Immobilization stress induces vasodepressor and altered neuroendocrine responses in the adult stroke-prone spontaneously hypertensive male rat.
The effects of acute (1 h) and daily repeated immobilization stress (14 days, twice-daily, 1 h) were studied on arterial blood pressure and heart rate and on the blood levels of several hormones in the adult (5 months old) stroke-prone spontaneously hypertensive rat (SHRSP) and in the age-matched normotensive Wistar-Kyoto (WKY) rat. The major result was the development of a long-lasting vasodepressor response in the SHRSP, while the same acute or repeated immobilization stress in the WKY rat led to the development of a prolonged vasopressor response. Differential changes to stress were also observed in practically all neuroendocrine axes with the exception of the pituitary-adrenal axis. The vasodepressor response to immobilization stress in SHRSP may be related to an exaggerated defence-like reaction causing an enhanced vasodilation in the skeletal muscle beds associated with a tachycardia similar to that in the normotensive control rats.
Narváez
J A
JA
Department of Histology and Neurobiology, Karolinska Institute, Stockholm, Sweden.
Aguirre
J A
JA
Härfstrand
A
A
Eneroth
P
P
Ganten
D
D
Agnati
L F
LF
Fuxe
K
K
D000804:Angiotensin II / Q000097:blood; D000818:Animals; D001794:Blood Pressure / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006728:Hormones / Q000097:blood*; D007103:Immobilization / Q000502:physiology*; D007986:Luteinizing Hormone / Q000097:blood; D008297:Male; D011388:Prolactin / Q000097:blood; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013972:Thyrotropin / Q000097:blood; D013997:Time Factors; D014667:Vasopressins / Q000097:blood
D006728:Hormones; D014667:Vasopressins; D000804:Angiotensin II; D011388:Prolactin; D007986:Luteinizing Hormone; D013972:Thyrotropin