Hypertension, Vol 3, 534-543, Copyright © 1981 by American Heart Association
Effect of cross-transplantation on normotensive and spontaneously hypertensive rat arterial muscle membrane
GR Campbell, J Chamley-Campbell, N Short, RB Robinson and K Hermsmeyer
Transplantation of arteries into the anterior eye chamber of rats for 8
weeks was used to test the hypothesis that the neurohumoral environment is
important in establishing the altered membrane potential (observable during
electrogenic ion transport inhibition) of vascular muscle in hypertension.
When caudal arteries from 12- to 16-week-old spontaneously hypertensive
rats (SHR) or genetically matched Kyoto- Wistar normotensive rats (KNR)
were transplanted into the opposite strain, there was no change in the
transport inhibited membrane potential (Em) of the arterial muscle cells
from that found in freshly excised donor arteries. However, when caudal
arteries from 2-week-old animals were transplanted into the anterior eye
chamber, the arteries always developed the appropriate Em for the host
animal. In other words, a genetically KNR artery developed the Em of an SHR
artery in an SHR host; conversely, a genetically SHR artery developed the
Em of a KNR artery in the KNR host. These results provide evidence that: 1)
the differences between th Em of caudal arteries from SHR and KNR are not
inherent in those muscle cells; 2) the change in Em is triggered in young
animals preceding development of hypertension, but not after hypertension
is established; and 3) the Em alteration of the caudal artery is
independent of structural changes that occur in the artery as a result of
increased blood pressure (because KNR transplants were not connected in
series with the host anterior eye chamber vasculature and subject to the
elevated blood pressures). We conclude that the arterial muscle cells up to
a certain age respond to an external factor that regulates their Em and
presumably their sensitivity to vasopressor agents.