The impact of glucocorticoids on beta-amyloid(1-42) (Abeta(1-42)) and NMDA-induced neurodegeneration was investigated in vivo. Abeta(1-42) or NMDA was injected into the cholinergic magnocellular nucleus basalis in adrenalectomized (ADX) rats, ADX rats supplemented with 25%, 100%, 2x100% corticosterone pellets, or sham-ADX controls. Abeta(1-42)- or NMDA-induced damage of cholinergic nucleus basa...

Endogenous corticosterone in rodent's hair would be a potential biomarker to assess the response of the hypothalamus-pituitary-adrenal axis to chronic stress. However, currently unknown is whether hair corticosterone is associated with endogenous corticosterone in blood and brain. The present study aimed to develop an enhanced assay for determination of endogenous corticosterone in blood, brain...

The present study demonstrates the effects of adrenalectomy and subcutaneously administered corticosterone on N-methyl-D-aspartate-induced neurodegeneration in the cholinergic magnocellular basal nucleus of the rat. NMDA was unilaterally injected into the nucleus basalis at different plasma corticosterone concentrations in adrenalectomized rats, in adrenalectomized animals with subcutaneously i...

Previous research in this laboratory demonstrated elevated plasma corticosterone and reduced protein kinase C (PKC) activity and selective isoform expression in the epidermis of dietary energy-restricted mice. Because PKC is implicated in skin carcinogenesis and because both energy restriction and glucocorticoid hormone inhibit skin carcinogenesis, the purpose of the present research was to det...

Corticosteroid-binding globulin (CBG) is a plasma protein that binds corticosterone and may regulate access of hormone to tissues. The role of CBG during a stress response is not clear. At least two hypotheses have been proposed: 1) CBG levels may increase in response to a stressor, thereby decreasing the amount of circulating free corticosterone, or 2) CBG levels may decline, making corticoste...

Evidence is presented for the potentiating role of corticosterone on axonal degeneration of serotonergic neurones during ageing. Aged rats, 24 months old, were implanted subcutaneously with 2 x 100 mg pellets of corticosterone. Serotonergic and cholinergic (ChAT- and NADPHd-positive) fibre degenerations in the anteroventral thalamic nucleus (AVT) were measured 2 months after corticosterone impl...

This experiment investigated the effects of different doses of Bacillus subtilis spore as a probiotic on the immune response, intestinal morphology and ileal dry matter digestibility in broiler chicks exposed to stress induced by corticosterone (CORT). Two hundred and eighty-eight one-day-old Ross 308 male broiler chicks were randomly assigned to six treatments in a <e...

A corticosterone model was used to study the effects of chronic and repeated stress during the rearing phase on physiology, the onset of lay and performance of laying hens in the subsequent laying period. Two hundred and seventy Hy-line brown layer pullets were reared in environmentally controlled battery cages. At 7, 11, and 15 weeks of age birds were exposed for 1 week to the following treatm...

Plasma corticosterone concentrations were measured in wild loggerhead sea turtles (Caretta caretta) in response to acute captivity (capture, serial bleeding, and restraint up to 6 hr). In general, concentrations of corticosterone dramatically increased 1 hr after capture, peaked at 3 hr, and decreased by 6 hr. Initial corticosterone concentrations were significantly lower in animals captured by...

We investigated how exogenous and endogenous glucocorticoids affect feather replacement in European starlings (Sturnus vulgaris) after approximately 56% of flight feathers were removed. We hypothesized that corticosterone would retard feather regrowth and decrease feather quality. After feather regrowth began, birds were treated with exogenous corticosterone or sham implants, or endogenous cort...