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Biomedical subjects

E Damian

Publications and source records attributed to E Damian.

At least 19 recordsLinked to original sources
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↗
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

[Enzymatic aspects of severely acute diarrheal disease in infants].

Acute dehydration of diarrhoea of the breast-fed child is a type of hypovolemic shock which, by its severity and frequency is one of the major emergencies of pediatrics. The liver, as the site of many metabolic processes is mainly affected in the frame of the multiple-tissue involvement which is characteristic for this condition. The authors carried out a study of several enzymes (total LDH and the thermally-labile fraction, gluthamatdehydrogenase, gammaglutamyltranspeptidase, acid and alkaline phosphatase) in 27 breast-fed children. Determination of the enzymes was done on hospitalization, and 10 days later. The study showed that all the enzymes that were evaluated had moderate increases in 40.7-71% of all cases. The increases were significant (p less than 0.001). After 10 days the enzyme titers showed a tendency to become normal again, and slightly higher values were found in only 15-12% of all cases. Minimal hepatopathy can be considered, associated to the clinico-biological evolution of this severe conditions of the breast-fed child pathology.

Acid Phosphatase↗
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

The antisteroid, antigonadotropic and metabolism-regulation activity of the pineal gland.

This is a synthetic presentation of the data accumulated along almost fourty years in the Institute of Endocrinology in Bucharest, on the biology of the pineal gland. Most of these were included in the book treating on the pineal gland as an organ of metabolic regulation. The works revealed hypoglycemic, anabolic, anticholesterolemic and glomerulotrophic action of the pineal peptides as opposed to the pinealectomy which induced completely opposite effects. It was also demonstrated that the pineal gland has an antisteroid action, being both anticorticosteroid and antiandrogenic; the antigonadotropic action was also revealed on the basis of the classical method in endocrinology in which two states of plus or of minus of the glandular secretions show diametrically opposed phenomena. Researches on the hormonology of the pineal gland led to the production of a biologically active peptide extract which was finally turned into a medicine under the name of Crinofizin. The therapeutic indications of this drug are also presented.

Adrenal Cortex Hormones↗
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

Decrease in high-density lipoprotein cholesterol after administration of melatonin-free pineal extract in the rat.

The work was focused on the effect of the pineal extract on HDL-cholesterol alongside the effect of the same extract on serum cholesterol and testosterone in the rat under basal conditions. HDL-cholesterol is utilized in the rat, preferentially by the Leydig cells for steroidogenesis. Administration of melatonin-free pineal extract, in doses of 2 ml/day/animal along 3, 6 and 12 days caused a statistically significant decrease in HDL-cholesterol of 19, 21 and 20%, respectively. The same depressor effect occurred 4 hr following a unique injection of pineal extract (-25%, p less than 0.001). Cholesterolemia decreased significantly alongside with HDL-cholesterol (14, 18, and 16% after 3, 6 and 12 days and 18% after 4 hr). The effect of the pineal extract on testosterone tested in only two experiments was to depress it significantly by 43% after 4 hr and 45% after 6 days of treatment. The decrease in testosterone level following the decrease of its major precursor, cholesterol, is discussed.

Animals↗
PubMedDate not supplied

Pineal compounds with antigonadotropic activity.

The work presents the experimental data reported by specialty literature as well as those reported by the authoress on studying the pineal substances with antigonadotropic activity, namely the indole compounds and pineal polypeptides. The effects observed after administration of melatonin--prototype of the pineal-indole family--and of more or less purified pineal extracts are presented. The matter discussed upon is whether or not melatonin or arginine-vasotocin are the pineal hormones responsible for the complex actions induced by the pineal extracts.

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

Effect of melatonin-free pineal extract on acid phosphatase activity in the testosterone-treated, castrated rat.

The effect of a melatonin-free pineal extract on acid phosphatase activity in the prostate of castrated and testosterone-treated rat was studied. Prostatic acid phosphatases in the mature rat are lysosomal and secretory, the former being inhibited by tartrate. Castration induces a decrease in the secretory phosphatases and an increase in the lysosomal ones with a subsequent increase in the tartrate-induced inhibition index. The specific activity of total acid phosphatase also rises. Administration of the pineal extract in the first 4 post-surgical days did not have a significant effect, but when it was prolonged to 7 days, it partially inhibited the effect of castration on prostatic acid phosphatase. Administration of testosterone to the castrated rat in the first 4 post-castration days, partially compensated the prostatic alterations, owing to the fact that the prostate is under the control of androgenic hormones. Administration of both pineal extract and testosterone in the first 4 post-castration days partially inhibited the effect of testosterone. The equillibrating role of the melatonin-free pineal extract and its effect in relation to the amount of time lapsed from surgery is discussed.

Acid Phosphatase↗