented by a number of floors (ranges), which
does not exceed ten. In each floor: a weak stimulus causes the
training reaction, an average sub-extreme stimulus - the activation
reaction, a strong stimulus – the stress. The ranges are separated
by the zone of non-reactivity, when increasing the stimulus level
above the stress one or decreasing below the training one causes
no reaction. Transition to the next range shows again the same
order of reactivity: the reactions of training, activation, and stress.
As it was mentioned above, an increase in the effect of an external
stimulus up to a high level and the rise to the second stage of the
stress reaction, the resistance stage, lead to the development of
hypertrophy of the adrenal cortex with an increase in the secretion
of corticosteroids increasing, in turn, resistance to the stimulus.
But L.Kh.Garkavi and co-authors could not explain the mechanisms
providing the human organism’s transition (bypassing exhaustion
and death stages) from one floor (range) of adaptation to a higher
one, under the conditions of further increase in the force of impact
above stress level.
Indeed, according to pathophysiology, without such adaptation
mechanisms increasing the tolerance, the body must die from
“exhaustion”, from failure of adaptation mechanisms, when
the organism transits from the first adaptation range to the
second. But in a PAS dependent people, this is not observed. This
indicates failure of the current level of physiology to explain the
mechanisms providing the body transition from one adaptation
range (reactivity) to a higher one. In the history of narcology,
attempts were made to explain the increase in tolerance organism
by different causes. They are accelerated disintegration of PAS in
the addict’s, development of chronic stress, activation of other
states inactive in normal conditions, or activation of systems that
fulfil other functions, but with an increase in a PAS dose are forcedly
involved in detoxification, etc. But all those assumptions have not
been scientifically confirmed. No matter how full modern scientific
research explain qualitative changes at the cellular and molecular
level that lead to an increase in tolerance in PAS dependent
patients, it is clear that these changes can only be of adaptive, not
pathological and damaging nature, otherwise they would lead
not to an increase in tolerance, but rather to a decrease in it, and
the body would already die when transiting from the first floor of
adaptation to the second.
Also, according to the dialectical principle of the mutual
transition of qualitative changes to quantitative ones, accumulation
of these changes should lead to qualitative and quantitative
changes in the neuroendocrine system which is responsible for the
adaptation of the whole body. I would like to quote L.Kh. Garkavi,
E.B. Kvakina, M.A.Ukolova (1977) - “it is possible to investigate
separately the changes in any one system or at any one level,
for example, molecular. But this is only a part of the changes in
the overall complex reaction of the body. “ Also, I would like to
quote I.N. Pyatnitskaya (1988): Integral functional reactions to
the intoxication of physiological systems are known to be no
less important in maintaining homeostasis than biochemical
protection”. Consequently, we can speak about change in the body’s
response to a drug.
Object and Methods of Investigation
Features of the response of the neuroendocrine system to any
external stimulus. Capacity of the endocrine system for positive
trophic changes. Hypertrophy and hyperfunction of the endocrine
system - histological and biochemical evidence. The response
of the body to any change in the internal environment depends
primarily on the functional state of the neuroendocrine system.
Thus, the cause of the altered body’s reactivity and a steady
increase in the overall tolerance of the body, should be sought in
the central mechanisms of adaptation - in the neuroendocrine
system. The increase in tolerance of the PAS dependent organism
can be explained by the functional tension of the neuroendocrine
system and by the reaction of persistent activation only within
one adaptation range. It is good health, physical activity, increased
protective capacities of the body to various hazards - hypothermia,
etc., which are clinically observed in the prodroma and possibly
in the initial stage of alcohol dependence. But tension in the
neuroendocrine system and the reaction of persistent activation fail
to explain the transition from a lower to a higher adaptation range
following PAS exposure above sub-extreme level and its further
increase! After all, in such a situation, the body must experience
stress with exhaustion and death! This can only be explained by the
transcendental functioning of the neuroendocrine system, which
can be possible only due to its adaptive hypertrophy, in response
to the regular exposure to the external factor. But is it possible?
According to the theory of physiology of the development of
interrelations between the structure and the function, in the course
of ontogenesis (individual’s development), functional activity is of
particular importance and it is stimulated by the flow of stimuli
affecting the organism as a result of changes in living conditions.
Functional activity is the leading factor causing adaptive
reactions in the body up to the development of morphological
changes. Morphological changes occur in organs or systems
stimulated by a flow of stimuli more regularly. Even in the early
1800s, J. Lamarck suggested that “the work builds up the organs”.
P. Lesgaft’s merit was the explanation of a specific morphological
alteration of the organism during the exercise process. V.Ru
showed that due to “trophic stimulation” in the working organ,
the assimilation process begins to dominate over the dissimilation
process, and morphological changes occur at the physiological
level. The increase in energy reserves results in an increase in
working efficiency. It can be argued that the regular use of PAS -
addressing the high response range - leads the entire body to the
state of the activation reaction - hypermetabolic state, which does
not contribute to the accumulation of reserves and the occurrence
of positive trophic changes in the body. But one should remember
that the hypermetabolic state develops in the “metabolic boiler”
- at the level of tissue adaptation mechanisms [4]. Perhaps, in the
higher adaptation mechanisms - the neuroendocrine system -
despite their tension, there are no hyper metabolization processes,
which contributes to the accumulation of reserves leading to
morphological changes in the neuroendocrine system in the form
of hypertrophy, are there?
The observations of L.Kh. Garkavi and co-authors indirectly
proves possible accumulation of reserves in the neuroendocrine
system during the activation reaction; “Although the metabolism
is highly active during the activation reaction, it is characterized
by an equilibrium”, since to ensure “equilibrium” of constantly
growing metabolic processes, a “powerful” neuroendocrine system
is necessary. But in PAS dependence, after the completion of the
activation reaction and in further enhancement of the stimulus above
the sub-extreme level and transition to the subsequent adaptation
floor, the “equilibrium” of the metabolic processes takes place,
too. But this is possible only when the functional adequacy of the
neuroendocrine systems grows in direct proportion to the strength
of the external factor, which is possible only with hypertrophic
neuroendocrine system and, as a consequence, its hyper
productivity. The neuroendocrine system consists of the Vegetative
Nervous System (VNS) and the endocrine part - the endocrine
glands. In the functioning of the vegetative nervous system, a
special mechanism is evolutionary provided that contributes to the
accumulation of reserves - “advanced excitation” described in the
1930s by P.K. Anokhin. Vegetative Nervous System (VNS) responds
to any stimulus with a somewhat excessive neurotransmitter
ejection, as if in anticipation of possible future high consumption.
VNS through neurotransmitters activates auxiliary and tissue
adaptation mechanisms, and due to excesses of neurotransmitter
ejection “takes a break” for its own recovery trophic processes.
Although VNS regulates all the processes in the body, it has been
established that there are biologically active substances produced
by different cells of the body that have a trophic effect on VNS itself.
One of such substances is the Nerve Growth Factor (NGF) - an
insulin-like substance that stimulates the growth of sympathetic
ganglia. NGF is produced in the salivary glands by the smooth muscle
fibers of the walls of internal organs. Similarly, the adaptive-trophic
effect on VNS is provided by neuropeptides: liberins, somatostatin,
enkephalins, endorphins, bradykinin, neurotensin, cholecystokinin,
ACTH fragments, oxytocin [5].
“When excited in neurons, metabolic processes are intensified,
the amount of RNA increases, and the synthesis of proteins in
neurons is enhanced. In neurons and glia cells surrounding them,
these processes are multidirectional. RNA in nerve cells is increased
due to the enhancement of its synthesis in a neuron and due to the
transport of RNA from glial cells to neurons “[6]. But, despite the
restorative and trophic processes, the vegetative nervous system
cannot hypertrophy (the adrenal medulla is a modified sympathetic
ganglion). Adaptive, positive, trophic changes, during pauses, allow
the sympathetic VNS just not to be exhausted, to maintain high
activity for a long time - a kind of hyper functionality. But there is
no doubt that the mechanism of “advanced excitation” also inherent
in the endocrine part of the neuroendocrine system, when the
endocrine glands, releasing excessive hormones, also “take a pause”
for their own trophic recovery processes, but unlike the VNS, these
processes lead them to hypertrophy and hyper productivity. After
all, hypertrophy resides in structures. Histological evidence of the
endocrine system hypertrophy with regular exposure to a mediumstrength
stimulus is Selye’s stress research: “adrenal glands bloom”.
Speaking of adrenal hypertrophy, one should mean the adrenal
cortex. As early as in 1930s, it was found that chronic morphinization
causes hypertrophy of the cortical layer of the adrenal glands in
rats, which produces the “adaptation hormones” - glucocorticoids
(hydrocortisone, cortisone and corticosterone), increasing the
tolerance of the organism to intensive stimuli [3]. There is no doubt
that hypertrophy of the adrenal cortex begins already during the
activation reaction, since the process of adrenal hypertrophy is not
an abrupt process. There is no doubt that due to the mechanism of
“advanced excitation” other endocrine glands also “take a pause”
for trophic recovery processes, which leads to their hypertrophy
and hyper functionality. Evidences of adaptive hypertrophy of the
endocrine system are L. Kh. Garkavi and co-authors’ observations
under conditions of training and activation reactions – enlargement
of the thymus gland and adrenal cortex, a prolonged increase in the
thyroid and reproductive gland functions.
Results of the Study and their Discussion
Thus, under the regular exposure to PAS as a sub-extreme stimulus, while hypermetabolic processes occur in the “metabolic boiler,” accumulation of reserves takes place in the endocrine system, as a result of “advanced excitation”. This accumulation of reserves leads to adaptive hypertrophy and hyperfunction of the endocrine system, which results in an increase in the tolerance of the body. That is why, a subsequent, increasing, potentially extreme dose of PAS has a sub-extreme non-pathogenic effect on the body. The condition persists for the further adaptation (Figure 1). Thus, in PAS dependence, in each range and in the transition to a higher adaptation range, one should speak not of the reaction dyad: activation and persistent activation, but of the reaction tetrad: activation, persistent activation, then stress with “anxiety reaction”, and the stage of resistance. And the hypertrophy of the endocrine system that has developed to this moment, does not allow development of the final stage of stress - exhaustion. At this moment, the zone of non-reactivity separating the ranges, is observed, when the intensification of the stimulus above the stress level or the weakening below the training one does not cause any reaction. With an increase in the dose of PAS and transition to another range, everything comes around. It is more correct to call such a process not a state of chronic stress, but a state of regular, unfinished stresses.
Figure 1: Biology of progressive adaptation and validation of the psychoactive substance dependence.
Stress without the exhaustion stage, no matter how regular it is,
cannot be considered as a disease. That allows the body to transit
to a higher range of adaptation without death. It becomes clear that
increased resistance in persistent activation reaction responding
to regular sub-extreme exposure to PAS and the resistance stage
in stress reaction responding to the further regular exposure to an
increasing dose of PAS are functional manifestations of adaptive
hypertrophic changes in the endocrine system. This process is
called progredient (progressive) adaptation. Beliefs about the unity
of form and function, the stereotyped thinking that “if changes in the
body are acquired and irreversible, therefore, they are pathological,”
have led to the erroneous judgment that the body’s dependencies
on PAS should be considered as diseases. There is the expression
“any disease is an adaptation.” But the opposite statement that
“any adaptation is a disease” in relation to PAS dependencies is
inadmissible. After all, hypertrophy of the endocrine system, its high
adaptation adequacy, leading to an increase in general and specific
resistance, do not result in failure or lack of adaptive capabilities.
Consequently, there is no need to compensate for the adaptive
capacity of the body at the expense of the tissues and the systems
of the body - the disease does not arise. Thus, increase in adaptive
capacity is directly proportional to the increase in a dose; the role
of receptors of the body’s protective systems (* - in the figure)
indicating possible PAS overdose, experience of narcotization are
also important.
Due to the vegetotrophic nature of PAS, in PAS dependencies,
in contrast to the disease, the mechanism of PAS action is also
different. Common pathogenic factors – without pronounced
vegetotrophy - cause damage at first, and only later a protective
reaction of the organism develops. PAS, simultaneously or
primarily, affect the receptors of VNS, which causes its timely or
even advanced reaction to possible damage from the PAS effect. In
PAS dependence, the increase in the exposure dose occurs through
the “non-pathogenic corridor” - between the signals of the body’s
protective systems - receptors indicating a possible overdose, and
the hypertrophying endocrine system (Figure 1). That is why the
acquired biological changes in PAS dependence are only of adaptive nature. And thereby, one should talk about the adaptive attraction,
adaptively changed behaviour, adaptively changed reactivity to PAS
or, conversely, about the readaptation - deprivation syndrome, and
so on. In the final stage of the dependence, depletion of the adaptive
capabilities of the organism, due to the hypotrophy of the endocrine
system, the receptors of the body’s protective systems indicate
possible PAS overdose. This leads to a parallel decrease in the dose
of PAS that a person is able to adapt, the effect of PAS turns out to be
sub-extreme again, and pathology is not observed either (Figure 1).
Pathology in PAS Dependence is an Accompanying Phenomenon
The explanation of the increased tolerance by means of the
adaptive hypertrophy of the endocrine system does not contradict
the development of biochemical theories of the euphoria etiology
and explains the internal mechanism of clinical manifestations
in PAS dependence. Under alcohol exposure, when abuse with
adaptive, qualitative or quantitative changes in the mechanisms
responsible for the euphoria is required to achieve euphoria and
acquire dependence, the accompanying increase in tolerance can be
explained by the endocrine system hypertrophy. The VNS activity
and productivity of the hypertrophying endocrine system in the
first stage of alcohol dependence explain maintaining the body
tone during the week intervals of sobriety, in the absence of alcohol
stimulation. Compensatory stress of VNS and sufficient production
of neurotransmitters or residual neurotransmitter excess, explain
adrenergic tension and expressed vegetative disorders in the
alcohol withdrawal syndrome.
The activity of the sympathetic part of VNS against the
background of the gradual exhaustion of the parasympathetic
department (the adrenergic system is more stable in ontogenesis,
too) also explains the qualitative change (according to narcotism
age) of the sedative PAS (hypnotics, alcohol, opiates) effect on the
body, transformation of their initial sedative action into a stimulating
one. The hypertrophy of the endocrine system due to prior
narcotization (and hence an increase in overall resistance) explains
the rapid development of alcohol dependence in former opium
addicts in alcoholization: rapid increase in alcohol tolerance, the
rapid formation of alcohol abstinence syndrome, the development
of binge drinking (to develop alcoholism in former drug addicts, it
is sufficient to develop only a specific tissue adaptation to alcohol).
Stimulation of the hypertrophic endocrine system and increase in
the overall resistance of the organism explain the fact that many
stimulants (caffeine), eliminating some effects of ethanol, however,
do not change its pharmacokinetics, but prolong its intoxicating
effect. Initially the psychomotor agitation in PAS-dependent people
getting narcosis can be based on the excitement of the active,
sympathetic department of VNS. As the PAS dependence develops,
due to the mechanism of “advanced excitation”, contributing to
adaptive activity-hyper functionality of the sympathetic VNS, the
hypertrophy and hyper productivity of the endocrine system lead
to the fact that the role of the entire neuroendocrine system as a
functional mechanism of protection and adaptation increases and
becomes the leading one.
Conclusion
a) Under regular sub-extreme exposure of the organism
to psychoactive substance, the mechanism of “advanced
excitation” allows to maintain the activity of the sympathetic
VNS, leads to hypertrophy of the adrenal cortex.
b) Under regular sub-extreme exposure to psychoactive
substance, adaptive maintenance of sympathetic VNS activity
and adaptive hypertrophic changes in the endocrine system
lead to an increase in the tolerance of the body.
c) In psychoactive substances dependence, due to the adaptive
activity of the sympathetic VNS, adaptive hypertrophy and
hyper productivity of the endocrine system, potentially
extreme doses have a nonpathogenic sub-extreme effect on
the human organism.
d) Dependence of the body on psychoactive substances due to the
increased tolerance of the organism and the transformation of
the effect of potentially extreme doses into the sub-extreme
effect is the adaptation process.
e) Recommendations: It is necessary to validate the dependence
of the body on psychoactive substances not as a disease, but as
a state of progredient adaptation.
References
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- AV Korobkov, AA Bashkirov, KT Vetchinkina (1980) Normal physiology. Chapter 28 Physiology of adaptation. Moscow High School 560: 499.
- IN Pyatnitskaya (1975) Clinical Drug Addiction. Moscow: Medicine, Leningrad branch 333: 3-6.
- IN Pyatnitskaya (1988) Alcohol abuse and the initial stage of alcoholism. Medicine 286: 77-80.
- VM Smirnov, VN Yakovlev (2004) Physiology of the central nervous system. Moscow: Academy, pp. 184-185.
- OI Kirillov (1994) Stress hypertrophy of the adrenal glands. Moscow: Science, pp. 176.
