Cardiovascular Regulation of GABAB Receptor in the Spinal Cord of the Rats.
- Author:
Suk Ho LEE
1
;
Joon Hyoek LEE
;
Kyu Taek LEE
;
Jong Kyun LEE
;
In Kyung SUNG
;
Sang Goon SHIM
;
Sang Goo LEE
;
In Koo KANG
;
Chang Sup KIM
;
Mun Suk CHOI
;
Kwang Hyun RYU
;
Poong Lyul RHEE
;
Jae Jun KIM
;
Kwang Cheol KOH
;
Seung Woon PAIK
;
Jong Chul RHEE
;
Kyoo Wan CHOI
Author Information
1. Department of Internal Medicine, college of medicine, Sung Kyun Kwan University Samsung Medical Center, Seoul, Korea.
- Publication Type:Original Article
- MeSH:
Adenylyl Cyclases;
Animals;
Baclofen;
Blood Pressure;
gamma-Aminobutyric Acid;
Heart;
Heart Rate;
Humans;
Injections, Spinal;
Male;
Membranes;
Punctures;
Rats*;
Rats, Sprague-Dawley;
Spinal Cord*
- From:Korean Journal of Medicine
1999;56(1):25-32
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVES: The purpose of present study is to investigate the influence of a spinal gamma-aminobutyric acid B (GABAB) receptor on a central regulation of blood pressure(BP) and heart rate(HR), and to define its mechanism in the spinal cord. METHODS: In urethane-anesthetized, d-tubocurarine- paralyzed and artificially ventilated male Sprague-Dawley rats, intrathecal administration of drugs were carried out using injecton cannula(33-gauge stainless steel) through the guide cannula(PE 10) which was inserted intrathecally at lower thoracic level through the puncture of a atlantooccipital membrane. RESULTS: Intrathecal injection of an GABAB receptor agonist baclofen(30, 60, 100 nmol) decreased both blood pressure and heart rate dose-dependently. Pretreatment with 8-bromo-cAMP(50 nmol), a cAMP analog or glipizide(50 nmol), a ATP-sensitive K+ channel blocker attenuated the depressor and bradycardic effects of baclofen (100 nmol) but not with 8-bromo-cGMP(50 nmol) a cGMP analog. CONCLUSIONS: The GABAB receptor in the spinal cord plays an inhibitory role in central cardiovascular regulation and that this depressor and bradycardic actions are mediated by the decrease of cAMP via the inhibition of adenylate cyclase and the opening of K+ channel.
