Article date: December 2000
By: Stephen A Douglas, Anthony C Sulpizio, Valerie Piercy, Henry M Sarau, Robert S Ames, Nambi V Aiyar, Eliot H Ohlstein, Robert N Willette in Volume 131, Issue 7, pages 1262-1274
Urotensin‐II (U‐II) and its G‐protein‐coupled receptor, GPR14, are expressed within mammalian cardiac and peripheral vascular tissue and, as such, may regulate mammalian cardiovascular function. The present study details the vasoconstrictor profile of this cyclic undecapeptide in different vascular tissues isolated from a diverse range of mammalian species (rats, mice, dogs, pigs, marmosets and cynomolgus monkeys).
The vasoconstrictor activity of human U‐II was dependent upon the anatomical origin of the vessel studied and the species from which it was isolated. In the rat, constrictor responses were most pronounced in thoracic aortae and carotid arteries: −log[EC50]s 9.09±0.19 and 8.84±0.21, Rmaxs 143±21 and 67±26% 60 mM KCl, respectively (compared, for example, to −log[EC50] 7.90±0.11 and Rmax 142±12% 60 mM KCl for endothelin‐1 [ET‐1] in thoracic aortae). Responses were, however, absent in mice aortae (−log[EC50] <6.50). These findings were further contrasted by the observation that U‐II was a ‘coronary‐selective’ spasmogen in the dog (−log[EC50] 9.46±0.11, Rmax 109±23% 60 mM KCl in LCX coronary artery), yet exhibited a broad spectrum of vasoconstrictor activity in arterial tissue from Old World monkeys (−log[EC50]s range from 8.96±0.15 to 9.92±0.13, Rmaxs from 43±16 to 527±135% 60 mM KCl). Interestingly, significant differences in reproducibility and vasoconstrictor efficacy were seen in tissue from pigs and New World primates (vessels which responded to noradrenaline, phenylephrine, KCl or ET‐1 consistently).
Thus, human U‐II is a potent, efficacious vasoconstrictor of a variety of mammalian vascular tissues. Although significant species/anatomical variations exist, the data support the hypothesis that U‐II influences the physiological regulation of mammalian cardiovascular function.
Urotensin‐II (U‐II) and its G‐protein‐coupled receptor, GPR14, are expressed within mammalian cardiac and peripheral vascular tissue and, as such, may regulate mammalian cardiovascular function. The present study details the vasoconstrictor profile of this cyclic undecapeptide in different vascular tissues isolated from a diverse range of mammalian species (rats, mice, dogs, pigs, marmosets and cynomolgus monkeys).
The vasoconstrictor activity of human U‐II was dependent upon the anatomical origin of the vessel studied and the species from which it was isolated. In the rat, constrictor responses were most pronounced in thoracic aortae and carotid arteries: −log[EC50]s 9.09±0.19 and 8.84±0.21, Rmaxs 143±21 and 67±26% 60 mM KCl, respectively (compared, for example, to −log[EC50] 7.90±0.11 and Rmax 142±12% 60 mM KCl for endothelin‐1 [ET‐1] in thoracic aortae). Responses were, however, absent in mice aortae (−log[EC50] <6.50). These findings were further contrasted by the observation that U‐II was a ‘coronary‐selective’ spasmogen in the dog (−log[EC50] 9.46±0.11, Rmax 109±23% 60 mM KCl in LCX coronary artery), yet exhibited a broad spectrum of vasoconstrictor activity in arterial tissue from Old World monkeys (−log[EC50]s range from 8.96±0.15 to 9.92±0.13, Rmaxs from 43±16 to 527±135% 60 mM KCl). Interestingly, significant differences in reproducibility and vasoconstrictor efficacy were seen in tissue from pigs and New World primates (vessels which responded to noradrenaline, phenylephrine, KCl or ET‐1 consistently).
Thus, human U‐II is a potent, efficacious vasoconstrictor of a variety of mammalian vascular tissues. Although significant species/anatomical variations exist, the data support the hypothesis that U‐II influences the physiological regulation of mammalian cardiovascular function.
British Journal of Pharmacology (2000) 131, 1262–1274; doi:10.1038/sj.bjp.0703690
DOI: 10.1038/sj.bjp.0703690
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