Neurohormones from Fish Tails: The Caudal Neurosecretory System

International Union of Basic and Clinical Pharmacology. XCII. Urotensin II, Urotensin II–Related Peptide, and Their Receptor: From Structure to Function

“…This system consists of two rows of magnocellular secretory neurons, termed Dahlgren cells (Dahlgren, 1914), symmetrically arranged in the ventral horn of the spinal cord, that project their axons into a neurohemal organ called the urophysis (Enami, 1959). The caudal neurosecretory system of teleosts is thus anatomically and functionally similar to the hypothalamo-neurohypophysial neurosecretory system (Bern et al, 1985;McCrohan et al, 2007).…”

“…As a matter of fact, in fish, UII induces a general spasmogenic activity that has been documented in various tissue preparations including the trout (Salmo gairdneri) urinary bladder, the trout posterior intestine, the guppy (Poecilia reticulata) oviduct, the goby sperm duct, the eel (Anguilla rostrata) caudal lymph heart (Bern et al, 1985), and the dogfish (Scyliorhinus canicula) vascular ring (Hazon et al, 1993). In unanesthetized trout (Oncorhynchus mykiss), intra-arterial administration of UII causes an increase in aortic blood pressure and a decrease in heart rate (Le Mével et al, 2008).…”

“…Because the urophysis is a neurohemal organ that is exclusively present in teleosts (Bern et al, 1985), it had long been thought that UII only existed in fish. However, subsequent studies have led to the identification of UII orthologs in amphibians (Conlon et al, 1992b) and mammals, including humans (Coulouarn et al, 1998).…”

Genetic and Pharmacological Manipulation of Urotensin II Ameliorate the Metabolic and Atherosclerosis Sequalae in Mice

“…[1][2][3][4] In the latter, UII is an 11 amino acid peptide with highly conserved C-terminal hexapeptide and disulfide bridge between 2 cysteine residues. Subsequent studies revealed that UII was the ligand for its own receptor, the rat orphan G-proteincoupled receptor-14/sensory epithelial neuropeptide-like receptor, which in humans is now known as the urotensin receptor (UT).…”

Ontogenetic Development of the Caudal Neurosecretory System in the Chum Salmon, Oncorhynchus keta, with Regard to Its Ultrastructural Changes and with Relation to Neuropeptide Y-immunoreactive Fibers

“…Serial sections were cut at a 10 μm thickness, mounted on the glass slides coated with Biobond (British BioCell, UK), and immunostained by the streptavidinbiotin method with a commercial kit (Nichirei, Tokyo). The following antisera at the specified dilutions were used as the primary antibodies: anti-Catostomus UI (1:4000; Suess et al 1986), anti-Gillichthys UII (1:3000; Bern et al 1985), and anti-porcine NPY (1:3000; UCB Bioproducts, Belgium). For simultaneous demonstration of NPY and UI or NPY and UII immunoreactivities in the same section, double immunohistochemical labeling was applied according to the recommendations of Nakane (1968) and Hsu and Soban (1982).…”