Serum melatonin levels in brain-dead organ donors.
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Adolescent↗
Biomedical subjects
Z Ostrowska
Publications and source records attributed to Z Ostrowska.
[Insulin-like growth factors (IGFs) and their binding proteins (IGFBPs)in physiologic and pathologic states].
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Acromegaly↗
Circadian variations in serum levels of LH, FSH, estradiol, testosterone and sex hormone binding globulin in acromegalic women with menstrual disturbances before and after transsphenoidal adenectomy.
Day/night profiles of serum GH, PRL, IGF-I, LH, FSH, testosterone (TT and FT), estradiol (E2) and SHBG were estimated in 12 acromegalic women with GH- and PRL-producing pituitary adenomas and 13 patients with GH-secreting pituitary tumors before and 3 months after transsphenoidal adenectomy. All the subjects studied have had irregular menstrual cycles. Blood for profile determinations was drawn from a peripheral vein at 3 h intervals for three 24 h periods (starting at 08.00). Before surgery all acromegalic women had high mean 24 h GH and IGF-I levels (with irregular peaks) even in the absence of hyperprolactinemia. Postoperative mean 24 h GH level was still high only in 5 out of 25 women studied, and that of IGF-I in 10 of these patients. In 12 acromegalic women with preoperative hyperprolactinemia and disturbed 24 h fluctuations postoperative 24 h mean level of PRL and its circadian rhythm were normal. Before surgery, the circadian variations of pituitary-sex hormone levels and SHBG capacity in serum were not impaired. However, mean 24 h levels of LH, FSH, TT, FT E2 and SHBG were altered mainly in patients with mixed type of GH and PRL producing adenomas. This may be related to the increased activity of GH/IGF-I axis on the one hand and to the excess of PRL on the other. The postoperative normalization of pituitary-sex hormone levels and SHBG capacity in serum was noted only in women with normal 24 h circadian variations of IGF-I levels.
Journal Article↗
Effect operative weight reduction on Hypothalamo-Pituitary, -adrenal and -ovarian axes function in obese women with menstrual disturbances.
The aim of the study was to evaluate insulin (Ins), pituitary hormones (GH, PRL, LH, FSH), sex hormone-binding globulin (SHBG) and insulin-like growth factor-I (IGF-I) under basal conditions as well as the changes in GH, PRL and F levels after insulin-induced hypoglycemia in 21 obese women before and one year after jejunoileostomy as well as in 20 healthy female volunteers with normal body weight (aged 27 to 36 years). Before surgery all obese women had irregular menstrual cycles. In 14/21 non-operated morbidly obese women and after operative weight reduction (jejunoileostomy), the GH, PRL and F response to insulin-induced hypoglycemia was lower than that in non-obese healthy controls. No difference, however, was observed in GH, PRL and F secretion in non-operated obese women as compared with obese women after jejunoileostomy. Hypothalamic disturbances in the release of GH, PRL and F corresponded to higher levels of sex steroid hormones, IGF-I, and also to lower values of LH/FSH index and SHBG capacity in serum. After jejunoileostomy the pituitary-ovarian axis function as well as SHBG and IGF-I concentrations were normalized only in patients with a noted body mass reduction and with normal preoperative GH, PRL and F secretion dynamics. In these women the menstruation became regular.
Journal Article↗
Central adrenergic system does not contribute to morphine stimulated pineal secretion of melatonin.
The effect of long-term morphine treatment of rats subjected to central chemical sympathectomy (CCS) was studied. The experiment was performed on 7-week-old male Wistar rats. CCS was performed with 6-hydroxydopamine injected into the lateral ventricle of the brain. The serum concentration of melatonin was assayed by specific RIA. The study showed that morphine alone significantly increased melatonin concentrations in serum. CCS alone significantly decreased melatonin concentrations in serum at the time of highest secretory activity of the pineal gland. Long-term morphine treatment of rats subjected to CCS significantly increased the serum concentration of melatonin. Therefore, it may be concluded that the central adrenergic system does not take part in the morphine-stimulated secretion of melatonin.
Journal Article↗
[Evaluation of selected parameters of collagen metabolism in rats after implantation of copolymer d,l-lactide and E-caprolacton with cortisol and progesterone].
Tests were carried out on the possibility of biodegradable copolymer d, l-lactide and E-caprolacton as a carrier system for a long-term substitution of progesterone and cortisole. During 120 days of the experiment almost linear profile of freeing of progesterone with average rate 0.5% of the initial amount of hormone (24 hours, what indicates a practical possibility of its application in hormonal substitution) was obtained. Simultaneously the influence of copolymer implants on the metabolism of collagen was tested marking the concentrations P I CP and P III NP in particular periods of the experiment. We did not notice any permanent changes of metabolism of collagen under the influence of the tested carrier system of the hormonal medicaments and the obtained changes of concentrations P I CP and P III NP are probably caused by the hormones freeing from the subgrade.
Animals↗
ACTH secretion, circadian variations of salivary free and total serum cortisol and urinary 17-OHCS excretion in active acromegaly following bromocriptine treatment.
The serum levels of ACTH, PRL, GH, somatomedin-C and cortisol (also in saliva) and urinary 17-OHCS excretion were investigated in 37 acromegalic males after radiotherapy. According to bromocriptine test (BC) 20 subject were classified as responders, and 17 as non-responders. ACTH concentration was normal in all acromegalic patients and remained unchanged after BC administration. Mean 24-h level of serum total cortisol was lower in untreated patients and it increased after BC treatment only in responders. No disturbances in circadian rhythm of free cortisol were observed in any of patients. A significantly elevated excretion of 17-OHCS was found in responders before and in non-responders before and after BC administration. In untreated responders significantly increased levels of GH were found which decreased significantly after bromocriptine. In non-responders no difference was found between the values before and after BC, both being significantly higher than those in controls. In both groups of patients significantly increased levels of PRL were observed which after BC decreased to the control values. The levels of somatomedin-C were changing in parallel to those of GH described above.
17-Hydroxycorticosteroids↗
The lack of melatonin rhythm in active acromegaly after radiotherapy.
The aim of the study was to evaluate the interrelation between the levels of growth hormone (GH), prolactin (PRL), somatomedin-C (Sm-C) and melatonin determined at 3 h intervals over a 24 h period (8.00, 11.00, 14.00, 17.00, 20.00, 23.00, 2.00 and 5.00) in 8 acromegalic patients after radiotherapy. The circadian rhythms and the interrelation between hormone and Sm-C levels were evaluated using Halberg's cosinor method and the correlation analysis, respectively. We observed a total abolition of melatonin rhythm with significantly lower nocturnal values in all patients which could be due to earlier radiotherapy.
Acromegaly↗
[Activities of certain endocrine glands in bronchial asthma].
The present reports on the effects of various levels of the endocrine system on the course of bronchial asthma are reviewed. Hypophyseal function in production of certain hormone and functioning of the hypothalamo, hypophyseal-thyroid, -adrenal, and -gonadal axis are discussed. Changes in the functions of endocrine glands may modify the course of allergic diseases.
Asthma↗
[Diagnostic value of the analysis of alpha fetoprotein levels in malignant neoplasms of the digestive system].
The concentration of alpha-fetoprotein (AFP) in serum was determined in 58 patients (35 males and 23 females) aged from 38 to 87 years treated surgically for malignant tumours of the digestive tract, including colonic carcinoma in 30, gastric carcinoma in 11, pancreatic carcinoma in 10 and oesophageal carcinoma in 7 cases. In 33 patients the tumour was disseminated (into the liver in 22 cases). On the ground of AFP concentration determinations in 40 patients (19 males and 21 females) aged 22 to 80 years operated on for non-neoplastic abdominal diseases the upper normal range was accepted as 9.42 ng/ml. Raised AFP concentration was found in only patient with advanced pancreatic carcinoma and multiple metastases to the liver and lymph nodes. The study showed that serum AFP level in cases of digestive tract malignancies is of limited diagnostic value.
Adult↗
[Sex hormone-binding globulin (SHBG) under physiological and pathological conditions].
The concentration of sex hormone-binding globulin (SHBG) in blood depends on the sex, age, metabolic status of the organism, liver function, and gonad function. The circadian rhythm of somatotropin secretion is an important regulator of SHBG synthesis and secretion, and its passage from vascular bed to the tissues depends on somatomedin-C. The concentration of SHBG in the serum is thus the resultant of the synthesis of this glycoprotein in the liver and the ability of its uptake in the cells of target tissues for sex hormones.
Circadian Rhythm↗
Circadian variations of serum triiodothyronine, thyroxine, corticosterone and lipids in starved rats.
Circadian variation of serum triiodothyronine (T3), thyroxine (T4), corticosterone (B) and lipids was studied in male Wistar rats after one week of the starvation. The animals were adopted to 12:12 h light-dark cycle (lights on from 7.00 to 19.00 h) and tap water was available ad libitum. Blood samples were drawn at 3 h intervals along a 24 h span. The hormone levels were measured by RIA kits, plasma lipids by photometric method. The results were evaluated by cosinor method. The presence of a circadian rhythm of T3 and B was found in control rats. The starvation resulted in changed circadian rhythm of T3 with lower values of mesor and amplitude, and while acrophase shifted from 14.48 to 2.12. In addition, the starvation induced circadian rhythm of T4 with acrophase at 1.00. The circadian rhythm of B showed significantly higher values of mesor and amplitude, while acrophase shifted from 17.42 to 4.06. The concentration of lipids was changed in the animals deprived of food as compared with controls.
Animals↗
Influence of melatonin on rat thyroid, adrenals and testis secretion during the day.
The effect of pinealectomy and exogenous melatonin on circadian rhythm of triiodothyronine (T3), thyroxin (T4), corticosterone and testosterone in sham-operated and pinealectomized rats were investigated. The hormones concentration were RIA-measured and the circadian rhythm secretion were analysed by cosinor method. The findings suggest that pinealectomy abolishes the rhythmical character of corticosterone secretion and disturbs the circadian rhythm of T3, T4 and testosterone. Exogenous melatonin has the suppressive effect of diurnal secretion of T3, T4 and testosterone in pinealectomized rats but stimulates the rhythmical corticosterone secretion.
Adrenal Glands↗
The levels of pituitary-testicular axis hormones and SHBG in active acromegaly following bromocriptine treatment.
Pituitary and testicular hormone secretion and sex-hormone binding globulin (SHBG) level were investigated in 15 males with active acromegaly in normal and hyperprolactinemic state. Basal serum folitropin (FSH) and lutropin (LH) levels did not change before and after the administration of bromocriptine and remained in normal range compared with those in healthy men. Serum total testosterone concentration and SHBG were decreased particularly in hyperprolactinemic patients, but their levels were significantly increased to the normal limits following bromocriptine application. Although slight changes in serum concentration of free testosterone (fT) and circadian rhythm of fT in saliva was observed before and following bromocriptine treatment, the statistical differences were not significant. The results of the present study suggest that in acromegaly the alterations in peripheral metabolism of sexual steroids may exist.
Acromegaly↗
Influence of melatonin on thyroid secretion in pinealectomized rats.
The influence of a single dose of melatonin administered to pinealectomized and sham operated rats at different times of day on serum T3, T4 concentrations was investigated. It was found that such melatonin influence depends upon a time of day. Both pinealectomy and exogenous melatonin did not influence the thyroid activity in the morning. The most remarkable pineal effect on the thyroid appeared during the night.
Animals↗
[Experimental studies of the effects of estradiol and thyroxine on the fascicular layer of the adrenal cortex].
We studied the effects of estradiol and thyroxine on the secretory function of the adrenal gland cortex in castrated female rats. We evaluated steroidogenesis on the basis changes in histochemical reaction to lipids and corticosterone blood concentrations in adrenal and peripheral veins obtained from RIA studies. It was found that estradiol stimulated or inhibited the synthesis of corticosterone in a dose-dependent manner. In contrast thyroxine alone or combined with estradiol (irrespective of the dose) enhanced steroidogenesis in the adrenal glands of castrated female rats.
Adrenal Cortex↗
Adrenal cortex hormones in male epileptic patients before and during a 2-year phenytoin treatment.
Serum levels of progesterone, cortisol and phenytoin as well as the excretion of 17-OHCS were determined in 45 male epileptics before and during 24 months of the therapy. A significant decrease of the hormones was found in untreated patients. Phenytoin administration caused further decrease of cortisol and its metabolite 17-OHCS levels and a compensation of progesterone serum concentration.
17-Hydroxycorticosteroids↗
[Role of gonadotropins in the biosynthesis of corticosteroids measured in the blood of the adrenal vein in castrated rats].
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18-Hydroxydesoxycorticosterone↗