Immunohistochemical distribution of the endothelin-converting enzyme-1 in the rat hypothalamo-pituitary axis.
We prepared a rabbit polyclonal antibody against an endothelin converting enzyme-1 (ECE-1) to examine the distribution of ECE-1 in the hypothalamus and the pituitary of the rat. By the Western blot analysis, the antibody specifically recognized ECE-1 proteins in membrane fractions of the rat hypothalamus. Immunohistochemical staining revealed ECE-1 immunoreactivity in both cell bodies and axons in some hypothalamic neurons. The immunopositive cell bodies were located in the paraventricullar and supraoptic nuclei; immunopositive axons were distributed in the suprachiasmatic, paraventricullar (PVN), and supraoptic (SON) nuclei. However no immunoreactivity was detected in the posterior pituitary gland. The present results indicate that ECE-1 converts the endothelin-1 (ET-1) from precursor big ET-1 to mature ET-1 in the PVN/SON. The big ET-1 existing in the posterior pituitary gland is thought to be escaped from the converting by ECE-1 in the hypothalamus.
Kurokawa
K
K
Department of Anatomy, Shiga University of Medical Science, Seta-Tsukinowacho, Otsu, Japan. kurokawa@shiga-med.ac.jp
Yamada
H
H
Liu
Y
Y
Kudo
M
M
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000096:biosynthesis*; D000072396:Endothelin-Converting Enzymes; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D008666:Metalloendopeptidases; D009474:Neurons / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D016282:Aspartic Acid Endopeptidases; D008666:Metalloendopeptidases; D000072396:Endothelin-Converting Enzymes