title: Glucocorticoid responses to stress in castrate and testosterone-replaced rams.
abstract: Stress is an important contributor to cardiovascular disease and to reduced immunity and fertility. As the role of androgens in stress is uncertain, we investigated the effects of testosterone (T) on hormonal responses to stress in conscious Romney Marsh wethers. Six T-treated sheep and six control sheep were stressed by exposure to a psychological and a metabolic stimulus. Baseline glucose levels were significantly lower in the treated animals compared with controls (p=0.002). T treatment significantly attenuated ACTH (p<0.01) and cortisol (p<0.05) responses to metabolic stress. Following psychological stress, ACTH responses were significantly lower in treated sheep compared with controls (p<0.05), but differences in mean cortisol responses did not reach significance. There were no significant differences in epinephrine or norepinephrine responses following either stressor. We conclude that T replacement in wethers lowers glucose and attenuates responses to metabolic and psychological stress. While the implications of these results for human physiology require further studies, they suggest that male hypogonadism may play a role in determining the risk of cardiovascular disease and diabetes.
authors.affiliation: Baker Heart Research Institute, PO Box 6492, St Kilda Road Central, Melbourne, Victoria 8008, Australia. tye.dawood@baker.edu.au
authors.forename: Tye
authors.initials: T
authors.lastname: Dawood
authors.forename: Maro R I
authors.initials: MR
authors.lastname: Williams
authors.forename: Meryl J
authors.initials: MJ
authors.lastname: Fullerton
authors.forename: Kathy
authors.initials: K
authors.lastname: Myles
authors.forename: Johannes
authors.initials: J
authors.lastname: Schuijers
authors.forename: John W
authors.initials: JW
authors.lastname: Funder
authors.forename: Krishnankutty
authors.initials: K
authors.lastname: Sudhir
authors.forename: Paul A
authors.initials: PA
authors.lastname: Komesaroff
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002318:Cardiovascular Diseases / Q000097:blood / Q000209:etiology; D004285:Dogs; D005938:Glucocorticoids / Q000378:metabolism*; D006854:Hydrocortisone / Q000097:blood; D007003:Hypoglycemia; D008297:Male; D009638:Norepinephrine / Q000097:blood; D010913:Pituitary-Adrenal System / Q000502:physiology; D012756:Sheep; D013315:Stress, Psychological; D013739:Testosterone / Q000097:blood / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D005938:Glucocorticoids; D013739:Testosterone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D009638:Norepinephrine