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1.
J Evol Biol ; 27(8): 1604-12, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24898271

ABSTRACT

Theory predicts that the sex making greater investments into reproductive behaviours demands higher cognitive ability, and as a consequence, larger brains or brain parts. Further, the resulting sexual dimorphism can differ between populations adapted to different environments, or among individuals developing under different environmental conditions. In the nine-spine stickleback (Pungitius pungitius), males perform nest building, courtship, territory defence and parental care, whereas females perform mate choice and produce eggs. Also, predation-adapted marine and competition-adapted pond populations have diverged in a series of ecologically relevant traits, including the level of phenotypic plasticity. Here, we studied sexual dimorphism in brain size and architecture in nine-spined stickleback from marine and pond populations reared in a factorial experiment with predation and food treatments in a common garden experiment. Males had relatively larger brains, larger telencephala, cerebella and hypothalami (6-16% divergence) than females, irrespective of habitat. Females tended to have larger bulbi olfactorii than males (13%) in the high food treatment, whereas no such difference was found in the low food treatment. The strong sexual dimorphism in brain architecture implies that the different reproductive allocation strategies (behaviour vs. egg production) select for different investments into the costly brains between males and females. The lack of habitat dependence in brain sexual dimorphism suggests that the sex-specific selection forces on brains differ only negligibly between habitats. Although significance of the observed sex-specific brain plasticity in the size of bulbus olfactorius remains unclear, it demonstrates the potential for sex-specific neural plasticity.


Subject(s)
Brain/anatomy & histology , Nesting Behavior/physiology , Sex Characteristics , Sexual Behavior, Animal/physiology , Smegmamorpha/physiology , Animals , Brain/physiology , Ecosystem , Female , Linear Models , Male , Organ Size/physiology , Selection, Genetic
2.
J Evol Biol ; 24(6): 1380-5, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21554471

ABSTRACT

Brain development shows high plasticity in response to environmental heterogeneity. However, it is unknown how environmental variation during development may affect brain architecture across life history switch points in species with complex life cycles. Previously, we showed that predation and competition affect brain development in common frog (Rana temporaria) tadpoles. Here, we studied whether larval environment had carry-over effects in brains of metamorphs. Tadpoles grown at high density had large optic tecta at metamorphosis, whereas tadpoles grown under predation risk had small diencephala. We found that larval density had a carry-over effect on froglet optic tectum size, whereas the effect of larval predation risk had vanished by metamorphosis. We discuss the possibility that the observed changes may be adaptive, reflecting the needs of an organism in given environmental and developmental contexts.


Subject(s)
Brain/growth & development , Metamorphosis, Biological , Rana temporaria/growth & development , Animals , Body Size , Brain/anatomy & histology , Larva/anatomy & histology , Larva/growth & development , Optic Lobe, Nonmammalian/growth & development , Organ Size , Population Density , Rana temporaria/anatomy & histology , Rana temporaria/physiology
3.
J Evol Biol ; 23(11): 2300-8, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20964761

ABSTRACT

An increasing number of studies have demonstrated phenotypic plasticity in brain size and architecture in response to environmental variation. However, our knowledge on how brain architecture is affected by commonplace ecological interactions is rudimentary. For example, while intraspecific competition and risk of predation are known to induce adaptive plastic modifications in morphology and behaviour in a wide variety of organisms, their effects on brain development have not been studied. We studied experimentally the influence of density and predation risk on brain development in common frog (Rana temporaria) tadpoles. Tadpoles grown at low density and under predation risk developed smaller brains than tadpoles at the other treatment combinations. Further, at high densities, tadpoles developed larger optic tecta and smaller medulla oblongata than those grown at low densities. These results demonstrate that ecological interactions - like intraspecific competition and predation risk - can have strong effects on brain development in lower vertebrates.


Subject(s)
Adaptation, Biological/physiology , Brain/growth & development , Competitive Behavior/physiology , Neuronal Plasticity/physiology , Predatory Behavior/physiology , Rana temporaria/growth & development , Animals , Body Weights and Measures , Larva/growth & development , Linear Models , Population Density , Sweden
4.
J Evol Biol ; 22(8): 1721-6, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19549140

ABSTRACT

Most studies seeking to provide evolutionary explanations for brain size variability have relied on interspecific comparisons, while intraspecific studies utilizing ecologically divergent populations to this effect are rare. We investigated the brain size and structure of first-generation laboratory-bred nine-spined sticklebacks (Pungitius pungitius) from four geographically and genetically isolated populations originating from markedly different habitats. We found that the relative size of bulbus olfactorius and telencephalon was significantly larger in marine than in pond populations. Significant, but habitat-independent population differences were also found in relative brain and cerebellum sizes. The consistent, habitat-specific differences in the relative size of bulbus olfactorius and telencephalon suggest their adaptive reduction in response to reduced (biotic and abiotic) habitat complexity in pond environments. In general, the results suggest that genetically based brain size and structure differences can evolve relatively rapidly and in repeatable fashion with respect to habitat structure.


Subject(s)
Adaptation, Physiological , Brain/anatomy & histology , Smegmamorpha/physiology , Animals , Biological Evolution , Breeding , Smegmamorpha/anatomy & histology
5.
J Evol Biol ; 22(3): 544-52, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19210595

ABSTRACT

The proximate and ultimate explanations for behavioural syndromes (correlated behaviours--a population trait) are poorly understood, and the evolution of behavioural types (configuration of behaviours--an individual trait) has been rarely studied. We investigated population divergence in behavioural syndromes and types using individually reared, completely predator- or conspecific-naïve adult nine-spined sticklebacks (Pungitius pungitius) from two marine and two predatory fish free, isolated pond populations. We found little evidence for the existence of behavioural syndromes, but population divergence in behavioural types was profound: individuals from ponds were quicker in feeding, bolder and more aggressive than individuals from marine environments. Our data reject the hypothesis that behavioural syndromes exist as a result of genetic correlations between behavioural traits, and support the contention that different behavioural types can be predominant in populations differing in predation pressure, most probably as a result of repeated independent evolution of separate behavioural traits.


Subject(s)
Behavior, Animal/physiology , Predatory Behavior/physiology , Smegmamorpha/physiology , Animals , Female , Male , Population Dynamics , Principal Component Analysis
6.
Horm Metab Res ; 37(3): 172-7, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15824972

ABSTRACT

Female rats were treated with beta-endorphin on the 19th day of pregnancy. Serotonin content of immune cells (peritoneal lymphocytes, monocyte-macrophage-granulocyte group (mo-gran), mast cells, blood lymphocytes, granulocytes and monocytes, thymus lymphocytes) were studied in the mothers (P-generation four weeks after delivery), in the male offspring (F1) generation (at seven weeks), in the female offspring (four weeks after their own delivery) and in their offspring (F2 generation, at seven weeks). P-mother cells' serotonin content was not influenced by endorphin treatment, while F1 generation's mo-gran and blood lymphocyte serotonin content was reduced (in contrast, histamine content of mo-gran increased). Four weeks after delivery, an increase in serotonin content was observed in the F1 generation in the peritoneal lymphocytes and mast cells as well as in blood lymphocytes. In contrast, serotonin content was reduced in blood granulocytes and monocytes. In the F2 (grandson) generation, a reduction in mast cell serotonin content and sensitization of blood and thymic lymphocytes to repeated endorphin treatment was provoked. The significant changes were more expressed in the F2 generation compared to F1, also appearing earlier. The results unequivocally suggest that the increase in endorphin levels during late pregnancy can cause permanent changes in the F1 and F2 generations, which means that the imprinting effect can be transgenerationally transmitted.


Subject(s)
Leukocytes/drug effects , Leukocytes/metabolism , Prenatal Exposure Delayed Effects , Serotonin/metabolism , beta-Endorphin/pharmacology , Animals , Female , Flow Cytometry , Gestational Age , Granulocytes/metabolism , Lymphocytes/metabolism , Mast Cells/metabolism , Monocytes/metabolism , Pregnancy , Rats , Rats, Wistar , Receptors, Steroid/metabolism , Sexual Behavior, Animal/physiology
7.
Horm Metab Res ; 36(1): 39-43, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14983405

ABSTRACT

Perinatally, the first encounter between the maturing receptor and its target hormone results in hormonal imprinting, which adjusts the binding capacity of the receptor for life. In the presence of an excess of the target hormone or foreign molecules than can be bound by the receptor, faulty imprinting carries life-long consequences. In cytogenic organs, imprinting could also be provoked in other periods of life (late imprinting). Imprinting also durably influences the production of the imprinter and related hormones. In the present study, single beta-endorphin doses was given to three-week old female rats at 3 microg/animal, and the serotonin in five brain regions (frontal cortex, striatum, hippocampus, hypothalamus and brain stem) and uterine estrogen receptor content were determined, thymic glucocorticoid receptor binding capacity was measured, and sexual behavior was tested at five months of age. Brain serotonin levels highly significantly decreased, while sexual activity (Meyerson index and lordosis quotient) increased. At the same time, uterine estrogen receptor affinity decreased. There was no change in receptor binding capacity in the thymus. We will go on to discuss interrelations between the results. The experiments demonstrate that a non-perinatal treatment with a molecule acting at receptor level (late imprinting) can also lastingly influence various indexes in non-cytogenic organs. The results call attention to the possible long-lasting influence of an endorphin surge (caused, for example, by pain) on brain serotonin content and sexual behavior.


Subject(s)
Brain Chemistry , Receptors, Estrogen/metabolism , Serotonin/analysis , Sexual Behavior, Animal/drug effects , Uterus/chemistry , beta-Endorphin/administration & dosage , Animals , Brain Stem/chemistry , Corpus Striatum/chemistry , Female , Frontal Lobe/chemistry , Hippocampus/chemistry , Hypothalamus/chemistry , Rats , Rats, Wistar , Weaning
8.
Hum Exp Toxicol ; 21(5): 231-4, 2002 May.
Article in English | MEDLINE | ID: mdl-12141392

ABSTRACT

Hormonal imprinting takes place perinatally at the first encounter between the hormone and its target receptor. This is needed for the normal finishment of the maturation of the receptor-signal transduction system. In excess of foreign molecules, which can also bind to the receptor, faulty imprinting develops with life-long consequences. Genistein, a soybean phytosteroid (isoflavone), has estrogen-like effects and can be bound by steroid receptors. In the present experiments, single neonatal treatment (imprinting) with 20 microg of genistein, or combined treatment with 20 microg of genistein+20 microg of benzpyrene was done and liver and thymus glucocorticoid receptors of adult male and female rats and uterine estrogen receptors were studied. There was no difference in the binding capacity of uterine estrogen receptors. Genistein treatment alone caused a significant reduction of liver glucocorticoid receptor density in males; however, there were no other significant alterations. After combined genistein+benzpyrene treatment, more.than half of the thymus and liver glucocorticoid receptor values significantly changed. The results call attention to the imprinting-modifying effect of a second (environmental) imprinter.


Subject(s)
Benzopyrenes/toxicity , Environmental Pollutants/toxicity , Genistein/toxicity , Receptors, Estrogen/metabolism , Receptors, Glucocorticoid/metabolism , Animals , Animals, Newborn , Benzopyrenes/administration & dosage , Drug Combinations , Environmental Pollutants/administration & dosage , Estrogens, Non-Steroidal/administration & dosage , Estrogens, Non-Steroidal/toxicity , Female , Genistein/administration & dosage , Injections, Subcutaneous , Liver/drug effects , Liver/metabolism , Male , Rats , Rats, Wistar , Thyroid Gland/drug effects , Thyroid Gland/metabolism
9.
Mech Ageing Dev ; 122(3): 327-34, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11311319

ABSTRACT

The glucocorticoid receptor of the newborn thymus binds dexamethasone with the same specificity, as the adult ones. The best competitors of dexamethasone on the glucocorticoid receptor are dexamethasone itself and mifepristone (RU486). Estradiol can compete with dexamethasone on the glucocorticoid receptor. This is true in the case of newborn or adolescent thymus alike. Allylestrenol can slightly compete with dexamethasone on the glucocorticoid receptor in newborn, however this does not occur in adolescents. The other ligands - causing imprinting or imprinting like phenomenon earlier -- as tocopherol, menadione, retinoic acid, vitamin D(3) -- do not compete in vitro with dexamethasone on the thymic glucocorticoid receptor in newborn and adolescent animals. Possibilities of imprinting mechanism, considering the results are discussed.


Subject(s)
Aging/metabolism , Receptors, Glucocorticoid/metabolism , Thymus Gland/metabolism , Animals , Animals, Newborn , Dexamethasone/metabolism , Female , Male , Mifepristone/metabolism , Rats , Rats, Wistar
10.
Acta Physiol Hung ; 88(2): 125-9, 2001.
Article in English | MEDLINE | ID: mdl-11999804

ABSTRACT

Newborn rats of both sexes were treated (imprinted) with 20 microg of benzpyrene. Two hours, 2 days, 1, 2, 3 weeks, 1 month and 2 months after imprinting the liver glucocorticoid receptors were studied for binding of dexamethasone. Two-hour and 2-day values were not appreciable. One week after treatment the receptor's affinity was extremely low both in control and treated treated animals. Two weeks after imprinting a significant difference in density (lower) and affinity (higher) was observed between the male treated and control animals. At 3 weeks and one month the binding capacity of treated and control animals was equal however, at 2 months Bmax of males increased and that of females decreased significantly in the neonatally benzpyrene treated animals. This means that for the development of perinatal imprinting effect a long time is needed, and the effect is manifested after a period of lability.


Subject(s)
Animals, Newborn/metabolism , Benzopyrenes/pharmacology , Liver/drug effects , Liver/metabolism , Receptors, Glucocorticoid/drug effects , Receptors, Glucocorticoid/metabolism , Animals , Binding, Competitive/drug effects , Dexamethasone/metabolism , Female , Glucocorticoids/metabolism , Male , Rats , Rats, Wistar , Reference Values , Time Factors
11.
Acta Physiol Hung ; 88(2): 131-7, 2001.
Article in English | MEDLINE | ID: mdl-11999805

ABSTRACT

Hormonal imprinting takes place perinatally, at the first encounter between the target hormone and its developing receptor. However, there is a secondary critical period of imprinting at puberty. In these periods molecules similar to the hormones (members of the same hormone family, antagonists, certain environmental pollutants, etc.) can cause faulty imprinting with lifelong consequences. In the present experiments 5+2 days of tamoxifen treatment (120 microg/day) at adolescent age dramatically (from approx. 40% to 10%) reduced the sexual activity (Meyerson index and lordosis quotient) of female rats, soon after the finishment of the treatment and between four to six weeks after treatment. Similar results were observed in animals neonatally treated with allylestrenol and tamoxifen treated at puberty. Thymic glucocorticoid receptor and uterine estrogen receptor binding capacity were not influenced.


Subject(s)
Aging/metabolism , Aging/psychology , Estrogen Antagonists/pharmacology , Receptors, Estrogen/metabolism , Receptors, Glucocorticoid/metabolism , Sexual Behavior, Animal/drug effects , Tamoxifen/pharmacology , Allylestrenol/pharmacology , Animals , Female , Progesterone Congeners/pharmacology , Rats , Rats, Wistar , Receptors, Estrogen/drug effects , Receptors, Glucocorticoid/drug effects
12.
Life Sci ; 67(20): 2531-7, 2000 Oct 06.
Article in English | MEDLINE | ID: mdl-11065175

ABSTRACT

For studying the mechanism of perinatal hormonal imprinting newborn rats were treated with a single injection of the antihormones, mifepristone (RU486) or tamoxifen (100 microg each). Glucocorticoid receptors of thymi of 6 weeks old male and female, and uterine estrogen receptors of 2 months old female rats were studied for dexamethasone or estradiol binding, respectively. Tamoxifen caused faulty imprinting both in the thymic and uterine receptors, increasing affinity and density of males, and decreasing females' glucocorticoid receptors as well, as decreasing the density of uterine estradiol receptors. Neonatal mifepristone treatment was indifferent to the thymus, and decreasing to density of uterine estrogen receptors. Males' body weight significantly decreased 6 weeks after tamoxifen treatment. The results suggest that imprinting can not be provoked by a molecule (hormone antagonist) which can bind to the receptor without any postreceptorial events (mifepristone/glucocorticoid receptor), in the presence of some postreceptorial effects the reaction takes place, however the strongest reaction can be observed by the hormone analogue (tamoxifen) with postreceptorial (agonist) effect, not considering that the receptor is the direct target of the molecule or a cross-reaction is present.


Subject(s)
Genomic Imprinting , Hormone Antagonists/pharmacology , Mifepristone/pharmacology , Receptors, Estrogen/metabolism , Receptors, Glucocorticoid/metabolism , Signal Transduction/physiology , Tamoxifen/pharmacology , Thymus Gland/drug effects , Uterus/drug effects , Animals , Animals, Newborn , Dexamethasone/metabolism , Estradiol/metabolism , Female , Genomic Imprinting/drug effects , Hormone Antagonists/administration & dosage , Injections, Subcutaneous , Male , Mifepristone/administration & dosage , Rats , Rats, Wistar , Tamoxifen/administration & dosage , Thymus Gland/metabolism , Uterus/metabolism
13.
Acta Physiol Hung ; 87(2): 139-43, 2000.
Article in English | MEDLINE | ID: mdl-11205961

ABSTRACT

The binding capacity of newborn and adult rat liver glucocorticoid receptors was compared, using receptor kinetic analysis. Neonatal receptors have (non-significantly) lower affinity and significantly less density to dexamethasone than adult ones. However, the neonatal binding is specific and there is no qualitative difference from the adult one.


Subject(s)
Animals, Newborn/metabolism , Liver/growth & development , Liver/metabolism , Receptors, Glucocorticoid/metabolism , Aging/metabolism , Animals , Cytosol/drug effects , Cytosol/metabolism , Female , Male , Rats , Rats, Wistar
14.
Horm Metab Res ; 31(9): 505-7, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10569251

ABSTRACT

In earlier experiments, the long-term effect of perinatal treatment (hormonal imprinting) with all-trans-retinol and all-trans-retinoic acid on the thymic glucocorticoid and uterine estrogen receptors was studied and was found effective. In the present experiments, the imprinting effect of four retinoids (13-cis-retinaldehyde, 13-cis-retinoic acid, 9-cis-retinaldehyde and 9-cis-retinoic acid) was investigated, using receptor kinetic analysis and sexual hormone (testosterone and progesterone) level determinations. Exclusively 13-cis-retinoic acid (isotretinoin) had an effect, significantly decreasing glucocorticoid receptor affinity and increasing serum testosterone level. Relationships with RAR-RXR receptor binding and teratogenicity is discussed.


Subject(s)
Isotretinoin/pharmacology , Receptors, Glucocorticoid/physiology , Testosterone/blood , Thymus Gland/drug effects , Animals , Animals, Newborn , Female , Genomic Imprinting , Male , Progesterone/blood , Rats , Rats, Wistar , Thymus Gland/metabolism
15.
Life Sci ; 65(1): PL1-5, 1999.
Article in English | MEDLINE | ID: mdl-10403499

ABSTRACT

Neonatal single treatment with vitamin K1 (50 microg/animal) significantly increased the density (Bmax) of thymic glucocorticoid receptors of the adolescent (6 weeks old) and uterine estrogen receptors of adult (10 weeks old) females. The same tendency was observed in the thymus of males and adult females, however without significance. Receptor affinity was (not significantly) influenced in the same direction. Considering that the steroid receptor imprinting effect of vitamins A and D as well as the imprinting-like effect of vitamin E was demonstrated earlier, the ability for neonatal steroid receptor imprinting of the whole lipid-soluble vitamin group is now justified.


Subject(s)
Receptors, Estrogen/metabolism , Receptors, Glucocorticoid/metabolism , Thymus Gland/metabolism , Uterus/metabolism , Vitamin K 1/pharmacology , Aging , Animals , Animals, Newborn , Binding Sites , Cytosol/metabolism , Female , Male , Rats , Rats, Wistar , Thymus Gland/cytology , Uterus/cytology
16.
Horm Res ; 51(6): 280-3, 1999 Dec.
Article in English | MEDLINE | ID: mdl-10640889

ABSTRACT

Single neonatal treatment with 25 microg vitamin D(3) significantly decreased the thymic glucocorticoid receptor density (B(max)) of 6-week-old male rats. In females, a similar treatment did not cause any changes. Single vitamin D(3) treatment (50 microg) during adolescence (i.e. 6-week-old animals) significantly increased the glucocorticoid receptor density in adult (10-week-old) males. No significant changes in receptor affinity (K(d)) could be observed. Considering that in earlier experiments similar neonatal treatments influenced bone mineral mass and sexual behavior, the hormonal imprinting effect of vitamin D(3) and its harmful effect on the development of other members of the steroid receptor superfamily, seems to be unquestionable.


Subject(s)
Aging/metabolism , Animals, Newborn/metabolism , Cholecalciferol/pharmacology , Hormones/physiology , Receptors, Glucocorticoid/metabolism , Thymus Gland/metabolism , Animals , Binding, Competitive , Dexamethasone/metabolism , Female , Glucocorticoids/metabolism , Male , Rats , Rats, Wistar , Receptors, Glucocorticoid/antagonists & inhibitors , Sex Characteristics , Thymus Gland/drug effects
17.
Acta Physiol Hung ; 86(1): 29-36, 1999.
Article in English | MEDLINE | ID: mdl-10755167

ABSTRACT

Hormonal imprinting develops perinatally at the first encounter between the maturing receptor and the target hormone, helping the normal accomplishment of receptor maturation. In the presence of hormone excess or foreign molecules able to bind to the maturing receptor, faulty imprinting takes place, which disturbs the normal receptor function for life. Earlier experiments demonstrated that the effect of faulty perinatal benzpyrene imprinting of the steroid hormone receptors is transmitted to the progeny generations. In certain organs which are maturing later (such as the uterus) imprinting can be executed at adolescence. In the present experiments pubertal benzpyrene imprinting caused a durable decrease in female's estrogen receptor density. The transgenerational effect of this type of imprinting was also studied. The pubertal imprinting of the parents was transgenerationally transmitted to the offspring generation in which--without further treatment--the density (Bmax) of the uterine estrogen receptors was significantly higher than that in the controls. There were measurable effects neither in the affinity (Kd) of uterine estrogen receptors nor in the Kd and Bmax of the male thymus glucocorticoid receptors. The experiments call attention to the profound and comprehensive imprinting effect of the environmental pollutant benzpyrene.


Subject(s)
Benzopyrenes/toxicity , Environmental Pollutants/toxicity , Receptors, Estrogen/metabolism , Receptors, Glucocorticoid/metabolism , Thymus Gland/metabolism , Uterus/metabolism , Animals , Cytosol/drug effects , Cytosol/metabolism , Dexamethasone , Female , Glucocorticoids , Kinetics , Ligands , Male , Rats , Rats, Wistar , Receptors, Estrogen/drug effects , Receptors, Glucocorticoid/drug effects , Thymus Gland/drug effects , Thymus Gland/growth & development , Uterus/drug effects , Uterus/growth & development
18.
Acta Biol Hung ; 50(4): 355-61, 1999.
Article in English | MEDLINE | ID: mdl-10735172

ABSTRACT

In this review, works to clear the effect of perinatal and pubertal benzpyrene imprinting to the steroid hormone receptors of adult animals are summarized. There is a comparison between the perinatal and adolescent effects and between the effects on the receptors of males and females. On the basis of the experiments benzpyrene is a general and dangerous imprinter which can influence durably the development of different steroid receptors given directly to the animals studied (perinatally) of given to the nursing mothers or influencing the offspring generations of the perinatally treated parents or grandparents. The results call attention to the outstanding deleterious effects of benzpyrene pollution.


Subject(s)
Benzopyrenes/pharmacology , Environmental Pollutants/pharmacology , Receptors, Steroid/drug effects , Age Factors , Animals , Female , Male , Rats , Rats, Wistar
19.
Orv Hetil ; 139(40): 2379-82, 1998 Oct 04.
Article in Hungarian | MEDLINE | ID: mdl-9796355

ABSTRACT

Diagnosis of drug allergy has been considered to be a multistage procedure consisting of detailed history of previous medication, analysis of symptoms, laboratory tests and provocation with the supposed sensitizing drug. Many laboratory methods are used for demonstration drug allergy, but opinions differ with regard to their specificity, sensitivity and reproducibility. Lymphocyte transformation test (LTT) is considered to be a valuable in vitro method in the diagnosis of drug allergy. For evaluation of LTT we introduced a tetrazolium-based colorimetric assay (MTT). Comparison of MTT assay with 3H-Thymidine incorporation in evaluation of Phytohaemagglutinin induced LTT resulted no significant difference in the dose-response curve. During the past 3 years 315 patients were tested with LTT-MTT method; 736 lymphocyte transformation tests mainly with antibiotics, topical anesthetics and painkillers were evaluated by MTT resulting 280 positive results. Physicians requested skin tests were performed with drugs induced no in vitro lymphocyte transformation and only 8 topical reactions without general symptoms were observed. MTT method was found to be a sensitive laboratory test in evaluation of LTT performable even in routine laboratories. Its application can lead to a substantial decrease in the number of patients who must be subjected to the possible risk of in vivo tests for the determination of the sensitizing drug.


Subject(s)
Colorimetry , Drug Hypersensitivity/immunology , Lymphocyte Activation , Drug Hypersensitivity/diagnosis , Humans
20.
Life Sci ; 63(6): PL 101-5, 1998.
Article in English | MEDLINE | ID: mdl-9718076

ABSTRACT

Single neonatal vitamin E treatment significantly altered the affinity (Kd) of thymic glucocorticoid receptors in male adolescent and adult rats. In six weeks old animals the affinity increased (and there is a tendency for an increase in receptor density), in twelve weeks old animals the affinity decreased. The thymic glucocorticoid receptors and uterine estrogen receptors of female animals were not influenced at all. Thousandfold tocopherol did not compete with labeled dexamethasone for their receptors, suggesting that neonatal vitamin E imprinting effect was not done at direct receptorial level.


Subject(s)
Receptors, Glucocorticoid/drug effects , Vitamin E/pharmacology , Animals , Animals, Newborn , Female , Kinetics , Male , Ovariectomy , Rats , Rats, Wistar , Receptors, Glucocorticoid/metabolism , Thymus Gland/drug effects , Uterus/drug effects
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