Catestatin, vasostatin, cortisol, and visual analog scale scoring for stress assessment in healthy dogs.

The neuroendocrine glycoprotein chromogranin A is a useful biomarker for stress in humans. Chromogranin A epitopes catestatin and vasostatin can be measured in dogs using radioimmunoassays. The objective of this study was to evaluate catestatin and vasostatin as canine stress biomarkers in a clinical setting. Blood and saliva were collected from 33 healthy dogs that were familiar with sampling procedures and the animal hospital environment (control group) and 30 healthy dogs that were unacquainted (stress group). During sampling, stress behavior was scored by the same observer using visual analog scale (VAS). Plasma was analyzed for catestatin and vasostatin, serum for cortisol, and saliva for catestatin. Differences between groups were analyzed using two-sample t-tests and P<0.05 was considered significant. Stress behavior VAS score in the control group was significantly lower than in the stress group during blood (P=0.002) and saliva (P=0.0009) sampling. Serum cortisol and saliva catestatin concentrations in the stress group were higher than the control group (P=0.003 and P<0.0001, respectively). Serum cortisol concentrations were correlated with those of saliva (r=0.34, P=0.04) and plasma catestatin (r=0.29, P=0.03). Plasma catestatin and vasostatin did not differ significantly between groups. In conclusion, concentrations of saliva catestatin, and serum cortisol, and stress behavior VAS scores were significantly higher in the stress group. The results indicate that saliva catestatin may be useful as a biomarker for acute psychological stress in dogs.

Bone metabolism markers in adolescent girls with eating disorders and weight loss: effects of growth, weight trend, developmental and menstrual status.

UNLABELLED: Serum concentrations of osteocalcin (OC) decrease and those of C-terminal telopeptide of type 1 collagen (CTX) increase during weight loss in adolescent girls with eating disorders (ED). The impact of weight loss on bone metabolism markers is greatest in premenarcheal girls. INTRODUCTION: Adolescents with ED stand a risk of not reaching optimal peak bone mass and develop osteoporosis. Previous investigations are contradictory as to how markers of bone formation and resorption change during weight loss and nutritional rehabilitation. METHODS: Serum OC and CTX were measured at assessment of 461 adolescent girls with ED and during treatment of 55 girls with anorexia nervosa. Bone metabolism was related to weight, weight change and growth rate. RESULTS: At assessment, OC concentrations were positively correlated with growth rate and inversely with age and (rate of) weight loss. Growth rate was the only predictor of CTX concentrations in premenarcheal girls. In postmenarcheal girls, CTX concentrations were inversely correlated with age and rate of weight loss. During weight gain, there was an increase of OC concentrations. CTX concentrations decreased at the onset of weight gain and increased when near normal weight was reached. CONCLUSIONS: Bone formation markers decrease and resorption markers increase during weight loss. The effects are independent of menstrual status but the impact on bone formation markers is greater in young, premenarcheal girls. Markers are normalised during weight gain but it is conceivable that repeated and/or prolonged weight loss in adolescents reduces peak bone mass.

Somatostatin receptors are strongly expressed in palmoplantar sweat glands and ducts: studies of normal and palmoplantar pustulosis skin.

BACKGROUND: The acrosyringium is the target for inflammation in the chronic and intensely inflammatory skin disease palmoplantar pustulosis (PPP). The sweat-gland apparatus seems to be an immunocompetent structure that probably contributes to skin defence. Furthermore, the sweat gland and duct may be a hitherto unrecognized neuroendocrine organ. AIM: To obtain further information about the neuroendocrine properties of the sweat-gland apparatus by examining expression of the somatostatin receptors (SSTRs) 1-5 in healthy palmar skin and in PPP skin. METHODS: Biopsy specimens were taken from 25 patients with PPP and 25 healthy controls. Immunohistochemical analysis was used to investigate expression of SSTRs 1-5. RESULTS: SSTRs 1-5 were expressed in both epidermal and endothelial structures. The staining intensity of the sweat-gland apparatus was more pronounced than that of the epidermis. Expression differed significantly between lesional PPP and normal plantar skin, with increased expression of SSTRs 3 and 4 in ducts in epidermis, and decreased expression of SSTR 1 in ducts in both papillary and reticular dermis. In specimens with pronounced inflammation, numerous dendritic cells with strong expression of SSTRs 1, 2 and 4 were seen, especially in the papillary dermis. CONCLUSIONS: The presence of SSTRs in palmoplantar skin, and specifically at high density in the sweat glands and ducts, might be of particular importance in skin neuroimmunoendocrinology. Although the relevance of the changes in SSTR expression in PPP skin compared with normal skin is unclear, our hypothesis is that these differences might influence the function of both the neuroendocrine and neuroimmunological properties of palmoplantar skin, especially in the sweat-gland apparatus.

Normal growth hormone secretion in overweight young adults with Down syndrome.

Down syndrome (DS) is associated with short stature and obesity. Adults with DS have several features in common with growth hormone (GH) deficient adult subjects. The aim of this study was to investigate GH secretion in young adults with DS and its relation to body composition as well as glucose and lipid metabolism. Ten young adults with DS (aged 24-32 years; 5 F) and ten controls matched for age and sex were examined regarding spontaneous nocturnal GH secretion and body composition. Stable isotope tracers were used to study glucose and lipid metabolism in the DS subjects. There was no difference in secretion of GH between the DS subjects and controls. The DS subjects had a higher BMI, fat mass proportion and HOMA (homeostasis model assessment) index compared with the controls. The rates of production of glucose and glycerol (reflecting lipolysis) in the DS subjects were increased (15.5+/-5.07 and 3.5+/-1.68 micromol/kg/min, respectively). The DS subjects showed normal GH secretion despite increased BMI and fat mass. The increased HOMA index and high rate of glucose production indicate peripheral and hepatic insulin resistance in adult DS subjects.

The importance of chromogranin A in the development and function of endocrine pancreas.

BACKGROUND: Chromogranin (Cg) A is expressed in neuroendocrine and neuronal tissues. It is involved in the generation of secretory granules and is cleaved to form biologically active peptides. Targeted ablation of the Chga gene resulted in increased plasma catecholamines, high blood pressure, and decreased size and number of adrenal medullary chromaffin granules. The aim of this study was to determine whether Chga null mice display changes in the morphology and function of the endocrine pancreas. MATERIALS AND METHODS: Sections of pancreata from Chga-/-, Chga+/- and Chga+/+ mice, were immunostained with antibodies against synaptophysin, CgA, CgB, secretogranin II and the four major pancreatic islet hormones. Plasma was analysed for glucose, insulin, glucagon, somatostatin and pancreatic polypeptide (PP). RESULTS: CgA epitopes were undetectable in the islets of Chga-/- animals. CgB and secretogranin II epitopes were expressed in the islets of all animal groups albeit with decreased expression in Chga-/- islets. The islet number and size were decreased in the Chga-/- animals compared with Chga+/+. The proportion of insulin cells was decreased but somatostatin and PP cells were increased in Chga-/- mice compared to Chga+/+ mice. The nuclear size was decreased in insulin cells and increased in somatostatin cells in Chga-/- mice. Plasma insulin level was markedly decreased in the Chga-/- mice although fasting plasma glucose and glucagon were normal. CONCLUSION: Ablation of the Chga gene affected the islet volume, the composition, distribution and nuclear size of islet cell types and plasma insulin concentration. Our data indicate decreased insulin cell function and increased glucagon cell function. Our study shows that CgA exerts a significant influence on the endocrine pancreas with importance in maintaining islet volume, cellular composition and function.

Immunohistochemical staining of human islet cells with region-specific antibodies against secretogranins II and III.

Chromogranins and secretogranins belong to the granin family of proteins, which are expressed in neuroendocrine and nervous tissue. In earlier publications we have described the development of region-specific antibodies against CgA and CgB. In this study we describe antibodies to SgII and SgIII and their usefulness for immunohistochemical staining. Peptides homologous to defined parts of secretogranins II and III were selected and synthesized. Antibodies were raised and immunostainings were performed on normal human pancreas. The SgII 154-165 (N-terminal secretoneurin), SgII 172-186 (C-terminal secretoneurin) and SgIII antibodies immunostained all insulin-immunoreactive cells, most of the glucagon cells and some of the pancreatic polypeptide cells. The SgII 225-242 antibody immunostained only the insulin-containing cells. None of the antibodies immunostained the somatostatin cells. This study is the first observation of the expression of SgIII in human tissues, where we show expression of SgIII in three of the four major islet cell types in human pancreas.

Regulation of insulin and glucagon secretion from rat pancreatic islets in vitro by somatostatin analogues.

Somatostatin is an inhibitor of hormone secretion through specific receptors (sst1-5). The aim of this study was to investigate the putative regulatory role of somatostatin analogues on the secretion of insulin and glucagon by rat pancreatic islets. After 48 h exposure only the non-selective agonists (somatostatin, octreotide and SOM-230) inhibited insulin accumulation. The inhibition of insulin secretion was accompanied by increased islet insulin contents. None of the analogues showed a consistent effect on the glucagon accumulation in the medium after 48 h. Since we observed a difference in the regulatory effect between the non-selective and selective analogues, combinations of selective analogues were studied. Combination of sst2+sst5 agonists inhibited the medium insulin accumulation, while combination of sst1+sst2 analogues caused a decrease in glucagon accumulation. After removal of somatostatin a rebound effect with increased insulin secretion were observed. This effect was reversed after 6 h. For SOM-230 insulin secretion continued to be suppressed even after the analogue was removed and returned to control values after 3 h. As for glucagon secretion there was an initial decline after culture with octreotide, while the other substances failed to induce any changes. In summary, non-selective somatostatin analogues or combinations of receptor selective analogues may cause inhibition of hormone secretion from rat pancreatic islets. For insulin and glucagon, combinations of sst2+sst5 and sst1+sst2, respectively may exert this effects. Thus, our data suggest that more than one sst must be involved to down-regulate islet glucagon and insulin secretion.

Somatostatin receptor subtypes mediate contractility on human colonic smooth muscle cells.

This study demonstrates the expression of functional somatostatin receptor (sstr) subtypes in human circular and longitudinal colonic smooth muscle cells (SMC). Native somatostatin (SS) and sstr subtype-specific analogues were used to characterize the sstr subtypes present in both cell types by contraction/relaxation studies. Qualitative and quantitative mRNA analysis and immunohistochemistry of sstr subtypes were also carried out. sstr subtype 2 mRNA was expressed in circular SMC, and various levels of subtypes 1, 2 and 3 mRNA were expressed in longitudinal colonic SMC. Native SS and each subtype-specific analogue exerted a modest, but significant, contraction, although inhibition of carbachol-induced contraction (relaxation) was the main effect on SMC from both layers. CH-288, a sstr subtype 1-specific analogue, and octreotide, a sstr subtype 2-specific analogue, were the most effective relaxant analogues on longitudinal and circular SMC, respectively. sstr subtypes display a distinct expression pattern on human colonic SMC; on circular SMC, subtype 2 is the only sstr, whereas sstr subtypes 1, 2 and 3 are expressed on human SMC isolated from the longitudinal layer. The contractile effects of SS are mediated through sstr subtype 2 and sstr subtype 1 on circular and longitudinal human colonic SMC, respectively.

Decreased maternal lipolysis in intrauterine growth restriction in the third trimester.

OBJECTIVE: Intrauterine growth restriction (IUGR) is a common complication of pregnancy. There are many possible aetiologic factors of maternal, placental and/or fetal origin. Often there is no known explanation. The aim of this study was to investigate whether a reduction in maternal energy substrate production could be one of the factors involved in IUGR. DESIGN: Measurement of maternal energy substrate production and glucoregulatory hormones in women with growth-restricted fetuses. SETTINGS: University Hospital, Uppsala, Sweden. POPULATION: Ten healthy pregnant women with IUGR were compared with eight recently reported healthy women with normal pregnancies. The women were studied at 35.4+/-1.6 weeks of gestation after an overnight fast. METHODS: Rates of glycerol and glucose production were analysed by gas chromatography/mass spectrometry following constant-rate infusion of [1,1,2,3,3-(2)H5]glycerol and [6,6-(2)H2]glucose. MAIN OUTCOME MEASURE: Third trimester glycerol and glucose production. RESULTS: Glycerol production, reflecting lipolysis, was lower in the women with IUGR than in those with normal pregnancies, 2.36+/-0.58 versus 3.06+/-0.66 micromol kg-1 minute-1 (P=0.033), whereas there was no difference in rate of glucose production (glucose production rate [GPR]), 12.1+/-1.5 versus 13.2+/-1.5 micromol kg-1 minute-1 (P=0.23). Plasma glycerol levels were increased in the women with IUGR (P=0.008). CONCLUSIONS: Lipolysis is lower in pregnancies complicated by IUGR as compared with normal pregnancies. Increased lipolysis during pregnancy provides substrate for maternal energy metabolism, which spares glucose for the fetus. A reduced maternal production of energy substrate could be one of several factors underlying IUGR. A lack of relationship between insulin levels and either lipolysis or GPR suggests defective regulation of energy substrate production in this group of pregnant women.

Octreotide scintigraphy and Chromogranin A do not predict clinical response in patients with octreotide acetate-treated hormone-refractory prostate cancer.

In this pilot study, the predictive value of Octreotide scintigraphy (Octreoscan) and/or Chromogranin-A (CgA) was investigated in patients with hormone-refractory prostate cancer treated with Octreotide acetate. In total, 20 patients with progressive disease and bone metastases entered the trial. At baseline Octreoscan, CgA, PSA, alkaline phosphates (ALP) and two self-administered questionnaires (EORTC QLQ C-30 (v3) and brief pain index) were performed and a diary of the pharmaceutical was started. The treatment consisted of Octreotide (Sandostatin LAR) acetate 30 mg intramuscular injection every month. The blood samples and questionnaires were repeated every month until 3 months. Clinical responder was defined as a patient with increased global health score more than 10 units and stable or decreased pain score without an increase in analgesic. In all, 17 patients were treated per protocol, and four were assessed as clinical responders. Six patients developed a reduction in ALP (median -26%, range -5 to -78%). All patients increased in PSA. At baseline, three patients had a negative Octreoscan and the patients with positive lesions, demonstrated uptake of low intensity. At baseline the CgA was elevated above the normal range in 15 of the patients, and during treatment five patients decreased their CgA to the normal range. Neither baseline Octreoscan nor CgA could identify the clinical reponders. A minority of patients improves their health-related quality of life. The decrease and normalization of CgA levels in five patients during therapy indicates therapeutic activity but Octreoscan and CgA could not identify clinical responders.

Expression of somatostatin receptor subtypes 1-5 in pancreatic islets of normoglycaemic and diabetic NOD mice.

OBJECTIVE: Somatostatin acts on five specific receptors (sst1-5) to elicit different biological functions. The non-obese diabetic (NOD) mouse is an experimental model of type 1 diabetes. The aim of this study was to investigate whether the islet expression of sst1-5 is affected during the development of diabetes in NOD mice, with insulitis accompanied by spontaneous hyperglycaemia. METHODS: By immunostaining for sst1-5 the expression and co-expression together with the four major islet hormones in pancreatic islets were investigated in female and male NOD mice at different stages of disease. The NOD related non-diabetic ICR mouse was also examined. RESULTS: The islet cells of diabetic NOD mice showed an increased islet cell expression of sst2-5 compared with normoglycaemic female NOD mice. This correlated to increasing age and extent of insulitis. Major findings from the co-expression investigations were that sst2 was expressed in a majority of beta-cells in the normoglycaemic NOD mice, but absent in the beta-cells in the diabetic NOD mice. A majority of the alpha-cells expressed sst2 and 5 in normoglycaemic and diabetic NOD mice. About 60% of delta-cells showed co-expression of sst4 and 5 in both normoglycaemic and diabetic NOD mice. 60% of pancreatic polypeptide (PP)-cells expressed sst4 in both groups. Insulitis was found to be accompanied by a down-regulation of sst in normoglycaemic animals. CONCLUSIONS: The difference in sst expression in the islets cells of diabetic mice may suggest either a contributing factor in the process leading to diabetes, or a defence response against ongoing beta-cell destruction.

Impaired cholecystokinin secretion and disturbed appetite regulation in women with polycystic ovary syndrome.

Increased amount of abdominal fat and obesity are common in polycystic ovary syndrome (PCOS). A higher prevalence of bulimia nervosa and greater cravings for sweets have also been reported in these patients. The present study aimed to compare meal-related appetite and secretion of the 'satiety peptide' cholecystokinin (CCK) and glucose regulatory hormones in PCOS women and controls. Sixteen pairs of women with PCOS and controls matched for age and body mass index participated in the study. After an overnight fast, blood samples were collected during ingestion of a standardized meal. We determined basal and postprandial blood levels of CCK, insulin, C-peptide, glucagon, cortisol, growth hormone and glucose. Self-ratings of appetite were assessed by a visual analog scale. PCOS women had a significantly lower meal-related CCK response (p < 0.05) with no association with satiety, as in the controls (r = 0.64). There was a tendency to higher ratings of craving for sweets in PCOS women (p = 0.07) but no correlation with insulin, as in the controls (r = 0.50). Within the PCOS group, ratings of craving for sweets were inversely related to testosterone (r = - 0.60) and the CCK response was positively correlated with levels of free testosterone (r = 0.50). We conclude that women with PCOS have reduced postprandial CCK secretion and deranged appetite regulation associated with increased levels of testosterone. Impaired CCK secretion may play a role in the greater frequency of binge eating and overweight in women with PCOS.

Differential secretion of gonadotrophins: investigation of the role of secretogranin II and chromogranin A in the release of LH and FSH in LbetaT2 cells.

This study investigated the role of the secretory granule proteins, secretogranin II (SgII) and chromogranin A (CgA), in the differential secretion of FSH and LH from LbetaT2 mouse gonadotroph cells. Exogenous activin, which synergises with GnRH, is essential for the release of FSH from these cells, but also has stimulatory effects on LH and enhances GnRH-induced LH secretion. Two experiments are reported. In experiment 1, cultures were supplemented with activin (0-50 ng/ml), with and without a daily 1 h treatment of 10 nM GnRH, for 3 days. Protein secretion and mRNA levels were measured. In experiment 2, cells were treated with activin (50 ng/ml) alone, a daily 1 h treatment of 10 nM GnRH, or a combination of both for 6 days. In addition, cells exposed to activin+GnRH for 3 days were subsequently left untreated or given activin or GnRH alone for a further 3 days for comparison with cells maintained in activin+GnRH for 6 days. Protein secretion, intracellular protein and mRNA levels were measured. FSH secretion was stimulated, dose dependently, by activin and this effect increased synergistically in the presence of GnRH. The close correlation between secreted and intracellular FSH and FSHbeta mRNA levels was maintained in cells that had undergone treatment withdrawal after previous exposure to activin+GnRH, but there was no correlation between FSH and the granins. These results are consistent with the view that FSH released in response to activin/GnRH is constitutively secreted via a granin-independent pathway. SgII secretion mirrored the GnRH-induced secretion of LH, but was unaffected by activin, which stimulated LH secretion and had a detrimental effect on CgA mRNA transcription. This confirms previous observations that the LH released in response to GnRH is co-released with SgII via a regulated, granin-dependent pathway, and, in addition, suggests that activin may stimulate LH secretion through a constitutive, granin-independent pathway.

Low utilisation of unactivated protein C in a patient with meningococcal septic shock and disseminated intravascular coagulation.

BACKGROUND: Activated protein C has recently been shown in a multicentre trial to significantly reduce mortality in patients with septic shock. There are also some case reports and minor studies demonstrating promising results with the unactivated form of protein C. However, in children with severe meningococcal infection, skin biopsies have demonstrated low expression of endothelial thrombomodulin and protein C receptors, suggesting low protein C activation capacity in severe meningococcal sepsis. METHODS: A patient with meningococcal septic shock was treated with two doses of the unactivated form of protein C, the first during intense activation of the coagulation system and the second during a phase of low grade or no activation. Repeated plasma samples were analysed for protein C concentration, which made it possible to compare pharmacokinetics and half-lives of the two administrations. A shorter half-life during intense coagulation was expected if there was an activation and consumption of the protein C administered. RESULTS: The calculated half-lives of protein C during intense and low grade activation were 32 h and 19 h, respectively, a magnitude similar to that reported in protein C-deficient patients without infection. CONCLUSION: The result indicates that whole body utilisation of the unactivated protein C was low. Endothelial impairment of protein C activation does not seem to be restricted to the skin vessels only.

A comparison between three commercial kits for chromogranin A measurements.

Chromogranin (CgA) has been shown to be an excellent marker for neuroendocrine tumours. There are now three commercial assays on the market. We wanted to compare the usefulness of the different kits in a clinical situation. We have thus measured CgA in 77 patients and compared the results from the different methods. CgA was measured with three different commercial kits according to the recommendations from the manufacturers (CGA-RIA CT; CIS bio international, Gif-sur-Yvette cedex, France, DAKO Chromogranin A ELISA kit; DAKO A/S, Glostrup, Denmark and CgA; EuroDiagnostica, Malmö, Sweden). The sensitivity and specificity differed between the different kits. The CIS kit showed a sensitivity of 67% and a specificity of 96%. The sensitivity and specificity were both 85% for the DAKO kit and 93% and 88% respectively for the EuroDiagnostica assay. We have concluded that CgA is an important tumour marker for all neuroendocrine tumours. However, different analytical properties of the respective kits give different performances, a fact that must be taken into consideration when comparing results from different clinical studies. A recognised international standard for CgA would be a step on the way to harmonisation, but antibody selection and construction of the assays will probably still influence the results.

Ratio between serum IL-8 and pepsinogen A/C: a marker for atrophic body gastritis.

BACKGROUND AND AIMS: Elevated serum gastrin and a low pepsinogen A/C ratio are well-recognized markers for atrophic body gastritis (ABG). We have shown that the presence of body atrophy is also associated with elevated serum pro-inflammatory cytokines. This study tested the hypothesis that serum cytokines provide additional information to gastrin and pepsinogens in screening for ABG. METHODS: Two hundred and twenty-six consecutive patients were investigated on referral for upper gastrointestinal endoscopy: 150 were patients with gastro-oesophageal reflux disease, receiving acid inhibitory medication either with proton pump inhibitors (n = 113) or with histamine2-receptor antagonists (n = 37), and 76 were nontreated controls, who had normal endoscopic findings. Gastric mucosal biopsies were sampled for histological examination (Sydney classification). Serum samples were analyzed for gastrin, chromogranin A (CgA), and pepsinogens A and C by RIA, and for the interleukins (IL)-1beta, IL-6, and IL-8 by ELISA. RESULTS: Subjects with ABG had significantly higher serum gastrin (P < 0.01) and serum CgA (P < 0.01) levels and significantly lower pepsinogen A/C ratios (P < 0.001) than those without ABG. Additionally, serum IL-1beta, IL-6 and, especially, IL-8 levels were significantly higher in the subjects with than in those without ABG (P < 0.0001, for all cytokines). To optimize the detection of body atrophy we defined the ABG index: the ratio between the simultaneously measured IL-8 and pepsinogen A/C. The area under the ROC curve for the ABG index was significantly greater than that for serum gastrin and for serum pepsinogen A/C alone (0.91 +/- 0.029 vs. 0.72 +/- 0.042, and vs. 0.83 +/- 0.031, P = 0.018 and P = 0.049). Using the ABG index at a cut-off value of 1.8 pg mL-1, 91% of the cases were classified correctly. CONCLUSIONS: The ratio between serum IL-8 and pepsinogen A/C accurately predicts the presence of ABG. We therefore propose the ABG index as a noninvasive screening test for ABG in population-based studies.

The impact of testicular and accessory sex gland function on sperm chromatin integrity as assessed by the sperm chromatin structure assay (SCSA).

BACKGROUND: The sperm chromatin structure assay (SCSA) provides an objective assessment of sperm chromatin integrity, which is essential for normal sperm function. SCSA is valuable as a fertility marker in epidemiological studies and in the clinical situation. Little is known about the impact of testicular and post-testicular function on SCSA parameters. METHODS: Ejaculates from 278 military conscripts of median age 18.1 (range 18-21) years were included. Levels of reproductive hormones, the length of the CAG repeat of the androgen receptor gene, sperm concentration, abstinence period and biochemical parameters of epididymal and accessory sex gland secretions were correlated to the SCSA parameters, DNA fragmentation index (DFI) and highly DNA stainable (HDS) cells. RESULTS: Negative correlations were found between sperm concentration and DFI (r = -0.119, P = 0.049) and HDS (r = -0.513, P < 0.0001). DFI was negatively correlated with levels of estradiol (r = -0.19, P = 0.002) and free testosterone (r = -0.13, P = 0.03). DFI also correlated positively with abstinence time (r = 0.17, P = 0.005), and with seminal concentrations of fructose (r = 0.18, P = 0.004) and zinc (r = 0.12, P = 0.04). CONCLUSIONS: Sex steroid production, spermatogenic function, abstinence time and seminal vesicle function appear to impact on sperm chromatin integrity and thereby on sperm fertilizing capacity. These findings may improve present understanding of the pathophysiology of male infertility.

Influence of steroids and GnRH on biosynthesis and secretion of secretogranin II and chromogranin A in relation to LH release in LbetaT2 gonadotroph cells.

The granin proteins secretogranin II (SgII) and chromogranin A (CgA) are commonly found associated with LH and/or FSH within specialised secretory granules in gonadotroph cells, and it is possible that they play an important role in the differential secretion of the gonadotrophins. In this study we have examined the regulation of the biosynthesis and secretion of SgII and CgA, in relation to LH secretion, in the LbetaT2 mouse pituitary gonadotroph cell line. Three experiments were carried out to investigate the effects of oestradiol (E2) and dexamethasone (Dex) in the presence and absence of GnRH (experiment 1), differing GnRH concentrations (experiment 2) and alterations in GnRH pulse frequency (experiment 3). In experiment 1, exposure to E2, Dex or E2+Dex, either with or without GnRH treatment, resulted in increased LH secretion. Steroids alone had no effect on LHbeta mRNA levels, but in the presence of GnRH LHbeta mRNA levels were increased in Dex- and E2+Dex-treated cells. GnRH receptor (GnRH-R) mRNA levels were up-regulated by Dex and E2+Dex, but were unaffected by GnRH. There were no steroid-induced changes in SgII or CgA mRNA, but increased levels of CgA mRNA were observed after GnRH treatment in cells cultured in the presence of Dex. In experiment 2, increasing concentrations of GnRH resulted in increases in LH secretion that were inversely dose-dependent. No changes in LHbeta, GnRH-R or SgII mRNA levels were observed, but there were dose-dependent increases in CgA mRNA levels. In experiment 3, GnRH was given as either 1 pulse/day or 4 pulses/day for 3 days. Both pulse regimes resulted in increased LH, SgII and CgA secretion compared with controls during the first 15 min pulse on day 3. Exposure to GnRH at 4 pulses/day increased LH and SgII secretion compared with controls during all 4 pulses, but secretion of both proteins was reduced during pulses 2-4 compared with pulse 1. CgA secretion also increased due to GnRH in pulse 1, but was decreased by GnRH treatment during pulse 2, and unchanged by GnRH during pulses 3 and 4. Total daily secretion of LH and SgII from cells given 1 pulse/day of GnRH increased compared with controls on all three treatment days, while total CgA secretion increased in response to GnRH on days 2 and 3 only. Intracellular levels of SgII, but not LH, decreased after GnRH treatment. In contrast, intracellular CgA was increased, but only after 4 pulses/day of GnRH. Levels of LHbeta, but not SgII, mRNA were increased by both pulse regimes, while CgA mRNA levels increased after 1 pulse/day of GnRH. These results indicate that there is a close correlation between the GnRH-stimulated release of LH and SgII from LbetaT2 cells, suggesting that SgII may have an influential role in the regulated secretion of LH, possibly by inducing LH aggregation to facilitate trafficking into secretory granules. CgA secretion does not appear to be closely associated with that of LH, but CgA expression does appear to be regulated by GnRH, which may indicate involvement in the control of LH secretion, possibly by influencing the proportion of LH in the different types of secretory granules.

Chromogranin A in human neuroendocrine tumors: an immunohistochemical study with region-specific antibodies.

Antibodies to six specific regions of the chromogranin A (CgA) molecule were used to study their immunoreactivity in human neuroendocrine (NE) tumors. Tissue specimens from endocrine pancreatic tumors (n = 14), duodenal carcinoids (n = 2), bronchial carcinoids (n = 5), ileal carcinoids (n = 5) appendix carcinoids (n = 2), medullary thyroid carcinomas (n = 6), parathyroid adenomas (n = 2), and pheochromocytomas (n = 8) were analyzed. The results showed that the NE tumor types expressed varying numbers of CgA fragments. A variation in frequency of the expression of immunoreactive cells was sometimes seen also within the same tumor type. The midportion fragment CgA 176-195 (chromacin) was the only fragment expressed in all tumors. Benign and malignant tumors expressed different patterns, being especially true of insulinomas and pheochromocytomas. These findings suggest that region-specific antibodies to CgA fragments can be used as a diagnostic tool for the characterization of NE tumors.

[Better treatment of heart failure by measurements of natriuretic peptides. There are still remaining problems when it comes to the interpretation of measurement levels]. / Bättre behandling av hjärtsvikt med mätning av natriuretiska peptider. Tolkningen av mätvärdena bereder dock fortfarande problem.

The heart is increasingly being recognised as a major endocrine organ involved in haemodynamic homeostasis. Natriuretic peptides, i.e. atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), affect renal, adrenal and central nervous system functions as well as vessel tonus and permeability thus causing decreased preload and afterload. Natriuretic peptides, BNP in particular, are independent risk factors for morbidity and mortality. They also have high negative predictive values for cardiac insufficiency indicating high diagnostic sensitivity for heart failure in outpatient practice. Monitoring of therapy for heart failure may be improved if BNP measurement is used in conjunction with clinical assessment. However, several problems remain to be solved, such as optimal decision limits in relation to sex and age for the assessment of heart failure.