Organ and development related difference in tissue norepinephrine concentrations in Dahl rats.
To determine organ and development related differences in tissue norepinephrine concentration (tNE) in Dahl salt-sensitive (S) and -resistant (R) rats, we measured the tNE of 16 organs, including the heart (left ventricle), kidney, cerebrum, brain stem, stomach, jejunum, ileum, colon, spleen, pancreas, liver, aorta, lung, bone, salivary gland, and muscle, at 1, 3, 5, 7, 9, 11 weeks old. Large differences were found in tNE among the organs of both S and R rats, ranging from 4.0 +/- 1.1 ng/g tissue (the bone of S rats) to 1234.8 +/- 32.5 ng/g tissue (the salivary gland of R rats). tNE in R rats increased development-dependently in 12 of 16 organs, but did not significantly change in the other three organs, and decreased in the bone. On the other hand, the development-dependent increase in tNE was suppressed in S rats, and the tNE values of S rats were significantly lower than those of R rats in 14 of 16 organs. To eliminate the baroreflexive effects on tNE, another group of 5-week-old S and R rats were subjected to sinoaortic denervation (SAD) or the sham operation. The tNE was measured in 10 organs in these animals at 9 weeks old. SAD did not alter the tNE in most of the organs in both S and R rats. There was no significant differences in mean arterial pressure (MAP) between S and R rats with baroreceptor intact at 9 weeks old. SAD slightly but significantly increased MAP in S rats, whereas not in R rats. There was no significant differences in plasma NE concentration (pNE) between S and R rats with the baroreceptor intact. SAD did not alter pNE in S or R rats. These results demonstrate that variations of the tNE were dependent on the organ and development. Many organs of S rats had lower tNE than those of R rats. The developmental-dependent increases in tNE in S rats were suppressed, compared with those in R rats. These tNE behaviors in S rats may not be related to blood pressure or baroreflex sensitivity, but might be involved in an abnormal sympathetic nerve activity.
Chen
Q H
QH
Second Department of Physiology, Kagawa Medical University, Japan. kgwphys1@kms.ac.jp
Nishida
Y
Y
Zhou
M S
MS
Murakami
H
H
Morita
H
H
Hosomi
H
H
Kosaka
H
H
D000818:Animals; D001011:Aorta / Q000737:chemistry / Q000294:innervation*; D001794:Blood Pressure / Q000502:physiology; D001923:Brain Chemistry / Q000502:physiology; D003714:Denervation; D004064:Digestive System / Q000737:chemistry / Q000294:innervation; D008297:Male; D009638:Norepinephrine / Q000032:analysis* / Q000097:blood; D011311:Pressoreceptors / Q000502:physiology; D051381:Rats; D020303:Rats, Inbred Dahl / Q000502:physiology*; D012469:Salivary Glands / Q000737:chemistry; D013564:Sympathetic Nervous System / Q000737:chemistry* / Q000502:physiology
D009638:Norepinephrine