Quantitative flow cytometry reveals a hierarchy of glucocorticoid effect on cell surface mouse mammary tumor virus gp52

Different responses to dexamethasone and prednisolone in the same depressed patients

RATIONALE

Patients with major depression show hypothalamic-pituitary-adrenal (HPA) axis hyperactivity, but the mechanisms underlying this abnormality are still unclear.

OBJECTIVES

We have compared two synthetic glucorticoids, dexamethasone and prednisolone, in their ability to suppress the hypothalamic-pituitary-adrenal (HPA) axis in depressed patients. Dexamethasone probes glucocorticoid receptor (GR) function, while prednisolone probes both GR and mineralocorticoid receptor (MR) function.

MATERIALS AND METHODS

We used a single-blind, repeated-measure design. We administered placebo, prednisolone (5 mg) or dexamethasone (0.5 mg), at 22:00, to 18 severe, treatment-resistant depressed inpatients (15 of them with a history of childhood trauma) and 14 healthy volunteers. On the following days, we collected salivary cortisol from 9:00 to 22:00.

RESULTS

Depressed patients had higher salivary cortisol levels compared with controls, at baseline and after both prednisolone and dexamethasone (p<0.001). Consistent with previous studies, depressed inpatients showed impaired suppression by dexamethasone: based on the analysis of the areas under the curve (AUCs), suppression by dexamethasone (0.5 mg) was -85% in controls vs -46% in depressed patients (p=0.018). However, the same depressed patients showed normal suppression by prednisolone (5 mg): suppression was -41% in controls and -36% in depressed patients (p=0.6).

CONCLUSIONS

We suggest that the additional effects of prednisolone on the MR explain the different responses to these glucocorticoids in the same depressed patients.

A novel prednisolone suppression test for the hypothalamic-pituitary-adrenal axis

We have developed a suppressive test for the hypothalamic-pituitary-adrenal (HPA) axis using prednisolone, which is similar to endogenous glucocorticoids. We used a single-blind, repeated-measure design in healthy volunteers. In the first phase of the study, we compared placebo or prednisolone 2.5 mg, 5 mg, or 10 mg; in the second phase of the study, we compared placebo or prednisolone 5 mg or dexamethasone.5 mg. On the following day, we collected plasma and salivary cortisol levels from 9 AM to 5 PM. Maximal average prednisolone plasma levels (at 9 AM after the 10-mg dose) were 30 to 35 ng/mL. At all doses, prednisolone caused a larger suppression of salivary cortisol (approximately 20% after 2.5 mg, 30% to 35% after 5 mg, and 70% to 75% after 10 mg) than of plasma cortisol (approximately 5% after 2.5 mg, 10% after 5 mg, and 35% after 10 mg). Dexamethasone.5 mg gave 80% suppression of plasma cortisol and 90% suppression of salivary cortisol. Plasma and salivary cortisol levels were more consistently correlated in each subject after prednisolone than after dexamethasone. We propose that prednisolone at the 5-mg dosage (which gave partial HPA suppression), together with the assessment of salivary cortisol, can be used to investigate both impaired and enhanced glucocorticoid-mediated negative feedback in large samples of patients with psychiatric disorders.