Regulation of uncoupling protein-2 and -3 by growth hormone in skeletal muscle and adipose tissue in growth hormone-deficient adults

The newly described uncoupling proteins, UCP2 and UCP3, may play a role in regulating energy expenditure (EE) in humans. GH deficiency (GHD) is associated with decreased lean body mass, increased adiposity, and reduced EE, which are reversed by GH treatment. In the present study we investigated whether GH treatment for 4 months influenced the expression of UCPs in skeletal muscle and adipose tissue in 22 GHD patients who were investigated before and after GH (n = 11) or placebo (n = 11) treatment. GH treatment increased the amount of lean body mass by 4.5% (P < 0.05) and decreased body fat mass by 12% (P < 0.05), whereas no changes in these parameters were observed after placebo treatment. The level of UCP3 messenger ribonucleic acid (mRNA) increased 3-fold (P < 0.005) in skeletal muscle and almost 2-fold (P < 0.05) in adipose tissue after GH treatment, with no changes observed after placebo treatment. Skeletal muscle UCP2 mRNA was slightly (25%), but significantly (P < 0.05), decreased, whereas the level of UCP2 mRNA in adipose tissue was unaffected after GH treatment. The T4 level was positively correlated with skeletal muscle UCP2 and UCP3 expression (r = 0.518; P < 0.05 and r = 0.463; P < 0.05, respectively). Furthermore, plasma free fatty acids were positively correlated with the expression of UCP2 (r = 0.573; P < 0.01) and UCP3 (r = 0.518; P < 0.05) in skeletal muscle. The marked increase in UCP3 expression after GH treatment indicates that the UCPs might play a role in the effects of GH on EE in GHD patients. Finally, the strong association between thyroid hormone and skeletal muscle UCP and the correlation between plasma free fatty acids and UCP expression in skeletal muscle indicate that these hormones/metabolites might influence UCP expression in humans as previously demonstrated in rodents.

Hormone replacement therapy affects body composition and leptin differently in obese and non-obese postmenopausal women

Leptin and oestrogen are both involved in the regulation of adipose tissue deposition and feeding behaviour. We investigated whether 5 years of hormone replacement therapy (HRT) affected serum leptin and body composition differently in 89 postmenopausal women treated with HRT compared with 178 controls. At baseline, leptin was significantly correlated with oestradiol (r=0.13, P<0.05) and in multiple backward regression analysis including oestradiol and any estimate of body fat, oestradiol remained a significant determinant of leptin levels. In the control group, all estimates of body fat determined by dual energy X-ray absorptiometry (DEXA) or anthropometry were increased (3.6-16.9%) and leptin increased 31.3% (16.03+/-1.02 to 20.84+/-1.2 ng/ml (s.e.m.), P<0.001). In the HRT group all estimates of body composition also increased during the 5-year observation but to a lesser extent than observed in the control group (1.0-8.5%). Leptin was raised by 19.7% (17.81+/-1.32 to 20.57+/-1.65 ng/ml, P<0.001). However, the DEXA scans revealed that the control group gained 2.4-fold more fat during the 5-year observation (1.9+/-0.3 vs 0.8+/-0.4 kg, P<0.05), and especially the trunk fat increased (1.4+/-0.2 vs 0.7+/-0.3 kg, P<0.05). This was reflected in the increase in leptin levels, which were increased by 7.4% in the control group compared with the HRT group (4.81+/-0.60 vs 2.76+/-0.87 ng/ml, P<0.05). Adjusting for the difference in adipose tissue revealed that HRT had no independent effect on leptin levels. Comparisons between obese (body mass index>25 kg/m(2)) and non-obese (<25 kg/m(2)) subjects by stratifying for HRT treatment using multiple linear regression revealed that the change in fat mass was significantly less among treated subjects (P=0.038) and especially in the non-obese subjects (P=0.001). The change in trunk fat was similarly correlated with treatment status (P=0.029) and with the degree of obesity (P=0.006). In conclusion, 5 years of HRT treatment significantly reduced fat mass accumulation, especially in the trunk region. This effect of HRT was more pronounced in non-obese as compared with obese subjects. The HRT-induced reduction in fat mass seems not to be mediated by leptin.

Differential expression of prostaglandin receptor mRNAs during adipose cell differentiation

To clarify the molecular basis for the prostaglandin (PG) mediated effects in adipose cells at various stages of their development, expression of mRNAs encoding receptors specific for prostaglandin E2, F2alpha and I2 (i.e. EP, FP, and IP receptors) was investigated in differentiating clonal Ob1771 pre-adipocytes, as well as in mouse primary adipose precursor cells and mature adipocytes. We have further characterized the differential expression of mRNAs encoding three subtypes of the EP receptor, i.e. EP1, EP3, and EP4, and examined the expression of mRNAs encoding the three isoforms (alpha, beta, and gamma) of the EP3 receptor. Altogether the results show that the expression of IP, FP, EP1, and EP4 receptor mRNAs was considerably more pronounced in pre-adipose cells than in adipose cells, mRNAs encoding the alpha, beta, and gamma isoforms of the EP3 receptor were all exclusively expressed in freshly isolated mature adipocytes. These data may indicate that PGI2, PGF2alpha, and PGE2 may interact directly with specific receptors in pre-adipose cells, whose transduction mechanisms are known to affect maturation related changes. In mature adipocytes, however, the equipment of mRNAs encoding the EP3 receptor isoforms is in agreement with the well known effect of PGE2 on adenylate cyclase and lipolysis in mature adipocytes.

Regulation of leptin by steroid hormones in rat adipose tissue

We investigated if steroid hormones regulate the secretion and the expression of leptin in female and male rat adipose tissue fragments in vitro. Dexamethasone time and dose-dependently increased the secretion and mRNA expression of leptin with a half-maximal stimulation of approximately 1 nM. A time-course revealed a maximal stimulatory effect of 17 beta-estradiol after 24 hours. In male adipose tissue 17 beta-estradiol increased leptin secretion (32% by 50 nM 17 beta-estradiol, P = 0.07 and 34% by 500 nM 17 beta-estradiol, P < 1780.05) after 24 hours. An additional effect of estrogen was seen in the dexamethasone (50 nM) stimulated cells (38% with 50 nM 17 beta-estradiol, P < 0.05 and 48% by 500 nM 17 beta-estradiol, P < 0.05). Basal secretion of leptin was equal in female and male adipose tissue, whereas the effects of 17 beta-estradiol (50 nM) and dexamethasone were significantly increased in female as compared with male adipose tissue. Progesterone, testosterone, dihydrotestosterone and dehydroepiandrostendione-sulfate neither affected leptin secretion in male nor female adipose tissue in vitro. Furthermore, to investigate the effect of estrogen female rats were ovariectomized (OVX) and the adipose tissue was incubated in vitro and compared with adipose tissue leptin secretion from sham operated rats (SHAM), and with ovariectomized rats treated with 17 beta-estradiol (EST). A decreased basal and dexamethasone-stimulated leptin secretion from OVX rats compared with SHAM rats was found (P < 0.005) whereas 17 beta-estradiol treatment of ovariectomized rats maintained a normal leptin secretion. However, the dexamethasone stimulation was equally increased above basal levels in SHAM, OVX and EST rats (3.7 +/- 1.2, 2.9 +/- 0.8, 4.2 +/- 1.4, NS, ANOVA) respectively.

Epinephrine stimulates human muscle lipoprotein lipase activity in vivo

Lipoprotein lipase (LPL) is involved in lipoprotein metabolism and nutrient partitioning in both adipose tissue and skeletal muscle, and LPL activity is regulated by various hormones and the nutritional state. However, the action of catecholamines has not been thoroughly investigated in humans. Therefore, the effects of exogenous epinephrine on skeletal muscle LPL (SM-LPL) activity and whole-body lipid oxidation were studied. Muscle biopsies were obtained from eight healthy subjects before, during, and after epinephrine infusion. Somatostatin was infused to suppress endogenous insulin production and insulin was infused at a constant rate to maintain basal insulin levels throughout the study. After an equilibrium period (120 minutes), epinephrine (0.05 microg/kg/min) was infused for another 120 minutes. Epinephrine stimulated SM-LPL activity by 21.8%+/-6.8% above basal levels from 1.44+/-0.25 to 1.69+/-0.28 micromol free fatty acid (FFA)/h/g muscle (P<.02), increased plasma FFA 270% from 0.147 to 0.544 mmol/L (P<.05), and increased lipid oxidation 45% from 4.37 to 6.36 mg/kg/min (P<.05). The increase in SM-LPL activity was positively correlated with the increase in whole-body lipid oxidation (R=.75, P<.05). Finally, lipid oxidation and SM-LPL activity were negatively correlated with whole-body glucose oxidation. Overall, the results demonstrate that epinephrine is able to stimulate SM-LPL activity in humans, and thus may have opposite effects on adipose tissue and SM-LPL activity.

Serum leptin levels and leptin expression in growth hormone (GH)-deficient and healthy adults: influence of GH treatment, gender, and fasting

Growth hormone (GH) treatment is associated with a reduction in fat mass in healthy and GH-deficient (GHD) subjects. This is mainly mediated via a direct GH action on adipose cells and stimulation of lipolysis. Leptin is secreted from adipose tissue and may be involved in signaling information about adipose tissue stores to the brain. Hormonal regulation of leptin is still not fully elucidated, and in the present study, we investigated both the long-term (4-month) and short-term (28-hour) GH effects on serum leptin and leptin gene expression in subcutaneous adipose tissue. In GHD adults (n = 24), leptin correlated with most estimates of adiposity (r = .62 to .86), as previously found in healthy subjects. However, no correlation was observed with intraabdominal fat determined by computed tomographic (CT) scan (INTRA-CT). GH treatment for 4 months had no independent effect on either serum leptin or leptin gene expression. In a short-term study, we found that fasting gradually reduced leptin levels in both healthy men and GHD adults, with a maximum reduction of 58% to 60% (P < .01) after 31 hours. No independent effect of GH suppression or GH substitution on serum leptin was found during fasting. Adipose tissue leptin mRNA correlated with serum leptin (r = .51, P < .01) and the body mass index ([BMI] r = .55, P < .05). Serum leptin levels and gene expression were significantly higher in women compared with men (26.6 +/- 5.8 v 10.0 +/- 1.30 ng/mL, P < .05). However, in regression analysis accounting for the gender differences in subcutaneous femoral adipose tissue (FEM-CT), the difference in serum leptin disappeared, indicating that subcutaneous femoral fat or factors closely related to femoral fat (eg, sex hormones) may be causal factors for the gender difference in leptin.

Physicians' abdominal auscultation. A multi-rater agreement study

BACKGROUND

Abdominal auscultation has an important position in the physical examination of the abdomen. Little is known about rater agreement. The aim of this study was to describe rater agreement and thus, indirectly, the value of the examination.

METHODS

In a semi-virtual setup 12 recordings of the intestinal sounds from 8 patients with acute abdominal pain and 4 healthy volunteers were presented to 100 physicians. The physicians were asked to characterize the intestinal sounds as normal or pathologic. Fisher's exact test was used for comparison between groups of physicians.

RESULTS

Overall, 72% of the answers with regard to healthy volunteers concluded that the sounds were normal (equalling agreement), whereas 64% of answers with regard to intestinal obstruction concluded that the sounds were pathologic (but agreement was higher due to agreement on wrong diagnosis in one case). Bowel sounds from colonic obstruction were diagnosed as pathologic in 94 of 100 answers. In peritonitis disagreement dominated. Specialists in gastrointestinal medicine diagnosed bowel obstruction significantly more poorly than non-specialists in gastrointestinal surgery (P < 0.05).

CONCLUSION

Rater agreement in normal subjects and in patients with intestinal obstruction was acceptable for a clinical examination. Abdominal auscultation is a helpful clinical examination in patients with acute abdominal pain.

Long term follow up of patients who underwent jejunoileal bypass for morbid obesity

OBJECTIVE

To describe our long term results after jejunoileal (JI) bypass for morbid obesity.

DESIGN

Retrospective study.

SETTING

Teaching hospital, Denmark

SUBJECTS

All 57 patients who underwent JI bypass for morbid obesity between January 1973 and December 1988.

INTERVENTIONS

Type A and type B JI bypass.

MAIN OUTCOME MEASURES

Weight loss, operative morbidity and mortality, and subjective evaluation of the results.

RESULTS

Mean duration of follow up was 15.9 years (range 8-22). There were no operative or early postoperative deaths, but there were 7 late deaths (12%). 5 patients developed postoperative complications (9%), and 11 patients (19%) required reoperation for side effects or complications. The mean body mass index (BMI, kg/m2) was reduced from 47.5 (range 40-60) to 32 (range 22-49) during the follow up period which corresponded to a weight loss of about 42 kg. Of the 39 patients who still had a JI bypass in 1994, nearly two thirds said that they were satisfied with the operation, though they nearly all had some side effects such as diarrhoea or intermittent abdominal pain.

CONCLUSION

As complications of JI bypass can develop at any time, we suggest that all patients who have had the operation should be regularly followed up at special clinics so that complications can be diagnosed and treated as soon as possible.

Juvenile myoclonic epilepsy: clinical and EEG features

We aimed to characterize the clinical profile and EEG features of 43 patients with juvenile myoclonic epilepsy. In a retrospective design we studied the records of, and re-interviewed, 43 patients diagnosed with JME from the epilepsy clinic data base. Furthermore, available EEGs were re-evaluated. Of the patients 72% were female and 28% male. Average age of onset was 13 (5.5-22) years for absences, 16 (5.2-25) years for myoclonic seizures, and 16 (8-29) years for generalized tonic-clonic seizures. Forty-two percent reported asymmetric or unilateral myoclonic jerks. Commonly reported precipitating factors were sleep deprivation (84%), stress (70%), and alcohol consumption (51%). EEG findings included rapid spike-wave and polyspike-wave.

Evidence of an increased number of type IIb muscle fibers in insulin-resistant first-degree relatives of patients with NIDDM

Insulin resistance is a common feature in first-degree relatives of NIDDM patients. To explore the mechanism(s) behind this condition in more detail, a percutaneous muscle biopsy (vastus lateralis) was performed in 25 first-degree relatives of NIDDM patients and 21 control subjects to examine muscle fiber composition and capillary density. Insulin-stimulated glucose disposal (Rd) was determined employing a hyperinsulinemic-(insulin infusion rate 0.6 mU x kg[-1] x min[-1]) euglycemic clamp. Rd (5.76 +/- 0.35 vs. 8.06 +/- 0.36 mg x kg lean body weight [LBW]-1 x min[-], P < 0.001) and estimated VO2max (49.3 +/- 2.8 vs. 57.2 +/- 3.5 mg x kg LBW[-1] x min[-1], 0.05 < P < 0.10) were decreased in the relatives. The number of type IIb fibers (29.5 +/- 2.5 vs. 21.0 +/- 2.8%, P < 0.05) was increased in the relatives, whereas no significant differences were found in other fiber types or capillary density between the groups. Correlations were observed between number of type I fibers (positive), number of type IIb fibers (negative), and capillary density (positive) versus Rd as well as estimated VO2max (P < 0.05). In a multiple linear regression analysis with Rd as a dependent variable, estimated VO2max, family history of NIDDM, and number of type IIb fibers (P < 0.001, r2 = 0.64) significantly determined the level of Rd, whereas capillary density did not. In conclusion, insulin-resistant first-degree relatives of NIDDM patients are characterized by an increased number of type IIb muscle fibers. Whether this finding reflects a reduced physical activity level and fitness in the relatives or is of primary genetic origin remains to be determined.

Effects of long-term total fasting and insulin on ob gene expression in obese patients

In the present study the effect of long-term fasting (6 days) on obese (ob) gene expression was examined in nine severely obese females of 34 +/- 3 years and with a body mass index of 46.4 +/- 2.3 kg/m2. Six days of fasting induced a significant weight loss (126.8 +/- 5.3 vs 120.5 +/- 5.1 kg, P < 0.0001). Insulin-stimulated glucose uptake (hyperinsulinemic, euglycemic clamp, insulin infusion rate 1.5 mU/kg per min) was markedly reduced following fasting (M-value 5.96 +/- 0.74 vs 2.79 +/- 0.23 mg/kg per min, P < 0.0001). Ob mRNA/beta-actin concentration in fat biopsies from abdominal subcutaneous adipose tissue was unchanged after 6 days of fasting (1.50 +/- 0.40 vs 1.47 +/- 0.36 arbitrary units, not significant), whereas serum leptin levels decreased significantly from 53.8 +/- 4.7 to 30.7 +/- 2.0 ng/ml (P < 0.0001) during the same period. No significant correlations were found between insulin-stimulated glucose uptake and serum leptin concentration, either prior to the fast or after the fast. Serum leptin levels were unchanged by hyperinsulinemia for 3 h during the clamp prior to the fast, while hyperinsulinemia for 3 h after 6 days of fasting increased serum leptin by 25% (P < 0.01). In conclusion, 6 days of fasting reduced serum leptin by about 40%. In contrast, ob mRNA in abdominal subcutaneous adipose tissue was unchanged. Furthermore, after 6 days of fasting insulin was able to increase the serum level of leptin significantly, indicating that the effect of insulin on the level of leptin is dependent on the nutritional state.

Expression of the two isoforms of prostaglandin endoperoxide synthase (PGHS-1 and PGHS-2) during adipose cell differentiation

Expression of mRNAs encoding the two prostaglandin endoperoxide synthase (PGHS) isoenzymes (PGHS-1 and -2) was investigated in differentiating clonal Ob1771 mouse preadipocytes and in mouse adipose tissues. Northern analysis revealed that the expression level of PGHS-1 mRNA was reduced by 98+/-0.2% (P <0.01) during differentiation of Ob1771 cells, whereas PGHS-2 mRNA was not detected. By reverse transcriptase-polymerase chain reaction analysis, however, both PGHS-1 and -2 mRNA was detected in Ob1771 preadipose cells. In addition. mRNAs encoding both isoforms were markedly expressed in primary adipose precursor cells with considerably lower expression levels in mature adipocytes (56 75% reduction, P<0.01). Furthermore, exposure to dexamethasone (10 nM) for both 24 h (explants of adipose tissue) and 48 h (Ob1771 adipose cells) resulted in enhanced expression of PGHS-1 mRNA. whereas expression of PGHS-2 mRNA in explants of adipose tissue (24 h incubation) was reduced by 83 +/- 9% (P<0.05). In contrast, exposure to angiotensin II (100 nM) enhanced expression of PGHS-1 mRNA both in mature adipocytes (4 h incubation) and explants of adipose tissue (24 h incubation), and elevated PGHS-2 mRNA expression in mature adipocytes (4 h incubation). In conclusion, this report suggests a differential expression of PGHS mRNAs during adipose cell differentiation, and further suggests that the machinery for prostaglandin synthesis in mature adipocytes may be induced by various hormones.

Systemic administration of insulin-like growth factor I (IGF-I) causes growth of the rat prostate

PURPOSE

To investigate the effects of insulin-like growth factor I (IGF-I) and epidermal growth factor (EGF) on the rat prostate. In addition, we investigated the effect of ornithine decarboxylase (ODC) inhibition with alpha-diflouromethylornitine (DFMO) on the expected growth of the prostate.

MATERIALS AND METHODS

Eight week old Wistar rats were allocated into groups of eight, receiving systemic treatment for 3 and 7 days with either IGF-I (400 micrograms/rat/day) or EGF (30 micrograms/rat/day) alone or in combination with DFMO.

RESULTS

Systemic treatment with IGF-I for 7 days resulted in a 29% (p < 0.01) increase in the mean wet weight of the ventral prostate. The mean weight of the dorsolateral lobe of the prostate increased by 39% (p < 0.05), and the seminal vesicle and coagulating gland increased 69% (p < 0.05) compared to controls. The ODC-activity in the prostate was significantly increased by IGF-I after 3 days of treatment, and administration of IGF-I concomitantly with DFMO significantly inhibited ODC activity and the weight increase of the prostate. Stereological examination of the prostate in the IGF-I-treated animals showed growth of the epithelial component of the gland. Systemic treatment with EGF did not affect the mean weight of the prostate or the seminal vesicle compared to controls.

CONCLUSION

The results demonstrate that treatment with IGF-I but not EGF for 7 days induces profound growth of the rat prostate and the seminal vesicle, and that the growth is dependent on an intact ODC-activity.

Long-term (6 months) effect of a new fermented milk product on the level of plasma lipoproteins--a placebo-controlled and double blind study

OBJECTIVE

We have recently demonstrated a short-term hypocholesterolemic effect (reduction of 8-10%) of a new fermented milk product taken for 6 weeks (Agerbaek et al, 1995; Richelsen et al, 1993). The present study was undertaken to investigate the more long-term (6 months) effect of this fermented product on the level of lipoproteins.

DESIGN

The study was randomized, double-blind, and placebo-controlled, and performed for a period of six months.

SUBJECTS

Eighty-seven non-obese and normocholesterolemic females and males, aged 50-70 y old, were included in the study.

INTERVENTION

200 ml of either the fermented milk product or placebo (chemically fermented) were given daily. The test product was fermented with a bacteria culture containing Enterococcus faecium and two strains of Streptococcus termophilus.

RESULTS

After one month the total- and LDL-cholesterol were significantly reduced in the fermented milk group as compared to placebo, LDL was reduced by 0.21 mmol/l vs 0.0 mmol/1 (P < 0.02). The maximal reduction of LDL-cholesterol was reached after 3 months in the test group with a reduction of 0.32 mmol/1 of initial values (P < 0.001). In the placebo group a gradual fall of total- and LDL-cholesterol was observed from 1-6 months of the study. Thus, after six months the reduction of LDL-cholesterol was similar in the two groups (P = 0.95) even though the reduction was significant in both groups in relation to initial values (P < 0.05). No changes in HDL-cholesterol or triglyceride were observed during the study. There were no differences in the response between women and men.

CONCLUSION

The fermented milk product resulted in a rapid reduction of LDL-cholesterol observed after one month but during long-term intake (6 months) the reduction of LDL-cholesterol was similar to the placebo product, indicating that low-fat milk or fermented milk products may have some hypocholesterolemic effects but the present tested product does not seem to be superior in that respect to the placebo milk product used in the present study.

Identification of steroid receptors in human adipose tissue

Steroids have the ability to alter adipose tissue distribution. Controversy exists as to whether these effects of sex hormones (oestrogen, progesterone and testosterone) on human adipose tissue are indirect or direct, as only very few studies have focused on steroid receptor status in human adipose tissue. In the present study, we reinvestigated steroid receptor status in human mature adipose tissue and human preadipocytes. Oestrogen, glucocorticoid and androgen receptors were found in human mature adipocytes from both women and men. The receptors were detected by ligand binding. Furthermore, the existence of the receptors was confirmed by demonstrating that adipocytes contained mRNA encoding the receptors. cDNA was generated using reverse transcriptase (RT) followed by polymerase chain reaction (PCR) amplification using specific primers (RT-PCR) for the specific steroid receptors. Adipocytes did not contain mRNA encoding the progesterone receptor (PR), and no progesterone binding was detectable in human adipocytes. Human preadipocytes contained glucocorticoid receptor (GR) mRNA and androgen receptor (AR) mRNA, whereas we were unable to detect oestrogen receptor (ER) mRNA and progesterone mRNA in human preadipocytes. In conclusion, oestrogen glucocorticoid and androgen receptors are present in mature adipocytes from subjects of both sexes, whereas adipocytes do not contain progesterone receptors. In preadipocytes, only glucocorticoid receptors and androgen receptors are present, whereas oestrogen receptors and progesterone receptors are not present.

Identification of oestrogen receptors and oestrogen receptor mRNA in human adipose tissue

The distribution of adipose tissue has a major impact on the morbidity and mortality associated with obesity. Furthermore, the distribution of adipose tissue seems to be regulated by sex hormones. Controversy exists over whether the effects of sex hormones (oestrogen and testosterone) on human adipose tissue are an indirect or a direct effect as contradictory results have been obtained when investigating the existence of these receptors in human adipose tissue. In the present study the authors reinvestigated the possible existence of oestrogen receptors (ERs) in human adipose tissue. Human adipocytes from both genders were found to contain specific oestrogen binding sites determined by ligand-binding techniques. The binding protein had a molecular weight of 65 kD (which is similar to that of the ER found elsewhere) and it was found that adipocytes contained mRNA encoding the ER. Moreover, human preadipocytes had no oestrogen-binding capacity and did not possess mRNA encoding the ER. Finally, the authors detected regional differences in receptor density. Women had an equal oestrogen-binding capacity in adipose tissue from the subcutaneous abdominal and the visceral depot, whereas men had twice as high oestrogen-binding capacity in subcutaneous adipose tissue compared with adipose tissue in the visceral fat depot. These findings indicate that mature human adipocytes possess ERs and thus, might be an oestrogen-responsive tissue and that oestrogen may be acting directly in mature adipocytes via its specific receptor. Human preadipocytes, however, seemed not to be an oestrogen-responsive tissue. Finally, preliminary data suggest that there might be differences in ER densities in different fat depots.

[Significance of fat distribution for metabolic risk factors in healthy males of normal weight]

A homogeneous group of non-obese men (n = 58), all 44 years old, were investigated in order to determine whether body fatness and especially abdominal fatness influence the metabolic risk profile in normal-weighted men. In addition, it was investigated which anthropometric measurements that were most closely associated with the risk profile. It was found that enhancement of total fatness, but particularly even a minor accumulation of the adipose tissue in the abdominal region in these otherwise non-obese men, was associated with a considerably adverse metabolic risk profile. Those risk factors that seemed to be most "sensitive" for abdominal fatness were HDL-cholesterol, the atherogenic index, triglyceride and fasting plasma insulin. The sagittal diameter (SD) seemed to be slightly better correlated to the risk profile than other anthropometric indices of abdominal fatness (e.g. WHR).

Nitric oxide-donating properties of mesoionic 3-aryl substituted oxatriazole-5-imine derivatives

1. The nitric oxide (NO)-releasing properties of two new mesoionic 3-aryl substituted oxatriazole-5-imine derivatives (GEA 3162 and GEA 3175) were characterized and compared with the known NO-donors 3-morpholino-sydnonimine (SIN-1) and S-nitroso-N-acetylpenicillamine (SNAP). 2. GEA 3162, GEA 3175, SIN-1 and SNAP inhibited adenosine 5'-diphosphate-induced platelet aggregation (IC50 values 0.18, 0.39, 3.73 and 2.12 microM, respectively). All four compounds induced a dose-dependent and more than 4 fold increase in cyclic GMP in platelets. The increase in cyclic GMP concentration was potentiated more than 1.5 fold by a phosphodiesterase inhibitor, zaprinast (10 microM) and inhibited 38-97% by oxyhaemoglobin (10-45 microM). 3. All of the four compounds studied converted oxyhaemoglobin to methaemoglobin and formed a paramagnetic NO-haemoglobin complex. All but GEA 3175 formed nitrite and nitrate in phosphate buffer. During a 40 min incubation, GEA 3162, SIN-1 and SNAP (100 microM) produced 50-70 microM NO2- + NO3- as determined by high performance liquid chromatography. The release of NO and NO2 by GEA 3175 was increased 140 fold in the presence of human plasma (0.14 and 19.7 ppb in the absence and presence of 1% human plasma, respectively) as analyzed by ozone chemiluminescence. 4. The results suggest that the mesoionic 3-aryl substituted oxatriazole-5-imine derivatives GEA 3162 and GEA 3175 as well as SIN-1 and SNAP release nitric oxide.

Relationship between sex hormones, body composition and metabolic risk parameters in premenopausal women

The metabolic complications associated with obesity are dependent upon the degree of obesity and the distribution of adipose tissue. In order to evaluate the associations between sex hormone status, metabolic risk parameters, obesity and distribution of adipose tissue, 25 premenopausal women with a wide range of body mass index (19.3-48.1 kg/m2 were studied. Body composition was determined by dual-energy x-ray absorptiometry scan and anthropometric measurements; in addition, lipid and sex hormone status were determined and an oral glucose tolerance test was performed. We found that sex hormone-binding globulin was correlated negatively with total fat mass (r = -0.77, p < 0.001) and especially with abdominal localization of adipose tissue (r = -0.85, p < 0.001). Free testosterone was correlated positively with total fat mass (r = 0.40, p < 0.05) and with abdominal fat accumulation (r = 0.64, p < 0.001). Free estrogen was correlated negatively with total amount of adipose tissue (r = -0.40, p < 0.05) but not with the distribution of adipose tissue. Finally, total fatness, abdominal localization of adipose tissue and free testosterone were all associated with elevated metabolic risk factors. However, multiple regression analysis revealed that only abdominal localization of adipose tissue was independently associated with a higher risk profile, whereas the effects of sex hormones or total fatness disappeared when abdominal localization of adipose tissue was included in the analysis. In conclusion, these findings in premenopausal women indicate that the connection between sex hormones and metabolic risk factors might be indirect, probably operating through alterations in the amount of adipose tissue in the abdominal region.

Serum concentrations of insulin-like growth factors (IGFs), IGF binding proteins 1 and 3 and growth hormone binding protein in obese women and the effects of growth hormone administration: a double-blind, placebo-controlled study

Obesity is associated with suppressed growth hormone (GH) concentrations but relatively little is known about insulin-like growth factors(IGFs) and binding proteins for GH and IGFs (GHBP and IGFBPs) and the modulatory effect of GH administration. In a double-blind, crossover design we studied the impact of 5 weeks of placebo or GH administration (0.03 mg.kg-1 body wt.day-1) in nine obese women (mean +/- SEM: age 30.4 +/- 2.4 years; body mass index 37.0 +/- 2.8 kg/m2) on IGF-I, IGF-II, IGFBP-1 and -3 and GHBP. Serum IGF-I (microgram/l) levels were subnormal and increased significantly following GH (117 +/- 16 (placebo) vs 434 +/- 33 (GH) vs 198 +/- 15 (control (p < 0.01)). By contrast, serum IGF-II (microgram/l) levels were in the normal range and remained unchanged (608 +/- 20 (placebo) vs 647 +/- 40 (GH) (NS)). Serum IGFBP-3 was in the normal range and increased significantly during GH treatment, although relatively less than IGF-I, such that the molar ratio between IGF-I and IGFBP-3 increased with GH treatment, whereas the ratio between IGF-I + IGF-II and IGFBP-3 remained unchanged. Serum IGFBP-1 was low in the placebo situation but became further and almost completely suppressed during GH treatment. During a 2-h hyperinsulinemic, euglycemic glucose clamp, IGFBP-1 decreased in the placebo study and remained suppressed during GH. Serum GHBP (nmol/l) levels were elevated substantially compared to non-obese controls (p < 0.001) and did not change during GH treatment (2.37 +/- 0.36 (placebo) vs 2.21 +/- 0.25 (GH) vs 0.80 +/- 0.19 (control)).(ABSTRACT TRUNCATED AT 250 WORDS)

Associations between different anthropometric measurements of fatness and metabolic risk parameters in non-obese, healthy, middle-aged men

OBJECTIVE

To investigate whether body fatness influences the metabolic risk profile in a group of healthy, normal-weighted men and to determine which anthropometric measurements that are most closely associated with the risk profile in this group of men.

DESIGN

A cross-sectional study where total fatness and abdominal fatness were determined by older (BMI, WHR, impedance) and more recent anthropometric indices (sagittal diameter (SD) and conicity index (Valdez et al., Int. J. Obes. 1993; 17: 955)). The metabolic risk profile was determined by lipoproteins, insulin, glucose and blood pressure.

SUBJECTS

The study comprised a homogeneous group of 58 men who were all healthy and normal-weighted (BMI = 24.2 +/- 1.8) and were all 44 years old.

RESULTS

In relation to total fatness, BMI was more closely correlated to the various risk parameters than the fat mass determined by bioelectrical impedance independent of using several different equations in estimating the fat mass. From simple comparison of correlation coefficients, SD and SDH (SD/height) seemed to be the best indices of abdominal fatness in predicting an enhanced metabolic risk profile. The conicity index was considerably inferior in comparison to the other indices of abdominal fatness. In multiple regression analysis abdominal fatness as determined by SD or SDH explained most of the variation in the metabolic risk profile and no significant influence of total fatness (BMI) was found when taking the influence of abdominal fatness into account. The most pronounced effect of abdominal fatness in these non-obese men was a reduction of HDL-cholesterol, an elevation of the triglycerid level and an elevation of the insulin level.

CONCLUSION

Thus, even a minor accumulation of adipose tissue in the abdominal region in these otherwise non-obese men was associated with a considerably adverse metabolic risk profile. SD or SDH seemed to be slightly more correlated to the risk profile than other anthropometric indices of abdominal adipose tissue mass (e.g. WHR). The new conicity index was inappropriate for predicting the risk profile associated with abdominal fatness in these non-obese men.

Inhibition of renal ornithine decarboxylase activity fails to reduce kidney size and urinary albumin excretion in diabetic rats with manifest kidney hypertrophy

Formation of polyamines has previously been shown to play an important role for initial kidney growth in experimental diabetes, as treatment of diabetic rats with a selective ornithine decarboxylase (ODC) inhibitor, initiated immediately after diabetes induction, abolishes the initial kidney growth. In order to investigate the role of polyamine formation for the maintenance of diabetic kidney hypertrophy, ODC inhibition was initiated after manifest kidney hypertrophy had occurred. The kidney weight in diabetic rats was significantly larger than in control rats after a diabetes duration of 7, 14, 50 and 71 days and the total glomerular volume was increased in kidneys from diabetic rats after a diabetes duration of 71 days. Renal activity of ODC was increased in diabetic rats throughout the study period of 71 days. Treatment of diabetic rats with the selective ODC inhibitor di-fluoro-methyl-ornithine (DFMO) was maintained for two periods (days 7-14 and days 50-71). DFMO treatment had no effect on 24-h food consumption, blood glucose concentration or body weight. However, despite almost total inhibition of the kidney ODC activity, there was no effect on kidney growth or total glomerular volume in the DFMO treated diabetic rats compared to placebo treated diabetic rats. Finally, the urinary albumin excretion was markedly increased in diabetic rats with no effects of ODC-inhibition. In conclusion, inhibition of ODC initiated in diabetic rats with manifest kidney enlargement had no effect on renal size, glomerular volume or urinary albumin excretion. These findings together with our previous findings indicate that the role of polyamines in diabetic kidney enlargement is restricted to the first week after diabetes induction.

Pharmacology of mesoionic oxatriazole derivatives in blood, cardiovascular and respiratory systems

Mesoionic oxatriazole derivatives were synthetized by GEA LTD1. The GEA compounds (GEAC) constitute a new class of NO-donors, some of which stimulate selectively guanylate cyclase abiding either platelets or leukocytes or lung tissues. In consequence, some of GEAC are potent anti-platelet, fibrinolytic, thrombolytic or broncholytic agents, both in vitro and in vivo. GEAC synergize with prostacyclin in their thrombolytic actions. They also suppress the release of histamine and leukotriene B4, and prevent degranulation of granulocytes. Methylene blue reduces, and zaprinast augments their pharmacological effects. It is suggested that within a series of the newly synthetized GEA compounds there are likely to be found potential candidates for treating either thrombotic or asthmatic disorders.

Mesoionic oxatriazole derivatives--a new group of NO-donors

A number of new 3-aryl-1,2,3,4-oxatriazole-5-imine derivatives (GEA Compounds--GEAC) were synthetized. GEAC are NO-releasers as evidenced by direct measurement of NO in headspace/NO-analyzer, by cooxygenation of oxyhaemoglobin to methaemoglobin in the Werringloer's test and by generation of nitrite in the Griess' reaction. During the release of NO from GEAC the consumption of O2 could be detected only when high concentrations of GEAC were used. The mechanism of release of NO from molecules of GEAC still remains hypothetical. Some of GEAC were found to remain stable for long periods of time, even at 37 degrees C. Both mutagenic properties and the pharmacodynamic profile of GEAC can be controlled by a mindful choosing of appropriate substituents.

Biopharmaceutical aspects of tolfenamic acid

The pharmacokinetics of tolfenamic acid is well described by a two-compartment model with relatively short half-lives (T/2 beta 1-2 hours) and tolfenamic acid is highly protein-bound with small volumes of distribution. It is cleared relatively fast (150-200 ml/min), mainly by hepatic metabolism and the metabolites are renally cleared as glucuronic acid conjugates. The peroral absorption is good and the peroral bioavailability is about 75%, as first pass metabolism accounts for about 20%. Tolfenamic acid shows linear pharmacokinetics and during multiple dosage regimen, i.e. thrice daily, no accumulation beyond the second dose is observed. The bioavailability in dependence of age and disease has been studied and only in the case of severe liver or kidney impairment, a change in dosage regimen seems warranted. The development of different formulations will be outlined, mainly on rectal delivery, on sustained release and rapid release oral formulations, on topical ointment, and on parenteral delivery. The problems with tolfenamic acid in pharmaceutical formulation caused mainly by poor solubility will be discussed. Formulations ready for the market now or very soon are Clotam capsules (tablets). Clotam retard tablets, Clotam suppositories, and Clotam oral suspension, whereas rapid tablets, topical ointments, and parenteral formulations need further development to be ready for marketing in the years to come.