Sympathetic and cardiovascular actions of orexins in conscious rats

American Journal of Physiology - Regulatory Integrative and Comparative Physiology - Tập 277 Số 6 - Trang R1780-R1785 - 1999
Tetsuro Shirasaka1,2, Masamitsu Nakazato3, Shigeru Matsukura3, Mayumi Takasaki1, Hiroshi Kannan2
1Departments of *Anesthesiology and
2Physiology and
3Internal Medicine, Miyazaki Medical College, Miyazaki 889–1692, Japan

Tóm tắt

The novel hypothalamic peptides orexin-A and orexin-B are known to induce feeding behavior when administered intracerebroventricularly, but little is known about other physiological functions. The renal sympathetic nerves play important roles in the homeostasis of body fluids and the circulatory system. We examined the effects of intracerebroventricularly administered orexins on mean arterial pressure (MAP), heart rate (HR), renal sympathetic nerve activity (RSNA), and plasma catecholamine in conscious rats. Orexin-A (0.3, 3.0 nmol) provoked an increase in MAP (94.3 ± 0.7 to 101.9 ± 0.7 mmHg and 93.1 ± 1.1 to 108.3 ± 0.8 mmHg, respectively) and RSNA (28.0 ± 7.0 and 57.9 ± 12.3%, respectively). Similarly, orexin-B (0.3, 3.0 nmol) increased MAP (93.9 ± 0.9 to 97.9 ± 0.9 mmHg and 94.5 ± 1.1 to 105.3 ± 1.7 mmHg, respectively). Orexin-A and -B at 3.0 nmol also increased HR. In other conscious rats, a high dose of orexin-A and -B increased plasma norepinephrine. Plasma epinephrine only increased with a high dose of orexin-A. These results indicate that central orexins regulate sympathetic nerve activity and affect cardiovascular functions.

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Tài liệu tham khảo

Allen M. A., 1997, Am. J. Physiol., 272, R1698

10.1016/S0149-7634(05)80149-6

10.2337/diab.45.10.1446

10.1073/pnas.96.2.748

10.2337/diab.46.12.2040

10.1016/S0092-8674(00)80937-X

10.1016/0163-7258(81)90081-4

10.1016/S0006-8993(99)01131-2

Kannan H., 1989, Am. J. Physiol., 256, R1325

10.1001/archinte.1989.00390070054005

10.1161/01.HYP.11.4.334

10.1113/jphysiol.1991.sp018480

Oomura Y., 1980, Handbook of the Hypothalamus: Physiology of the Hypothalamus., 2, 557

10.1523/JNEUROSCI.18-23-09996.1998

10.1016/S0092-8674(00)80949-6

10.1161/01.HYP.31.1.409

Shimazu T., 1979, Acta Physiol. Pol., 30, 1, 10.1002/actp.1979.010300101

10.1016/0006-8993(93)90647-6

10.1146/annurev.ne.06.030183.001413

Tidgren B., 1989, Am. J. Physiol., 257, F682

10.1016/S0014-5793(98)01266-6

10.1523/JNEUROSCI.18-19-07962.1998

10.1007/BF00592494

10.1016/0165-1838(91)90106-D

10.1038/372425a0

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American Journal of Physiology - Regulatory Integrative and Comparative Physiology

Tập 277 Số 6

R1780-R1785

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