JPET xPharm- The Comprehensive Pharmacology Reference

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Helke, C. J.
Right arrow Articles by Phillips, E. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Helke, C. J.
Right arrow Articles by Phillips, E. T.

Thyrotropin-releasing hormone receptor activation in the spinal cord increases blood pressure and sympathetic tone to the vasculature and the adrenals

CJ Helke and ET Phillips

Department of Pharmacology, Uniformed Services University of the Health Sciences, Bethesda, Maryland.

Cardiovascular and regional hemodynamic effects of the intrathecal (i.t.) administration of a thyrotropin-releasing hormone (TRH) analog, MK-771 (L-pyro-2-aminoadipyl-histidyl-thiazolidine-4-carboxamide), were studied in rats. MK-771 (0.01-5.0 micrograms i.t.) caused dose-related increases in mean arterial pressure (MAP) and heart rate (HR). TRH (10 micrograms i.t.), but not TRH-free acid, produced similar cardiovascular effects. The MAP response to MK-771 (i.t.) remained primarily intact after cervical spinal cord transection, whereas the HR response was attenuated (37% of control). The MAP response to MK-771 was blocked by peripheral administration of pentolinium or phentolamine, and was partially attenuated by adrenalectomy. The HR response was reduced by pentolinium or atropine. Assessment of changes in regional blood flow and vascular resistance with the radioactive microsphere technique showed that MK-771 increased total peripheral resistance and vasoconstricted cutaneous, skeletal muscle, adrenal, renal and intestinal vascular beds. Cardiac output and stroke volume were not altered. MK-771 had no effect on vascular resistance locally or in other central nervous system structures. However, blood flow was elevated by MK-771 in spinal cord and brain. These data show that TRH receptor activation in the thoracic spinal cord, presumably in the intermediolateral cell column, elevated MAP by increased sympathetic activity to the peripheral vasculature and the adrenals. However, the HR response to TRH receptor activation required a supra-spinal component and was mediated in part by vagal inhibition.

Volume 245, Issue 1, pp. 41-46, 04/01/1988
Copyright © 1988 by American Society for Pharmacology and Experimental Therapeutics




This article has been cited by other articles:


Home page
 Endocr. Rev.Home page
E. A. Nillni and K. A. Sevarino
The Biology of pro-Thyrotropin-Releasing Hormone-Derived Peptides
Endocr. Rev., October 1, 1999; 20(5): 599 - 648.
[Abstract] [Full Text]

Home page
 J. Neurophysiol.Home page
M. Kolaj, S. J. Shefchyk, and L. P. Renaud
Two Conductances Mediate Thyrotropin-Releasing-Hormone-Induced Depolarization of Neonatal Rat Spinal Preganglionic and Lateral Horn Neurons
J Neurophysiol, September 1, 1997; 78(3): 1726 - 1729.
[Abstract] [Full Text] [PDF]

Home page
 Circ. Res.Home page
S. Suzuki, P. Pilowsky, J. Minson, L. Arnolda, I. Llewellyn-Smith, and J. Chalmers
Antisense to Thyrotropin Releasing Hormone Receptor Reduces Arterial Blood Pressure in Spontaneously Hypertensive Rats
Circ. Res., October 1, 1995; 77(4): 679 - 683.
[Abstract] [Full Text]


Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 1988 by the American Society for Pharmacology and Experimental Therapeutics.