Increased oxytocin-monomeric red fluorescent protein 1 fluorescent intensity with urocortin-like immunoreactivity in the hypothalamo-neurohypophysial system of aged transgenic rats

• Published in: Neuroscience research 2018-03, Vol.128, p.40-49
• Main Authors: Ohno, Shigeo, Hashimoto, Hirofumi, Fujihara, Hiroaki, Fujiki, Nobuhiro, Yoshimura, Mitsuhiro, Maruyama, Takashi, Motojima, Yasuhito, Saito, Reiko, Ueno, Hiromichi, Sonoda, Satomi, Ohno, Motoko, Umezu, Yuichi, Hamamura, Akinori, Saeki, Satoru, Ueta, Yoichi
• Format: Article
• Language: English
• Subjects: Aging; Aging - physiology; Animals; Arginine Vasopressin - metabolism; Corticotropin-Releasing Hormone - metabolism; Corticotropin-Releasing Hormone - pharmacology; Green Fluorescent Proteins - drug effects; Green Fluorescent Proteins - genetics; Luminescent Proteins - metabolism; Neurons - drug effects; Neurons - metabolism; Oxytocin; Oxytocin - metabolism; Paraventricular Hypothalamic Nucleus - physiopathology; Paraventricular nucleus; Rats, Transgenic; Red Fluorescent Protein; Supraoptic nucleus; Supraoptic Nucleus - physiopathology; Synapsins - drug effects; Synapsins - metabolism; Urocortin; Urocortins - metabolism; Vasopressin
• ISSN: 0168-0102; 1872-8111
• DOI: 10.1016/j.neures.2017.08.001

•Transgenic rats expressing the oxytocin-mRFP1 fusion gene were generated.•The mRFP1 fluorescence was increased in the hypothalamus of aged transgenic rats.•The increased urocortin-LI cells co-existed in mRFP1 cells of aged transgenic rats. To visualize oxytocin in the hypothalamo-neurohypophysial system, we generated a transgenic rat that expresses the oxytocin-monomeric red fluorescent protein 1 (mRFP1) fusion gene. In the present study, we examined the age-related changes of oxytocin-mRFP1 fluorescent intensity in the posterior pituitary (PP), the supraoptic nucleus (SON) and the paraventricular nucleus (PVN) of transgenic rats. The mRFP1 fluorescent intensities were significantly increased in the PP, the SON and the PVN of 12-, 18- and 24-month-old transgenic rats in comparison with 3-month-old transgenic rats. Immunohistochemical staining for urocortin, which belongs to the family of corticotropin-releasing factor family, revealed that the numbers of urocortin-like immunoreactive (LI) cells in the SON and the PVN were significantly increased in 12-, 18- and 24-month-old transgenic rats in comparison with 3-month-old transgenic rats. Almost all of urocortin-LI cells co-exist mRFP1-expressing cells in the SON and the PVN of aged transgenic rats. These results suggest that oxytocin content of the hypothalamo-neurohypophysial system may be modulated by age-related regulation. The physiological role of the co-existence of oxytocin and urocortin in the SON and PVN of aged rats remains unclear.