Gonadal steroid modulation of the diabetes (db/db) mutation-induced hyperlipometabolic, hypogonadal syndrome: Restoration of female reproductive tract cytochemical and structural indices

Selenium-vitamin E combination modulates endometrial lipid peroxidation and antioxidant enzymes in streptozotocin-induced diabetic rat

Diabetes mellitus is associated with diabetic impairment of uterine function, ultimately leading to reduced fertility. Its etiology may involve oxidative damage by reactive oxygen substances, and protection against this damage can be offered by antioxidant supplementation. In the present study, the effects of a vitamin E-plus-selenium (VESe) combination on lipid peroxidation (MDA) and the scavenging enzyme activity in the uterine endometrium of streptozotocin (STZ)-induced diabetic rats were investigated. Twenty-four female rats were equally divided into three groups as follows: group I (control); group II (diabetic); group III (diabetic + VESe), STZ + vitamin E (60 mg/kg over 1 day) + selenium-treated (Na2SeO3, 1 mg/kg over 1 day). After 4 weeks of receiving the VESe treatment, endometrium samples were taken from the uterus. Although the VESe treatment decreased the MDA and blood glucose levels in the STZ group, the observed values remained significantly higher than in the controls. Catalase, superoxide dismutase, and glutathione peroxidase activities and body weight gain were significantly (p < 0.01) lower in STZ groups as compared to control group, whereas their activities were (p < 0.01) increased by VESe treatment. However, there was no significant difference on body weight gain and uterine weights between control and STZ + VESe groups. In conclusion, the endometrial complications caused by oxidative stress, and the abnormal blood glucose levels in diabetic of rats, can be alleviated by strengthening the physiological antioxidative defense through the administration of vitamin E and Se.

Estradiol ameliorates diabetes-induced changes in vaginal structure of db/db mouse model

INTRODUCTION

Women with diabetes experience diminished genital arousal, reduced vaginal lubrication, vaginal atrophy, dyspareunia, and increased infections. Limited studies are available investigating the effects of diabetic complications on the vagina.

AIMS

The goals of this study were to investigate type 2 diabetes-induced changes in vaginal structure, and to determine if estradiol treatment ameliorates these changes.

METHODS

Eight-week-old female diabetic (db/db) mice (strain BKS*Cg-m+/+Lepr(db)/J) and age-matched control normoglycemic female littermates were used to investigate the effects of type 2 diabetes on vaginal tissue structural integrity. Diabetic animals were divided into two subgroups: diabetic treated with vehicle only and diabetic treated with pellets containing estradiol. At 16 weeks, the animals were sacrificed, and the vaginal tissues were excised and analyzed by histological and immunohistochemical methods to assess diabetes-induced changes in vaginal tissue and the extent by which these parameters are restored by estradiol treatment.

MAIN OUTCOME MEASURES

The effects of type 2 diabetes and estradiol supplementation were investigated on vaginal histoarchitecture.

RESULTS

Diabetic animals exhibited high blood glucose levels (>600 mg/dL), increased body weight (43.0 +/- 6.0 g vs. 24.4 +/- 2.0 g), and reduced plasma estradiol levels (65.5 +/- 6.6 pg/mL vs. 80.77 +/- 13.2 pg/mL) when compared to control animals. Diabetes resulted in significant thinning of the epithelium (P <or= 0.05), marked decrease in the muscularis area (P </= 0.05), distinct truncation of elastic fibers, and significant reduction of the nitrergic immunoreactive nerve fibers (P <or= 0.05). Treatment of diabetic animals with estradiol restored epithelial thickness (P <or= 0.05), muscularis area (P <or= 0.05), and elastic fiber distribution, and partially restored the density of nitrergic nerve fibers.

CONCLUSIONS

The data in this study demonstrate that type 2 diabetes disrupts vaginal structural integrity and that estradiol supplementation ameliorates the diabetes-induced vaginal pathology.

Progesterone and its derivatives are neuroprotective agents in experimental diabetic neuropathy: a multimodal analysis

One important complication of diabetes is damage to the peripheral nervous system. However, in spite of the number of studies on human and experimental diabetic neuropathy, the current therapeutic arsenal is meagre. Consequently, the search for substances to protect the nervous system from the degenerative effects of diabetes has high priority in biomedical research. Neuroactive steroids might be interesting since they have been recently identified as promising neuroprotective agents in several models of neurodegeneration. We have assessed whether chronic treatment with progesterone (P), dihydroprogesterone (DHP) or tetrahydroprogesterone (THP) had neuroprotective effects against streptozotocin (STZ)-induced diabetic neuropathy at the neurophysiological, functional, biochemical and neuropathological levels. Using gas chromatography coupled to mass-spectrometry, we found that three months of diabetes markedly lowered P plasma levels in male rats, and chronic treatment with P restored them, with protective effects on peripheral nerves. In the model of STZ-induced of diabetic neuropathy, chronic treatment for 1 month with P, or with its derivatives, DHP and THP, counteracted the impairment of nerve conduction velocity (NCV) and thermal threshold, restored skin innervation density, and improved Na(+),K(+)-ATPase activity and mRNA levels of myelin proteins, such as glycoprotein zero and peripheral myelin protein 22, suggesting that these neuroactive steroids, might be useful protective agents in diabetic neuropathy. Interestingly, different receptors seem to be involved in these effects. Thus, while the expression of myelin proteins and Na(+),K(+)-ATPase activity are only stimulated by P and DHP (i.e. two neuroactive steroids interacting with P receptor, PR), NCV, thermal nociceptive threshold and intra-epidermal nerve fiber (IENF) density are also affected by THP, which interacts with GABA-A receptor. Because, a therapeutic approach with specific synthetic receptor ligands could avoid the typical side effects of steroids, future experiments will be devoted to evaluating the role of PR and GABA-A receptor in these protective effects.

Hypercytolipidemia-induced cellular lipoapoptosis: Cytostructural and endometabolic basis of progressive organo-involution following expression of diabetes (db/db) and obese (ob/ob) mutation syndromes

Onset expression of Type 2 (NIDDM) diabetes and obesity metabolic syndromes (DOS) are characterized by premature, progressive cytoatrophy and organo-involution induced by dysregulated cellular gluco- and lipo-metabolic cascades. The consequential systemic, interstitial and intracellular hyperlipidemia disrupts normal cytointegrity and metabolic responsivity to the established hypercaloric pericellular environments. The sequential cytostructural, metabolic and endocrine disturbances associated with the development of progressive DOS-associated hypercytolipidemia compromises cellular metabolic response cascades and promotes cytochemical disturbances which culminate with nuclear lipoapoptosis and cytoatrophy. The dramatic alterations in interstitial glucose and lipid (free fatty acids/triglycerides) concentrations are recognized to influence interstitial and cytoplasmic microchemical environments, which markedly alter cellular nutrient diffusion and active trans-membrane flux rates. The progressive exacerbation of interstitial and cytoplasmic lipid imbibition has been demonstrated to be associated with DNA fragmentation by lipo-infiltration into the chromatin matrix, inducing structural disruption and physical dissolution, indexed as nuclear lipoapoptosis. Therapeutic reduction of the severity of hypercytolipidemia-induced structural and cytochemical compromise promotes the restoration of homeostatic metabolic support for normalized cytostructural indices and supportive cellular gluco- and lipo-metabolic cascades. The re-establishment of a homeostatic interstitial microenvironment moderates the severity of cytolipidemic compromise within affected cell types, reduces nuclear lipo-infiltration and DNA lipo-dissolution, resulting in the preservation of cytostructural integrity. Through the therapeutic restoration of extra- and intra-cellular microchemical environments in genetically dysregulated metabolic syndrome models, the coincident cytochemical, endocrine and metabolic disturbances associated with progressive hypercytolipidemia, resulting from the expressed systemic hypercaloric environmental and hepato-pancreatic endometabolic disturbances which characterize Type 2 (NIDDM) diabetes-obesity and metabolic (X) syndromes, may be ameliorated.