Gestational changes in hamster adrenal cortex: Morphometric and ultrastructural stereologic studies

Summary In the hamster, the weight of the adrenal glands increases during the course of gestation, with the highest value at day 5. In comparison to non-pregnant control animals, there were no changes in the volume of the zona glomerulosa (ZG) and zona fasciculata (ZF), while the volume of the zona reticularis (ZR) increased notably. The average volume of ZG-cells rose at day 5 of pregnancy and thereafter gradually decreased to that of control hamsters. A marked drop in the volume of ZF-cells was seen at days 5 and 10 of pregnancy, whereas at day 15 the cells were larger than in controls. At day 5 of pregnancy, a conspicuous increase in the cell volume was found in ZR, followed by lower values at day 10 and again higher than in control hamsters at day 15. The total number of parenchymal cells in hamster adrenal cortex increased at day 10 of gestation, then underwent a marked decrease, reaching the control value at the final day of pregnancy; this drop was mainly due to a reduction in the number of ZF-cells. The changes in the cell volume were paralleled by rather proportional changes in the volume of the mitochondrial compartment and in the quantity of smooth endoplasmic reticulum. The volume of the lipid-droplet compartment significantly rose in the course of gestation in both ZF- and ZR-cells. The cortisol output by adrenal homogenates gradually decreased during pregnancy.Study performed in partial fulfillment of the Ph.D. Thesis of Magdalena Nowak     

Early changes of Cl− efflux and H+ extrusion induced by osmotic stress in Arabidopsis thaliana cells

In various plant materials changes in turgor pressure, following hyper- or hypo-osmotic stress, were associated with the activation or inactivation of the plasma membrane H⁺-ATPase, respectively. To see if the turgor changes might indirectly influence H⁺-ATPase activity by regulating ion fluxes through plasma membrane, we investigated, in cultured cells of Arabidopsis thaliana (L.) Heynh., the early effects of hyper- and hypo-osmotic stress on Cl^? fluxes in comparison, in the case of hyper-osmotic treatment, with its effect on net H⁺ extrusion. The results obtained showed that hyper-osmotic stress (200 mM mannitol) quickly reduced Cl^? efflux (?70%) from cells preloaded with ³⁶C1^? for 18 h. This inhibiting effect was independent of the simultaneous mannitol-induced stimulation of Cl^? influx and rapidly reversible after removal of the hyper-osmotic treatment. The inhibition of Cl^? efflux was associated with a stimulation of net H⁺ extrusion, and these two effects showed the same dependence on the external mannitol concentration. Fusicoccin (FC, 20 µM), which stimulated H⁺ extrusion to about the same extent as 200 mM mannitol, did not affect Cl^? efflux. When cells preloaded with ³⁶C1^? for 18 h in the presence of mannitol (from 25 up to 200 mM) were eluted in a mannitol-free medium an early and strong increase in Cl^? efflux was found. The increase of Cl- efflux was already detectable for a small hypo-osmotic jump (25 mM), and was reduced (?50%) by the anion channel inhibitor A9C (300 µM). These results lead to exclude a direct causal relationship mediated by E_m changes between the effects of osmoticum on Cl^? efflux and net H⁺ extrusion, and favour the view that the changes in turgor pressure induced by hyper/hypo-osmotic stress may respectively induce an early inactivation/activation of stretch-sensitive anion channels.     

The effects of ageing on the morphology and function of the zonae fasciculata and reticularis of the rat adrenal cortex

Summary The morphological counterpart of the well-known age-dependent marked impairment of glucocorticoid secretion of rat adrenals was investigated by use of morphometric techniques. For this purpose 4-, 8-, 16- and 24-month-old rats were studied. Despite the notable lowering of both basal and ACTH-stimulated production of corticosterone by collagenase-dispersed inner adrenocortical cells, ACTH and corticosterone plasma concentrations displayed significant increases with ageing. Zona fasciculata (ZF) and zona reticularis (ZR) showed a notable hypertrophy in aged rats, which was due to rises in both the average volume and number of their parenchymal cells. The hypertrophy of ZF and ZR cells was in turn associated with increase in the volume of the mitochondrial compartment and proliferation of smooth endoplasmic reticulum, i.e., the two organelles involved in steroid-hormone synthesis. All these morphologic changes, conceivably due to the chronic exposure to high levels of circulating ACTH, are interpreted as a response enabling ZF and ZR to compensate for their age-dependent lowering in glucocorticoid secretion. Stereology also demonstrated that ZF and ZR cells underwent a striking age-related lipid-droplet repletion. Lipid droplets are the intracellular stores of cholesterol esters, the obligate precursors of steroid hormones in rats. This finding is in keeping with the contention that the mechanism underlying the age-dependent decline in rat-adrenal glucocorticoid secretion mainly involves impairments of the utilization of intracellular cholesterol previous to its intramitochondrial transformation to pregnenolone.     

Protective effects of cyclosativene on H2O2-induced injury in cultured rat primary cerebral cortex cells

Sesquiterpenes have attracted much interest with respect to their protective effect against oxidative damage that may be the cause of many diseases including several neurodegenerative disorders and cancer. Our previous unpublished work suggested that cyclosativene (CSV), a tetracyclic sesquiterpene, has antioxidant and anticarcinogenic features. However, little is known about the effects of CSV on oxidative stress induced neurotoxicity. We used hydrogen peroxide (H₂O₂) exposure for 6 h to model oxidative stress. Therefore, this experimental design allowed us to explore the neuroprotective potential of CSV in H₂O₂-induced toxicity in new-born rat cerebral cortex cell cultures for the first time. For this aim, MTT and lactate dehydrogenase release assays were carried out to evaluate cytotoxicity. Total antioxidant capacity (TAC) and total oxidative stress (TOS) parameters were used to evaluate oxidative changes. In addition to determining of 8-hydroxy-2-deoxyguanosine (8-OH-dG) levels, the single cell gel electrophoresis (or Comet assay) was also performed for measuring the resistance of neuronal DNA to H₂O₂-induced challenge. Our results showed that survival and TAC levels of the cells decreased, while TOS, 8-OH-dG levels and the mean values of the total scores of cells showing DNA damage (Comet assay) increased in the H₂O₂ alone treated cultures. But pre-treatment of CSV suppressed the cytotoxicity, genotoxicity and oxidative stress which were increased by H₂O₂. On the basis of these observations, it is suggested that CSV as a natural product with an antioxidant capacity in mitigating oxidative injuries in the field of neurodegenerative disorders.     

Subunit composition of the seed globulins of Lupinus albus

The seed globulins separated from Lupinus albus are all oligomeric proteins. Vicilins, i.e. globulins 4,5,6 and 7, and to a minor extent legumins,     

Immunohistochemical Typing of Adenocarcinomas of the Pancreatobiliary System Improves Diagnosis and Prognostic Stratification

MethodsThis was a retrospective observational cohort study on patients with adenocarcinoma of the pancreatobiliary system who underwent diagnostic core needle biopsy or surgical resection at a tertiary referral center. 409 tumor samples were analyzed with up to 27 conventional antibodies used in diagnostic pathology. Immunohistochemical scoring system was the percentage of stained tumor cells. Bioinformatic analysis, internal validation, and survival analysis were performed.ResultsHierarchical clustering and differential expression analysis identified three immunohistochemical tumor types (extrahepatic pancreatobiliary, intestinal, and intrahepatic cholangiocarcinoma) and the discriminant markers between them. Among patients who underwent surgical resection of their primary tumor with curative intent, the intestinal type showed an adjusted hazard ratio of 0.19 for overall survival (95% confidence interval 0.05–0.72; p value = 0.014) compared to the extrahepatic pancreatobiliary type.ConclusionsIntegrative immunohistochemical classification of adenocarcinomas of the pancreatobiliary system results in a characteristic immunohistochemical profile for intrahepatic cholangiocarcinoma and intestinal type adenocarcinoma, which helps in distinguishing them from metastatic and pancreatobiliary type adenocarcinoma, respectively. A diagnostic immunohistochemical panel and additional extended panels of discriminant markers are proposed as guidance for their pathological diagnosis.     

Effects of streptozotocin-induced experimental diabetes on the morphology and function of the zona fasciculata of rat adrenal cortex

The effects of a severe streptozotocin (STZ)-induced diabetes on the morphology and function of the adrenal zona fasciculata were examined in rats with intact or pharmacologically interrupted hypothalamic-hypophyseal-adrenal axis. In animals with an intact hypothalamic-hypophyseal axis, STZ-diabetes induced hypertrophy of the cells of the zona fasciculata and a rise in the plasma corticosterone concentration. Conversely, in rats in which the hypothalamic-hypophyseal axis had been interrupted, experimental diabetes provoked atrophy of the zona fasciculata cells, and a lowering in the plasma corticosterone level. The effects of STZ-diabetes were completely reversed by insulin infusion in both groups of rats. The hypothesis is discussed that the chronic lack of insulin may directly inhibit the growth and steroidogenic capacity of the rat zona fasciculata and that this effect of experimental diabetes may be masked in rats with an intact hypothalamic-hypophyseal axis by the concurrent enhancement of ACTH release due to chronic stress resulting from the metabolic consequences of prolonged diabetes.     

Antioxidant efficacy of iridoid and phenylethanoid glycosides from the medicinal plant Teucrium chamaedris in cell-free systems

Twelve glycosides, seven iridoids and five phenylethanoids, have been isolated from leaf and root methanolic extracts of Wall Germander (Teucrium chamaedrys), a Mediterranean species historically used as a medicinal plant. Among them, three iridoid and one phenylethanoid glycosides have been isolated and characterized for the first time. All of the structures have been elucidated on the basis of their spectral data, especially 1D and 2D NMR experiments.The antioxidative properties of pure metabolites, as well as of crude organic extracts of the plant, have been analyzed on the basis of their DPPH radical scavenging capability. The antioxidant capacity in cell-free systems of the isolated metabolites was carried out by measuring their capabilities to inhibit the synthesis of thiobarbituric acid reactive species in assay media using as oxidable substrates a vegetable fat and the pentose sugar 2-deoxyribose and to prevent oxidative damage of the hydrosoluble bovine serum albumin (BSA) protein. Phenylethanoid glycosides resulted efficacious DPPH radical, while iridoid glycosides prevent massively the 2-deoxyribose and BSA oxidations in assay media.