December 21, 2016

Influence of aging on adrenal responsiveness in a population of eleven healthy beagles

Goy-Thollot Isabelle, Decosne-Junot Christelle, Bonnet Jeanne-Marie, Published by Elsevier on July 25, 2006,

The article aims to discover what the effects of aging are on the adrenal cortex response of cortisol and aldosterone in healthy adult Beagles. It is interesting because age-related alterations in adrenal cortex secretions have been found in rodents, monkeys, dogs, and humans, but the findings have been ambiguous. It was hypothesized that the adrenal cortex would produce varying levels of aldosterone and cortisol as the organism aged. I predicted the adrenal gland would produce lower levels of both hormones because the older organism would be less efficient at producing these hormones.

      Eleven healthy Beagles, all male to avoid the influence of hormone cycles in females, were evaluated twice every five years, and had their plasma basal cortisol and aldosterone, cortisol and aldosterone following ACTH-stimulation, sodium, and potassium concentrations and arterial blood pressure measured. The study found a significant age-related increase in basal cortisol. Inversely, both post ACTH-stimulated aldosterone levels, and basal aldosterone values plummeted with age. This significant decrease can be explained by the decrease in glomerulosa zone sensitivity to ACTH in older dogs. ACTH stimulation test measures how well the adrenal glands respond to adrenocorticotropic hormone. ACTH is a hormone produced in the pituitary gland that stimulates the adrenal glands to release a hormone called cortisol.

Reviewed by Jonathan Guzman