Role of interleukin-10 in the synovial fluid of the anterior cruciate ligament injured knee.

OBJECTIVE: This review assesses the roles of IL-10 in post ACL reconstruction OA, and highlights the potential therapeutic effects of this cytokine. MATERIALS AND METHODS: We conducted a systematic review of the literature in order to consolidate evidence of IL10 profiles in synovial fluid (SF) of patients with ACL tears. The review was conducted in accordance with the PRISMA statement. In total, 10 studies were found to be pertinent and were considered in depth. Seven studies reported on trends in IL-10 concentrations after an ACL tear; in addition, three studies described IL-10 concentrations after ACL reconstruction. In all studies, IL-10 levels were assessed using enzyme-linked immunosorbent assay. RESULTS: IL-10 levels in SF were higher after ACL injury and ACL reconstruction compared to control knees. IL-10 levels were most elevated shortly after injury, but, decreased to more normal levels in chronic lesions. In contrast, the inflammatory cytokine TNF-α remained higher than controls immediately subsequent to, and, even 5 years post-injury. CONCLUSIONS: IL-10 is a modulatory cytokine with an active role in antagonizing TNF-α in the knee joint environment. Consideration of the role of IL-10 in the knee has now shifted from simply a key biomarker to having active therapeutic potential in the prevention of OA after ACL injury.

Testosterone a key factor in gender related metabolic syndrome.

Metabolic syndrome (MetS) is highly correlated with cardiovascular diseases. Although an excess of body fat is a determinant factor for MetS development, a reduced level of testosterone plays a fundamental role in its regulation. Low testosterone level is highly related to insulin resistance, visceral obesity and MetS. We have searched in Pubmed clinical trial with the password: testosterone and insulin resistance, and testosterone and MetS. We found 19 studies on the correlation between testosterone level with insulin resistance and 18 on the effect of testosterone therapy on MetS. A high correlation between low testosterone and insulin resistance has been found in men, but not in women. Testosterone administration in hypogonadal men improved MetS and reduced the mortality risk. Androgen and oestrogen receptors are expressed in adipocytes, muscle and liver tissue, and their activation is necessary to improve metabolic control. Normalization of testosterone level should be the primary treatment in men, along with caloric restriction and physical exercise. These findings come mainly from correlative data, and there remains a need for randomized trials to strengthen this evidence. This review will consider the effects of testosterone on the regulation and development of MetS in men and women.

Intravenous immunoglobulin transfusion in colostrum-deprived dairy calves.

Immunoglobulin transfusion is employed in the management of the failure of passive transfer (FPT). The aim of this study was to investigate the dose of immunoglobulin G (IgG) needed to reach a protective concentration (>10 g/L) in colostrum-deprived dairy calves. Twenty-eight Holstein Friesian newborn male calves were randomly assigned to either a control group (CG) or a treatment group (PG). Calves in the CG received 4 L of high quality colostrum within 12 h of birth. Calves in the PG received 62.7 ± 3.1 g of IgG IV in 2.6 ± 0.3 L of plasma within 6 h after birth. Serum immunoglobulin G (sIgG) and serum total protein (sTP) concentrations were assayed before and after (24 h, 72 h and 1 week after birth) plasma transfusion or colostrum ingestion. Serum (s) IgG and sTP concentrations increased in both groups throughout the period of observation. Mean sIgG and sTP concentrations after colostrum ingestion or plasma transfusion were higher in the CG than in the PG (P <0.01). Nine treated calves developed diarrhoea during the study and four were humanely euthanased due to progressive clinical deterioration. None of the calves in the CG showed signs of disease or died during the study. The dose of IgG used in this trial effectively provided an adequate sIgG concentration in colostrum-deprived calves (>10 g/L). Calves in the CG had significantly lower morbidity and mortality rates compared to those in the PG, suggesting that plasma transfusion alone is ineffective in providing complete protection against neonatal disease.

Biophysical characterization of a binding site for TLQP-21, a naturally occurring peptide which induces resistance to obesity.

Recently, we demonstrated that TLQP-21 triggers lipolysis and induces resistance to obesity by reducing fat accumulation [1]. TLQP-21 is a 21 amino acid peptide cleavage product of the neuroprotein VGF and was first identified in rat brain. Although TLQP-21 biological activity and its molecular signaling is under active investigation, a receptor for TLQP-21 has not yet been characterized. We now demonstrate that TLQP-21 stimulates intracellular calcium mobilization in CHO cells. Furthermore, using Atomic Force Microscopy (AFM), we also provide evidence of TLQP-21 binding-site characteristics in CHO cells. AFM was used in force mapping mode equipped with a cantilever suitably functionalized with TLQP-21. Attraction of this functionalized probe to the cell surface was specific and consistent with the biological activity of TLQP-21; by contrast, there was no attraction of a probe functionalized with biologically inactive analogues. We detected interaction of the peptide with the binding-site by scanning the cell surface with the cantilever tip. The attractive force between TLQP-21 and its binding site was measured, statistically analyzed and quantified at approximately 40 pN on average, indicating a single class of binding sites. Furthermore we observed that the distribution of these binding sites on the surface was relatively uniform.

Perineal choristoma and atresia ani in 2 female Holstein Friesian calves.

Atresia ani, a congenital anomaly of the anus, can be associated with other types of malformation. Two female Holstein Friesian calves had imperforate anus, rectovaginal fistula, and perineal choristomas. In one case, the choristoma was composed of mature adipose and fibrous tissue with nephrogenic rests. In the other calf, the choristoma consisted of fragments of trabecular bone coated by cartilage and containing marrow, mixed with mature adipose and fibrous tissue, striated muscle fibers, nerves, and vessels. This combination of malformations resembles the association of anorectal malformations and perineal masses in children.

Ghrelin control of GH secretion and feeding behaviour: the role of the GHS-R1a receptor studied in vivo and in vitro using novel non-peptide ligands.

Energy homeostasis is controlled by a complex regulatory system of molecules that affect food intake and that are critical for maintaining a stable body weight during life. Ghrelin is a peptide of 28 amino acid synthesized predominantly by the stomach and the gut, which activate the type 1a growth hormone (GH) secretagogue receptor (GHS-R1a), a G-protein coupled receptor. The acylated form of ghrelin potently stimulates GH secretion both in vitro and in vivo in several animal species, including humans. Beside the endocrine effect, ghrelin shows also extraendocrine activities, including stimulation of feeding behaviour. Several classes of small synthetic peptide and non-peptide ligands of the GHS-R1a have been described and are able to release GH and stimulate food intake. However, in time, it appeared that the stimulating effects on GH secretion could be divorced from those on food intake, suggesting that more than a single receptor might be involved. Several experimental data have even questioned the physiological role of ghrelin in the control of GH secretion and energy metabolism. By using novel agonists, partial agonists, and antagonists for the GHS-R1a receptor, we have studied whether the stimulation of this receptor could account for the purported physiological role of ghrelin. Our results demonstrate that the ability to bind in vitro the GHS-R1a is not predictive of the in vivo biological activity of the compounds and that the endocrine and extraendocrine effects could be mediated also by receptors different from the GHS-R1a.

Feeding behavior during long-term hexarelin administration in young and old rats.

Ghrelin, a 28-amino-acid peptide isolated from the stomach, is the natural ligand of the GH-secretagogues receptor-1a (GHS-R1a) and, so far, the only discovered circulating appetite-stimulating hormone. Similarly to ghrelin, many synthetic compounds belonging to the GHS family stimulate both GH secretion and feeding, whereas some stimulate GH secretion only. In the past years, studies have focused on the potential of the GHS to stimulate GH release during long-term treatment in humans and experimental animals. Few data are available about the extraendocrine effects of the GHS during several weeks of treatment, particularly in old rats. The aim of the present study was first to identify the lowest dose of hexarelin giving maximal stimulation of food intake both in young (3-month-old) and old rats (24-month-old). A dose-response study (80-320 microg/kg, s.c.) revealed that hexarelin at the dose of 80 microg/kg gave reproducibly maximal stimulation of food consumption in young as well as in old rats. Second, we evaluated the effect of 8-week daily sc treatment with hexarelin in young and old male rats. The outcome of the chronic study was that hexarelin (80 microg/kg, s.c., once daily) maintained a persistent significant orexigenic action throughout the treatment period, both in young and old rats. Interestingly, hexarelin treatment did not affect body weight gain either in young or old rats. We conclude that hexarelin is endowed with long-lasting orexigenic activity and might represent a potential therapeutic approach for pathological conditions characterized by a decline in food intake.

Central ghrelin gastroprotection involves nitric oxide/prostaglandin cross-talk.

BACKGROUND AND PURPOSE: Ghrelin, a gut-brain peptide, is considered a gastroprotective factor in gastric mucosa. We investigated the role of prostaglandins (PG) and the possible interplay between PGs and nitric oxide (NO) in ghrelin gastroprotection against ethanol (EtOH)-induced gastric lesions. EXPERIMENTAL APPROACH: We examined the effects of (1) central ghrelin (4 mug per rat) injection on PGE(2) accumulation in normal or EtOH-lesioned gastric mucosa, (2) pretreatment with indomethacin (10 mg kg(-1), p.o.), a non-selective cyclooxygenase (COX) inhibitor, and with a selective COX-1, SC560 (5 mg kg(-1), p.o.) or COX-2 inhibitor, celecoxib (3.5 mg kg(-1), p.o.) on ghrelin gastroprotection against 50% EtOH (1 mL per rat)-induced gastric lesions, (3) the NO synthase inhibitor, L-NAME (70 mg kg(-1), s.c), on gastric PGE(2) content in ghrelin-treated rats and (4) central ghrelin on the expression of constitutive and inducible NOS and COX mRNA and on the localization of the immunoreactivity for COX-2 in the gastric mucosa exposed to EtOH. KEY RESULTS: Ghrelin increased PGE(2) in normal mucosa, whereas, it reversed the EtOH-induced PGE(2) surge. Ghrelin had no effect on mucosal COX-1 expression but reduced the EtOH-induced increase in COX-2 expression and immunoreactivity. Indomethacin and SC560, but not celecoxib, removed ghrelin gastroprotection. L-NAME prevented the PGE(2) surge induced by ghrelin and, like indomethacin, reduced EtOH-induced PGE(2) increase. Ghrelin enhanced eNOS expression and reduced iNOS mRNA. CONCLUSIONS AND IMPLICATIONS: This study shows that COX-1-derived PGs are mainly involved in ghrelin gastroprotection and that the constitutive-derived NO together with PGE(2) are involved in ghrelin gastroprotective activity.

Chronic intracerebroventricular TLQP-21 delivery does not modulate the GH/IGF-1-axis and muscle strength in mice.

OBJECTIVE: Biallelic ablation of VGF determines a dwarf phenotype. VGF precursor protein encodes for different biologically active peptides none of which has been related to growth or muscular abnormalities. Here we present the first attempt to fill this gap. We tested the hypothesis that a recently identified VGF-derived peptide, TLQP-21, shown to centrally modulate metabolic functions, could also modulate growth hormone (GH)-axis and muscle strength. DESIGN: Adult male mice were chronically icv injected with TLQP-21 (15 microg/day for 14 days). Physiological, molecular and behavioral parameters related to the GH/IGF-1-axis were investigated. RESULTS: Except for a reduction in the soleus weight, TLQP-21 did not affect GH/IGF-1-axis mediators, muscle strength and muscle weight. CONCLUSIONS: Results collected exclude a role for TLQP-21 in modulating the GH/IGF1-axis and muscle functions. VGF-derived peptides involved in the dwarf phenotype of VGF-/- mice have to be identified yet.

Central dysregulations in the control of energy homeostasis and endocrine alterations in anorexia and bulimia nervosa.

In the last decades we have come to understand that the hypothalamus is a key region in controlling energy homeostasis. A number of control models have been proposed to explain the regulation of feeding behavior in physiological and pathological conditions, but all those based on imbalances of single factors fail to explain the disrupted regulation of energy supply in eating disorders such as anorexia nervosa and bulimia nervosa, as well as other psychiatric disorders. A growing amount of evidence demonstrates that many signaling molecules originated within the brain or coming from the adipose tissue or the gastro-enteric tract are involved in the highly complex process controlling food intake and energy expenditure. The recent discovery of leptin, ghrelin, and other factors have made it possible to penetrate in the still undefined pathophysiology of eating disorders with the hope of finding effective treatments for such diseases.

Obestatin inhibits feeding but does not modulate GH and corticosterone secretion in the rat.

Obestatin is a recently discovered 23 amino acids peptide derived from the ghrelin gene. As opposed to ghrelin, obestatin was shown to inhibit food intake in mice. The aims of this research were to study the effects of acute obestatin treatment on feeding behavior in the rat and its effects on GH and corticosterone secretion. Our results demonstrate that in young-adult male rats, obestatin effectively blunts the hunger caused by short-term starvation. Obestatin did not modify GH secretion in 10-day-old rats and did not antagonize the GH-releasing effects of hexarelin. Moreover, obestatin administration had no effects on spontaneous corticosterone secretion. In conclusion, these data demonstrate that in young-adult male rats the newly discovered obestatin can inhibit feeding but does not modify GH and corticosterone release in infant rats.

TLQP-21, a VGF-derived peptide, increases energy expenditure and prevents the early phase of diet-induced obesity.

The vgf gene has been identified as an energy homeostasis regulator. Vgf encodes a 617-aa precursor protein that is processed to yield an incompletely characterized panel of neuropeptides. Until now, it was an unproved assumption that VGF-derived peptides could regulate metabolism. Here, a VGF peptide designated TLQP-21 was identified in rat brain extracts by means of immunoprecipitation, microcapillary liquid chromatography-tandem MS, and database searching algorithms. Chronic intracerebroventricular (i.c.v.) injection of TLQP-21 (15 mug/day for 14 days) increased resting energy expenditure (EE) and rectal temperature in mice. These effects were paralleled by increased epinephrine and up-regulation of brown adipose tissue beta2-AR (beta2 adrenergic receptor) and white adipose tissue (WAT) PPAR-delta (peroxisome proliferator-activated receptor delta), beta3-AR, and UCP1 (uncoupling protein 1) mRNAs and were independent of locomotor activity and thyroid hormones. Hypothalamic gene expression of orexigenic and anorexigenic neuropeptides was unchanged. Furthermore, in mice that were fed a high-fat diet for 14 days, TLQP-21 prevented the increase in body and WAT weight as well as hormonal changes that are associated with a high-fat regimen. Biochemical and molecular analyses suggest that TLQP-21 exerts its effects by stimulating autonomic activation of adrenal medulla and adipose tissues. In conclusion, we present here the identification in the CNS of a previously uncharacterized VGF-derived peptide and prove that its chronic i.c.v. infusion effected an increase in EE and limited the early phase of diet-induced obesity.

Evidence for a role of the GHS-R1a receptors in ghrelin inhibition of gastric acid secretion in the rat.

Ghrelin, the endogenous ligand of the GH secretagogue receptor (GHS-R) has been previously shown to inhibit gastric acid secretion in pylorus-ligated rats. Two isoforms of GHS-R have been identified: GHS-R(1a) and GHS-R(1b). The present study aimed: (i) to characterise the type of GHS-R involved in the central gastric inhibitory activity of ghrelin by using des-octanoyl ghrelin, and synthetic GHS-R(1a) agonist (EP1572) and antagonist (D-Lys(3)-GHRP-6) and (ii) to investigate the relationship between ghrelin and cortistatin (CST) in the control of gastric acid secretion by using the natural neuropeptide CST-14 and the synthetic octapeptide CST-8. The specific interactions of all the compounds with GHS-R(1a) were determined by comparing their ability to displace labelled ghrelin or somatostatin from its receptors on rat hypothalamic membranes or on rat cardiomyocyte, respectively. Intracerebroventricular administration of 0.01 and 1 nmol/rat des-octanoyl ghrelin did not affect gastric acid secretion in pylorus-ligated rats, whereas EP1572 either i.c.v. (0.01-1 nmol/rat) or i.p. (10 and 20 nmol/kg) inhibited acid gastric secretion. Preteatment with D-Lys(3)GHRP-6 (3 nmol/rat, i.c.v.) was able to remove the inhibitory action of ghrelin (0.01 nmol/rat, i.c.v.) on gastric acid volume and acid output, thus indicating that the type 1a GHS-R likely mediates the gastric inhibitory action of ghrelin. This is supported by binding data showing that D-Lys(3)GHRP-6, but not des-octanoyl ghrelin, binds to hypothalamic GHS-R. CST-14 (1 nmol/rat, i.c.v.) did not affect either basal or ghrelin inhibition of gastric acid secretion. CST-8 (1 nmol/rat, i.c.v.) was able to counteract the gastric ghrelin response. The observation that CST-14 binds both GHR-S and somatostatin receptors, whereas CST-8 specifically displaces only ghrelin binding, indicates that CST-8 behaves as a GHS-R(1a) antagonist.

Intracerebroventricular acute and chronic administration of obestatin minimally affect food intake but not weight gain in the rat.

We studied the effect of the acute central administration of obestatin on food intake and body weight in short-term starved male rats, and those of 28-day continuous intracerebroventricular (icv) infusion of obestatin in free feeding rats. In 16-h starved rats, obestatin induced a trend toward a reduction of food intake that did not reach statistical significance. In fed rats, the icv infusion of obestatin significantly decreased food consumption in the first day of treatment; but the anorexigenic effect of obestatin vanished thereafter. Interestingly, the body weight of rats infused for 28 days with obestatin was superimposable to that of the respective control at all time intervals. In all, our results indicate that the anorexigenic effect of obestatin is of little account and that the peptide does not modify energy metabolism in the long-term administration.

Ghrelin in gastroenteric pathophysiology.

Ghrelin, an acylated peptide produced predominantly by the stomach, has been discovered to be a natural ligand of the growth hormone secretagogue receptor 1a (GHS-R1a). It is localized in distinct cells of the gastric mucosa, mainly distributed in the mid portion of the oxyntic gland characterized by P/D1 granules in man and X/A-like granules in rodents. The ghrelin cell represents the second most frequent endocrine cell type after the enterochromaffin-like cells in gastric oxyntic mucosa, pointing to a potentially relevant role in the physiology of the stomach. Ghrelin has no relevant homology with any known gastrointestinal peptide and displays strong GH-releasing activity both in animals and in humans. However, in addition to stimulating GH secretion, ghrelin possesses several other endocrine and extraendocrine biological activities that are explained by the widespread distribution of ghrelin and GHS-R1a expression. In the rat, ghrelin exerts a control in gastric acid secretion and motility: the gastric acid secretion is stimulated by peripheral administration of high doses of ghrelin, but inhibited by very low doses of ghrelin delivered into the central nervous system. Moreover, ghrelin provides a potent and dose-related gastroprotective action against ethanol- and stress-induced gastric ulcers. The integrity of both nitric oxide (NO) system and capsaicin afferent nerves are required for the gastroprotective effect of ghrelin, whereas the vagus nerve might be involved in conveying ghrelinergic signal from periphery to the brain. In addition, prostaglandins derived by the constitutive cyclooxygenase (COX) activity are essential for the protective activity of ghrelin in ethanol and stress-induced gastric lesions. Given its prevailing role in physiological and pathophysiological gastric function, the discovery of ghrelin will open new perspectives and potential clinical implications in the gastroenteric field.

Effects of hexarelin against acid-independent and acid-dependent ulcerogens in the rat.

The effects of intracerebroventricular (icv) or subcutaneous (sc) hexarelin (Hexa) administration, against gastric ulcers induced by ethanol (50%, 1 ml/rat/os) or Indomethacin (20 mg/kg/os) were examined in conscious rats. Hexa at 1 nmol/rat, icv or 10 nmol/kg, sc reduced ethanol-induced ulcers by 47% and 32% respectively. Hexa, but not ghrelin significantly worsened (+40%) Indomethacin-induced ulcers when injected sc. Hexa-gastroprotection against ethanol-induced ulcers was removed by the GHS-R antagonist (D-Lys3)-GRPR-6 and by the inhibitor of NO-synthase (NOS) Nomega-nitro-L-arginine methyl ester. Semiquantitative RT-PCR assay of gastric NOS mRNA isoforms revealed that the reduction in iNOS-derived NO and the increase of constitutive-derived NO are relevant for the gastroprotection of Hexa against ethanol-induced gastric damage.

IGF-I stimulates proliferation of spontaneously immortalized human keratinocytes (HACAT) by autocrine/paracrine mechanisms.

HaCaT keratinocytes are derived from adult human skin and although spontaneously immortalized, remain highly related to their normal counterparts. We observed that HaCaT cells can proliferate in serum-free medium (SFM), in contrast to normal human keratinocytes whose growth in vitro requires a feeder layer and/or the supplementation with hormones and growth factors. Since autocrine production of growth factors has been proposed as the pathway that cells may exploit to escape growth regulation, we have investigated whether this is occurring in HaCaT cultured in SFM. Either epidermal growth factor (EGF) or insulin-like growth factor-1 (IGF-I) was effective and dose-dependently stimulated HaCaT replication. The ability of these keratinocytes to express EGF and IGF-I and their receptors was investigated by northern blot and reverse transcriptase-polymerase chain reaction (RT-PCR). We report that HaCaT cells synthesize mRNAs for IGF-I, IGF-II, IGF-IR and EGF-R but not EGF mRNA. Immunoneutralization of IGF-I with specific monoclonal antibodies blocked spontaneous HaCaT proliferation in SFM, as did incubation with antibodies against IGF-IR. These data demonstrate that an autocrine/paracrine loop based on IGF-I may allow HaCaT keratinocytes to proliferate autonomously in culture in contrast to keratinocytes in primary culture. A similar mechanism may be involved in the development of hyperproliferative diseases of human skin and its functional disruption may represent the target for therapeutic approaches.

Moexipril and quinapril inhibition of tissue angiotensin-converting enzyme activity in the rat: evidence for direct effects in heart, lung and kidney and stimulation of prostacyclin generation.

The activation of angiotensin converting enzyme (ACE) may contribute to the development of vascular and myocardial structural changes. The level of ACE is stable in human plasma, and only limited data are available on its regulation at the tissue level. The aim of this study was to characterize the effects of two ACE inhibitors, moexipril and quinapril on tissue ACE activity. Adult male rats were treated intragastrically once daily for 6 days either with 2 mg/kg moexipril or quinapril. After single treatment, moexipril and quinapril effectively inhibited ACE activity in plasma and slightly in heart and aorta, whereas after 6 days of treatment they inhibited ACE activity in plasma (87% and 94%, respectively), lung (92% and 93%), myocardium (26% and 23%), kidney (21% and 20%), and aorta (39% and 40%), but not in skeletal muscle. Interestingly, the two ACE-inhibitors also induced a significant increase in cardiac homogenates of 6-keto-PGF1alpha levels, an important index of PGI2 generation. To test whether the reduced effects of ACE inhibitors in heart and kidney were caused by a limited availability of the drugs, 100 microl of lung, heart and kidney homogenates from control rats were incubated in vitro with moexipril and quinapril immediately before assay. Both drugs were more effective in lung than heart and kidney homogenates, with inhibition values superimposable to those obtained in vivo. These results clearly indicate that inhibition of tissue ACE activity does not depend primarily on the availability of ACE inhibitors in each organ.

Ghrelin protects against ethanol-induced gastric ulcers in rats: studies on the mechanisms of action.

Ghrelin, the endogenous ligand for GH secretagogue receptors, has been reported to influence acid gastric secretion and motility, but its potential gastroprotective effect is unknown. The aims of this study were 1) to examine the effects of central and peripheral administration of ghrelin on ethanol-induced gastric ulcers in conscious rats, and 2) to investigate the possible roles of nitric oxide (NO), vagal nerve, and sensory fibers in the gastric effects of ghrelin. Ghrelin was administered either intracerebroventricularly or sc 30 min before ethanol, and mucosal lesions were examined macroscopically. Additionally, rats were either treated with the inhibitor of NO synthesis N(omega)-nitro-L-arginine methyl ester (L-NAME) or underwent bilateral cervical vagotomy or capsaicin-induced sensory denervation. Conventional histology and immunohistochemistry for ghrelin, gastrin, and somatostatin were performed on gastric specimens from representative rats. Central ghrelin (4-4,000 ng/rat) dose-dependently reduced ethanol-induced gastric ulcers by 39-77%. Subcutaneous ghrelin administration (80 micro g/kg) reduced ulcer depth only. L-NAME and capsaicin, but not vagotomy, prevented the gastroprotective effect of central ghrelin (4000 ng/rat). This is the first evidence that ghrelin exerts a potent central gastroprotective activity against ethanol-induced lesions. The gastroprotective effect of ghrelin is mediated by endogenous NO release and requires the integrity of sensory nerve fibers.

EP1572: a novel peptido-mimetic GH secretagogue with potent and selective GH-releasing activity in man.

EP1572 UMV1843 [Aib-DTrp-DgTrp-CHO]) is a new peptido-mimetic GH secretagogue (GHS) showing binding potency to the GHS-receptor in animal and human tissues similar to that of ghrelin and peptidyl GHS. EP1572 induces marked GH increase after s.c. administration in neonatal rats. Preliminary data in 2 normal young men show that: 1) acute i.v. EP1572 administration (1.0 microg/kg) induces strong and selective increase of GH levels; 2) single oral EP1572 administration strongly and reproducibly increases GH levels even after a dose as low as 0.06 mg/kg. Thus, EP1572 is a new peptido-mimetic GHS with potent and selective GH-releasing activity.