Antishock effects of corticosterone on dextran-induced shock in rats

Abstract

To study the effects of glucocorticoid on the shock state, dextran-induced shock in rats was used as an experimental model system. The rats were divided into three groups, viz., control (group A), adrenalectomized (group B), and adrenalectomized corticosterone supplemented (2 mg/rat for 4 days; group C), and 5% dextran solution was given intravenously to each rat. In group B, remarkable increases in the histamine levels in both plasma and the paw cutaneous tissue, hemoconcentration, and intractable hypotension were observed. Most rats in group B died during the shock experiment without showing any recovery when the cannulas were inserted into the left carotid artery for the measurement of blood pressure. But in group C, most rats eventually survived and recovered to a normal state within 2 h, so that corticosterone clearly ameliorated the shock state of adrenalectomized rats by dextran administration. These results suggested that the ameliorating effects of corticosterone in the dextran-induced shock states are due to the acceleration of the rate of clearance of circulating chemical mediators that are represented by histamine and are due to the alteration of overall responsiveness of the animals to a complex array of factors that threaten the status of the animals, as represented by the amelioration of the vascular activity.

Brain Mast Cells Act as an Immune Gate to the Hypothalamic-Pituitary-Adrenal Axis in Dogs

“…Indeed, IgE-dependent immediate hypersensitivity reactions are frequently associated with dysfunctions of the cardiovascular or respiratory systems, which can have life-threatening consequences for allergic individuals (3,4). However, both pharmacologic glucocorticoids and physiologic adrenal corticosteroids can ameliorate the severity of these dysfunctions and suppress the subsequent immune-mediated inflammation (6,35,(38)(39)(40)(41). Thus, an activation of cortisol secretion after degranulation of intracranial mast cells could conceivably evoke a life-saving host defense response against severe systemic anaphylaxis or respiratory disorders when a type I allergic reaction is triggered by peripheral mast cells.…”

Effects of environmental stress on tissue survival and neutrophil recruitment in surgical skin flaps in relation to plasma corticosterone levels in the rat

“…This apparent low reproducibility in flap survival could depend on numerous factors, including differences in strain, sex, feeding, experimental and flap design, timing and dosage of drugs, as well as post-surgical infections. Another factor with potential to influence the degree of flap survival is variability in the levels of circulating endogenous corticosteroids, a notion that gains support from the following observations: 1) treatment with glucocorticoids can improve the survival of skin flaps in the rat [4,5]; 2) neutrophil recruitment induced by flap surgery has been indicated to be detrimental for skin flap survival [6,7]; 3) glucocorticoid treatment inhibits inflammatory neutrophil recruitment [8]; 4) adrenalectomy or hypophysectomy generally makes rats more responsive to pro-inflammatory stimuli [9][10][11]. Therefore, considering that exposure of rats to ''novelty'' increases plasma corticosterone levels [12][13][14], we hypothesized that the time allowed for acclimatization after transporting animals from the supplier may influence the degree of flap survival.…”

Unilateral intracarotid injection of holmium microspheres to induce bilateral MRI-validated cerebral embolization in rats

“…In many experiments, dextran is used as vehicle of choice (Miyake et al, 1993;Takagi et al, 1997). However, dextran injections in rats are a model for inflammation and shock (Gulati et al, 1983;Kogure et al, 1986) and we therefore think that direct injection into the cerebral arteries should be avoided. In our pilot experiments with dextran as vehicle for the microspheres, several rats exhibited severe paw edema.…”