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Nuts about Grapes

Dr. Cottenpurg has become a consultant for Huron Vineyards who wish to establish a scientific basis for their enterprise by using biotechnology to develop the "Supreme Grape". They are interested in producing high quality red wine which would not only be suitable for the Canadian palate but also pander to our propensity for promoting a healthy lifestyle. Dr. Cottenpurg has been interested in studies suggesting that consumption of red wine may be protective against coronary artery disease and decides to explore the possibilities that some component of the wine may alter vascular smooth muscle function. His enthusiastic new post doc, Jorge Luis, is quite excited and offers to do the necessary experiments.

Jorge Luis sets up rat aortic rings in physiological salt solutions and records isometric tension in response to different agonists. He compares the responses of intact rings with those that have been denuded of the endothelium by gently rubbing the luminal surface with curved forceps. Red wine added to the bathing fluids produced a definite relaxation of rings pre-contracted with the adrenergic agonist, phenylephrine (PE) (see Fig 1). Pretreatment with a fixed concentration of the wine alters the responses to a subsequent addition of PE (see Fig. 2). By testing the effects of serial dilutions of the wine, Jorge-Luis is able to estimate an EC50.

The Red Huron, the most potent product of the Huron estates, is twice as powerful as others tested, including two Cabernet Sauvignons (a French from 1990 and a California 1991), and a California Burgundy (all red wines). In several experiments, a white Bordeaux (French 1990) and a California Chardonnay (1989), another white wine, are extremely weak and are not investigated further.


Fig 1. Shows a single representative trace. The addition of PE (10-5M) produces a sustained contraction. Addition of Red Huron Wine (RHW) produces a prompt relaxation.

rhw1.jpg (9687 bytes)


Fig. 2. Shows the responses of aortic rings to the cumulative addition of PE in control tissues (black circles) and those pretreated with a 1:100 dilution of RHW (open circles). (A) Shows results from tissues that had an intact endothelium. (B) Refers to tissues that were denuded of endothelium as described. Each data point is the Mean SEM from 4 separate experiments.

rhw2.jpg (32918 bytes)

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