beta-Alanine and taurine microinjected into the rat caudal ventrolateral medulla increase blood pressure.
Unilateral microinjections of GABA, glycine, beta-alanine and taurine into the caudal ventrolateral medulla (CVLM) of the rat, led to an increase in blood pressure and heart rate. The responses to glycine, beta-alanine and taurine but not to GABA could be blocked by strychnine. The responses to taurine and beta-alanine but not to GABA and glycine could be blocked by 6-aminomethyl-3-methyl-4H-1,2,4-benzothiadiazine-1,1-dioxide (TAG), an antagonist of taurine. The taurine antagonist alone injected bilaterally into the CVLM produced a decrease in blood pressure. From CVLM areas microperfused with Krebs solution, spontaneous release of GABA, glycine, beta-alanine and taurine was detected and high K+ stimulation caused a calcium-dependent release of GABA, beta-alanine and taurine. These results suggest that beta-alanine and taurine as well as GABA may be involved in modulation of the cardiovascular control within the CVLM.
Department of Pharmacology, Showa College of Pharmaceutical Sciences, Tokyo, Japan.
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Kubo
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Amano
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Ishizuka
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Ozaki
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology*; D001933:Brain Stem / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D018756:GABA Antagonists; D005998:Glycine / Q000494:pharmacology; D008526:Medulla Oblongata / Q000502:physiology*; D008845:Microinjections; D051381:Rats; D017208:Rats, Wistar; D018009:Receptors, Glycine; D017981:Receptors, Neurotransmitter / Q000037:antagonists & inhibitors; D013654:Taurine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D015091:beta-Alanine / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology
D018756:GABA Antagonists; D018009:Receptors, Glycine; D017981:Receptors, Neurotransmitter; D015091:beta-Alanine; D013654:Taurine; D005680:gamma-Aminobutyric Acid; D005998:Glycine