Slovakia online
THE IMPACT OF NEONATAL NUTRITION ON LIPOLYSIS AND BINDING OF CATECHOLAMINES IN ADIPOCYTES OF RAT
MACHO, L., FICKOVA, M., ZORAD, S.
Underfeeding or overfeeding of rats during the suckling period, realized by the adjustment of the number of sucklings per litter, are followed by important changes in the function of endocrine glands and hormonal stimulation of lipolysis in adipocytes.For explanation of causes of the differences in the stimulation of lipolysis the changes of beta-receptors in adipocytes were studied in animals with different neonatal nutrition. The number of suckling pups in litter was adjusted to 4, 8, 14 on the second postnatal day. After weaning (at the age of 30-500 days) the size of adipocytes, basal and norepinephrine stimulated lipolysis, the binding of [^3]H-dihydroalprenolol in adipocytes were determined. In neonataly underfed animals, in comparison to overfed, those a decrease in the size of adipocytes, a diminution of basal lipolysis and lower stimulation of lipolysis by norepinephrine were observed. The decrease in binding capacity (at the age of 30-60 days) and of affinity of beta-receptors (at the age of 60 to 360 days) were found in neonatally overfed rats. These results showed that the changes of beta-adrenergic receptors in adipocytes of animals with neonatal nutritions have a role in the alteration of the stimulation of lipolysis in adipocytes. (Tab. 2, Fig. 4, Ref. 29.)
Key words: adipocytes; lipolysis; beta-receptors; neonatal nutrition; rat.
Bratisl Lek Listy 1995; 96: 581-585
METHYLENE BLUE AS AN ENDOCRINE MODULATOR: INTERACTION WITH THYROID GLAND HORMONES
SCHREIBER, V.
Methylene blue (MB) is a thiazine dye used in the treatment of
methemoglobinemia. Since it was shown to scavenge free radicals,
it is now being examined clinically in reperfusion syndrome and
septic shock. We tested methylene blue in a series of experimental
endocrine situations, in which this scavenging effect could play
a role. Indeed, we observed that MB partly inhibited the increase
in adenohypophyseal weight and cAMP and prolactin levels after
the administration of estrogens in male rats. MB also inhibited
the increase of another scavenger of free radicals, the metalloenzyme
ceruloplasmin in the blood of estrogenized rats. MB also inhibited
the stimulation of bone mass after estradiol in male rats. In
this respect, it behaved as an antiestrogen. In the bones, MB
also prevented the increase of bone minerals induced by estradiol.
MB also produced a decrease in adenohypophyseal ascorbic acid
content an potentiated the effect of estradiol in the same direction.
Surprisingly, blood thyroxine levels increased consistently in
rats after MB treatment. An interaction of MB with thyroid hormone
synthesis and/or actions thus should be evaluated. This idea is
supported by our observation of an antagonistic action of MB in
carbimazole-induced rise in thyroid weight and decrease in thyroxine
blood levels. (Ref. 14.)
Key words: methylene blue; pituitary; ceruloplasmin; bones; thyroid gland.
Bratisl Lek Listy 1995; 96: 586-587
GLUTAMATE NEUROTRANSMISSION, STRESS AND HORMONE SECRETION
JEZOVA, D., JURANKOVA, E., VIGAS, M.
Glutamate neurotransmission has been investigated in relation to several physiological processes (learning, memory) as well as to neurodegenerative and other disorders. Little attention has been paid to its involvement in neuroendocrine response during stress. Penetration of excitatory amino acids from blood to the brain is limited by the blood-brain barrier. As a consequence, several toxic effects but also bioavailability for therapeutic purposes are reduced. A free access to circulating glutamate is possible only in brain structures lacking the blood-brain barrier or under conditions of its increased permeability. Excitatory amino acids were shown to stimulate the pituitary hormone release, though the mechanism of their action is still not fully understood. Stress exposure in experimental animals induced specific changes in mRNA levels coding the glutamate receptor subunits in the hippocampus and hypothalamus. The results obtained with the use of glutamate receptor antagonists indicate that a number of specific receptor subtypes contribute to the stimulation of ACTH release during stress. The authors provided also data on the role of NMDA receptors in the control of catecholamine release, particularly in stress-induced secretion of epinephrine. These results were the first piece of evidence on the involvement of endogenous excitatory amino acids in neuroendocrine activation during stress. Neurotoxic effects of glutamate in animals are well described, especially after its administration in the neonatal period. In men, glutamate toxicity and its use as a food additive are a continuous subject of discussions. The authors found an increase in plasma cortisol and norepinephrine, but not epinephrine and prolactin, in response to the administration of a high dose of glutamate. It cannot be excluded that these effects might be induced even by lower doses in situations with increased vulnerability to glutamate action (age, individual variability). (Tab. 1, Fig. 6, Ref. 44.)
Key words: glutamate neurotransmission; glutamate receptors; stress; hormone release; blood-brain barrier.
Bratisl Lek Listy 1995; 96: 588-596
CLINICAL ROLE OF THE NATRIURETIC HORMONES
LAZUROVA, I., LICHARDUS, B.
Out of all until now discovered natriuretic factors it is still
the atrial natriuretic factor (ANF) which is the most significant
with its diuretic, natriuretic and vasodilatory effects. Its effect
is antagonstic to sodium retention factors. The increase of its
levels in arterial hypertension is more of secondary character,
but according to some authors the functional deficit of ANF secretion
can be applied also primarily in the development and maintenance
of high blood pressure. ANF levels represent a good marker of
the clinical severeness and are of prognostic value.Increased
levels were detected also in cases of renal failure and partially
in hepatic cirrhosis.
Natriuretic hormone, in comparison to ANF, is a natriuretic and
vasoconstrictive substance, the effect of which is based on the
mechanism of sodium pump inhibition. Chemically the main candidate
is represented by endogenous ouabain, or a digitalis-like activity.
It increases physiologically due to the expansion of extracellular
fluid during gravidity and in newborn. Its pathological increase
is brought about by some forms of essential hypertension and in
the diseases associated with fluid retention and edema development.
Cirrhosis of the liver can reflect both the degree of sodium retention
and haemodilution, as well as the severeness of hepatic lesion.
(Tab. 2, Ref. 30.)
Key words: ANF; inhibitor of Na-K-ATPase; digoxin-like activity; arterial hypertension; heart failure; hepatic cirrhosis.
Bratisl Lek Listy 1995; 96: 597-599
SEXUAL STEROID HORMONES INSENSITIVITY SYNDROMES
STARKA, L., HAMPL, R.
Background: Today more than one hundred mutations are known
of the gene for androgen receptor (AR) and merely one mutation
of that for estrogen. The current trend in research has included
the completation of the list of receptor defects and seeking the
coincidence with their variable clinical manifestations.
Aim: The aim of the study is to review the current state
of the research on the defects of androgen and estrogen receptors
and to draw attention to the clinical manifestations of the resistance
to the sexual steroid hormones and currently to present own contributions
in this problem.
Methods: Diagnostic application of the androgen resistance
dynamic test residing in investigation of the SHBG level after
adrogen or anabolics administration. Molecular-biological analysis
of AR defects with Phe 878 Ser mutation.
Conclusions: Perspective acknowledgement of androgen and
estrogen receptor defects allows a more precise diagnosis statement
and perhaps also therapy of various forms of resistance to steroid
sexual hormones. It can contribute to the understanding of some
subsequent pathological processes dependent on the expression
of androgens and estrogens. (Tab. 1, Ref. 20.)
Key words: androgen receptor; estrogen receptor; hormonal resistance; diagnosis of hormones insensitivity.
Bratisl Lek Listy 1995; 96: 600-604
CUSHING'S SYNDROME IS STILL A POTENTIAL KILLING DISEASE
KREZE, A.
The paper summarizes the studies documenting the outlasting of increased cardiovascular mortality in patients with Cushing's syndrome even after the hypercortisolism resolution. Despite the hypercortisolism resolution the mortality during the subsequent period of life is up to four-fold higher than in the comparable population as a whole. The pathogenesis of this cardiovascular risk is based on arterial hypertension, steroid cardiomyopathy and hyperlipidaemia with subsequent atherosclerosis. The post mortem material bears a parallel of the extent of atheromatous changes and duration of hypercorticolism. The prevention has to its disposition two mutually complementing means. The first is represented by clinical screening of hypercorticolism which enables an early recognition and therapy of the Cushing's syndrome. The successive measure resides in increased attention to the cardiovascular system even after hypercorticolism resolution. (Tab. 1, Fig. 1, Ref. 25.)
Key words: Cushing's syndrome; cardiovascular mortality; hypercorticolism screening.
Bratisl Lek Listy 1995; 96: 605-608
THE EFFECT OF INSUFFICIENT IODINE SUPPLY ON THE SIZE AND FUNCTION OF THE THYROID GLAND
ZAMRAZIL, V., CEROVSKA, J., BILEK, R., SIMECKOVA, A., VRBIKOVA, J., DVORAKOVA, M., HNIKOVA, O., JANECKOVA, M., TOMISKA, F.
Background: The supply of iodine indisputably affects the
function of the thyroid gland. It is not clear, however, as to
what extent a moderate iodopenia affects common thyroid parameters.
Objectives, starting point and main purpose: The aim of
the study is to evaluate the influence of iodopenia (ioduria below
50 microg of iodine per litre of urine) on the values of T4, T3,
TSH, the ankle-jerk time and sonographically ascertained thyroid
gland volume in randomly selected sample of Czech population from
4 regions.
Methods: Ioduria was assessed by means of Sandel-Kolthoff
method, total thyroxine, triiodothyronine and thyreotropic hormone
by immunoluminiscence method; the volume of the thyroid gland
sonographically according to Gutekunst and the ankle-jerk reflex
by electromagnetic record method.
Results: Iodopenia affects a majority of investigated parameters
in dependence on age. T4 is significantly higher in iodopenic
adults, T3 is significantly higher in iodopenic children, TSH
is significantly higher in iodopenic adults and the ankle-jerk
time is prolonged in iodopenic adults. The statistical significance
of the effect of iodopenia on the volume of thyroid gland was
not proved.
Conclusions: Iodopenia of a mediate degree affects commonly
used parameters of the thyroid gland function in dependence on
age and other factors which are to be more precisely analyzed
using a larger sample. The statistical significance of the effect
of iodopenia on the volume of thyroid gland was not proved. (Tab.
1, Fig. 5, Ref. 13.)
Key words: iodine; iodopenia; thyroid gland; T4; T3; TSH; ankle-jerk time.
Bratisl Lek Listy 1995; 96: 609-612
THE CURRENT AND FUTURE IODINATED SALT SITUATIONS ON THE SUPPLEMENTATION IN THE POPULATION
LANGER, P., SIGMUNDOVA, V., KAPLANOVA, M., LINKOVA, M., TAJTAKOVA, M., SICHULOVA, A., LONGAUEROVA, Z., SKLENARIKOVA, Z.
Iodine content was estimated in 401 samples of table salt (out of which 365 from the distribution network and 101 from households). The values of 85.5 % of samples from the distribution network were in normal range (i.e. 25±10 mg KI/kg), while 9.8 % of samples showed the values below that range. The samples from households showed lower values, only 70.2 % being in normal range and 28.6 % below that which was 3times more than in those from the distribution network. Such difference may be explained by the loss of iodine from the salt during the storage due to the effects of moisture, temperature and light. However, less satisfactory iodine levels were found in the salt imported from Poland (9 of 28 samples below the normal range, i.e. 32 %), Austria (5 from 9 samples below normal range, i.e. 55 %) and in the sea salt (7 from 11 samples below normal range, i.e. 63 %), while satisfactory values were found in the salt from Germany (all 5 samples examined were in normal range). From 1126 samples from the distribution network examined during 1981-1986 were 63.6 in normal range, while 88.4 % out of 612 samples examined during the period 1987-1990 hat their iodine levels in normal range. Present data show satisfactory iodine content in the salt which justifies the assumption of satisfactory iodine intake in the population of Slovakia. (Tab. 2, Ref. 6.)
Key words: iodine in salt; Slovakia; iodine deficiency.
Bratisl Lek Listy 1995; 96: 613-615
ASPIRATION FINE-NEEDLE BIOPSY IN PREOPERATIVE DIAGNOSIS OF NON-TOXIC NODULAR GOITRES
HNILICA, P., PODOBA Jr., J.
The ascertainment of diagnostic reliability of fine needle aspiration
biopsy in preoperative examination of non-toxic goitres is performed
by comparing its results with the findings of the definitive histologic
examination. The set of patients did not include those with the
cytological finding of Hurtle tumour for the impossibility to
distinguish between adenomas and carcinomas from oxyphilic cells
by means of cytologic examination. Aspirates were stained by
May, Grunwald and Giemsa method. Histologic results were gained
from 185 patients. Cytologic findings were considered as benign
in 95 cases (however 3 cases of cancer were revealed by the histologist
- false negativity). In 90 cases, atypia, findings of suspectivity,
or diagnosis of malignity were described, however the histologist
evaluated 49 cases of goitres as being benign (false positivity).
Totally 44 cases of malignant tumours were histologically diagnosed.
Diagnostic sensitivity in our set of patients was 0.97 and diagnostic
specificity was 0.46.
In accordance with the available literature, fine needle cytodiagnosis
is considered to represent an appropriate screening method in
the process of decision as to whether conservative or surgical
therapy with histologic verification in patients with non-toxic
nodular goitres is to be indicated. (Tab. 1, Ref. 6.)
Key words: aspiration fine-needle biopsy; non-toxic nodular goitres; diagnosis; histology; cytology; screening; thyroid caracinoma.
Bratisl Lek Listy 1995; 96: 616-618
CHRONOLOGICAL COURSE OF CHANGES IN THE PROPORTION OF PAPILLARY AND FOLICULAR CARCINOMAS IN AUTHORS OWN SET OF PATIENTS DURING THE PERIOD 1960-1993
NEMEC, J., ZAMRAZIL, V., DVORAK, J., ZEMAN, V.
Background: Differenciated carcinoma of the thyroid gland
is globally changing its character and occurrence frequency.
Methods: Retrospective analysis of patients sent to the
Clinic of Nuclear Medicine in Prague, Motole in order to undergo
the radioactive iodine therapy during the period from 1960 to
1993 in comparison to the set of patients of the 1950-1959 period.
Main results: A conspicuous change took place in the proportion
of papillary and follicular carcinomas. The previous predominance
of follicular carcinoma has turned to the predominance of papillary
carcinoma, the occurrence of which is increasing. The authors
see the causes not only in introduction of iodisation which decreases
the occurrence of more aggressive forms of differenciated carcinoma,
but also in radioactive fall, as well as in the change of diagnostic
procedures.
Conclusions: The occurrence of differenciated carcinoma
is so far increasing, but in the recent years the increase of
more aggressive forms of the disease (follicular carcinoma) has
ceased and an expressive increase of less aggressive papillary
carcinoma is continuing. (Tab. 1, Ref. 14.)
Key words: papillary carcinoma; follicular carcinoma; thyroid gland; iodidation.
Bratisl Lek Listy 1995; 96: 619-621
THE EFFECTIVENESS OF IODINE PROPHYLAXIS OF ENDEMIC GOITRE IN SLOVAKIA FROM THE ASPECT OF PHYSICAL AND ULTRASONOGRAPHIC EXAMINATION OF THYROID GLAND
PODOBA, jr. J., HNILICA, P., SRBECKY, M., PODOBOVA, M.
Being aimed at the effectivity of iodine prophylaxis of endemic goitre the authors examined 2946 children and adolescents at the age of 6-18 years during the period from 1989 to 1995 in 6 regions of Slovakia. The thyroid glands were examined physically and ultrasonographically. The authors have found out that the occurrence rate of diffuse goitre is acceptable and it is not meeting the criteria of endemic goitre. No case of nodular goitre was revealed. Similarly to the relative frequency of diffuse goitre, neither the ultrasonographically measured volumes of thyroid glands differed among various areas. They are comparable with the volumes detected in countries with a sufficient iodine supply. The use of criteria for iodine deficiency evaluation recommended by WHO (goitre occurrence, thyroid gland volume, ioduria) leads the authors to consider the current prophylaxis of endemic goitre as being effective and successful. (Tab. 5, Ref. 20.)
Key words: iodine prophylaxis of endemic goitre; goitre occurrence; ultrasonographic volumetry of the thyroid gland; ioduria.
Bratisl Lek Listy 1995; 96: 622-626