Effects of hormone replacement on growth hormone and prolactin exercise responses in postmenopausal women

Studies were conducted to identify a 64-kD thylakoid membrane protein of unknown function. The protein was extracted from chloroplast thylakoids under low ionic strength conditions and purified to homogeneity by preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Four peptides generated from the proteolytic cleavage of the wheat 64-kD protein were sequenced and found to be identical to internal sequences of the chloroplast-coupling factor (CF1) alpha-subunit. Antibodies for the 64-kD protein also recognized the alpha-subunit of CF1. Both the 64-kD protein and the 61-kD CF1 alpha-subunit were present in the monocots barley (Hordeum vulgare), maize (Zea mays), oat (Avena sativa), and wheat (Triticum aestivum); but the dicots pea (Pisum sativum), soybean (Glycine max Merr.), and spinach (Spinacia oleracea) contained only a single polypeptide corresponding to the CF1 alpha-subunit. The 64-kD protein accumulated in response to high irradiance (1000 mumol photons m-2 s-1) and declined in response to low irradiance (80 mumol photons m-2 s-1) treatments. Thus, the 64-kD protein was identified as an irradiance-dependent isoform of the CF1 alpha-subunit found only in monocots. Analysis of purified CF1 complexes showed that the 64-kD protein represented up to 15% of the total CF1 alpha-subunit.     

Effects of hormonal replacement therapy on plasma sex hormone-binding globulin, androgen and insulin-like growth factor-1 levels in postmenopausal women

Plasma sex hormone-binding globulin (SHBG) levels are important in the regulation of plasma free and albumin-bound androgens and estrogens. In postmenopausal women associated to the decrease of estrogen production, a decrease of plasma SHBG levels occurs. Hormone replacement therapy (HRT) in postmenopausal women modulates plasma SHBG levels, in relationship with the different regimens and routes of administration. The present study aimed to compare the effect of different HRT on plasma SHBG levels in relationship with the changes of plasma androgen [dehydroepiandrosterone sulphate (DHEAS), testosterone (T), androstenedione (A)] and insulin-like growth factor-1 (IGF-1) levels. In a retrospective study 443 postmenopausal women were studied and divided into 2 groups. The group 1 (n = 170) was subdivided in 4 groups of women as follows: A) treated with transdermal 17-beta estradiol + medroxyprogesterone acetate, B) treated with oral conjugated estrogens, C) treated with sequential HRT (estradiol valerate (EV) + norgestrel), and D) treated with a combined HRT (micronized estradiol (E2) + noretisterone acetate). Women of group 2 (n = 273) did not receive HRT and served as controls. All groups of women treated with different HRT showed plasma estradiol levels significantly higher than controls (p < 0.01), showing the highest values in women treated with oral HRT. Plasma SHBG levels were not significantly different between patients treated with transdermal 17-beta estradiol + medroxyprogesterone acetate and controls. On the other hand, all the groups of patients treated with oral conjugated estrogen with or without progestagens showed plasma SHBG levels significantly higher than controls (p < 0.01). Plasma SHBG levels were higher in the group treated with estrogen alone than in groups of women treated with sequential or combined HRT. Plasma DHEAS, T and A levels in patients treated with different HRT regimens were in the same range of levels as control women. Plasma IGF-1 levels were not significantly affected by the various HRT regimens and remained in the same range as controls. In conclusion, plasma SHBG levels increase following oral HRT while are not affected by transdermal HRT. Plasma IGF-1 and androgen levels are not influenced from oral or transdermal HRT.     

Effects of hormone replacement therapy on QT interval

We evaluated the electrocardiograms of 208 postmenopausal women (ages 40 to > or = 70 years) without heart disease, medications that could alter the QT interval, use of vaginal estrogens, unknown hormone replacement therapy, or electrocardiographic abnormalities both with (n = 76) and without (n = 132) hormone replacement therapy, and found no significant effects of hormone replacement therapy status on heart rate, QT interval, or the corrected QT interval. Thus, estrogen and/or progesterone effect does not explain the gender differences in myocardial repolarization.     

Study on the relationship between plasma prolactin levels and androgen metabolism in man

The purpose of the study was to investigate the effect of hyperprolactinemia on the metabolism of androgens in man. A group of 6 normal men was treated for 4 consecutive days, on separate periods, with Sulpiride which is known to raise plasma prolactin (PRL) concentration. The effect of the treatment on plasma steroids was verified in basal conditions and under stimulation by HCG. In the controls, a parallel rise in testosterone (T) and dihydrotestosterone (DHT) was observed in response to HCG stimulation. In experimental hyperprolactinemia, the rise in T in response to HCG, similar to that of the controls, was accompanied by a markedly diminished rise in DHT. Similar results were observed in a patient with hyperprolactinemia following apparent accidental section of the pituitary stalk. These data demonstrate the interference of increased levels of PRL in the metabolism of testosterone into the active DHT form by 5alpha-reductase. They suggest that this mechanism could possibly impair the gonadal function in man.     

Modulation of prolactin receptors in the rat hypothalamus in response to changes in serum concentration of endogenous prolactin or to ovine prolactin administration

Specific binding of 125I-labeled rat prolactin (125I-rat PRL) to hypothalamic membranes was studied in Sprague-Dawley rats after ovine PRL administration and in relation to rat PRL serum variations induced by ectopic pituitary implants or by drugs which stimulate (domperidone) or inhibit (bromocriptine) PRL release. Repeated treatments with ovine PRL markedly increased specific binding values of 125I-rat PRL to hypothalamic membranes of female rats. Repeated treatments with domperidone also increased specific PRL binding in the hypothalamus. This effect was associated with an increase in PRL serum levels. Similar results were obtained in male rats after renal pituitary implants which resulted in a state of chronic hyperprolactinaemia. In contrast, a subchronic treatment with bromocriptine decreased specific PRL binding in the hypothalamus and concomitantly caused a sharp reduction in PRL serum levels. Scatchard analysis of data obtained from competition curves showed that the variations in the level of PRL binding to hypothalamic membranes were related to the number of PRL binding sites but not to the dissociation constant (Kd), which was unaffected by different treatments or by pituitary implantation. These results demonstrate a correlation between circulating concentrations of PRL and number of its receptors in the rat hypothalamus and give further support to the hypothesis that these binding sites may have a specific functional role in regulating the homeostasis of pituitary PRL secretion.     

Gender differences in response to nicotine replacement therapy: Objective and subjective indexes of tobacco withdrawal.

K. A. Perkins (see record 1996-00322-006) recently proposed that nicotine reinforcement controls smoking to a greater degree among men than women and that consequently, nicotine replacement therapy (NRT) during smoking cessation should benefit men more than women. The authors tested this hypothesis. Polysomnographic measures of sleep and self-report indexes of tobacco withdrawal were collected pre- and postcessation from an active nicotine patch group and a placebo patch group in a randomized, double-blind clinical trial (N?=?34). Objective sleep parameters supported Perkins's hypothesis and indicated that among women, NRT may be less effective at suppressing certain withdrawal responses compared with men and may produce some iatrogenic effects. Valid and reliable self-report measures of withdrawal did not reveal gender differences in response to NRT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Plasma tryptophan levels and prolactin response to fenfluramine in healthy volunteers

A case of extraluminal migration of a foreign body that produced chronic sialoadenitis is reported. Seven years earlier, the patient had swallowed a fish bone that was not recovered. The little literature available on these uncommon lesions is reviewed.     

Effects of estrogen replacement therapy on PET cerebral blood flow and neuropsychological performance

Reports that estrogen may protect against age-associated memory decline and Alzheimer's Disease have kindled interest in the effects of estrogen replacement therapy (ERT) on cognition and brain function. As part of a 9-year study in the Baltimore Longitudinal Study of Aging, we are performing annual magnetic resonance imaging, positron emission tomography (PET), and neuropsychological assessments to examine brain structure and function in individuals aged 55 and older. PET measurements of regional cerebral blood flow (rCBF) are obtained under 3 conditions: rest and verbal and figural delayed recognition memory tasks. Fifteen women receiving ERT (with or without the addition of progesterone) were compared with a matched sample of 17 untreated women. There were no significant differences between groups in regional brain volumes or ventricular size. However, ERT users and nonusers showed significant differences in PET-rCBF relative activation patterns during the memory tasks. During verbal memory processing, there were significant interactions in rCBF activations for the right parahippocampal gyrus, right precuneus, right frontal regions, and left hypothalamus. During figural memory processing, significant interactions were observed for right parahippocampal and inferior parietal regions and for left visual association and anterior thalamic regions. ERT users also showed better performance on neuropsychological tests of figural and verbal memory and on some aspects of the PET activation tests, although the two groups did not differ in education, overall verbal ability, or performance on other neuropsychological tests. These findings confirm our previous observation of the beneficial effects of ERT on figural memory. Moreover, differences in rCBF activation patterns between ERT users and nonusers suggest an area for future research to examine mechanisms through which ERT may influence memory and other cognitive abilities.     

The effect of prolactin on the response of human lymphocytes to phytohaemagglutinin

Lymphocytes were collected from ten normal human males and incubated with or without phytohaemagglutinin (PHA) in the absence or presence of ovine prolactin in concentrations found in normal individuals and in human pregnancy. Prolactin consistently inhibited lymphocyte transformations. The degree of inhibition became progressively less as PHA concentrations were increased.     

Effects of castration and replacement therapy on sexual behavior of adult male rhesuses.

Observed the sexual behavior of 10 male rhesus monkeys before and after castration and during replacement therapy with testosterone propionate. In 10 tests before castration, all of the Ss ejaculated at least once, and in Weeks 21-25 and 51-55 after castration, 50 and 30%, respectively, ejaculated at least once. In the 35 postcastration tests given over a 55-wk period, 2 males did not ejaculate. 50% of the Ss achieved intromission 1 yr after castration. The percentage of castrated Ss showing intromission and ejaculation and the frequency of these responses were higher than those reported for most nonprimate species but did not differ greatly from those reported for the dog. Within 1 wk testosterone propionate restored whatever aspects of behavior were affected to precastration levels. (22 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of estrogen replacement therapy on the lipoprotein profile in postmenopausal women with ESRD

BACKGROUND: Patients with ESRD have excessive cardiovascular morbidity and mortality. In postmenopausal women with normal renal function, estrogen replacement therapy decreases cardiovascular mortality by 50%, in part because of their beneficial effects on the lipoprotein profile. Because of similarities in the lipoprotein profile between healthy, postmenopausal women, and women with ESRD, we examined the effects of estrogen replacement on lipoproteins in 11 postmenopausal women with ESRD. METHODS: In a randomized, placebo-controlled crossover study (8 week treatment arms) using 2 mg daily of oral, micronized estradiol, 11 postmenopausal women with ESRD were treated. Neither baseline lipid nor lipoprotein abnormalities were used as entry criteria for study participation. RESULTS: Blood estradiol levels were 19 +/- 4 with placebo and 194 +/- 67 pg/ml (P = 0.024) with estradiol treatment. Total HDL cholesterol concentrations increased from 52 +/- 19 mg/dl to 61 +/- 20 mg/dl (16%), with placebo and estradiol treatments, respectively (P = 0.002). Apolipoprotein A1 increased by 24.6% (P = 0.0002) with estradiol intervention. HDL2 concentrations were 19 +/- 13 with placebo and 24 +/- 16 with estradiol treatment (P = 0.046). There were no differences in total or LDL cholesterol, other lipoprotein fractions including Lp(a), and triglycerides with 2 mg daily estradiol treatment. No significant side effects were observed. CONCLUSIONS: Therefore, using standard dosage regimens for estrogen replacement therapy in postmenopausal women with ESRD, HDL cholesterol is increased to an extent that would be expected to improve their cardiovascular risk profile. Further studies are needed to assess whether estrogen replacement therapy decreases the incidence or severity of cardiovascular disease in ESRD patients to a similar degree compared with other women.     

Effects of thyroid hormone replacement therapy on nocturnal apnea in elderly patients with hypothyroidism

BACKGROUND AND STUDY AIMS: Dieulafoy's disease is a rare cause of upper gastrointestinal tract hemorrhage. The aim of the study was to evaluate the efficacy of endoscopic hemostasis and to analyze the mortality of patients with hemorrhage due to Dieulafoy's disease. PATIENTS AND METHODS: The retrospective analysis included patients from our institution who had undergone urgent endoscopic examination of the upper digestive tract and hemostatic interventions in the period between January 1994 and December 1996. RESULTS: Twenty-five patients were examined (18 men and 7 women, average age 52.6, SD+/-15.3, range 25-78). In 20 patients endoscopic injection sclerotherapy was performed (diluted epinephrine 1:10,000 plus polidocanol 1%) and Nd:YAG laser photocoagulation in five patients. In all patients a total of 44 interventional endoscopies were carried out. Repeated endoscopic hemostasis did not prove successful in two patients (8%, 2 men), and they were treated operatively. During the postoperative period one patient died because of multiorgan failure. The total mortality rate of all patients in which endoscopic hemostasis was done was 16% (4/25). None of the 21 surviving patients had rebleeding on long-term follow-up (mean: 29.4 months). CONCLUSIONS: Endoscopic hemostasis is a major therapeutic advance in the management of Dieulafoy's disease hemorrhage. Interventional endoscopy has decreased the need for surgical management and significantly reduced mortality.     

Effects of hormone replacement therapy in bone resorption, in post-menopausal women

BACKGROUND: The effects of different therapies on bone loss rate can be measured using biochemical markers of bone resorption such as urinary hydroxyproline. AIM: To study the effects of hormone replacement therapy on urinary hydroxyproline in postmenopausal women. PATIENTS AND METHODS: Eighty three postmenopausal women without hormone replacement therapy, 54 postmenopausal women receiving hormone replacement therapy and 16 premenopausal women (considered as the control group) were studied. Hydroxyproline was measured in an early morning urine sample, after one day of diet without meat or gelatin. RESULTS: Urinary hydroxyproline in premenopausal women was 33.7 +/- 7.9 mg/g creatinine. The figure for postmenopausal women with hormonal replacement therapy was 33.7 +/- 5.9 mg/g creatinine. Postmenopausal women without replacement therapy had an urinary hydroxyproline of 47.4 +/- 8.5 mg/g creatinine, significantly higher than that of premenopausal and supplemented women. In 21 postmenopausal women, hydroxyproline was measured before and after three months of replacement therapy, values decreased 35.5 +/- 11% in this period and there was a direct correlation between initial values and the degree of reduction (r = 0.69, p < 0.001). CONCLUSIONS: Postmenopausal women receiving hormone replacement therapy have a urinary hydroxyproline excretion similar to that of premenopausal women.     

Effects of oophorectomy and hormone replacement therapy on ophthalmic artery blood flow velocity waveforms

Our objective was to compare ophthalmic artery flow velocity waveforms in unilateral oophorectomized patients not on hormone replacement therapy with findings in bilateral oophorectomized patients on hormone replacement therapy. Ten patients who underwent hysterectomy and unilateral oophorectomy and 10 women treated by hysterectomy and bilateral oophorectomy were studied using color and pulsed Doppler ultrasonography 1 day before and on days 7 and 28 after surgery. Serum estradiol levels were measured serially. Bilateral oophorectomy patients were given hormone replacement therapy (conjugated estrogen, 0.625 mg/day, and medroxyprogesterone acetate, 2.5 mg/day) orally starting on day 8 after surgery. The pulsatility index values of the ophthalmic artery in unilateral oophorectomy patients were 1.93 +/- 0.41, 2.10 +/- 0.26, and 1.68 +/- 0.27 for 1 day before and on days 7 and 28 after surgery, respectively. The pulsatility index values of the ophthalmic artery in bilateral oophorectomy patients were 1.99 +/- 0.39, 2.17 +/- 0.47, and 1.75 +/- 0.32 for 1 day before and on days 7 and 28 after surgery, respectively. No significant differences were found between pulsatility index values in the unilateral and bilateral oophorectomy patients in each time period. The pulsatility index values on day 28 decreased significantly compared with the findings on day 7 in both groups (P < 0.05). The serum estradiol levels were significantly reduced from 1 day before to day 7 day after surgery and were significantly elevated by day 28 after surgery (P < 0.05) in both groups of patients. No significant differences were found between the serum estradiol levels in the unilateral and bilateral oophorectomy patients in each time period. Vascular tone in the ophthalmic artery seems to change according to serum estradiol levels, a finding that may help explain some of the beneficial effects of hormone replacement therapy for bilateral oophorectomized patients.     

Effect of acute ethanol ingestion on prolactin in menopausal women using estradiol replacement

The current study was to answer the question: Is enough mercury absorbed from dental amalgam fillings to produce renal damage? One hundred healthy adults (18-44 years old) filled out health questionnaires and voided urine samples. Urine mercury concentration and N-acetyl-beta-glucosaminidase (NAG) were measured. Subjects were grouped into those having amalgam fillings (N = 66) and those without (N = 34). Median (95% Confidence Interval) urine mercury was 1 (1-2) and 0 (0-0.6) ng/ml (P < 0.01) and median urine NAG was 23 (18-27) and 16 (11-18) units (P < 0.05) in the two groups respectively. People with mercury amalgam fillings excreted slightly more mercury than people without them, and have a very small increase in urinary NAG excretion that is probably of no clinical significance. This dose of mercury absorbed from amalgam appears to be too little to be a public health hazard for renal injury.