2917
Views & Citations1917
Likes & Shares
Using atomic emission spectrometry, the
content of Sodium (Na) and Potassium (K) in an epidermal derivative was
measured in healthy subjects (n=9991). According to the spectrometry data, 4
groups were formed depending on the value of the Na/K ratio: Group 1: Na/K<1
(n=1834), Group 2: Na/K – 1 to 5 (n=6884), Group 3: Na/K – 5 to 10 (n=893) and
Group 4: Na/K>10 (n=380). A correlation analysis (Pearson) of the KNa bond
tightness was conducted in the total sample (n=9991) and in each of the groups
with different values of Na/K.
It was found that the correlation
coefficient r in the total sample (r_{KNa}=0.61; p<0.05)
was noticeably lower than in any of the four groups (r_{KNa}=0.850.97;
p<0.05). It was also established that the reduction of r_{KNa} was due
to the presence of the spectrometry data of Group 1 (where Na/K<1) in the
total sample. As a hypothesis, the authors suggest that there is a connection
between the brain electrical activity (BEA) and the synchronous (critical) work
of membrane K^{+}/Na^{+}ATPases in epidermal cells.
Keywords: Na and Khomeostasis, Electrical activity of the brain,
Oxidative/nitrosative stress, Epidermis, Selforganized criticality
INTRODUCTION
In our previous
studies [18] were obtained evidence accessories for the homeostasis of electrogenic
metals (K, Na, Ca) in epidermis to the phenomena of selforganized criticality
(SC). This was evidenced by:
1)
Power
dependence between the content of K, Na and Ca in epidermis and the number of
individuals in certain intervals of concentration values;
2)
Fractal
distribution of the spectrometry data of these metals in epidermis;
3)
Synchronous
(critical) nature of operation of Na^{+}/K^{+}ATPase, which is
the main transporter of Na^{+} and K^{+} ions through the cell
membrane.
The conclusion
about the possibility of synchronous (critical) functioning of Na^{+}/K^{+}ATPases
was made by us after we had established a reliable and stable linear
relationship (Pearson) between the concentration values of these metals
(according to the spectrometry data) [9].
However, the r_{KNa}
coefficient, which ranged from 0.6 to 0.7 in different samples, seemed to us
too ‘humble’ for the synchronous (as a ‘single mechanism’) operation of
membrane pumps. This parameter, apparently, should be significantly higher if
we are talking about critical processes. Therefore, we tried to find out what
it was that contributed (directly or indirectly) to the probable
‘understatement’ of the KNa level.
It is
significant that the ratio of the average values of [Na] and [K]
(bootstrapmethod), according to our data, in such a substrate as hair in 947
healthy individuals was almost identical – 1.5 [7].
At the same
time, by spectrometry of epidermis (hair), we observed pronounced scattering of
individual metal concentrations: sodium – 0.645 μg/g to 9240 μg/g; and
potassium – 0.045 to 6505.1 µg/g [8], which allows for the existence of a
spread among the individual values of the [Na]/ [K] ratio. It was interesting
to find out the individual [Na]/[K] fluctuations in healthy individuals of most
productive working age (20 to 49 years).
At the same
time, one cannot exclude the connection between the [Na]/[K]ration and the
critical (synchronous) mode of operation of the membrane Na^{+}/K^{+}ATPase.
We analyzed correlations between [Na] and [K] depending on the value of
[Na]/[K] to confirm or reject such a possibility. The analysis results are
presented in this paper.
MATERIALS AND METHODS
Determination
of sodium (Na) and potassium (K) in hair was done in a laboratory of the Center
for Biotic Medicine (Moscow) using mass spectrometry with inductively coupled
plasma (ICPMS) on a NexION 300D spectrometer (Perkin Elmer Inc., Shelton, CT,
USA). Practically healthy Moscow residents aged 20 to 49 were under observation
(n=9991), of which 4999 (50.04%) were males and 4992 (49.96%) – females.
Hair samples
for the spectrometry study were taken from the subjects following a mandatory
informed consent procedure. In the occipital region, a tuft of hair 2 cm long
and 0.5 cm thick was cut off close to the scalp.
To minimize the
possibility of environmental contamination, hair samples were washed with
acetone and then rinsed thrice with deionized water with subsequent air drying
at 60°C. Further treatment of the samples was performed using microwave
degradation. Specifically, 50 mg hair samples were introduced into a Teflon
container and added to 5 ml of concentrated analytical grade HNO_{3}
(SigmaAldrich Co, St. Louis, MO, USA). Decomposition was performed in a Berghof speedwave four system (Berghof
Products & Instruments, Germany) for 20 min at 170180°C. After
decomposition, deionized water was added to get a final volume of 15 ml.
A correlation
analysis (Pearson) of the obtained data was carried out with determination of
the correlation coefficient r_{KNa} (pairwise
correlations between the concentration values of K and Na in the substrate). We
tested the normal distribution hypothesis using the JarqueBera test [1] and
the KolmogorovSmirnov test [4]. Because of this test, it was possible with
high probability to refute the hypothesis of normal distribution of chemical
elements. Therefore, an alternative approach (the bootstrap method) was used,
which does not require a normal distribution of the priori ensemble [2].
The Matlab
software tool was used for statistical data processing.
RESULTS AND DISCUSSION
The
distribution of individuals depending on the [Na]/[K] ratio was as follows:
[Na]/[K]<1 was detected in 1834 subjects (18.4%); [Na]/[K] from 1 to 5 – in
6884 subjects (68.9%); [Na]/[K] from 5 to 10 – in 893 subjects (8.9%);
[Na]/[K]>10 – in 380 subjects (3.8%). The correlation coefficient r between
[Na] and [K] was found in each of these groups. The results are presented in Table 1.
As can be seen
from Table 1, the values of
coefficient r were higher in all the four subgroups (regardless of the
[Na]/[K] ratio value) as compared to the total sample.
It was
interesting to find out which one of the presented subgroups contributed the
most to the ‘understatement’ of r in the general sample as compared
to all the other subgroups. In that respect, the most ‘suspicious’ was subgroup
1 with the [Na]/[K] ratio<1, which fundamentally distinguished it from all
the others.
Therefore, we
decided to find out in what way the presence of subgroup 1 in the total sample
affected the r coefficient value alone or in conjunction with each of the
subgroups or any combinations thereof (Table
2).
It is
significant that the addition of subgroup 1 (where Na/K<1) to each of the
three other subgroups (separately and in various combinations, Table 2) resulted in a noticeable
(almost twofold) decrease in r_{KNa}. That does not seem
accidental. It seems highly likely that it was the presence of individuals from
subgroup 1 (Na/K<1) in the total sample that accounted for such an
extraordinary ‘humble’ (0.61) value r_{KNa} for general
sampling.
The synchronous
(critical) mode of operation of Na^{+}/K^{+}ATPases, as we
noted earlier, is combined with a high level of r_{KNa}. Interestingly,
the value of this parameter in subgroup 1 itself (r_{KNa}=0.86;
p<0.05) is indicative of synchronous operation of the Na^{+}/K^{+}
pump in individuals with an ‘inverted’ Na/K coefficient (<1). This fact has
little relation to the inhibitory influence of subgroup 1 on the r_{KNa},
which requires further investigation of the possible causes of such an effect.
In this regard, the level of Na and K in the biosubstrate (hair) depending on
the value of the Na/K ratio was of special interest.
Using the
bootstrapmethod [2], which does not require a normal distribution of a priori
ensemble, the mean and interval values of these metals were found pursuant to
the hair spectrometry data. The results are presented in Table 3.
The results (Table 3) indicate a marked variability
in the Na/K ratio (subgroup average) from 0.65 to 22.6. The mean values of [Na]
and [K] differed significantly among the subgroups (Table 3). The minimum average level of sodium (223.4 µg/g) was in
subgroup 1, the maximum (539.4 µg/g) in subgroup 4; whereas for potassium, the
average minimum (32.7 µg/g) was in subgroup 4, while the maximum (384.8 µg/g)
was in subgroup 1.
When analyzing
the presented data, a natural question arises: why does the correlation
coefficient r_{KNa}, while being extremely high (~0.9) in each of
the subgroups, become noticeably lower (0.61) when subgroup 1 is added to the
total sample?
As already
mentioned, the most significant difference of subgroup 1 from the rest is the
‘inverted’ Na/K ratio. The connection between this ‘inversion’ and the decrease
of r_{KNa}
may be regarded as one of the possible reasons for the decrease. Let us explain
this in detail.
A close
relationship between [Na] and [K] in the substrate (r_{KNa} ~0.9),
indicating the synchronous (critical) nature of the membrane Na^{+}/K^{+}ATPases,
was found in all (without exception) the subgroups studied (including subgroup
1, where Na/K<1). It was combined with significantly (p<0.05) different
content of sodium and potassium in the biosubstrate for each of these subgroups
(Table 3). This allows us to assume
the existence of some kind of an external synchronizer for the membrane Na^{+}/K^{+}ATPases,
which should be heterogeneous in its frequency characteristics (and/or
consisting of several oscillatory systems). In the role of such a synchronizer,
one can imagine, at least hypothetically, the brain electrical activity (BEA)
with a known set of differentfrequency rhythms detected by the electroencephalography
(EEG) rhythms.
The
physiological frequency ranges of EEG rhythms are known  δ (delta): 0.54.0
Hz; θ (theta): 4.08.0 Hz; α (alpha): 8.013.0 Hz; β1 (beta 1): 13.020.0 Hz; β_{2}
(beta 2): 20.030.0 Hz. These rhythms differ not only in frequency, but also in
other parameters that have an important diagnostic value (amplitude, power,
topography, etc.). The main is the αrhythm, most pronounced in the caudal
(occipital and parietal) areas of the cerebral cortex.
It cannot be
ruled out that exactly αrhythm may turn out to be the most demanded
synchronization factor Na^{+}/K^{+}ATPases (or order parameter) in individuals of
subgroup 2 (68.9%) with the average values of basic indicators found in them
(according to our data): Na/K=2.3; [Na]=260.6 µg/g and [K]=127.5 µg/g.
An indirect
confirmation of the possible effect of BEA on the level of potassium and sodium
in the epidermis can be found in our work [7], where we studied the dynamics of
the level of Na and K (hair spectrometry) in 10297 healthy individuals (5160
men and 5137 women) of different age groups (2 to 85 years). The results are
presented in Table 4.
The level of Na
and K in the epidermis was found as a median with the boundaries of the
confidence interval (the bootstrap method). The ratio of medians (Me [Na]/Me
[K]) in each age group was as mentioned in Table
5.
In the absolute
majority of healthy subjects (Table 5),
which we investigated in the cited paper [7], the ratio [Na]/[K] (median)
ranged from 2.1 to 2.4 (starting from the age of 20). It is should be noted
that it is quite close (2.3) to the same parameter ([Na]/[K]) obtained in the
present work for most individuals (68.9%) but using the mean values of [Na] and
[K] (Table 3). After replacing the
average with the median, the [Na]/[K] ratio was almost unchanged (2.1 vs. 2.3).
The [Na]/[K]
ratio in the younger age group (2 to 9 years) turned out to be less than 1
(0.86), i.e. the same ‘inverted’ ratio as in subgroup 1 (Table 3). In Table 3,
this ratio (0.65) is calculated from the mean values of [Na] and [K]. The
replacement of the average by the median had practically no effect on the value
of this parameter (0.68 vs. 0.65).
Why is the fact of
‘inversion’ of [Na]/[K] ratio in children from 2 to 9 years old so important?
The answer is that at this age (up to 13 years old) the dominant EEG rhythm is
the θ rhythm [3], whose participation in the appearance of the ‘inverted’
[Na]/[K] coefficient in 18.4% of people of mature age (2049 years) in our
observations seems likely. This requires verification and refinement in
combined (EEG+spectrometry)
studies, but at the same time allows for the possibility of the BEA influence
(as an order parameter) on the operation of membrane ATPases. Moreover, this
assumption (in addition to the possible ‘synchronizing’ action of BEA on the
operation of membrane pumps) will include, as shown by our data, the
probability of a significant effect of BEA on the level and the ratio of [Na]
and [K] in the substrate.
It is not very
clear why the presence of subgroup 1 ([Na]/[K]<1) in the total sample causes
a noticeable decrease in the tightness of the relationship between [Na] and
[K], whereas in subgroup 1 itself the r_{KNa} turned out to be
high (0.86; Table 1). One possible
explanation for such ‘inconsistency’ can be as follows:
As already
mentioned, the [Na]/[K] ratio for the whole body is ~1.3 with the predominant
localization of sodium in the extracellular space and potassium  inside the
cell [5]. The main membrane pump, Na^{+}/K^{+}ATPase, which
works against the electrochemical gradient of these metals, under whose
influence Na^{+} ions tend to get into the cell and K^{+} ions
tend to leave it, provides this distribution. An important feature of the Na^{+}/K^{+}ATPase
operation is its ability (per unit time) to remove more Na^{+} ions
from the cell than K^{+} ions, which this pump has time to ‘pump’ into
the cell. By the way, this explains the existence and relative constancy of the
membrane potential.
The ratio of
[Na] and [K] we found earlier (by average values) in such biosubstrate as hair
amounted to 1.5 [7], i.e., almost did not differ from that for the whole body
(1.3). Therefore, it seemed that distribution of these metals in the epidermis
(with a predominance of Na) is normative and may be found in all healthy
individuals without exception. However, that is not confirmed by the data we
obtained.
In 18.4% of
healthy individuals (subgroup 1, Table 1)
[Na]/[K] was <1 (average 0.65). In addition, the presence of this subgroup
in the general population explains the noticeable decrease in r_{KNa}
(down to 0.61), compared with the same parameter in each of the fractions and
its average value (r_{KNa}=0.9).
Therefore, we
are ready to assume that a decrease in the Na content in a substrate with
predominance of K may indicate (at least in some individuals with the lowest
[Na] value and the highest [K]) significant changes in the distribution of
these metals inside and outside the cell. This, in our opinion, may be due to a
change in the direction of the electrochemical gradient of Na^{+} and K^{+}
ions or, in other words, the reversal of the pump function of Na^{+}/K^{+}ATPase
(‘pumping’ K^{+} ions from the cell and ‘pumping’ Na^{+} ions
into the cell). In this case, the known proportion of ion exchange for a given
pump (3 Na^{+} ions vs. 2 K^{+}
ions) can be maintained.
It is known
that such a reversion (due to changes in the membrane potential and the content
of sodium and calcium in the cell) occurs with the sodiumcalcium exchanger
(NCX) [6].
Due to the high
level (0.86) of r_{KNa} in individuals with [Na]/[K]<1 (Table 1), technical reasons are less
likely to explain the reduction of sodium in the biosubstrate (storage
conditions of the sample and/or its processing).
Another aspect
of sodiumpotassium homeostasis in the epidermis (which is closely related to
the results of this work) needs to be discussed. We are talking about the
interpretation and diagnostic value of the data of hair spectrometry and the
possibility of their extrapolation on the body as a whole.
The results of
the study have convinced us that these data do not reflect changes in metal
homeostasis at the level of the whole body, and, therefore, they neither allow
us to judge about the adequate availability of Na and K, nor help us to
identify their dangerous deficit or excess.
Thus, the mean
values of [Na] and [K] in all subgroups differ from each other with high
reliability (Table 3). At the same
time, the average value of [Na] in subgroup 1 is more than twice lower than in
subgroup 4, and the average value of [K] in subgroup 1 is almost 12 times
higher than in subgroup 4 (!). The scattering of individual values of these
metals in the epidermis, which we have already mentioned, is even more
impressive: Na – from 0.645 μg/g to 9240 μg/g; K – from 0.045 to 6505.1 µg/g.
It must be noted that all the measurements were carried out in practically
healthy subjects showing no pathological symptoms.
Therefore, to
avoid unjustified generalizations, the results of hair spectrometry, as well as
possible changes in metal homeostasis, should only be attributed to the given
substrate  epidermis, which, as shown by our experience, can be productively
used in studying the complex problems of modern bioelementology.
1.
Bera AK, Jarque CM (1980)
Efficient tests for normality, homoscedasticity and serial independence of
regression residuals. Econ Lett 6: 255259.
2.
Davison AC, Hinkley VD (1997)
Bootstrap methods and their application. Cambridge University, UK.
3.
Евин ИА (2008) Синергетика
сознания. – М. – Ижевск: НИЦ «Регулярная и хаотическая динамика». – 128 с.
4.
Lilliefors H (1967) On the
KolmogorovSmirnov tests for normality with mean and variance unknown. J Am
Statistical Assoc 62: 399402.
5.
Маршалл В.Дж (2000) Клиническая
биохимия. – М. – СПб.: «БИНОМ» – «Невский диалект». – 368 с.
6.
Nicholls JG, Martin AR, Wallace
BG, Fuchs PA (2001) From neuron to brain. Sinauer Associates, Inc., Publ.,
Sunderland, Massachusetts, p: 672.
7.
Petukhov VI, Dmitriev EV,
Baumane LKh, Skalny AV, Lobanova YuN (2016) Electrogenic metals in epidermis:
Relationship with cell bioenergetics. Insights Biomed 1: 914.
8.
Petukhov VI (2017) What are the
limits, if any, of normal content of electrogenic metals (K, Na, Ca) in epidermis?
Insights Biomed 2: 1317.
9.
Petukhov VI, Dmitriev EV,
Kalvinsh I, Baumane LKh, Reste ED, et al. (2011) Metalligand homeostasis in
epidermic cells of Chernobyl accident liquidators. Vitamins Trace Elements 1:
18.
QUICK LINKS
 SUBMIT MANUSCRIPT
 RECOMMEND THE JOURNAL

SUBSCRIBE FOR ALERTS
RELATED JOURNALS
 Journal of Biochemistry and Molecular Medicine (ISSN:26416948)
 Food and NutritionCurrent Research (ISSN:26381095)
 Journal of Astronomy and Space Research
 Journal of Veterinary and Marine Sciences (ISSN: 26897830)
 Journal of Genomic Medicine and Pharmacogenomics (ISSN:24744670)
 Journal of Microbiology and Microbial Infections (ISSN: 26897660)
 Journal of Womens Health and Safety Research (ISSN:25771388)