Topographical distribution of neurons containing endothelin type A receptor in the rat brain

Abstract

Endothelin (ET) was originally identified as a vasoactive peptide biosynthesized in vascular endothelial cells. Because ET has also been found in the brain as a neuropeptide, it has been thought to belong to the group of brain-vascular peptide hormones. To date, type A and type B receptors for ET have been found. To elucidate the topographic distribution of type A receptor (ET-AR) in the brain, we raised a specific antibody to the C-terminal (64 amino acids) peptide of rat ET-AR and immunostained rat brain sections with this antibody. Immunoreactivity for ET-AR was detected in neuronal cell bodies and also in the many proximal and some distal parts of their fibers. Nerve cell bodies containing strong ET-AR-immunoreactivity were distributed in the lateral part of the reticular formation, the nucleus of the solitary tract and its surrounding area, the dorsal midline area and medial longitudinal fasciculus, the subependymal layer of the fourth ventricular roof, the caudolateral area of the pontine tegmentum, the locus coeruleus, the rostral pontine area of the lateral reticular formation, the retrorubral area, the substantia nigra, the ventral tegmental area, the periventricular region lateral to the rostral mesencephalic aqueduct and caudal third ventricle, the arcuate hypothalamic nucleus, the caudomedial area of the zona incerta, the periventricular hypothalamic nucleus, the parvocellular portion of the paraventricular hypothalamic nucleus, and the periglomerular region of the olfactory bulb. In addition, the Purkinje cells of the cerebellar cortex, the nerve cells in the mesencephalic trigeminal nucleus, and the magnocellular neurons of the supraoptic and paraventricular hypothalamic nuclei showed weak immunoreactivity. The distribution of highly ET-AR-immunoreactive neurons is quite similar to that ofcatecholamine neurons.

Association of Pressure Induced Hypertension with Specific Area of Ventrolateral Surface of Medulla Oblongata and Catecholamine Neurons.

“…Further experiments are under way in our laboratory, showing that these neurons are also endothelin type A receptor (ET-AR) immunopositive (data, not shown). Kurokawa et al [20] have already reported that the distribution of a major part of ET-AR-immunopositive neurons is quite similar to that of catecholamine neurons, which is in agreement with our above observations. The previous reports suggest that the neurons from RVLM to intermediolateral gray column (IML) are either glutamate or adrenaline-containing [10].…”

Cellular distribution of the endothelin system in the human brain

“…These previous studies used radioimmunoassay to determine the presence of ET receptors. An apparently conflicting result was obtained by Kurokawa et al (1997) who, using antibodies to the amino terminus of ET A , observed the opposite in the rodent brain viz. abundant ET A immunolabelling.…”

Mexico City normal weight children exposed to high concentrations of ambient PM2.5 show high blood leptin and endothelin-1, vitamin D deficiency, and food reward hormone dysregulation versus low pollution controls. Relevance for obesity and Alzheimer disease

“…ET-1 blood levels alter key regulatory mechanisms of the cerebral circulation by modulating endothelial NO synthase phosphorylation and NO production through Rho-associated protein kinase (Faraco et al, 2013). The significant vasoconstrictive and pro-inflammatory ET-1 effects at selected brain loci could also alter leptin regulatory circuits and BBB transport in urban children (Freeman et al, 2014;Faraco et al, 2013;Kurokawa et al, 1997;Mathison et al, 2007;Rossi and Maliszewska-Scislo, 2008). The ET1-induced cerebrovascular dysfunction may contribute to the vascular alterations associated with neuroinflammation.…”