Characterization of neuromedin U effects in canine smooth muscle
| Autor: | Timothy D. Westfall, A C Sulpizio, Ishrat J. Mannan, Susan Gruver, V. Nambi Aiyar, Gerald P. McCafferty, Lisa C. Contino, Mark Pullen, J. Paul Hieble, Jyoti Disa |
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| Rok vydání: | 2002 |
| Předmět: |
Male
medicine.medical_specialty Guinea Pigs Urinary Bladder Uterus Drug Evaluation Preclinical Ileum Receptors Cell Surface Biology Cell Line Guinea pig Mice Dogs In vivo Internal medicine medicine Animals Humans Intestinal Mucosa Receptor Pharmacology Urinary bladder Binding Sites Neuropeptides Ferrets Membrane Proteins Muscle Smooth Small intestine Rats Receptors Neurotransmitter Intestines medicine.anatomical_structure Endocrinology Molecular Medicine Female Rabbits Neuromedin U Muscle Contraction |
| Zdroj: | The Journal of pharmacology and experimental therapeutics. 301(3) |
| ISSN: | 0022-3565 |
| Popis: | Two endogenous receptors for the potent smooth muscle-stimulating peptide neuromedin U (NmU) have recently been identified and cloned. Pharmacological, binding, and expression studies were conducted in an attempt to determine the receptor(s) involved in the smooth muscle-stimulating effects of NmU. The NmU peptides caused a concentration-dependent contraction of canine isolated urinary bladder. NmU did not have this same effect in the urinary bladder from rat, guinea pig, rabbit, mouse, or ferret. Although NmU had no effect on canine uterus it did cause contraction of canine stomach, ileum, and colon. As well as causing contraction of canine bladder in vitro, NmU administered systemically resulted in a significant increase in urinary bladder pressure in vivo. High-affinity binding sites for NmU were identified in canine bladder. The four NmU peptides porcine NmU-8, rat NmU-23, human NmU-25, and porcine NmU-25 displaced (125)I-NmU-25 binding with similar K(i) values (0.08-0.24 nM). A different binding profile was revealed in human embryonic kidney-293 cells transiently expressed with the canine NmU-2 receptor where porcine NmU-8 (K(i) = 147.06 nM) was much less potent than the other NmU peptides. Using TaqMan, expression of NmU-1 was detected in human urinary bladder, small intestine, colon, and uterus. Expression of NmU-2 was much lower or absent in these human tissues and undetectable in canine bladder and stomach. The results of this study reveal significant species differences in the activity of NmU. The contractile activity in human and canine smooth muscle seems to be mediated by the recently cloned NmU-1 receptor. |
| Databáze: | OpenAIRE |
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