The Body Fat-Cognition Relationship in Healthy Older Individuals: Does Gynoid vs Android Distribution Matter?

OBJECTIVE: To examine the relationship between regional and whole body fat accumulation and core cognitive executive functions. DESIGN: Cross-sectional study. SETTINGS AND PARTICIPANTS: 78 healthy men and women aged between 65 and 75 years recruited through consumer's database. MEASUREMENTS: DXA measured percentage total body fat, android, gynoid distribution and android/gynoid ratio; inhibition and working memory updating through Random Number Generation test and cognitive flexibility by Trail Making test. First-order partial correlations between regional body fat and cognitive executive function were computed partialling out the effects of whole body fat. Moderation analysis was performed to verify the effect of gender on the body fat-cognition relationship. RESULTS: Results showed a differentiated pattern of fat-cognition relationship depending on fat localization and type of cognitive function. Statistically significant relationships were observed between working memory updating and: android fat (r = -0.232; p = 0.042), gynoid fat (r = 0.333; p = 0.003) and android/gynoid ratio (r = -0.272; p = 0.017). Separating genders, the only significant relationship was observed in females between working memory updating and gynoid fat (r = 0.280; p = 0.045). In spite of gender differences in both working memory updating and gynoid body fat levels, moderation analysis did not show an effect of gender on the relationship between gynoid fat and working memory updating. CONCLUSIONS: Results suggest a protective effect of gynoid body fat and a deleterious effect of android body fat. Although excessive body fat increases the risk of developing CDV, metabolic and cognitive problems, maintaining a certain proportion of gynoid fat may help prevent cognitive decline, particularly in older women. Guidelines for optimal body composition maintenance for the elderly should not target indiscriminate weight loss, but weight maintenance through body fat/lean mass control based on non-pharmacological tools such as physical exercise, known to have protective effects against CVD risk factors and age-related cognitive deterioration.

Short hairpin ribonucleic acid constructs targeting insulin-like growth factor binding protein-3 rehabilitated decreased testosterone concentrations in diabetic rats.

BACKGROUND: The aim of this study was to determine if shRNA constructs targeting insulin-like growth factor binding protein-3 can rehabilitate decreased serum testosterone concentrations in streptozotocin-induced diabetic rats. MATERIAL/METHODS: After 12 weeks of intracavernous administration of IGFBP-3 shRNA, intracavernous pressure responses to electrical stimulation of cavernous nerves were evaluated. The expression of IGFBP-3 at mRNA and protein levels was detected by quantitative real-time PCR analysis and Western blot, respectively. The concentrations of serum testosterone and cavernous cyclic guanosine monophosphate were detected by enzyme-linked immunosorbent assay. RESULTS: After 12 weeks of intracavernous administration of IGFBP-3 shRNA, the cavernosal pressure was significantly increased in response to the cavernous nerves stimulation compared to the diabetic control group (p<0.01). Cavernous IGFBP-3 expression at both mRNA and protein levels was significantly inhibited. Both serum testosterone and cavernous cyclic guanosine monophosphate concentrations were significantly increased in the IGFBP-3 shRNA treatment group compared to the diabetic control group (p<0.01). CONCLUSIONS: These results suggest that IGFBP-3 shRNA may rehabilitate erectile function via increases of concentrations of serum testosterone and cavernous cyclic guanosine monophosphate in streptozotocin-induced diabetic rats.

Tissue bioaccumulation patterns, xenobiotic biotransformation and steroid hormone levels in Atlantic salmon (Salmo salar) fed a diet containing perfluoroactane sulfonic or perfluorooctane carboxylic acids.

In the present study, groups of juvenile Atlantic salmon (Salmo salar) were fed gelatine capsules containing fish-food spiked with PFOA or PFOS (0.2 mg kg(-1) fish) and solvent (methanol). The capsules were given at days 0, 3 and 6. Blood, liver and whole kidney samples were collected prior to exposure (no solvent control), and at days 2, 5, 8 and 14 after exposure (Note: that day 14 after exposure is equal to 7d recovery period). We report on the differences in the tissue bioaccumulation patterns of PFOS and PFOA, in addition to tissue and compound differences in modulation pattern of biotransformation enzyme genes. We observed that the level of PFOS and PFOA increased in the blood, liver and kidney during the exposure period. Different PFOS and PFOA bioaccumulation patterns were observed in the kidney and liver during exposure- and after the recovery periods. Particularly, after the recovery period, PFOA levels in the kidney and liver tissues were almost at the control level. On the contrary, PFOS maintained an increase with tissue-specific differences, showing a higher bioaccumulation potential (also in the blood), compared with PFOA. While PFOS and PFOA produced an apparent time-dependent increase in kidney CYP3A, CYP1A1 and GST expression, similar effects were only temporary in the liver, significantly increasing at sampling day 2. PFOA and PFOS exposure resulted in significant decreases in plasma estrone, testosterone and cortisol levels at sampling day 2, and their effects differed with 17α-methyltestostrerone showing significant decrease by PFOA (also for cholesterol) and increase by PFOS. PFOA significantly increased estrone and testosterone, and no effects were observed for cortisol, 17α-methyltestosterone and cholesterol at sampling day 5. Overall, the changes in plasma steroid hormone levels parallel changes in CYP3A mRNA levels. Given that there are no known studies that have demonstrated such tissue differences in bioaccumulation patterns with associated differences in toxicological responses in any fish species or lower vertebrate, the present findings provide some potential insights and basis for a better understanding of the possible mechanisms of PFCs toxicity that need to be studied in more detail.

Are sex steroids involved in the sexual growth dimorphism in Eurasian perch juveniles?

Individual growth and food intake were monitored in Eurasian perch (Perca fluviatilis L.) juveniles (13.5+/-3.4 g initial body weight) to determine whether androgens and estrogens may mediate sex-related growth differences. Fish were individually tagged with chips and implanted with cocoa butter containing 20 microg of either 17alpha-methyltestosterone (MT) or 17beta-estradiol (E(2)) per gram of fish body; controls were implanted with cocoa butter without hormones. All fish were bled at the end of the experiment for measurement of E(2) in females and testosterone (T) in males (MT was not measured) and triiodothyronine (T3) in both genders. Survival, gonadosomatic index and hepatosomatic index were not affected by steroid treatments. Relative food intake (RFI), feed efficiency (FE) and specific growth rate (SGR) were higher in females than in males in all treatments. MT treatment significantly lowered RIF, FE and SGR in both sexes, while E(2) treatment showed no significant effect on growth and feeding parameters. In contrast to E(2) and T concentrations, T3 levels were significantly and positively correlated with SGR and RFI. The results provide evidence that MT may affect sexually related growth dimorphism by decreasing food intake and FE in Eurasian perch.

Transdermal testosterone gel (Cellegy).

Cellegy is developing a drug delivery system designed to facilitate the transdermal and topical delivery of testosterone for the potential treatment of male hypogonadism (as Tostrex) and decreased sexual energy in post-menopausal women (asTostrelle) [218118], [314726], [351823]. Following phase III dinical trials of Tostrex for male hypogonadism, initiated in March 2000 [361133], an NDA submission for male hypogonadism was filed in June 2002, after a pre-NDA meeting with the FDA late in 2001 [453374]. By March 2002, phase II/III clinical studies in postmenopausal women were underway in the US [444857].

Uptake and depletion of plasma 17alpha-methyltestosterone during induction of masculinization in muskellunge, Esox masquinongy: effect on plasma steroids and sex reversal.

Oral administration of 17alpha-methyltestosterone (MT) was used to induce masculinization of sexually undifferentiated muskellunge, Esox masquinongy. Three groups of muskellunge (mean weight, 2.5 +/- 0.6 g) were submitted to MT treatment (15 mg of MT/kg) for 60 days. An additional one group was used as a control (hormone-free diet). Food was distributed over a 10-h period by using automatic belt feeders. Blood was sampled in both control and treated fish at different intervals during and after feeding: before (0 h), at 3 h, 6 h, and cessation of feeding (10 h), and after a fast of 22 h (32 h). MT had no significant effect on growth and survival in muskellunge 6 months after the treatment. Concentrations of plasma MT increased during the feeding period and reached their maximum levels 6 or 10 h after starting feeding. This rapid increase of MT indicated a rapid absorption of this steroid. Plasma MT levels then declined and reached a radir by 22 h after cessation of feeding, suggesting that MT is rapidly metabolized and excreted. The profiles of plasma testosterone during the MT treatment did not differ significantly between control and MT-treated groups. During and after the MT treatment, the concentration of plasma testosterone did not differ significantly between control and MT-treated groups. Moreover, no sexual dimorphism of testosterone levels was observed. Six months after treatment, the sex ratio in MT-treated groups (33% males, 62% females, and 5% intersex) was opposite to control (70% and 30%, respectively) and differed significantly. This suggests that at 15 mg of MT/kg over 60 days, a paradoxical feminization took place.

Determination of doping methyltestosterone by capillary electrophoresis immunological analysis with thermally reversible hydrogel and laser-induced fluorescence.

In this paper thermally reversible hydrogel used as a replaceable packed material for capillary electrophoresis was examined. A simple and rapid method of detecting doping methyltestosterone (MTS) was developed, which demonstrated the potential of strong affinity antibodies (k(d) = 10(9)) as a selector for immunologically based separations in serum, not in urine, by capillary electrophoresis. Polyclonal antibodies (Ab) were polymerized on the hydrogel and applied in the separation of fluorescein isothiocyanate (FITC)-labeled antigen and free antigen with laser-induced fluorescence detector (LIF). The results indicated that N-isopropylacrylamide (PNIPA) hydrogel is a steady, replaceable gel. The specific determination of MTS did not require reaching equilibrium of immunological reaction and the PNIPA hydrogel including antibodies can be stockpiled at 4 degrees C, in preparation for determining MTS at any time. It can be used to determine MTS with good precision with a sensitivity lower than 50 ng/mL. The theoretical plate numbers obtained could reach 168,449 for free-antigen. Details of the preparation of hydrogel cross-linked polyclonal antibody and of typical separations of bound and free antigen are presented.

Determination of progesterone and 17-hydroxyprogesterone by high performance liquid chromatography after pre-column derivatization with 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-propionohydra zide.

Progesterone, 17-hydroxyprogesterone and four other 3-keto steroids were determined by high performance liquid chromatography with fluorescence detection. Each steroid was derivatized with 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene++ +-3- propionohydrazide (BODIPY FL hydrazide) and separated on a Wakosil 5C4 column with acetonitrile-water (7 + 3) as mobile phase. The limits of detection of progesterone, 17-hydroxyprogesterone, dehydroepiandrosterone, androstenedione, testosterone and 17-methyltestosterone were 550-3700 fmol per 10 microliters injection (signal-to-noise ratio = 5) serum. The calibration curves were linear up to 1000 ng/ml serum. The proposed method was most sensitive among the available high performance liquid chromatographic methods after fluorescence and chemiluminescence pre-labeling with dansylhydrazine.

Effects of drugs which influence renal transport systems on the urinary excretion of the beta 2-adrenoceptor agonist clenbuterol and the anabolic steroids ethinylestradiol and methyltestosterone.

The aim of this study was to determine whether the illegal application of clenbuterol, ethinylestradiol and methyltestosterone in cattle as growth promoters can be concealed by co-treatment with drugs that affect urinary excretion. Six male veal calves were fed with 0.8 micrograms clenbuterol kg-1 of body weight (BW), 3.5 micrograms ethinylestradiol kg-1 BW and 35 micrograms methyltestosterone kg-1 BW together twice daily for 28 days. At the eighth day of clenbuterol, ethinylestradiol and methyltestosterone treatment each calf was additionally fed either with probenecid, para-aminohippuric acid, trimethoprim, famotidine or cimetidine at three different doses which were increased in weekly intervals. During the treatment 24 h-urine and blood samples (once daily) were obtained and analysed for clenbuterol, ethinylestradiol and methyltestosterone by specific enzyme immunoassay. By high performance liquid chromatography/enzyme immunoassay it was determined whether these drugs or their metabolites interfered with the immunological detection of the growth promoters. Clenbuterol, ethinylestradiol and methyltestosterone could be detected in plasma and urine throughout the whole experiment. Co-treatment with probenecid led to a five-fold reduction in urinary excretion of ethinylestradiol and co-treatment with trimethoprim led to a three-fold reduction in urinary excretion of clenbuterol. None of the drugs reduced urinary excretion of the growth promoters to concentrations below the limit of detection. The detection of these three growth promoters in urine samples from calves which were co-treated with the drugs tested in this study can thus not be prevented.

Determination of carbonic anhydrase-III by enzyme-immunoassay in liver, muscle and serum of male rats with streptozotocin-induced diabetes mellitus.

Insulin has a plethora of metabolic effects but its action on carbonic anhydrase-III (CA-III), a key enzyme in acid-base regulation, has been little studied. The present studies examined the effects of streptozotocin induced diabetes on the concentrations of CA-III. The concentration of CA-III in the liver, muscles and serum of rats with experimental diabetes mellitus was measured by the method of enzyme-immunoassay. Streptozotocin-induced diabetes mellitus resulted in a reduction in concentration of CA-III in the liver and serum, but not in skeletal muscles, of adult male rats. A 98% reduction in hepatic CA-III content relative to control values was observed. The reduction in CA-III content in the liver was restored to control value by administration of insulin. The CA-III content in serum of diabetic rats declined to approx. 25% of control values, but the reduction was unaffected by administration of insulin. The concentration of CA-III in the liver and serum of diabetic rats was not influenced by administration of methyltestosterone. Although the content of CA-III in m. rectus femoris, m. tibialis craniaris and m. soleus differed, no significant difference of CA-III content was found between diabetes mellitus and control rats. The effect of chronic diabetes mellitus on CA-III content was obviously different between liver and muscle, suggesting that the regulation of CA-III biosynthesis differs between these two tissues. These results suggest that biosynthesis of CA-III in hepatocytes of rats is influenced by irregular patterns of GH secretion brought about by diabetes mellitus.

The effect of methyltestosterone on the growth hormone response to the dopamine receptor agonist, apomorphine.

1. There is some evidence that androgens affect dopaminergic function in animals and man. We investigated the effect of methyltestosterone (MT) (30 mg po) on the growth hormone (GH) response to the dopamine (DA) receptor agonist, apomorphine (Apo) HC1 (0.5 mg sc), in 9 normal men. MT was given 2 hr before Apo. 2. The peak plasma MT concentration was present 1 hr after administration (19.9 +/- 19.5 ng/ml; X +/- SD); the concentration at 4 hr was 7.2 +/- 4.9 ng/ml. At the time of Apo administration, plasma MT varied from 6.0-24.1 ng/ml. 3. There was no significant effect of MT on Apo-GH secretion (interaction F(7,56) = 1.08; p = NS). The mean individual peak GH concentration after Apo alone was 20.2 +/- 11.9 (X +/- SD) vs 22.2 +/- 9.9 ng/ml when MT preceded Apo (p = NS). 4. These results suggest that exogenous androgens do not affect DA receptor function in males with normal androgenic function. Lack of effect due to an insufficient dose or duration of administration of MT cannot be excluded.

Stable-isotope methodology in the bioavailability study of 17 alpha-methyltestosterone using gas chromatography-mass spectrometry.

The application of a stable-isotope coadministration technique for estimating the relative bioavailability of 17 alpha-methyltestosterone is described. Eight healthy male subjects were administered orally a single 10-mg 17 alpha-methyltestosterone tablet together with a 10-mg 17 alpha-methyltestosterone-d3 solution. The serum concentrations of 17 alpha-methyltestosterone and 17 alpha-methyltestosterone-d3 were determined by gas chromatography-mass spectrometry with selected ion monitoring using 17 alpha-methyltestosterone-d6 as an internal standard. The extent of absorption from the tablet formulation was comparable to that from the oral solution. The stable-isotope methodology was compared with the conventional cross-over method for evaluating the bioavailability of 17 alpha-methyltestosterone.

Quantitative determination of methyltestosterone and methyltestosterone-d3 in serum by gas chromatography-mass spectrometry.

A method for the quantitative estimation of methyltestosterone and methyltestosterone-d3 in biological fluids has been developed using gas chromatography-mass spectrometry-selected-ion monitoring. Methyltestosterone-d6 was used as an internal standard. Methyltestosterone and methyltestosterone-d3 in serum were determined based on the peak height ratios of the molecular ions of methyltestosterone, methyltestosterone-d3 and methyltestosterone-d6. Sensitivity, specificity, precision, accuracy and reproducibility of the present method were demonstrated to be satisfactory for application to pharmacokinetic and bioavailability studies.