Search PubMed⌕ Search

Biomedical subjects

G Csaba

Publications and source records attributed to G Csaba.

At least 451 records · Page 25Linked to original sources
PubMed1980

Effect of gonadotropins and thyrotropin on the testes and ovaries of the newly hatched chicken.

In newly hatched male and female chickens thyrotropin (TSH) and gonadotropins (FSH, LH) were found to increase the number of spermatogonia or Sertoli cells in the seminiferous cord, and the number of granulosa cells in the ovarian follicle. The effect of gonadotropins was more pronounced than that of TSH. Regarding the overlapping effect of thyrotropin and gonadotropins, in both male and female neonatal gonads the hormones similar in structure seem to be able to substitute each other. They do not however, change each other's effect on the parenchymatous tissue (number of spermatogonia and Sertoli cells in the male, and number of follicles in the female) if they are administered one after the other.

Animals↗
PubMed1980

The overlapping effect of gonadotropins and TSH on embryonic chicken gonads.

Determination of gonadal weight, seminiferous canalicule diameter, thickness of ovarian cortex and medulla, as well as of gonadal cell counts in 20-day chicken embryos exposed to gonadotropin (FSH and LH) or TSH at 15 days of pre-hatching life has shown that the examined hormones were able to evoke gonadal response also prenatally. TSH was found to overlap gonadotropin effect in causing increase of seminiferous canalicule diameter, testicular weight and gonocyte counts. In respect of the latter two parameters TSH was even more active than an identical dose of gonadotropin. This indicates that the interstitial and germinal cell receptors of the embryonic testis are not able to differentiate between chemically related, but - in adulthood - functionally different hormones. The ovarian effect of TSH was significant in respect of enhancing organ weight and oocyte mitosis, but not significant for the other parameters.

Animals↗
PubMed1980

Binding and internalization of 3H-epinephrine in Tetrahymena.

Exposure of Tetrahymena to exogenous epinephrine is followed by appearance of the hormone in the cell membrane, intracytoplasmic vacuoles and nucleus. The intra-nuclear localization is always heterochromatic. Only a minor proportion of the applied epinephrine dose gains access to the nucleus, while the bulk of it attaches to the membrane.

Animals↗
PubMed1980

Effect of litoralon (gamma-L-glutamyl-taurine) on the tail involution of tadpoles in vitro.

Litoralon (gamma-L-glutamyl-taurine), a newly discovered hormone of the parathyroid increases the involution of the explanted tail tip of Rana arvalis tadpoles in vitro, while it antagonizes significantly the similar effect of triiodothyronine. This finding, in accordance with the results of earlier in vivo experiments, implies a direct effect of Litoralon on the target tissues.

Animals↗
PubMed1980

Complex morphological study of the effect of glutaurine in mast cells.

Glutaurine produces rapid and intensive degranulation of mast cells without affecting the composition of their granules. The mast cells of the individual organs differ in the type and extent of degranulation. There is a wide scale between excessive degranulation (mast cells of subcutaneous connective tissue and of the peritoneum), and unresponsiveness (mast cells of thyroid and lymph nodes), and there are also differences in time. The peritoneal mast cells stain positively with safranin, swell excessively and assume bizarre forms in response to 5 micrograms/rat glutaurine intraperitoneally. Frequent occurrence of lymphocyte-mast cell contacts seems typical. Glutaurine increases 3H-histidine uptake of the peritoneal fluid cells in general and 35S sulphate incorporation in the peritoneal mast cells in particular. Accumulation of these substances is more marked at 1 hour than at 3 hours after application.

Animals↗
PubMed1980

Influence of the pineal body on experimental TSH dominance in rat.

Iodide uptake of the thyroid following the joint administration of 1-methyl-2-mercapto-imidazole (MMI) and TSH was studied by autoradiography at various points of time throughout 125 days in pinealectomized and sham-operated rats. In the pinealectomized group iodide uptake decreased. The enhanced TSH effect also decreased by the end of the experiment, suggesting the existence of a mechanism antagonizing the TSH effect. It is assumed that prolonged TSH dominance stimulates the pineal which, in turn, inhibits iodide uptake by the thyroid. This mechanism would thus prevent the TSH dominant state to influence the thyroid. As this prevention occurred also in pinealectomized animals it is postulated that some other as yet unknown structures exert a similar effect. It is suggested that the pineal body acts upon the follicular cells of the thyroid, exerting thus a peripheral inhibitory effect on iodide-uptake.

Animals↗
PubMed1980

Effect of glutaurine on the pineal gland of the rat.

Glutaurine (gamma-L-glutamyl-taurine), the recently discovered hormone of the parathyroid enhances the aggregation and subsequent degeneration of mitochondria in the pinealocyte processes of the rat pineal gland. It also stimulates autophagy, probably through its general lysosome activating effect.

Animals↗
PubMed1979

Study of FSH-TSH functional overlap by cockerel testicle test.

Comparison of the neonatal effects of FSH and TSH in the cockerel testicle test revealed that the latter caused a greater increase of testicular weight, tubular diameter and testicular interstital tissue. This finding suggests the possibility of FSH-TSH functional overlap during the perinatal critical period of receptor maturation.

Animals↗
PubMed1979

Analysis of the antagonistic effect of gamma-L-glutamyl-taurine on glucocorticoid and triiodothyronine.

gamma-L-Glutamyl-taurine, a newly discovered parathyroid hormone, considerably inhibited the cytochemically detected transcription-inducing effect (appearance of free histone) of prednisolone and triiodothyronine. Such an inhibition took place also if the morphogenetic hormones were given not simultaneously with, but after the administration of litoralon. Litoralon injected alone also displayed inductor properties increasing the number of nuclei containing free histone.

Animals↗
PubMed1979

Analysis of the progress of hormone-receptor amplification during differentiation in regenerating planarians.

Planarians developing from isolated regenerates, when pretreated with epinephrine at different periods of their second regeneration, show a higher rate of sugar uptake than the controls, which were not treated with epinephrine. The hormone receptor development can be influenced most effectively by pretreatments performed during the 1--3 and 6--9 day periods, though some effect can be evoked at any time in the course of the second regeneration. The head regenerates developing from the anterior end of the original midpiece (and regenerating tails the second time, B1) were found to be most sensitive, while the similar regenerates developing from the hindpiece of the original planarian (C) showed the weakest reactivity. The experiments provide further evidence that the hormone receptors' activity can be amplified in the course of regenerative development, leading thus--at a later stage--to a more intense sugar uptake response of the cells.

Animals↗
PubMed1979

Effect of hormones and related compounds on the multiplication of Tetrahymena.

The vertebrate hormone triiodothyronine, the commonly occurring animal and plant hormone serotonin, and the plant alkaloid gramine, chemically related to the latter, stimulated the multiplication of Tetrahymena. Neither epinephrine nor gibberellin had such an effect. These experimental observations support the previous suggestion that unicellular animals possess structures capable of responding to certain hormones, which do not seem to elicit specific responses of the unicellular animal, but rather act through the activation of certain general functions.

Alkaloids↗
PubMed1979

The effect of sympathicomimetic agents on carbohydrate metabolism of planaria.

Epinephrine, ephedrine, dopamine and isoproterenol considerably influence carbohydrate utilization in planaria. Dopamine alone and in combination is the most potent, while ephedrine the least effective in this respect. The finding of increased responses to combined treatment supports the view of the existence of different receptor sites for the sympathicomimetic drugs. The results substantiate conclusions concerning the phylogenesis of hormone receptors.

Animals↗
PubMed1979

Possibility of long-lasting amplification of insulin receptors by a single treatment at newborn age.

Administration of insulin to newborn rats was shown to amplify the hormone receptors. Blood sugar values in animals thus treated were lower in the adult age, which could be explained by increased sensitivity to endogenous insulin; the decrease of blood sugar in response to exogenous insulin was similar in magnitude, however, it occurred at a lower level compared to the controls. These changes were more marked in female than in male rats.

Aging↗