PubMed Health⌕ Search

Biomedical subjects

I Bădescu

Publications and source records attributed to I Bădescu.

16 recordsLinked to original sources
PubMed1992

Total and free amino acids in the "Crinofizin" pineal extract.

In order to establish the chemical nature of Crinofizin, a protidic extract obtained from bovine pineal, the amino acids content was analysed using two analytic programs: one for biologic fluids, the other for protein hydrolysates. The results showed that the pineal extract contains besides the common protein amino acids reported earlier, others, rare in proteins, such as hydroxyproline, hydroxylysine and 1-methylhistidine as well as non-protein amino acids. From among the latter, the alpha-aminoadipic acid, beta- alanine, O-cysteine, are found only in a bound form, and are detected only by hydrolysis. Other amino acids, such as taurine, glutamine, citruline are present only in free form whereas the alpha-amino-n-butyric acid, GABA, ethanolamine and ornithine are present in both forms, free or bound. The paper discusses the physiologic significance of some amino acids.

Amino Acids↗
PubMed1991

Purification and physico-chemical characterization of the antigonadotropic fractions obtained by ultrafiltration from the pineal extract.

In order to isolate the antigonadotropic factor from a pineal extract prepared from bovine pineals the authors first applied ultrafiltration, which yielded three fractions: F1 greater than 10 kDa, 1 kDa less than less than F2 less than 10 kDa, and F3 less than 1 kDa. Examination of the biologic activity showed that only F1 and F2 have a statistically significant antigonadotropic activity. Ion exchange chromatography of F1 yielded two subfractions: one, F11, which was not retained, and another one, F12, which was retained by the exchanger. Both subfractions showed biologic activity. While F11 is closer to F2 less than 10 kDa, F12 has a molecular weight around 13.7 kDa, as resulted after applying the SDS-PAGE procedure. The F1 fraction has a proteic content of 903 micrograms/ml, F11 = 308 micrograms/ml and F12 = 247 micrograms/ml. Amino acids assay showed that the F12 subfraction has the same composition as F1 and the F11 subfraction also has free amino acids which indicates a process of adsorption of small molecules on large molecules. The F2 less than 10 kDa fraction, biologically active, has a proteic content of 433 micrograms/ml and an amino acids composition similar to F11 except for cysteine and methionine. The F3 less than 1 kDa fraction with a proteic content of 79 micrograms/ml having an amino acid composition in which prevails the glutamic acid shows poor antigonadotropic activity. The results of this study, as well as the fact that the antigonadotropic activity is concentrated in fractions both above and under 10 kDa, suggests at least two hypotheses: either that the pineal antigonadotropic factor exists under various molecular forms in which the activity is preserved, or that the antigonadotropic factor is a peptide with strong aggregation properties as demonstrated in our study.

Amino Acids↗
PubMed1991

Melatonin involvement in oxidative processes.

The fact that the pineal gland, by its melatonin (MT) production, responds to environmental light variations (the day-night cycle), being also a modulator of the body adaptation to these conditions, may lead to the assumption of its involvement in the body oxidative processes. The redox capacity of melatonin was followed-up in vitro by the chemiluminescence phenomenon. The system generating chemiluminescence as well as free radicals was made up of luminol and H2O2. Incubation of melatonin in doses of 0.08-0.5 microM/ml with the generating system showed that in doses under 0.25 microM/ml melatonin has a pro-oxidative effect while in doses above this value it has an antioxidative effect. The diagram of the results shows the answer specific to a modulator. The study of the correlation between the dose of melatonin with highest pro-oxidative properties and the various peroxide concentrations in the generating system showed that melatonin gets antioxidative properties with the increase in peroxide concentrations (less than 8 mM/ml). In the presence of a hypothalamic homogenate, which is a stimulant of the chemiluminescence-generating system (PXI = 16), melatonin has a dose-dependent antioxidative effect. Similar results were also obtained by adding tryptophan--a free radicals acceptor (PXI = 0.1) and the substrate in melatonin synthesis to the reaction medium. Melatonin in low concentrations (greater than 0.1 microM/ml) has an antioxidative effect while in higher doses it has a dose-dependent pro-oxidative effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

Anti-LH and FSH activity of melatonin-free pineal extract.

The influence of melatonin (MEL)-free pineal extract on luteinizing hormone (LH) and follicle stimulating hormone (FSH) was studied comparatively with that of MEL. Administration of pineal extract to rats, 3 days running, was found to induce a statistically significant decrease of serum LH and FSH. This effect was also demonstrated by the biological tests used, namely, a decrease in weight of both rat ventral prostate (anti-LH activity) and mouse uterus (anti-FSH activity). MEL administered for 3 days, in doses of 1 microgram/day in the ventral prostate weight test or of 10 microgram in the uterine weight test, failed to induce comparable effects. The identity of the pineal substances responsible for the anti-gonadotropic activity of the pineal gland is discussed.

Animals↗
PubMedDate not supplied

Comparative study of the effects of melatonin-free pineal extract and melatonin on biochemical and hormonal parameters in the rats.

A melatonin-free pineal extract administered to rats in doses of 2 ml/day/animal along 12 days, induced a statistically significant drop in urinary 17 KS, cholesterolemia, hepatic, adrenal and testicular cholesterol. The dose of 1 microgram melatonin/day/animal did not alter these biochemical indices. This dose administered for 3 days did not affect the serum level and testicular concentration of testosterone, unlike the pineal extract which lowered significantly serum and testicular testosterone. Unlike the pineal extract administration of melatonin in doses of 10 micrograms/day/animal along 3 days had no effect on DNA, RNA and testicular proteins. Administration of the pineal extract lowered significantly serum LH and FSH after 3 days whereas melatonin in doses of 50 micrograms/day/animal did not have a similar effect. Furthermore, while the pineal extract inhibited the post-castration elevation of LH and FSH, melatonin in doses of 50 micrograms/day/animal had no effect. The same difference was noted with rats under GnRH stimulation: the pineal extract inhibited the pituitary response to GnRH whereas melatonin did not. The authors conclude that the effects produced by the pineal extract are not mediated by melatonin.

17-Ketosteroids↗
PubMedDate not supplied

Effect of pineal treatment on testicular biochemical parameters under basal conditions and after stimulation with HCG in the rat.

The effect of a melatonin-free pineal extract on sialic and ascorbic acid, nucleic acids (DNA RNA), proteins, total, free and esterified cholesterol in the rat testis under basal conditions and after stimulation with HCG was followed up. The pineal extract induced a decrease in sialic and ascorbic acid, total and esterified cholesterol, but it increased the proteins and RNA after 3 days of treatment, under basal conditions. The decrease in RNA and proteins was noticed after 30 days of treatment. Administration of HCG increased the sialic and ascorbic acids and decreased the total and esterified cholesterol, proteins and DNA without affecting RNA and free cholesterol in the testicular tissue. Concomitant administration of HCG and pineal extract showed that the pineal treatment corrected partially and sometimes completely the increasing or decreasing effect produced by HCG on the biochemical indices studied. The decrease in testicular esterified cholesterol the latter associated with androgen hormone synthesis, brings into discussion the role of the pineal gland in testicular testosteronogenesis, as the same pineal extract also caused a decrease in testosterone. The authors also discuss the regulating role of the pineal gland on some testicular biochemical indices.

Animals↗
PubMedDate not supplied

Effect of pineal treatment on rat HDL-cholesterol under basal conditions and under stimulation with HCG.

The effect of the pineal extract and that of two fractions, f1 and f2, one above, the other 10,000 daltons obtained by ultrafiltration of the extract, on HDL-cholesterol as well as on cholesterolemia and testosterone, under basal conditions and under exogenous HCG stimulation was followed up. Under basal conditions, the pineal extract induced a statistically significant decrease in the 3 biochemical indices, an effect which was also recorded with the two fractions, with the difference that the effect of f2 is more intense and significant as compared to f1, whereas the effect of the pineal extract appears more intense than that of the fractions. Under exogenous HCG stimulation, the pineal extract and less the fractions, partly inhibited the lowering effect of HCG on cholesterol and the rising effect of this hormone on testosterone. The role of the equilibrating agent of the pineal extract on HDL-cholesterol, cholesterolemia and testosterone, is discussed.

Animals↗
PubMedDate not supplied

Anti LH and FSH activity of the human urinary antisteroid substance.

The antisteroid urinary substance was checked out for its effect on LH and FSH under endogenous (castrated animal) and exogenous (administration of releasing hormone-GnRH) stimulation of the rat hypophysis. Administration of this substance partly blocked the castration induced LH and FSH serum increase by 65% and 37% respectively (p less than 0.01) and inhibited the GnRH stimulating effect depressing serum LH by 50% and FSH by 33% (p less than 0.05). In both experiments the LH and FSH content of the hypophysis was not influenced.

Animals↗
PubMedDate not supplied

Decrease of testosterone, cholesterol and ascorbic acid in the rat testis after administration of pineal polypeptides.

Administration of 2 ml/day/animal, of melatonin-free pineal extract to the rat for three days induced a significant decrease in the testicular tissue concentration of testosterone, cholesterol and ascorbic acid. A dose of 1 microgram melatonin/day/animal given for 3 days did not alter these biochemical elements implied in testicular steroidogenesis.

Animals↗
PubMedDate not supplied

Studies on the purification of the antigonadotropic melatonin-free pineal extract.

Partial purification of a melatonin-free extract obtained from bovine pineal and showing an antigonadotropic activity was studied. The following methods were utilized: Sephadex gel filtration, ultrafiltration, precipitation by alcohol, ammonium sulphate and trichloracetic acid. The fractions obtained by all these procedures as well as the dialysed extract were biologically tested through the mouse uterine test. The protein contents in all the substances studied were assayed by Lowry's method. The results showed that in the extract studied, the antigonadotropic activity was present both in the fraction under 10,000 and in the fraction above 10,000, the latter containing 72% of the proteins from the total extract.

Animals↗
PubMedDate not supplied

Circadian variations of ascorbic acid and cholesterol in the testis of intact and pinealectomized rats.

The circadian variations of the testicular ascorbic acid and testicular cholesterol in the intact and pinealectomized rat were followed up. The results show that in both lots there are diurnal variations of these biochemical indices. Pinealectomy does not alter the values curve as concerns the testicular ascorbic acid but causes a reversal in the testicular cholesterol curve especially during the darkness period (the intact rat has an increased value of 2400 hrs whereas the pinealectomized one has the lowest value for the same hour).

Animals↗
PubMedDate not supplied

Inhibitory action of pineal extract on LH and FSH.

The influence of melatonin-free pineal extract on luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was studied. Administration of bovine pineal extract in intact rats was found to induce a statistically significant decrease of serum LH and FSH. The pineal extract also inhibited the 24-hour-post-castration rise of serum and pituitary LH and FSH in mature male rats. The stimulating effect of gonadotropin-releasing hormone (GnRH) on pituitary LH and FSH was also inhibited in intact animals. The antigonadotropic activity of melatonin-free pineal extract, melatonin and arginine-vasotocin (AVT) is discussed.

Animals↗