Serum hydrocortisone (cortisol) values in glaucomatous and normotensive Beagles.

Serum hydrocortisone (cortisol) values were measured by radioimmunoassay in 5 normortensive and 20 glucomatous Beagles at 1 AM, 7 AM, 1 PM, and 7 PM. Significant differences (P < 0.01) in mean serum values of cortisol occurred between glaucomatous (20.9 ng/ml) and normotensive (9.5 ng/ml) Beagles. The slightly increased serum cortisol values in glaucomatous Beagles at 1 AM and 7 AM coincided with increases in intraocular pressure of glaucomatous Beagles. However, neither the normotensive nor glaucomatous Beagles exhibited any diurnal variations in serum cortisol values.