Effects of estrogen/medrogestone therapy on the apoprotein B-containing lipoproteins in postmenopausal women with type 2 diabetes mellitus under satisfactory and non-satisfactory glycemic control. (1/5)

BACKGROUND: Information is lacking on the effects of hormone replacement therapy in women with diabetes, especially during moderate chronic hyperglycemia. OBJECTIVES: To study the effects of HRT on the lipid profile and the low density lipoprotein subclass distribution in women with type 2 diabetes under satisfactory and non-satisfactory glycemic control. METHODS: Fifty-four postmenopausal women after a 6 week run-in diet were randomized to receive either placebo (HbA1c < 8%, n = 13; HbA1c > 8%, n = 17) or HRT (HbA1c < 8%, n = 11; HbA1c > 8%, n = 13) for 12 weeks. HRT consisted of cyclical conjugated estrogens 0.625 mg/day plus medrogestone 5 mg/day. At the beginning and at the end of each treatment period the LDL subclass distribution was estimated by density gradient ultracentrifugation. RESULTS: At the baseline and during the study, the HbA1c level was significantly higher in hyperglycemic patients than in the near-normoglycemic controls (baseline 10.2 +/- 2.9 vs. 6.5 +/- 0.7%, P < 0.01). They showed a trend for higher total and LDL cholesterol, triglycerides and lower high density lipoprotein-cholesterol compared to near-normoglycemic controls, as well as significantly higher triglyceride concentrations in very low density lipoprotein, intermediate density lipoprotein and LDL-1 particles and cholesterol content in LDL-1 and -2 particles. HRT decreased LDL-cholesterol in both groups. In the normoglycemic patients a small increase in HbA1c was observed (6.5 +/- 0.7 vs. 7.4 +/- 1%, P = 0.04). In all cases, HRT did not modify the proportion of LDL represented by denser LDLs. CONCLUSIONS: HRT did not modify the LDL subclass distribution, even in the presence of moderate chronic hyperglycemia in women with type 2 diabetes.  (+info)

Effects of hormone replacement therapy on the main fatty acids of serum and phospholipids of postmenopausal women. (2/5)

BACKGROUND: The anti-atherosclerotic effects of hormone replacement therapy (HRT) in postmenopausal women are partly mediated by improvement of the lipid and lipoprotein profiles. The present study aimed to investigate the effects of HRT on the main fatty acids of serum and phospholipids in postmenopausal women. PATIENTS AND METHODS: Serum samples of two groups of postmenopausal women, receiving either single oestrogen or in combination with progestogens, were analysed before and after a 6- month treatment period. RESULTS: Of the main serum fatty acids, there was a significant reduction in palmitic (p < 0.05) and arachidonic acids (p < 0.001), followed by an increase in oleic (p < 0.05) and linoleic acids (p < 0.05) in postmenopausal women receiving HRT compared to single oestrogen. The main fatty acids in phospholipids showed a similar pattern in those women. CONCLUSION: The above results demonstrate the beneficial effects of HRT in reducing the risk of cardiovascular disease through modification of the fatty acid profiles of postmenopausal women.  (+info)

Steroid-protein interactions. Stopped flow fluorescence studies of the interaction between steroid hormones and progesterone-binding globulin. (3/5)

Stopped flow fluorometry, measuring changes in the intrinsic fluorescence of progesterone-binding globulin (PBG), was used to determine the association and dissociation rates of the interaction of PBG with seven delta4-3-ketosteroids. The rates of formation and dissociation of the PBG-progesterone complex were measured as a function of concentration and temperature. At 20 degrees, kon = 8.7 X 10(7) M-1 S-1 and koff = 0.060 S-1. The association rate constants for progesterone, deoxycorticosterone, testosterone, testosterone acetate, and medrogestone were found to be the same within experimental error. The different affinities of PBG for these steroids result from the dissociation rate constants of the steroids which ranged from 0.43 S-1 for testosterone to 0.024 S-1 for medrogestone. Two corticosteroids, corticosterone and cortisol, were both bound somewhat more slowly (approximately 5 X 10(7) M-1 S-1). Reflecting their very low affinity for PBG both steroids dissociate very rapidly: corticosterone at 1.4 S-1 and cortisol at 90 S-1. The ratio of association to dissociation rate constants gave affinity constants in agreement with independently determined constants.  (+info)

Assessment of testicular testosterone production and Leydig cell structure. (4/5)

Advances in two techniques have made the problem of assessing the acute and/or chronic effects of toxic agents on Leydig cell structure and testosterone synthesis and secretion amenable to study. First, in vitro testicular perfusion has been perfected to a point where it closely resembles in situ testosterone secretion. Second, now it is possible to quantify the proportion of Leydig cell cytoplasm occupied by the cellular organelles which contain steroidogenic enzymes. Herein, we report that inhibition of Leydig cell steroidogenic enzymes is reflected by reduced testosterone secretion by in vitro perfused rat and rabbit testes. Moreover, the activity of specific steroidogenic reactions can be monitored by measuring the secretion of reaction substrate(s) and product(s) from in vitro perfused testes. Testosterone secretion by in vitro perfused testes from five species is highly and positively correlated with the volume density of smooth endoplasmic reticulum in Leydig cell cytoplasm. Exploitation of these findings will allow toxicologists to quantitatively assess the effect of toxicants on Leydig cell testosterone biosynthesis and secretion, to identify the specific steroidogenic enzymes affected, to assess whether the membranous environment of the steroidogenic enzymes is compromised, and perhaps even to predict the deleterious effect of a toxic agent on Leydig cell steroidogenic function from a stereological assessment of Leydig cell ultrastructure.  (+info)

Ultrasonographic measurement of endometrial thickness during hormonal replacement therapy in postmenopausal women. (5/5)

The objective of this study was to measure endometrial thickness by transvaginal ultrasonography during two regimens of hormonal replacement therapy (HRT) in postmenopausal women and to compare these data with endometrial histology. Transvaginal ultrasonographic evaluation of endometrial thickness and endometrial biopsy were performed in 80 postmenopausal women before and after 6 months of HRT (between the 24th and the 28th day of the cycle). The group was randomized so that 40 women (Group A) were treated with a continuous sequential regimen consisting of 5 micrograms/day of estradiol continuously and 5 mg/day of medrogestone from the 17th to the 28th day of the cycle; and 40 women (Group B) were given continuous administration of 50 micrograms/day estradiol and 5 mg/day medrogestone. Prior to therapy, there was no significant difference in mean endometrial thickness between the groups. After 6 months of therapy, endometrial thickness was significantly increased in comparison with basal values in both groups. The mean value was significantly higher (p < 0.001) in Group A (8.5 +/- 3.7 mm) than in Group B (3.6 +/- 1.3 mm). In Group A, endometrial thickness was < or = 4 mm in 16.7% of patients and < or = 8 mm in 69.5% of patients. In Group B, 91% of patients had an endometrium of < or = 4 mm. In both groups, the thickness of the atrophic endometrium was less than that of the other histological types of endometrium (4.1 +/- 0.3 mm for Group A and 3.5 +/- 1.2 mm for Group B). In Group A, the difference in mean endometrial thickness between the proliferative and secretory endometrium was not statistically significant. In both groups, the transvaginal ultrasonographic measurement of endometrial thickness of < or = 4 mm had a high sensitivity for detecting atrophic endometrium (83.3% for Group A and 93.7% for Group B).  (+info)