Decavanadate possesses alpha-adrenergic agonist activity and a structural motif common with trans-beta form of noradrenaline.
Decavanadate, an inorganic polymer of vanadate, produced contraction of rat aortic rings at a relatively high concentration compared to phenylephrine, an agonist of alpha-adrenergic receptor. This effect was blocked by two known alpha-adrenergic receptor antagonists, prazosin and phenoxybenzamine. Decavanadate, formed by possible dimerization of V5 under acid conditions, possessed a structural feature of two pairs of unshared oxygen atoms at a distance of 3.12 A, not found in its constituents of V4 or V5. A structural motif of O..O..O using such oxygen atoms is recognized in decavanadate. This matches with a similar motif of N..O..O that uses the essential amino and hydroxyl groups of the side-chain and the m-hydroxyl group in trans-beta form of noradrenaline. The interaction of such a structural motif with the membrane receptor is likely to be the basis of the unusual noradrenaline-mimic action of decavanadate.
Venkataraman
B V
BV
Department of Biochemistry, Indian Institute of Science, Bangalore, India.
Ravishankar
H N
HN
Rao
A V
AV
Kalyani
P
P
Sharada
G
G
Namboodiri
K
K
Gabor
B
B
Ramasarma
T
T
D000316:Adrenergic alpha-Agonists / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D001011:Aorta / Q000187:drug effects; D066298:In Vitro Techniques; D009682:Magnetic Resonance Spectroscopy; D008968:Molecular Conformation; D009119:Muscle Contraction / Q000187:drug effects; D009638:Norepinephrine / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis; D051381:Rats; D017208:Rats, Wistar; D014638:Vanadates / Q000737:chemistry / Q000494:pharmacology*
D000316:Adrenergic alpha-Agonists; D011108:Polymers; D014638:Vanadates; D009638:Norepinephrine