A 55-year-old male undergoes a total abdominal colectomy. Which of the following statement(s) is/are true concerning the hormonal response to the surgical procedure?

a. Adrenocorticotropic hormone (ACTH) is secreted from the anterior pituitary gland

c. An increased secretion of aldosterone and ADH may contribute to postoperative fluid retention

One of the earliest consequence of a surgical procedure is the rise in levels of circulating cortisol that occur in response to a sudden outpouring of ACTH from the anterior pituitary. The rise in ACTH stimulates the adrenal cortex to elaborate cortisol which remains elevated for 24–48 hours after operation. The neuroendocrine responses to operation also modify the various mechanisms that regulate salt and water excretion. Alterations in serum osmolarity and tonicity of body fluids secondary to anesthesia and operative stress, stimulate the secretion of aldosterone and ADH. Thus, the ability to excrete a water load after elective surgical procedures is restricted, and weight gain secondary to salt and water retention is usual following an operation. Alterations occur in response to the endocrine pancreas following elective operation. Insulin elaboration is diminished and glucagon concentrations rise. The rise in glucagon and the corresponding fall in insulin are important signals to accelerate hepatic glucose production, and, with other hormones (epinephrine and glucocorticoids), gluconeogenesis is maintained.