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Biomedical subjects

D Parrini

Publications and source records attributed to D Parrini.

27 records · Page 2Linked to original sources
PubMed1981

[Effect of cold stress on the concentrations in the hypothalamus, pituitary, and blood of beta-lipotropin and beta-endorphin in the rabbit].

To evaluate the rabbit availability in beta-Lipotrophin studies we have investigated their brain, pituitary and plasmatic concentrations in basal conditions and after cold-stress. Previous silicic Acid extract and Sephadex G-75 column chromatography, the two peptides were measured through two specific and sensitive RIAs. The results reveal the presence of beta LPH and beta EP and their increase after cold-stress in hypothalamus, pituitary and peripheral plasma concentrations while not in midbrain.

Animals↗
PubMed1981

[Neonatal adaptive phenomenon: secretion of beta-lipotropin, and beta-endorphin in the first week of life].

beta Lipotrophin and beta Endorphin plasma levels have been measured in 35 newborns subdivided in 5 groups of 12, 24, 48, 72 and 168 hours of life, 10 umbilical mixed blood samples were also evaluated. After plasma extraction (3 ml) and G-75 Sephadex column chromatography, the peptides were measured by two specific RIAs. beta LPH and beta EP levels were high in umbilical cord plasma (241.0 +/- 43.3 and 70.0 +/- 8.5 pg/ml respectively). A progressive decrement was then observed until the 72th hour of life (28.1 +/- 13.2 and 8.7 +/- 4.8 pg/ml respectively) but the elevated levels found at 24th hour demonstrate an active synthesis and release from fetal and neonatal pituitary. After a slight and transient decreased activity during the first week of life, the statistically significant increase of both beta LPH and beta EP observed at seven day indicate that at this moment pituitary function is restored.

Chromatography, Gel↗
PubMed1981

beta-lipotrophin and beta-endorphin plasma levels during pregnancy.

beta-lipotrophin (beta-LPH) and beta-endorphin (beta-EP) plasma levels were measured by radioimmunoassay after glass powder extraction and Sephadex G-75 column chromatography in plasma samples from controls (ten healthy males and twenty-six young women in early follicular phase), from eighty-two pregnant women in weeks 9-40 after their last menstrual period, from nine women just after delivery and the cord blood of their neonates, in fifteen mixed cord blood samples and in seven amniotic fluid samples obtained by amniocentesis. No sex differences were found in beta-LPH (120.6 +/- 8.5 pg/ml) or beta-EP (31.1 +/- 2.4 pg/ml) plasma levels or in their molar ratio (1.34 +/- 0.09) (MR). beta-LPH plasma levels increased in early pregnancy (13-16 weeks) (185.0 +/- 27.1 pg/ml) and remained high until weeks 21-24, then declining to levels similar to those of controls. beta-EP plasma levels were significantly depressed in weeks 9-12 (20.7 +/- 5.3 pg/ml), subsequently increasing to a maximum at weeks 36-37 (42.7 +/- 6.8 pg/ml). beta-LPH/beta-EP molar ratio was about double normal in early pregnancy and decreased to normal in the second half. The present data indicate that beta-LPH and beta-EP present different patterns throughout pregnancy and that beta-EP levels increase progressively, reaching the highest concentrations at term. At delivery, both beta-LPH and beta-EP showed maximum values (beta-LPH: 230.2 +/- 20.4 pg/ml; beta-EP: 78.0 +/- 7.4 pg/ml) and a MR of 1.02 +/- 0.10 indicating that stressful situations, such as labour, stimulate a simultaneous rise in beta-LPH and beta-EP plasma levels. Cord blood specimens showed a wide range of values (beta-LPH:75-347 pg/ml; beta-EP: 16-287 pg/ml) with a MR of 1.21 +/- 0.14. Amniotic fluid samples obtained late in the third trimester of pregnancy were characterized by beta-LPH levels of 119.4 +/- 26.4 pg/ml and beta-EP levels of 29.6 +/- 7.5 pg/ml.

Amniotic Fluid↗
PubMed1978

Effect of epimestrol on gonadotropin and prolactin plasma levels and response to luteinizing hormone-releasing hormone/thyrotropin-releasing hormone in secondary amenorrhea and oligomenorrhea.

The effects of epimestrol (5 mg every 6 hours for 5 days) on basal levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (Prl), estradiol, progesterone, and dehydroepiandrosterone sulfate, and on the response to LH-releasing hormone (LH-RH) and thyrotropin-releasing hormone (TRH) stimulation, were studied in 18 cases of secondary amenorrhea and oligomenorrhea of hypothalamic-pituitary origin, in three cases of anorexia nervosa, in two cases of long-lasting progestin-induced amenorrhea, and in one case of precocious menopause. The results in the first 18 patients indicate that epimestrol treatment induces a significant increase in LH and Prl levels after 24 hours, while the FSH increase becomes significant only after 4 days of therapy. Twelve hours after discontinuation of treatment, all three hormone levels decreased significantly to values similar to the basal levels, while the pituitary response to LH-RH indicated a much more marked LH secretion than before treatment. A second test, performed 36 hours after the last drug administration, again showed a significantly higher LH response than that found under basal conditions. No significant variations were observed in the FSH response to LH-RH, nor in the Prl response to TRH. These data suggest that epimestrol interferes at the level of the centers responsible for Prl and gonadotropin secretion in the manner of a weak estrogen.

Adolescent↗
PubMedDate not supplied

Beta-lipotropin and beta-endorphin in physiological and surgical menopause.

Beta-lipotropin (beta-LPH) and beta-endorphin (beta-EP) plasma levels were characterized by a significant decrease in postmenopausal females (22 subjects aged from 56 to 70 yr) when compared to fertile women (22 subjects from 31 to 45 yr). On the contrary, ACTH plasma levels determined in 10 of the premenopausal and 13 of the postmenopausal subjects reported above showed constant levels in both groups. A significant increase in the beta-LPH/beta-EP molar ratio was observed in postmenopausal females. The plasma beta-LPH and beta-EP levels studied before and 6 months after ovariectomy, showed a significant decrease in 8 out of 10 patients, while they remained constant in the other 2. Two subjects, in whom postsurgical samples were taken during a flushing episode, showed beta-LPH and beta EP plasma levels which were both higher than the corresponding preovariectomy values. The results suggest that these changes may be important in explaining modifications in behavior and mood frequently found in postmenopausal females and in patients undergoing surgical castration in the fertile age.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Puerperal breast feeding does not stimulate circulating opioids in humans.

ACTH, beta lipotropin (beta LPH), beta endorphin (beta EP), Prolactin (PRL) and Cortisol were measured in the first five days of puerperium at 9:00, before and 30 minutes after suckling, in 7 healthy lactating women. With the exception of PRL plasma levels which decline, although remaining at high concentrations during the observation period, all the other parameters showed a sudden fall from the high levels found at delivery, reaching stable normal levels (beta LPH, beta EP, Cortisol) or concentrations which were 50% lower than normal (ACTH), from the second day of puerperium. Suckling confirms its capacity to release plasma PRL, while all the other indices remain unmodified. Despite the experimental evidence that serotoninergic neurons are involved both in the PRL response to suckling and the circadian rhythmicity and stress response of proopiocortin-related peptides, the present results suggest that breast feeding is not a stressful situation, as no typical proopiocortin-related peptide response is evident, and that the activation of PRL release is related to stimulation of serotoninergic neurons which differ from those involved in the control of proopiocortin-related peptide secretion.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Different patterns of central and peripheral beta EP, beta LPH and ACTH throughout life.

The aim of the present study was to evaluate the relationship between central and peripheral concentrations of proopiocortin-related peptides in different periods of life. One hundred and eighty-nine plasma samples from normal subjects (18-87 years) obtained in basal conditions, and 20 cerebrospinal fluid (CSF) samples obtained by lumbar puncture from healthy volunteers (18-75 years) were studied. beta Lipotropin (beta LPH), beta endorphin (beta EP) and ACTH were measured by specific RIA after silicic acid plasma extraction and gel chromatography (beta LPH and beta EP). No sex differences were found in the patterns of the three peptides either in the plasma or in CSF. In the plasma samples, both beta LPH and beta EP concentrations showed a pattern throughout life which was expressed by a paraboloid function with the lowest values found in young and old subjects and with peaks at 51.3 and 48.2 years, respectively. On the contrary, ACTH values failed to be represented by a significant linear or curvilinear regression and presented only a slight decrease in subjects over 75 years of age. CSF levels of beta LPH were significantly lower in 45-76 year old subjects (18.8 +/- 12.6 fmol/ml, M +/- SD) than in 18-44 year old subjects (34.5 +/- 15.8; p less than 0.05), as were those of beta EP (elderly: 41.2 +/- 19.7; young: 94.2 +/- 36.7; p less than 0.05), which showed a significantly linear inverse correlation with age (r = 0.6062, p less than 0.01). These CSF samples did not show any ACTH variations connected with age.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗