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L-Cysteine and L-AP4 microinjections in the rat caudal ventrolateral medulla decrease arterial blood pressure.
Auton Neurosci. 2014 Dec; 186:45-53.AN

Abstract

The thiol amino acid L-cysteine increases arterial blood pressure (ABP) when injected into the cerebrospinal fluid space in conscious rats, indicating a pressor response to centrally acting L-cysteine. A prior synaptic membrane binding assay suggests that L-cysteine has a strong affinity for the L-2-amino-4-phosphonobutyric acid (L-AP4) binding site. The central action of L-cysteine may be vial-AP4 sensitive receptors. The present study investigated cardiovascular responses to L-cysteine and L-ap4 microinjected into the autonomic area of the caudal ventrolateral medulla (CVLM) where inhibitory neurons regulate ABP via pre-sympathetic vasomotor neurons. Both the injection of L-cysteine and L-AP4 in the CVLM sites identified with L-glutamate produced the same depressor and bradycardic responses in urethane-anesthetized rats. Neither a prior antagonist microinjection of MK801 for the N-methyl-D-aspartate (NMDA) receptor nor CNQX for the non-NMDA receptor attenuated the responses to L-cysteine, but the combination of the two receptor blocking with an additional prior injection abolished the response. In contrast, either receptor blockade alone abolished the response to L-AP4, indicating distinct mechanisms between responses to L-cysteine and L-AP4 in the CVLM. The results indicate that the CVLM is a central active site for L-cysteine's cardiovascular response. Central L-cysteine's action could be independent of the L-AP4 sensitive receptors. Cardiovascular regulation may involve endogenous L-cysteine in the CVLM. Further multidisciplinary examinations are required to elaborate on L-cysteine's functional roles in the CVLM.

Authors+Show Affiliations

Basic Sciences, Institute of Biomedical and Health Sciences, Hiroshima University, Japan. Electronic address: yumitake@hiroshima-u.ac.jp.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

25450419

Citation

Takemoto, Yumi. "L-Cysteine and L-AP4 Microinjections in the Rat Caudal Ventrolateral Medulla Decrease Arterial Blood Pressure." Autonomic Neuroscience : Basic & Clinical, vol. 186, 2014, pp. 45-53.
Takemoto Y. L-Cysteine and L-AP4 microinjections in the rat caudal ventrolateral medulla decrease arterial blood pressure. Auton Neurosci. 2014;186:45-53.
Takemoto, Y. (2014). L-Cysteine and L-AP4 microinjections in the rat caudal ventrolateral medulla decrease arterial blood pressure. Autonomic Neuroscience : Basic & Clinical, 186, 45-53. https://doi.org/10.1016/j.autneu.2014.09.018
Takemoto Y. L-Cysteine and L-AP4 Microinjections in the Rat Caudal Ventrolateral Medulla Decrease Arterial Blood Pressure. Auton Neurosci. 2014;186:45-53. PubMed PMID: 25450419.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - L-Cysteine and L-AP4 microinjections in the rat caudal ventrolateral medulla decrease arterial blood pressure. A1 - Takemoto,Yumi, Y1 - 2014/10/02/ PY - 2014/07/28/received PY - 2014/09/12/revised PY - 2014/09/21/accepted PY - 2014/12/3/entrez PY - 2014/12/3/pubmed PY - 2015/8/5/medline KW - Arterial blood pressure KW - CNQX KW - CVLM KW - MK801 KW - Rats KW - l-AP4 KW - l-Cysteine SP - 45 EP - 53 JF - Autonomic neuroscience : basic & clinical JO - Auton Neurosci VL - 186 N2 - The thiol amino acid L-cysteine increases arterial blood pressure (ABP) when injected into the cerebrospinal fluid space in conscious rats, indicating a pressor response to centrally acting L-cysteine. A prior synaptic membrane binding assay suggests that L-cysteine has a strong affinity for the L-2-amino-4-phosphonobutyric acid (L-AP4) binding site. The central action of L-cysteine may be vial-AP4 sensitive receptors. The present study investigated cardiovascular responses to L-cysteine and L-ap4 microinjected into the autonomic area of the caudal ventrolateral medulla (CVLM) where inhibitory neurons regulate ABP via pre-sympathetic vasomotor neurons. Both the injection of L-cysteine and L-AP4 in the CVLM sites identified with L-glutamate produced the same depressor and bradycardic responses in urethane-anesthetized rats. Neither a prior antagonist microinjection of MK801 for the N-methyl-D-aspartate (NMDA) receptor nor CNQX for the non-NMDA receptor attenuated the responses to L-cysteine, but the combination of the two receptor blocking with an additional prior injection abolished the response. In contrast, either receptor blockade alone abolished the response to L-AP4, indicating distinct mechanisms between responses to L-cysteine and L-AP4 in the CVLM. The results indicate that the CVLM is a central active site for L-cysteine's cardiovascular response. Central L-cysteine's action could be independent of the L-AP4 sensitive receptors. Cardiovascular regulation may involve endogenous L-cysteine in the CVLM. Further multidisciplinary examinations are required to elaborate on L-cysteine's functional roles in the CVLM. SN - 1872-7484 UR - https://www.unboundmedicine.com/medline/citation/25450419/L_Cysteine_and_L_AP4_microinjections_in_the_rat_caudal_ventrolateral_medulla_decrease_arterial_blood_pressure_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1566-0702(14)00154-4 DB - PRIME DP - Unbound Medicine ER -