AJP - Regulatory, Integrative and Comparative Physiology, Vol 257, Issue 5 1034-R1039, Copyright © 1989 by American Physiological Society
Renal sympathetic nerve activity and plasma catecholamines during eating in cats
K. Matsukawa, T. Honda and I. Ninomiya
Department of Cardiac Physiology, National Cardiovascular Center, Research Institute, Osaka, Japan.
We measured renal sympathetic nerve activity (RNA) and arterial plasma
concentration of norepinephrine (NE) and epinephrine (EPI) before, during,
and after eating in six conscious cats. Eating continued for a period of 5
min. RNA, heart rate (HR), and arterial blood pressure (AP) increased
almost simultaneously with the onset of eating and reached a maximum value
of 192%, 221 beats/min, and 121 mmHg at 2.5-5 min after the onset of
eating, respectively. The plasma NE level increased significantly (P less
than 0.05) during eating from the control value of 0.56 ng/ml and reached a
maximum value of 1.33 ng/ml at 4.5-5 min, whereas the plasma EPI level did
not change significantly from the control value of 0.12 ng/ml. The plasma
levels of NE and EPI were unaffected by the blood samplings. The
relationship between the changes in RNA and the plasma NE level during
eating had a significant (P less than 0.05) positive correlation (r =
0.52). The result suggests that plasma NE concentration tends to increase
with the rise in RNA during eating.
