[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.

Growth hormone isoforms and segments/fragments: Molecular structure and laboratory measurement

Endocrine diagnostic tests are dependent on the molecular characteristics of protein hormones, a property that is also intimately tied to function. The structure-function relationship is of particular importance for multifunctional protein hormones such as growth hormone (GH). For clinical diagnosis, it is imperative to understand the relationship between GH structure (and its molecular fragments) and function and their potential interaction with single or multiple receptors. The existence of a single or aggregated intact GH 22 kDa form such as the 20 kDa GH isoform has been described, but GH fragments cannot be excluded a priori. Recent advances and probable similarity of GH with other protein hormones such as natriuretic peptides (ANP, BNP and their proANP and proBNP fragments) and POMC (ACTH, beta-endorphin, etc.) lend support to the hypothesis that GH fragments should also be present. This brief review focuses on GH heterogeneity and feasible post-synthesis events. The aim of the review is to describe which GH forms/fragments have already been recognized and/or are potentially present in the circulation. The impacts of GH isoforms (namely the intact 20 and 22 kDa isoforms) and fragments thereof on quantitative measurement are discussed with reference to traditional immunoassay technology and innovative immunofunctional laboratory assays.

Growth hormone isoforms, segments/fragments: Does a link exist with multifunctionality?

Understanding the relationship between growth hormone (GH) structure (its molecular fragments) and function via interaction with single or multiple receptors is of particular importance in clinical diagnostics and physiologic biochemistry. Direct and indirect actions of GH are numerous ranging from carbohydrate and lipid metabolism to growth effects at muscle and vessels. To this end, we have focused on the influence of physical exercise on GH synthesis and release into the circulation. Physical exercise is a physiological condition to which GH multifunctionality is inextricably linked and is thus important physiologically and pathologically. This review describes the potential human GH fragments with respect to protein hormone multifunctionality and the molecular regions of potential action. The intent of the review is to highlight human GH fragments and hypothesize their potential physiologic role. GH fragmentation is also reviewed in relation to the effects of physical exercise and hormone multifunctionality.

Urinary high performance reverse phase chromatography cortisol and cortisone analyses before and at the end of a race in elite cyclists

A functional and basic method for the quantitative analysis of urine cortisol (F) and cortisone (E) using a Solid-Phase Extraction column and HPLC with ultraviolet detection is here described and validated to analyse urine samples. Urine specimens were analysed to study F and E relation and ratio in athletes and healthy sedentary subjects. The F and E concentrations in random urine specimens were significantly higher in the post exercise versus pre exercise condition in cyclists (F: 136+/-93 nmol/l versus 67+/-50 nmol/l (p<0.001); E: 797+/-400 nmol/l versus 408+/-252 nmol/l (p<0.001)). The F/E ratio was 0.18+/-0.11 versus 0.16+/-0.07, respectively, and a significant difference was only demonstrated comparing sedentary (0.11+/-0.07) and cyclist individuals at rest (p<0.05).

Effect of prolonged physical exercise on urinary proANP1-30 and proANP31-67

Dynamic exercise strongly affects atrial natriuretic peptides (ANP), in particular the mature bioactive alphaANP and the proANP fragments, namely proANP1-98, proANP1-30 and proANP31-67. The proANPs influence kidney functions and their plasma levels increase after physical exercise. We measured urinary proANP1-30 and proANP31-67 levels before and at the end of physical exercise in 28 well-trained male cyclists. For the first time, the proANP1-30 and proANP31-67 urinary levels in athletes before and at the end of a prolonged agonistic bicycle race were measured. Urinary creatinine and total proteins were also measured. The urinary proANP31-67, creatinine and total protein levels were significantly higher at the end of exercise than before. In contrast, proANP1-30/protein and proANP31-67/protein ratios decreased after exercise. Even proANP1-30/creatinine and proANP31-67/creatinine ratios were lower after exercise. A significant correlation between proANP1-30 and proANP31-67 urinary levels at the end of exercise was found. The proANP31-67/creatinine ratio before and after exercise also showed a significant correlation. The variation of urinary proANP fragments confirmed their possible role in physical exercise. In particular, it could be interpreted as a response of the body or kidney to renal impairment occurring during exercise.

Urinary insulin-like growth factor-I measurement in an actual sport competition, an additional approach in laboratory antidoping tests

BACKGROUND

The insulin-like growth factor hormone (IGF-I) is an important protein hormone under investigation with physical exercise and for doping detection. Urinary IGF-I level in fact represents a relevant measurement when the postexercise proteinuria is under analysis. To verify the IGF-I level variation in the circulation and in urinary excretion in the occasion of a competition, the plasma and urine IGF-I in athletes before and after an actual competitive event were measured.

METHODS

Twenty well-trained cyclists took part in a competition (102 km) and concluded the intense physical exercise in approximately 2(1/2) h. Urine and blood samples were collected from each athlete 10-20 min before and at the end of the competition. Plasma and urine total IGF-I (pIGF, uIGF), total urinary proteins (uPr), and creatinine (uCr) concentrations were measured.

RESULTS

The uIGF [from 76.2+/-15.8 to 256.9+/-29.1 ng/l (p<0.001)], uPr [from 29.4+/-6.7 to 325.9+/-95.1 mg/l (p<0.005)], and uCr [from 6.3+/-1.0 to 10.0+/-0.8 mmol/l (p<0.005)] significantly increased. The pIGF was 262.6+/-14.3 and 247.3+/-11.8 microg/l before and end-exercise, respectively. A statistical correlation between uIGF and uPr was demonstrated (p<0.001). The pIGF/uIGF ratio was significantly (p<0.05) decreased comparing the end with before the competition.

CONCLUSIONS

The pIGF/uIGF significantly decreased at the end, compared with before the competition, suggesting a changed uIGF excretion. This increment appeared to be increased, although not significantly, considering the ratio with uCr.

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.

Effects of Acute, Heavy-Resistance Exercise on Urinary Peptide Hormone Excretion in Humans

To examine physical exercise-related changes in urinary excretion of protein/peptide hormones and to correlate modifications with the general increase in post-exercise proteinuria, urine C-peptide, insulin and insulin-like growth factor-I (IGF-I) and their plasma concentrations were measured. Plasma and urinary C-peptide, insulin and IGF-I before (Bex) and at the end (Eex) of physical exercise (a 2.5-hour competition, 102 km) were analysed in 20 young cyclists. At Eex compared with Bex, concentration of urinary C-peptide decreased slightly but significantly (21.3 +/- 2.7 vs. 13.5 +/- 1.7 nmol/l), but urinary insulin and urinary IGF-I concentrations significantly increased at Eex (92.5 +/- 4.2 vs. 131.4 +/- 15.7 pmol/l and 10.0 +/- 2.1 vs. 33.6 +/- 3.8 pmol/l, respectively). Plasma insulin and plasma C-peptide significantly decreased, whereas plasma IGF-I was unchanged. Urinary concentrations of total proteins and creatinine significantly increased. Both Eex urinary C-peptide/urinary protein and urinary C-peptide/urinary creatinine ratios were significantly reduced. The correlation between C-peptide and insulin in plasma was confirmed at Bex as well as Eex, but in urine only at Bex. An increased renal tubular reabsorption of C-peptide at the end of exercise might be suggested, but the expected values considering creatinine excretion were almost three times less. The Eex urinary insulin concentration was higher than expected, considering the circulation levels, but lower when compared with the expected concentration considering creatinine excretion. Physical exercise proteinuria, related to an increased protein filtration and a saturation of the mechanisms responsible for the reabsorption, does not appear similar for all peptide hormones.

Urinary insulin-like growth factor I in athletes, before and after physical exercise, and in sedentary subjects

BACKGROUND

Insulin-like growth factor I (IGF-I), like growth hormone (GH), is excreted in urine in a smaller fraction than the concentration found in blood. Exercising subjects undergo post-exercise proteinuria. The present work aims to propose a method for urinary IGF-I analysis (uIGF-I) by defining urinary concentration in sedentary individuals and athletes before and after strenuous exercise.

METHODS

Urine samples were collected from 30 sedentary healthy male individuals during the morning and from 30 well-trained cyclists, before and after a competition of about 3 h (150 km). uIGF-I was measured in undiluted acidified urine by radioimmunoassay (RIA) method using a purified polyclonal rabbit antibody, human 125I-IGF-I and a second anti-rabbit antiserum. The acidification of the urine samples and the excess of IGF-II addition in the incubation medium of the assay were used to dissociate the binding and to block the interference from IGF binding proteins (IGFBPs). Urinary growth hormone (uGH), total protein (utPr) and creatinine (ucr) concentrations were also measured by immunoradiometric assay (IRMA), colorimetric and capillary electrophoresis methods, respectively.

RESULTS

The analysis range was 0-2500 ng/l (0-327 pmol/l), the intra- and inter-assay coefficients of variations (CVs) ranged from 2.3% to 7.8%, respectively. The detection limit was 0.6 pg/tube. The uIGF-I/creatinine (cr) ratio in healthy subjects was 70 +/- 8 pg/mg cr. The uIGF-I/creatinine ratio (pg/mg cr) was different (p<0.001) in athletes before vs. after competition 93 +/- 27 vs. 136 +/- 13. Athletes' [uIGF-I/total proteins] ratio (ng/mg tPr) before and post-exercise was 2.3 +/- 0.5 and 2.5 +/- 0.3, respectively.

CONCLUSIONS

uIGF-I assay appears to be an effective way of monitoring IGF-I excretion. In the cyclists, in the pre-exercise state, uIGF-I was comparable with that measured in sedentary healthy individuals. In the cyclists, after strenuous exercise, the increased uIGF-I/cr and uGH/cr ratios suggested a relation with the post-exercise proteinuria. In conclusion, proteinuria physiologically obtained, such as post-exercise proteinuria, might be a new approach in IGF-I system investigation.

The measurement of insulin-like growth factor-I (IGF-I) concentration in random urine samples

The aim of the present study was to assess a suitable expression of the urinary concentration of a protein/ peptide hormone such as insulin-like growth factor-I (IGF-I), measured in the urine of healthy individuals when the specimen collection is executed randomly. One hundred and twenty male subjects were divided by age into four groups, namely healthy sedentary young (SYA) and older (SOA) adults, older (OC) and young (YC) children. In a single urine specimen, randomly collected during the morning from each individual, total urinary IGF-I was measured by immunoradiometric method, and urinary creatinine (uCr) and total proteins (utPr) were measured by capillary electrophoresis and spectrophotometric methods, respectively. The urinary IGF-I concentrations were not significantly different in all groups investigated and they were (mean +/- SD): 82.7 +/- 82.8 ng/l, 103.5 +/- 83.3 ng/l, 80.4 +/- 64.4 ng/l in OC, SYA and SOA, respectively; only in the YC group there was a tendency to higher values (125.2 +/- 93.2 ng/l) compared with the other groups. utPr ranged from 26 to 40 mg/l and did not demonstrate significant differences between groups. The urinary IGF-I correlated with uCr and utPr, and statistical significance was observed in all measurements. The measurement of urinary IGF-I in random urine and its ratio to utPr is an innovative, useful way of investigation of urinary protein/peptide hormones.

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.