Aging differentially modifies sensitivity of nerve blood flow to vasocontractile agents (endothelin-1, noradrenaline and angiotensin II) in sciatic nerve.
This study examined the influence of the vaso-constricting agents (noradrenaline, endothelin-1 and angiotensin II) in Sprague-Dawley rats aged 2, 6 and 24 months by evaluating epineurial arteriolar vasoreactivity in response to superfused teat agents. Nerve blood flow (NBF) was measured using microelectrode H2 polarography. In 24-month-old rats, NBF was decreased and vascular resistance (VR) was increased compared with 2- and 6-month-old rats. All of the constricting agents reduced NBF in the 2-, 6- and 24-month groups, however, the effects of the constricting agents reduced significantly with age. These results suggest that during aging, there is a decline of vasoconstrictive responses to noradrenaline, endothelin-1 and angiotensin II in peripheral nerve and that these changes may be due to altered function of receptors.
Kihara
M
M
Department of Neurology, Kinki University, School of Medicine, Ohno-Higashi, Osaka-Sayama, Osaka, Japan. miki@med.kindai.ac.jp
Nakasaka
Y
Y
Mitsui
Y
Y
Takahashi
M
M
Schmelzer
J D
JD
D000375:Aging / Q000502:physiology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001160:Arterioles / Q000187:drug effects* / Q000502:physiology; D001794:Blood Pressure; D019332:Endothelin-1 / Q000494:pharmacology*; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012584:Sciatic Nerve / Q000098:blood supply*; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D009638:Norepinephrine