These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Enhanced contractile response to phenylephrine and increased density of [3H]PN200-110 binding sites in thoracic aorta isolated from dietary magnesium-deficient rats.
    Author: Sakaguchi H, Ishiguro S, Miyamoto A, Nishio A.
    Journal: Magnes Res; 1994 Dec; 7(3-4):199-206. PubMed ID: 7786683.
    Abstract:
    The present study was undertaken to examine whether the enhanced contractile response to phenylephrine observed in thoracic aorta isolated from dietary magnesium-deficient rats depends on an increased density of alpha 1-adrenoceptor or calcium channels. Adult male Wistar rats were fed with a magnesium-deficient diet (0.001 per cent magnesium) for 30 days with control groups (0.07 per cent magnesium). The contractile response to phenylephrine was significantly inhibited by nifedipine in both aortas without endothelium, and the degree of the inhibition was significantly greater in magnesium-deficient rats than in controls. Membranes were isolated from both thoracic aortas without endothelium, and the binding of [3H]PN200-110 or [3H]prazosin to the membranes was studied. A single binding site for [3H]PN200-110 or [3H]prazosin was evident for both membranes with high affinity. Dietary magnesium-deficiency increased significantly the maximal number (Bmax) of [3H]PN200-110 binding sites, but not Bmax of [3H]prazosin, and did not alter the binding affinity of both ligands. These results suggest that increased density of calcium channels participates in the enhanced contractile response to phenylephrine in thoracic aortas isolated from dietary magnesium-deficient rats.
    [Abstract] [Full Text] [Related] [New Search]