Recent development of determination methods for adrenocortical hormones and catecholamines

Newly developed resins and high-performance liquid chromatography (HPLC) with column switching technique have enabled on-line solid-phase extraction, purification and derivatization for highly sensitive determination in recently developed determination methods for serum cortisol, urinary 17-ketosteroids (17-KS), urinary conjugated 17-KS fractions and urinary free catecholamines (CA). These methods are (1) determination of serum cortisol by HPLC with a BSA-ODS column (TSK) and serum sample direct injection, (2) determination of fluorescently derivatized serum cortisol with sulfuric acid and ethanol by column switching HPLC, (3) determination of urinary 17-KS with no need of previous hydrolysis of the conjugated forms, (4) HPLC of conjugated 17-KS fluorescently prelabelled with dansyl hydrazine, (5) HPLC of urinary free catecholamines (CA) with on-line extraction using a cation exchange column and on-line fluorescent derivatization with 1,2-diphenylethylenediamine, (6) ion pair HPLC of urinary free CA with on-line extraction using a hard boric acid gel column and postcolumn trihydroxyindole derivatization, and (7) HPLC of urinary free CA with on-line extraction and solid-phase derivatization using a boric acid gel column, o-phthalaldehyde and 2-mercaptoethanol, have achieved no previous or simple sample extraction, more rapid, accurate and higher sensitive determination comparison with ordinary methods for these substances and furthermore, some methods have enabled fully automated analysis.     

Biochemistry and physiology of anabolic hormones used for improvement of meat production

A number of hormones are involved in endocrine regulation of growth. In general, these hormones enhance body protein accretion and metabolise fat stores resulting in increased lean growth rates. Most practical importance was obtained by sex hormones (oestrogens and androgens), beta-agonists and growth hormone - whether legally or illegally. Efficiency of growth promotion ranges between 0% and +20% depending on the prerequisites such as species, breed, gender, age, reproductive status, body score or feeding of the animals. Oestrogens and androgens mediate their activity via intracellular receptors - directly in muscular tissue as well as indirectly via stimulation of growth hormone from the hypophysis and other growth factors from liver plus several further organs. In addition, mineral absorption in the gut is improved. The outstanding efficiency of trenbolone is based on its androgenic plus antiglucocorticoid activity. Melengestrolacetate is thought to act indirectly via stimulation of endogenous ovarian oestradiol in non-pregnant heifers. The necessary dosages and residue formations depend on the pharmacokinetic parameters of each substance and extrapolations between compounds are hardly possible. Growth hormone and beta2-agonists use independent pathways for growth promotion not related to steroid biochemistry.     

On the centennial of hormones. A tribute to Ernest H. Starling and William M. Bayliss

Ernest H. Starling introduced the term hormone 100 years ago in his Croonian Lectures to the Royal College of Physicians in June 1905. It was demonstrated for the first time that one part of the body could influence the function of another distant part. Starling for the first time suggested the word hormone. This review attempts to trace the development of studies in endocrinology, beginning in the middle of the nineteenth century. Starling discovered secretin, the first hormone, in collaboration with William M. Bayliss, and they introduced the hormone concept with recognition of chemical regulation. Thus the name hormone sparked multidisciplinary research in endocrinology and molecular biology, which shed light on the chemical communication within the organism.     

Correlation between plasma and saliva adrenocortical hormones in response to submaximal exercise

This study examined the relationships between plasma and saliva adrenocortical hormones in response to long-duration submaximal exercise. In nine healthy, physically active, female volunteers, blood and saliva samples were taken at rest and every 30 min during a 120-min cycling trial at 50–55% VO_2max for cortisol and dehydroepiandrosterone (DHEA) analysis. Correlation analysis revealed a moderate but significant relationship between plasma and saliva cortisol (r = 0.35, P < 0.02) and plasma and saliva DHEA (r = 0.47, P < 0.001) during the submaximal exercise. When expressed in percent of resting values, the correlations between the plasma and saliva concentrations were higher for both hormones during the exercise (cortisol: r = 0.72; DHEA: r = 0.68, P < 0.001). The results thus suggest that, even under prolonged exercise conditions, non-invasive saliva samples may offer a practical approach to assessing pituitary–adrenal function, especially when compared with individual basal values.     

Comparison of thymocyte and T lymphocyte gangliosides from C3H/HeN and C3H/HeJ mice

Gangliosides have been prepared from resting murine thymocytes and splenic T cells. Profoundly different two-dimensional thin layer chromatography (2D TLC) patterns were observed between these two cell types. Thymocytes contained 28-30 discrete gangliosides of which eight represented major gangliosides. Splenic T lymphocytes from both strains had much simpler patterns, with six to seven major gangliosides and 12-13 minor gangliosides. Computerized analysis of the thymocyte ganglioside patterns between LPS-responder C3H/HeN mice and lipopolysaccharide (LPS)-hyporesponsive C3H/HeJ mice revealed no significant difference in the major gangliosides. However, with splenic T cell gangliosides, there is a striking difference in the relative proportion of three homologous gangliosides between the two strains. Consistent with previous observations on macrophage gangliosides, the ratio of N-acetylneuraminic acid-containing ganglioside to N-glycolylneuraminic acid-containing ganglioside was higher in both thymocytes and T-cells from the LPS-responder strain. These results show that sialic acid-containing glycolipids from thymocytes and T lymphocytes between endotoxin responder and hyporesponder strains manifest small but significant changes. These differences are present in unstimulated cell populations and may represent a manifestation of the Lps gene.     

Immunomodulatory activity of monophosphoryl lipid A in C3H/HeJ and C3H/HeSnJ mice.

Treatment with nontoxic monophosphoryl lipid A (MPL) derived from a polysaccharide-deficient, heptoseless Re mutant of either Salmonella typhimurium or Salmonella minnesota R595 enhanced the immunoglobulin M (IgM) anti-type III pneumococcal polysaccharide (SSS-III) antibody response of C3H/HeSnJ mice. Such an adjuvant effect was not observed in lipopolysaccharide-nonresponder C3H/HeJ mice. Nevertheless, C3H/HeJ spleen cells produced a weak mitogenic response to both preparations of MPL in vitro, and C3H/HeJ mice showed a significant increase in serum IgM levels without an increase in numbers of splenic IgM-secreting plaque-forming cells after in vivo treatment with MPL. A significant increase in serum IgG3 levels was accompanied by a transient decrease in serum IgG1 levels in C3H/HeSnJ mice given MPL; such non-antigen-specific polyclonal effects were not observed in C3H/HeJ or in athymic nu/nu mice. Since the enhanced antibody response to SSS-III has been attributed to the inactivation of suppressor T cells by MPL and since suppressor-T-cell activity is demonstrable in both C3H/HeSnJ and C3H/HeJ mice, these findings imply that (i) the suppressor T cells of C3H/HeJ mice are refractory to inactivation by MPL and (ii) some of the polyclonal and mitogenic effects produced in C3H/HeJ mice are due to the direct action of MPL on B lymphocytes.     

Estrogen-producing adrenocortical carcinoma. A light and electron microscopic study

A case of adrenocortical carcinoma with feminization seen in a man aged 35, is reported. The levels of estron (E1) and estradiol (E2) in the venous blood draining the tumor were high, and it was confirmed by in vitro assay of tumor cells taken from the primary tumor of the left adrenal gland that the tumor produced estrone. The light microscopic examination demonstrated that the primary tumor was composed of mixture of large cells with pleomorphic nuclei and vacuolated cytoplasm and uniform cells with ovoid nuclei and eosinophilic cytoplasm. The electron microscopic examination on the latter cells revealed numerous large and irregularly shaped mitochondria with mostly tubular or lamellar and occasionally vesicular cristae and electron-dense matrix, well-developed smooth-surfaced endoplasmic reticulum in the cytoplasm. However, lipid droplets and lysosomes or lipofuscin granules were scanty. From these findings, it is suggested that cells of the present tumor have characteristics of those in the zona reticularis of the adrenal cortex as well as in the fetal cortex, and the functional property of this tumor is well correlated with its morphological features.     

A meta-analysis of the MTHFR C677T polymorphism and schizophrenia risk.

Epigenetic mechanisms such as methylation of DNA, could lead to abnormal neurodevelopment and may be important in the etiology of schizophrenia. Maternal dietary folate intake may play a role in determining methylation levels. The MTHFR gene C677T polymorphism influences folate metabolism and intracellular availability of folate metabolites for methylation. We carried out a meta-analysis of MTHFR C677T genotype and schizophrenia risk, and found that TT homozygotes had a significantly increased risk, OR 1.48 (1.18-1.86). This supports the hypothesis that folate status is a determinant of schizophrenia risk. Larger studies of this issue are required, together with studies of maternal genotype which could identify whether maternal folate status during pregnancy is important.