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Volume 36 / No. 3 / 2002
Lucia Kubovcakova, Ester L. Sabban, Richard Kvetnansky, Olga Krizanova
Institute of Experimental Endocrinology, Slovak Academy of Sciences,
Bratislava, Slovakia;
New York Medical College, Valhalla, NY, USA
E-mail: ueenkubo@savba.sk
Objective. Corticotropin-releasing hormone deficient mice (CRH-KO) serve
as an interesting model to understand the role of CRH in the regulation of
adrenomedullary system. The aim of this study was to compare tyrosine
hydroxylase (TH) and phenylethanolamine N-methyltransferase (PNMT) on the levels
of gene expression and protein in adrenal medulla of CRH-KO mice, their CRH
(+/+) mates and Sprague-Dawley (SD) rats.
Methods. Levels of TH and PNMT mRNA were determined by reverse
transcription with subsequent polymerase chain reaction (RT-PCR) and quantified
relatively to the housekeeper glyceraldehyde-3-phosphate dehydrogenase. The
amount of TH and PNMT protein was determined by Western blot analysis and
visualized by enhanced chemiluminiscence.
Results. We detected a clear signal of 645 bp for TH mRNA and of 260
bp for PNMT mRNA in adrenal medulla of rats and CRH (+/+) mice, with higher
concentration of TH and PNMT mRNA in rat adrenal medulla. Subsequently, TH and
PNMT immunoprotein was measured and we found significantly higher amount of TH
and also PNMT protein in the rat compared to CRH (+/+) mice. On the other hand,
the amount of TH and PNMT immunoprotein in adrenal medulla of CRH-KO mice was
significantly lower compared to CRH (+/+) mice.
Conclusions. Our results indicate the lower production of adrenomedullary
TH and PNMT protein in CRH (+/+) mice compared to rats, which reflects the lower
gene expression of these enzymes in adrenal medulla of mice. We also
demonstrated the differences in TH and PNMT protein levels between CRH (+/+) and
CRH-KO (-/-) mice.
Key words: Corticotropin-releasing hormone – CRH knock-out mice
– Adrenal medulla – Tyrosine hydroxylase – Phenylethanolamine-N-methyltransferase
ENDOCRINE REGULATIONS, Vol. 36, 107–113, 2002
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J. Jensovsky, E. Ruzicka, N. Spackova, B. Hejdukova
Department. of Clinical Endocrinology and Osteo-center, Central Military
Hospital, 169 02 Prague, Czech Republic
E-mail: Jiri.Jensovsky@UVN.cz
Objective. Recently, it has been repeatedly shown that patients with
subclinical hypothyroidism (SH) formerly considered as completely symptom free,
may have numerous minimal, often non-specific subjective complaints, and that in
those patients it is possible to prove many subtle but objective deviations. We
decided to quantify whether there are event related potential (ERP) deviations
as electrophysiological markers of cognitive activity in patients with SH and
whether ERP could be influenced by thyroxine treatment leading to normalization
of TSH level in serum.
Subjects and design. Event related potential (ERP) was examined in thirty
one patients (mean age 52±12.5 years) with SH and without any other endocrine
or metabolic diseases and in 29 subjects of the control group. From 31 patients
20 women (mean age 61.8±6.8 years) were selected and divided into a group
of 10 women treated six months with L-thyroxine until the normalization of TSH
and remaining 10 women receiving placebo. ERP examination was repeated and all
such patients also underwent neuropsychological examination consisting of the
Wechsler Memory Scale and the MMPI/100 (Minnesota Multiphasic Personality
Inventory). The interval between the diagnosis of SH and final evaluation of
treatment was 16 months.
Results. In SH thyroxine treated patients the average P3 wave latency was
374 ms (SD 40.6) , while in placebo group it was 340 ms (SD 32.3.
P<0.01). In addition, the treatment with thyroxine normalized the TSH level
resulted in a decrease of P3 wave latency from 374±36.3 ms to 343±16.3 ms
(P<0.01). However, in the placebo group such changes were not observed, the
latency of P3 being 387±24.3 ms at the beginning and 379±36.5 ms at the end of
observation period. No significant correlations between P3 wave latency and
thyroid parameters were found. In thyroxine treated group a significant
improvement in verbal memory (P<0.01), visual memory (P<0.01) and total
memory scores (P<0.01) was found, while no changes in these parameters were
observed in the placebo group. No significant differences were found in the MMPI
test evaluation.
Conclusions. SH patients had significantly longer P3 wave latency in ERP
examination as compared to healthy individuals which gives evidence for impaired
cognitive functions in SH patients. In these patients the normalization of TSH
level by thyroxine treatment resulted also in the normalization of P3 wave
latency. In addition, also verbal, visual and total memory scores improved
significantly with the TSH normalization.
Key words: Subclinical hypothyroidism – Thyroxine treatemnt – Event
related potential –Memory scores
ENDOCRINE REGULATIONS, Vol. 36, 115–122, 2002
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K. B. Santra, C. K. Manna
Endocrinology Laboratory, Department of Zoology, University of Kalyani,
Kalyani-741235 , Nadia, W.B., India
E-mail: manna_kly@sify.com
Objective. To study the effects of methylmethane sulphonate (CH3OSO2CH3),
on the testicular tissue of the adult wild Indian house rat (Rattus rattus).
Methods. A single intraperitoneal dose of methylmethane sulphonate
(20 mg/kg) was administered and the effects were observed 2, 7, 15, 30 and 45
days later.
Results. Significant changes of the body, testes and accessory
reproductive organs weight and a major depletion of the relative
percentages of the spermatid and spermatozoa were noticed at 2, 7, 15 and 30
days after treatment. Gradual decrease in the seminiferous tubular area and
Sertoli cell nuclear diameter was observed at 7, 15 and 30 days of treatment
groups. The sperm population and sperm morphological abnormalities were also
noticed in these three groups.
Histochemical studies clearly revealed that the intensity of staining of the
acid and alkaline phosphatase within 7 and 15 days after treatment was
decreased, while the quantity of lipid materials was increased especially on the
2nd and 7th day after treatment. However, no significant changes were noticed in
the delta5-3beta-HSDH and 17beta-HSDH enzymatic activity in the
treated animals.
Conclusion. These observations showed the antispermatogenic activity of
methylmethane sulphonate on the testicular tissues and various accessory
reproductive organs in the wild Indian house rat (Rattus rattus).
Key words: Methylmethane sulphonate – Spermatogenesis - Wild
Indian house rat - Dehydrogenase
ENDOCRINE REGULATIONS, Vol. 36, 123–131, 2002
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J. Klvanová, J. Brtko
Institute of Experimental Endocrinology, Slovak Academy of Sciences and
Institute of Preventive and Clinical Medicine, Bratislava, Slovakia
E-mail: klvanova@upkm.sk
Retinol (ROL), retinal (RAL) and retinoic acid (RA) are physiologically active forms of vitamin A. All-trans retinoic acid (ATRA) can be formed by oxidation from all-trans retinal (ATRAL). Isomerization of RA is considered to be an important metabolic pathway of retinoids. RA isomers transactivate various response pathways via their cognate nuclear receptors that act as ligand inducible transcription factors. The aim of this study was to establish a rapid and simple method for determination of ATRA, 13-cis retinoic acid (13CRA) and ATRAL by HPLC. In our laboratory, we slightly modified the method of Miyagi et al. (2001) and separated ATRA, 13CRA and ATRAL by simple isocratic normal phase HPLC. Both retinoic acid isomers and ATRAL were eluated within 13 min and all components were well resolved. The coefficients of variation (C.V.) for RAs and RAL were from 3.0 to 5.4 %.
ENDOCRINE REGULATIONS, Vol. 36, 133–137, 2002
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THYROID HORMONE RECEPTORS: METHODS AND PROTOCOLS (Editor: Aria Baniahmad). Published by Humana Press, Totowa, New Jersey, USA. Price: US $ 99.50
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