Autonomic Nervous System and Vegetative ControlImmuno-localization of kynurenine aminotransferase (KAT) in the rat medulla and spinal cordKapoor, Ranjna1; Okuno, Etsuo2; Kido, Ryo2; Kapoor, Vimal1,3Author Information 1School of Physiology and Pharmacology, University of New South Wales, Sydney, NSW 2052, Australia 2Department of Biochemistry, Wakayama Medical College, 27 Kyuban-cho, Wakayama 640, Japan 3Corresponding Author: Vimal Kapoor Received 6 August 1997; accepted 23 August 1997 NeuroReport: November 10th, 1997 - Volume 8 - Issue 16 - p 3619-3623 Buy Abstract IN the mammalian brain, kynurenine aminotransferase (KAT) is pivotal to the synthesis of kynurenic acid, a preferential antagonist at the strychnine-insensitive NMDA-glycine site. As NMDA receptors are involved in autonomic function, we have examined the immunohistochemical localization of KAT in the medulla and spinal cord of the rat. KAT immunoreactivity (KAT-li) was found throughout these areas, in both glia and neurons. Unlike the mainly astrocytic localization in forebrain structures, KAT-li was predominantly neuronal, notably in areas important for blood pressure and heart rate regulation: ventral medulla, nucleus ambiguus, nucleus of the solitary tract and intramediolateral cell column of the spinal cord. The presence of KAT in these nuclei supports a neuromodulatory role for kynurenic acid in NMDA-mediated autonomic function. © Lippincott-Raven Publishers.