23 - Glucocortoids and stress response, Apolosky

23 - Glucocortoids and stress response, Apolosky - ARTICLE...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
ARTICLE 23: Glucocortiocoids Goal of paper : To coordinate the diverse actions of GCs on the stress response in different body systems. Three views are integrated: 1. View of Selye – stress induced secretion of GCs enhances and mediates stress responses 2. View of Ingle – basal GC levels are permissive of stress response 3. GCs limit the stress response and contribute to recovery from it General Endocrine Response to Stress: First Wave of Hormone action (w/in seconds of stressor) - ↑ in catecholamine (epinephrine, norepinephrine) (SNS), CRH (hypothalamus), ACTH (pituitary), oplates - ↓ in GnRH (hypothalamus), gonadotropins (pituitary) - ↑ GH (pituitary) - specific case of ↓ fluid volume (haemorrhage), ↑ in AVP (pituitary) and renin (kidney) Second Wave – steroid Hormones (w/in minutes of stressor) - ↑ in glucocorticoids - ↓ in gonadal steroids Hormones of first wave produce rapid effects via second messengers Steroids of second wave produce effects approx. an hour (or greater) after onset - bulk of steroid actions are genomic Hormone effects bring on physiological changes of the stress response - diversion of energy to exercising muscle - enhanced substrate delivery to muscle via enhanced cardiovascular tone - stimulation of immune function - inhibition of reproductive physiology and bahviour - decreased feeding and appetite - sharpened cognition and increased cerebral perfusion rates and local cereberal glucose utilization GC Actions: Modulating Actions – alter organisms response to stressor Permissive - produced by GCs present before stressor, prime the defence mechanisms by which an organisms responds to stress, and act during initial stress response, associated with basal levels of GC, or increased basal levels of GC Stimulating - produced by stress-induced ↑ in GCs and enhance effects of first wave hormones Suppressive Actions - produced by stress-induced ↑ in GCs and prevent stress response from overshooting Preparative Actions – do not affect the immediate response, can be mediating or surepressive, alter organisms response to subsequent stressor or aid in adapting to a chronic stressor - mediating or suppressive - do not affect immediate response rather they prepare organism for future encounters w/ stressor
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 03/18/2012 for the course BIO 3UU3 taught by Professor Dr.rollo during the Spring '12 term at McMaster University.

Page1 / 4

23 - Glucocortoids and stress response, Apolosky - ARTICLE...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online