OP0174 POLYDATIN PREVENTS CALCIUM PYROPHOSPHATE CRYSTAL-INDUCED ARTHRITIS IN MICE

Background:

Acute calcium pyrophosphate (CPP) crystal-induced inflammation is characterized by the massive release of cytokines and pro-inflammatory mediators and, from a clinical point of view, pain and limited joint function. Contrary to the precipitation of urate crystals that can be prevented through the use of hypouricemic drugs, there is no pharmacological therapy that can prevent the formation of pyrophosphate crystals.

Polydatin (PD),a natural precursor of resveratrol, is a stilbenoid mainly contained in grape juice and bark of Polygonum Cuspidate. Its antioxidant, anti-inflammatory and immunomodulating properties have been demonstrated in several experimental models. We have recently shown that this compound is able to prevent the inflammatory response to pathogenic crystals in vitro (1).

Objectives:

The aim of this study was to assess the anti-inflammatory preventing effect of polydatin in the mouse model of acute crystal-induced arthritis.

Methods:

A suspension of sterile CPP crystals (0.3 mg/20 μL PBS) have been injected intra-articularly (i.a.) into one ankle joint of Balb/c mice under isoflurane anesthesia. Animals were randomized in 5 groups: 1- CPP injection, 2- CPP + PD, 3- CPP + colchicine (control drug), 4- CPP + vehicle (control. N 1), 5- PBS injection (control N. 2). Polydatin and colchicine were administered by gavage (respectively 40 mg/kg and 1mg/kg in 200 μL PBS/EtOH/glucose) at 24, 15 and 1 h before and 1, 6 and 24 h after (prophylactic model) or 1, 6 and 24 h after (therapeutic model) i.a. injection of CPP crystals.

Ankle swelling was measured at different time points using a precision caliper. After 48h (peak of the acute phase) mice were euthanized and blood and ankle joints were collected for inflammatory cytokine (IL-1ß and KC) determination and histological analysis, respectively.

Results:

The mean change in ankle swelling after i.a injection was 0.595±0.434 mm. Prophylactic treatment with PD and colchicine significantly diminished ankle swelling to 0.175±0.115 mm and 0.137±0.100 mm, respectively (Kruskal Wallis p 0.0025; Dunn’s post test p < 0.01 CPP vs PD+CPP). The therapeutic administration of PD did not have significant effects on delta swelling (0.468±0.372 mm - PD vs 0.243±0.152 mm - colchicine). In mice treated with CPP crystals, histological analysis revealed areas of edema and increased cell infiltrate in articular and periarticular tissues and the presence of reactive lymphnodes. Tissue necrosis around inflamed tissue has been observed. Treatment with PD importantly reduced cell infiltrate in the prophylactic but not in the therapeutic protocol.

Serum IL-1ß and KC levels, which increased significantly (p<0.05) after 48h from i.a injection, diminished in non significant manner after prophylactic and therapeutic treatment. The gene expression study revealed a reduction of IL-1ß and KC mRNA after PD and colchicine treatment in both groups.

Conclusion:

PD can effectively prevent acute inflammatory response to crystals in the mouse model of CPP arthritis. Oral PD prophylactic treatment showed a similar effect of colchicine in reducing ankle swelling and cell infiltrate. However, only colchicine showed to be effective in the therapeutic protocol.

These results raise the possibility that PD might have utility in the prevention of crystal-induced acute attacks in humans.

References:

[1]Oliviero F, et al. Polydatin and resveratrol inhibit the inflammatory process induced by urate and pyrophosphate crystals in thp-1 cells.Foods 2019 Nov 7;8(11). pii: E560.

Disclosure of Interests:

Francesca Oliviero: None declared, Francesca Galuppini: None declared, Anna Scanu: None declared, Paola Galozzi: None declared, Vanni Lazzarin: None declared, Paolo Sfriso: None declared, Gianpietro Ravagnan: None declared, Roberta Ramonda Speakers bureau: Novartis, Celgene, Janssen, Pfizer, Abbvie, Lilly, Paolo Spinella: None declared, LEONARDO PUNZI: None declared, Gianmaria Pennelli: None declared, Roberto Luisetto: None declared

P5467Gender related differences in the clinical significance of elevated pulse pressure in the young. Results from the HARVEST study

Background

Elevated pulse pressure (PP) is a well known cardiovascular risk factor in the elderly. Whether PP is a harbinger of adverse outcome also in young individuals is still a matter of debate. Moreover, the prognostic significance of elevated PP in the young seems to differ according to gender. Recently, we showed that PP was a predictor of adverse outcome only in young women while in men PP even had a protective effect.

Aim

The aim of the present study was to identify clinical, metabolic and haemodynamic characteristics associated with high PP in young hypertensive adults and to investigate whether these associations differed according to gender.

Methods

We investigated 1207 young stage I hypertensives (878 males) from the HARVEST Study, a long-term observational study involving 17 centres in the North-East of Italy. Mean age was 33.1±8.5 years and BP 145.5±10.6/93.5±5.7 mmHg. At the baseline patients underwent office and ambulatory blood pressure measurements and biochemical analyses and were followed at 6-month intervals until they developed hypertension requiring pharmacological treatment. For the analysis patients were divided into PP tertiles. All comparisons between males and females were tested with age-adjusted two-way ANCOVA using PP and sex as predictors.

Results

PP was 52.8±11.4 mmHg in men and 49.4±9.4 mmHg in women (p<0.001). Metabolic data did not differ between the two genders. Echocardiographic stroke volume was higher in men than women (82.1±15.7 ml vs 70.8±16.4 ml, p<0.001). No between-sex difference was found for peripheral resistance. Twenty-four-hour urinary norepinephrine/creatinine was higher in women than men (68.2±59.6 vs 54.4±66.5 mcg/mg, p=0.023), whereas no difference was found for epinephrine. Stratification by PP tertile showed that men in the top tertile were younger and had lower BMI than those in the bottom tertile (p<0.001 and p=0.002), while the opposite trend was found for women (p<0.001 and p=0.002) with a significant PP-sex interaction (p<0.001 for both). Heart rate and systolic white coat effect progressively increased across PP tertiles in both genders (p<0.001 for both). Glucose and triglycerides increased with increasing PP among women while the opposite was found for men, with a significant trend for glucose (p=0.025). At the end of follow-up (mean 7.9 years) females in the top PP tertile presented higher systolic BP (p=0.004), diastolic BP (p=0.071) and heart rate (<0.001), compared to males of the corresponding tertile.

Conclusions

Young hypertensive women were characterized by increased sympathetic activity whereas men showed a hyperkinetic state. High PP was associated with greater BMI and worse metabolic profile in women, and with better metabolic data in men. This different pathogenetic background may account for the worse time-course of isolated systolic hypertension in women compared to men shown by previous studies.

Acknowledgement/Funding

None

IGF-I/IGFBP system: metabolism outline and physical exercise

The GH/IGF-I system plays a well-known hormonal role and its effects, mainly anabolic and insulin-sensitizing, are mediated through endocrine as well as paracrine/ autocrine mechanisms. This system includes the binding proteins, namely GH binding proteins and IGF-I binding proteins (IGFBP). As expected, this axis plays a key role in organism modification in consequence of a physical exercise. Physical activity, training, and exercise capacity chiefly involve anabolism process modifications of various tissues, in particular muscular adjustments. Numerous investigators found a correlation among the level of exercise tolerance, muscle strength or walking speed and IGF-I/IGFBP-3 concentrations. However, also inverse and absent correlations between circulating IGF-I concentrations and acute or chronic exercise responses have been reported. IGF-I is generally accepted as an important GH mediator with metabolic effects, through both endocrine and paracrine or autocrine mechanisms. GH is the main regulator of the hepatic synthesis of IGF-I and IGFBP-3, which is the most abundant IGF carrier in human plasma. Recently, it has been shown that the physical exercise stimulatory impact on skeletal muscles is mediated through an increased local IGF-I synthesis with an IGFPB involvement. An absent association of exercise performance and circulating IGF-I may indicate that exercise will exert muscle strength by predominately locally derived paracrine or autocrine mediators rather than endocrine circulating IGF-I. The present review considers the general aspects of the IGF/IGFPB system and the role of the IGF/IGFPB system in relation to physical exercise (type, duration, etc.) taking into account the training aspects.

Glycaemic fall after a glucose load. A population-based study

BACKGROUND AND AIMS

A blood glucose (BG) fall after an oral glucose load has never been described previously at a population level. This study was aimed at looking for a plasma glucose trend after an oral glucose load for possible blood glucose fall if any, and for its impact on coronary mortality at a population level.

METHODS AND RESULTS

In subjects from an unselected general population, BG and insulin were detected before and 1 and 2h after a 75-g oral glucose load for insulin sensitivity and β-cell function determination. Blood pressure, blood examinations and left ventricular mass were measured, and mortality was monitored for 18.8±7.7 years. According to discriminant analysis, the population was stratified into cluster 0 (1-h BG < fasting BG; n=497) and cluster 1 (1-h BG ≥ fasting BG; n=1733). To avoid any interference of age and sex, statistical analysis was limited to two age-gender-matched cohorts of 490 subjects from each cluster (n=940). Subjects in cluster 0 showed significantly higher insulin sensitivity and β-cell function, lower visceral adiposity and lower blood pressure values. Adjusted coronary mortality was 8 times lower in cluster 0 than 1 (p<0.001). The relative risk of belonging to cluster 1 was 5.40 (95% CI 2.22-13.1).

CONCLUSION

It seems that two clusters exist in the general population with respect to their response to an oral glucose load, independent of age and gender. Subjects who respond with a BG decrease could represent a privileged sub-population, where insulin sensitivity and β-cell function are better, some risk factors are less prevalent, and coronary mortality is lower.

[The mediterranean diet model in inflammatory rheumatic diseases]

The Mediterranean diet is based on a pattern of eating closely tied to the Mediterranean region, which includes Greece and southern Italy. Essentially, the traditional diet emphasizes foods from plant sources, limited meat consumption, small amounts of wine and olive oil as the main fat source. The beneficial effects of the Mediterranean diet has been proven not only to cardiovascular diseases but also for diabetes, obesity, arthritis and cancer. Its anti-inflammatory and protective properties are linked to the large presence of omega-3 polyunsaturated fatty acids, vitamins, but especially to the constituents of extra virgin olive oil: oleic acid, phenolic compounds olecanthal, a new recently discovered molecule, with natural anti-inflammatory properties. It has been shown that the Mediterranean diet can reduce disease activity, pain and stiffness in patients with inflammatory arthritis and may thus constitute a valuable support for patients suffering from these diseases.

[Role of omega-3 polyunsaturated fatty acids in diet of patients with rheumatic diseases]

The beneficial effects of omega-3 polyunsaturated fatty acids have been widely described in the literature in particular those on cardiovascular system. In the last decade there has been an increased interest in the role of these nutrients in the reduction of articular inflammation as well as in the improvement of clinical symptoms in subjects affected by rheumatic diseases, in particular rheumatoid arthritis (RA). Nutritional supplementation with omega-3 may represent an additional therapy to the traditional pharmacological treatment due to the anti-inflammatory properties which characterize this class of lipids: production of alternative eicosanoids, reduction of inflammatory cytokines, reduction of T-lymphocytes activation, reduction of catabolic enzymes activity. The encouraging results of dietetic therapy based on omega-3 in RA are leading researchers to test their effectiveness on patients with other rheumatic conditions such as systemic lupus erythematosus and ankylosing spondylitis. Nutritional therapy based on food rich in omega-3 or on supplementation with fish oil capsules, proved to be a valid support to he treatment of chronic inflammatory rheumatic diseases.

Urine cortisol and cortisone and water intake in athletes

AIM

The aim of this study was to investigate the urine cortisol (F) and cortisone (E) relation, having a well-defined water intake.

METHODS

Urine specimens were collected from 10 male trained cyclists (19+/-1 year, 70+/-4 kg, 179+/-4 cm), at rest just before the test (pre-exe) and until 45 min after the cycle ergometer exercise test (45 min at 50-60% VO2max) (post-exe) in the morning. This investigation measured the diuresis in the pre-exe and post-exe after each athlete had drunk 1 L of water from waking-up, after bladder emptying, to the start of the test (pre-exe) and 1 L during the 45 min after the exercise (post-exe).

RESULTS

Urinary F and E concentrations demonstrated a significant decrease comparing pre-exe with post-exe (177+/-134 vs 64+/-21 and 706+/-475 vs 372+/-178 nmol.L(-1) respectively, p < 0.05). This significant decrease was verified when diuresis and urinary creatinine were taken into account and the ratio measured.

CONCLUSION

One litre of water intake after exercise seemed to have no effect on urine F and E excretion. Moreover the urine F/E ratio was not statistically different comparing pre-exe with post-exe.

[Fish oil supplementation in rheumatoid arthritis]

The beneficial properties of fish oil are well known and are related to its fatty acid composition rich in omega-3 polyunsaturated fatty acids. In the last years a variety of epidemiological and clinical studies have demonstrated the efficacy of fish oil supplementation in the rheumatic diseases, in particular in rheumatoid arthritis. The anti-inflammatory effects of fish oil are linked to the production of alternative eicosanoids, to the reduction of proinflammatory cytokines, to the inhibition of the activation of T lymphocytes and of catabolic enzymes. Fish oil supplementation could represent a valuable support to the traditional pharmacological treatment of rheumatoid arthritis.

Measurement of free IGF-I saliva levels: Perspectives in the detection of GH/IGF axis in athletes

OBJECTIVES

To examine an immunoassay for measuring free IGF-I in a saliva specimen (free sIGF-I) and to study the levels in relation to the training conditions comparing young athletes and sedentary females.

DESIGN AND METHODS

The analysis was carried out by modifying a commercial kit for plasma matrix to measure the free sIGF-I. The plasma free and total IGF-I fractions, hGH and salivary total proteins were also measured. Saliva and blood specimens were collected from 15 well-trained young female volleyball athletes and from a control group of 14 young sedentary females.

RESULTS

The calibration curve to assay free sIGF-I covered the range 0.05-5.00 microg/L. The detection limit was 0.07 microg/L. The within-run and between-run imprecision CVs were 10% and 13% respectively. The average recovery was 88%. Free sIGF-I, measured in 15 athletes and in 14 young sedentary females, was 0.10+/-0.03 and 0.20+/-0.05 micarog/L respectively (p<0.001).

CONCLUSIONS

There were decreased levels of free sIGF-I in well-trained athletes, compared with sedentary females. This decrease could be related to a greater tissue requirement by the active muscle subjected to intense exercise for several days.

Effect of licorice on the reduction of body fat mass in healthy subjects

The history of licorice, as a medicinal plant, is very old and has been used in many societies throughout the millennia. The active principle, glycyrrhetinic acid, is responsible for sodium retention and hypertension, which is the most common side-effect. We show an effect of licorice in reducing body fat mass. We studied 15 normal-weight subjects (7 males, age 22-26 yr, and 8 females, age 21-26 yr), who consumed for 2 months 3.5 g a day of a commercial preparation of licorice. Body fat mass (BFM, expressed as percentage of total body weight, by skinfold thickness and by bioelectrical impedance analysis, BIA) and extracellular water (ECW, percentage of total body water, by BIA) were measured. Body mass index (BMI) did not change. ECW increased (males: 41.8+/-2.0 before vs 47.0+/-2.3 after, p<0.001; females: 48.2+/-1.4 before vs 49.4+/-2.1 after, p<0.05). BFM was reduced by licorice: (male: before 12.0+/-2.1 vs after 10.8+/-2.9%, p<0.02; female: before 24.9+/-5.1 vs after 22.1+/-5.4, p<0.02); plasma renin activity (PRA) and aldosterone were suppressed. Licorice was able to reduce body fat mass and to suppress aldosterone, without any change in BMI. Since the subjects were consuming the same amount of calories during the study, we suggest that licorice can reduce fat by inhibiting 11beta-hydroxysteroid dehydrogenase Type 1 at the level of fat cells.

GH/IGF system, cirrhosis and liver transplantation

The GH-related effects are primarily mediated by insulin-like growth factor I (IGF-I), a peptide hormone almost completely produced by the liver. Liver cirrhosis is usually accompanied by a fall in protein turnover. Furthermore, an important consequence of chronic liver disease (CLD) is growth hormone/insulin-like growth factor (GH/IGF) axis modification and growth failure. Nutritional status also suffers in this condition, and IGF-I has been proposed as a marker of hepatocellular dysfunction, malnutrition and survival. CLD is characterised by alterations of various clinical biochemistry laboratory parameters. Aminotransferases, bilirubin, plasma proteins, together with prothrombin time and gamma globulins, are usually examined for laboratory diagnostic and/or monitoring purposes. These traditional parameters are also used in the perioperative liver transplantation, but an early signal of graft functioning has still not been established. The aim of the present work is a review of the possibility offered by the clinical biochemistry laboratory GH/IGF investigation in the outcome of liver transplantation.

Plasma atrial natriuretic peptide (ANP) fragments proANP (1-30) and proANP (31-67) measurements in chronic heart failure: a useful index for heart transplantation?

The family of the atrial natriuretic peptides, proANP fragments and the active alphaANP, is strongly related to heart disease. The aim was to study in CHF subjects the relation of mdANP and NtANP with brain natriuretic peptide (BNP) and with other traditional medical parameters. Sixteen CHF patients (aged 51.9+/-13.7 years) and 16 healthy subjects age matched (50.8+/-5.9 years) were selected. Both NtANP and mdANP were higher in CHF patients than in healthy subjects (1436+/-288 vs. 288+/-22 pmol/l p<0.001 and 2305+/-383 vs. 423+/-65 pmol/l p<0.0001, respectively). BNP in CHF patients was 28.0+/-9 pmol/l (reference values 1.7+/-1.8 pmol/l). Both NtANP and mdANP demonstrated positive correlation with BNP, p<0.0001 and with left atrial end-systolic volume, p<0.05. BNP correlated with left ventricular mass, p<0.03. In conclusion, plasma NtANP and mdANP analyses are useful laboratory markers in CHF patient investigation and follow up. In particular, they could be employed as non-invasive parameters to follow up worsening of systolic dysfunction until heart transplantation is required.

Plasma lactate, GH and GH-binding protein levels in exercise following BCAA supplementation in athletes

Branched chain amino acids (BCAA) stimulate protein synthesis, and growth hormone (GH) is a mediator in this process. A pre-exercise BCAA ingestion increases muscle BCAA uptake and use. Therefore after one month of chronic BCAA treatment (0.2 gkg(-1) of body weight), the effects of a pre-exercise oral supplementation of BCAA (9.64 g) on the plasma lactate (La) were examined in triathletes, before and after 60 min of physical exercise (75% of VO2 max). The plasma levels of GH (pGH) and of growth hormone binding protein (pGHBP) were also studied. The end-exercise La of each athlete was higher than basal. Furthermore, after the chronic BCAA treatment, these end-exercise levels were lower than before this treatment (8.6+/-0.8 mmol L(-1) after vs 12.8+/-1.0 mmol L(-1) before treatment; p < 0.05 [mean +/- std. err.]). The end-exercise pGH of each athlete was higher than basal (p < 0.05). Furthermore, after the chronic treatment, this end-exercise pGH was higher (but not significantly, p = 0.08) than before this treatment (12.2+/-2.0 ng mL(-1) before vs 33.8+/-13.6 ngmL(-1) after treatment). The end-exercise pGHBP was higher than basal (p < 0.05); and after the BCAA chronic treatment, this end-exercise pGHBP was 738+/-85 pmol L(-1) before vs 1691+/-555 pmol L(-1) after. pGH/pGHBP ratio was unchanged in each athlete and between the groups, but a tendency to increase was observed at end-exercise. The lower La at the end of an intense muscular exercise may reflect an improvement of BCAA use, due to the BCAA chronic treatment. The chronic BCAA effects on pGH and pGHBP might suggest an improvement of muscle activity through protein synthesis.

Correlations of growth hormone (GH) and insulin-like growth factor I (IGF-I): effects of exercise and abuse by athletes

The importance of hormones on body metabolism when physical exercise is carried out has been established for a long time. Growth hormone (GH) is crucial in energy metabolism as well as in body anabolism. Recent studies have increased our knowledge of GH's mechanisms of action. In particular, insulin-like growth factor I (IGF-I), the main hormone mediating the principal GH effects and other protein structures (i.e. the binding proteins related to these two hormones), has been recognized as playing a crucial role. The biochemical aspects relating to the molecules of the GH/IGF-I axis have been described here. Furthermore, the belief that GH and IGF-I enhance performance has induced an 'abuse' of GH (and possibly of IGF-I) by competitive sports athletes and amateurs. The present study outlines the best methods available to uncover abuse, as well as a series of potential research projects to recognize doping. The review also underlines the principal variables measurable in the laboratory and summarizes published reference ranges of these parameters. These biochemical and laboratory profiles describe principal experimental approaches, with the hope that this will stimulate new ideas on the subject of detecting doping practices.

A rapid urine creatinine assay by capillary zone electrophoresis

Using capillary zone electrophoresis, the urine creatinine (uCr) assay was validated in extemporaneous diluted urine, both in healthy subjects and athletes, with the uCr concentration as a reference value to compare excretion rates of other metabolites in the same samples. The electrokinetic sample injection was carried out at 10 kV per 10 s; UV absorbance detection was at 254 nm. Using standard samples, the creatinine migration mean time in 100 mmol/L acetate buffer, pH 4.4, was 3.3+/-0.2 min; the repeatability for absolute migration mean time was 0.6% and peak height repeatability was 2.9%. The correlation coefficient of the standard curve was r = 0.999 and the detection limit was 23.1 micromol/L. Intra- and interassay coefficients of variation (CV) were 3.0 and 3.6%, respectively; recovery was 99+/-3% and linearity was r= 0.98. Normal urine samples were diluted 1:80 in run buffer. The present CE urine creatinine assay showed a good correlation with HPLC and with Jaffe methods (r = 0.98 and r = 0.97, respectively; p < 0.0001). The uCr in the morning urine samples of 34 healthy males (M), 38 healthy females (F), and 83 male athletes (A) was 10.4+/-6.1 mmol/L, 10.8+/-8.1 mmol/L and 13.2+/-6.5 mmol/L, respectively. The uCr difference (p < 0.02) between M and A and a correlation (p < 0.05) with age in A were observed.

Free carnitine and acetyl carnitine plasma levels and their relationship with body muscular mass in athletes

The purpose of the present study was to investigate the relationship between plasma carnitine concentration and body composition variation in relation to muscular and fat masses since there is no experimentally proved correlation between plasma carnitine and body masses. We used bioelectric impedance analysis (BIA), to determine body composition and to have a complete physical fitness evaluation. The post-absorptive plasma free carnitine and acetyl carnitine plasma levels, body composition as Fat-Free Mass (FFM) and Fat Mass (FM) in kg, as well as in percent of body mass, were analysed in 33 healthy subjects. A significant negative correlation was found between plasma acetyl carnitine and FFM in weight (kg) as well as in percent of body mass (respectively p < 0.0001; p < 0.01); a significant positive correlation was found only between FM in percent and plasma acetyl carnitine (p < 0.01). The observed negative correlation between plasma acetyl carnitine and muscular mass variation might reflect an oxidative metabolic muscle improvement in relation to muscular fat free mass increment and might be evidence that muscle metabolism change is in relation to plasma acetyl carnitine concentration.

Regulation of corticosteroid receptors in patients with anorexia nervosa and Cushing's syndrome

We have studied 16 patients with anorexia nervosa (11 with a stabilised weight loss and 5 in the weight-losing phase), 11 healthy controls, and 10 patients with Cushing's syndrome, by measuring plasma cortisol (by enzyme-immunoassay), ACTH (by RIA), corticosteroid (Type I-mineralocorticoid and Type II-glucocorticoid) receptors in mononuclear leukocytes (by radio-receptor assay), and lymphocyte subpopulations (by cytofluorimetry). In anorexic patients with a stabilised weight loss and in Cushing's syndrome the mean value of both Type I and Type II corticosteroid receptors in mononuclear leukocytes was significantly lower than in controls. The correlation between Type II receptors and plasma cortisol was inverse in stabilised anorexia nervosa and in Cushing's syndrome, and direct in healthy controls. Anorexic patients in the weight-losing phase showed a significant increase in plasma cortisol levels and a normal number of Type II receptors. From these results we hypothesise that in anorexia nervosa there is a progression from an increase in plasma cortisol in the weight-losing phase, to a concomitant decrease in Type II receptors when the disease is stabilised.

Pigment epithelium-derived factor behaves like a noninhibitory serpin. Neurotrophic activity does not require the serpin reactive loop

Pigment epithelium-derived factor (PEDF), a neurite-promoting factor, has an amino acid primary structure that is related to members of the serine protease inhibitor (serpin) family. Controlled proteolysis of native PEDF (50 kDa) with either trypsin, chymotrypsin, elastase, or subtilisin yields in each case one major limited product of 46 kDa as analyzed by SDS-polyacrylamide gel electrophoresis. N-terminal sequence analysis of the isolated 46-kDa products indicates a favored cleavage region located toward the C-terminal end of PEDF. A proteolyzed PEDF protein reaction mixture reveals two overlapping sequences: that of the N terminus of intact PEDF and that of an internal region, consistent with cleavage of PEDF about position 382. These data indicate that PEDF protein has a globular conformation with one protease-sensitive exposed loop that contains the homologous serpin-reactive site. Cleavage within the reactive-site loop of PEDF does not cause a conformational change in the molecules (the stressed (S)-->relaxed (R) transition) and results in heat denaturation identical to its native counterpart. This lack of conformational change is also seen upon cleavage within the reactive-site loop of the noninhibitory serpin ovalbumin. Furthermore, the PEDF neurite-promoting function is not lost with cleavage of the exposed loop. Recombinant PEDF polypeptide fragments with larger truncations from the C-terminal end show neurotrophic activity. Our results clearly indicate that integrity of the PEDF homologous serpin reactive center is dispensable for neurotrophic activity. Thus, the PEDF induction of neurites must be mediated by a mechanism other than serine protease inhibition. Altogether our data indicate that PEDF belongs to the subgroup of noninhibitory serpins and that its N-terminal region confers a neurite-promoting activity to the protein. The neurotrophic active site of PEDF is separated from the serpin reactive-site loop, not only in the primary structure, but also in the folded protein structure.

Identification of immunoreactive thyrotropin-releasing hormone in human neoplasia

Immunoreactive TRH (IR-TRH) was identified in extracts derived from seven human cancer tissues, including two oat cell carcinomas. The IR-TRH concentrations ranged from 29-189 pg/g. Tumor IR-TRH exhibited immunological identity with synthetic pyroglu-his-proamide and coeluted with synthetic [3H]TRH after high pressure liquid chromatography on a mu Bondapak C-18 column. These data extend the number of hypothalamic peptide hormones identified in human neoplastic tissues.

[Basal prolactinemia and level after stimulation with TRH in juvenile gynecomastia]

TSH and PRL in basal conditions and after stimulus with TRH, gonadotrophin in basal conditions and after stimulus with GnRH, plasma testosterone, urinary oestrogens and peripheral thyroid hormones have been evaluated in 11 subjects with puberal gynaecomastia, 7 with post-puberal gynaecomastia and 14 normal controls. With respect to the normal controls, only patients with post-puberal gynaecomastia showed higher levels of basal PRL and after TRH stimulus. The behaviour of these patients could suggest that in subjects with post-puberal gynaecomastia there may be persistent endocrine imbalance, whereas in puberal gynaecomastia such imbalance is only transitory and is exhausted prior to the onset of mammary tumefaction.