The effect of half, double, and quadriple concentrations of the normal (2gm/litre or 10mM) concentration of glucose in the Kreb’s physiological saline were tested on vascular tissues activated by 3M noradrenalline or 100mM potassium chloride olution. The smooth muscle tissues were from isolated tail artery which were perfused with and bathed with calcium buffered physiological saline and with which six consecutive calcium concentration response curves were constructed  for each glucose concentration.

It has been shown that desensitization of the responses of vascular smooth muscle could occur if the physiological saline composition is altered. The extent to which Bay K 8644 and nifedipine affect the calcium responses of a vascular
smooth muscle and their effects on desensitized tissue responses are yet to be quantified and this is what this study aims at doing on calcium-mediated responses in the rat tail artery and on the desensitization of the responses of the

Previous investigators could not account for the factors causing the initial decline between the first and subsequent responses. They rather had neglected the first  few responses or the first concentration response curve (CRC) in the name of allowing the tissue to stabilize. The second or even the third CRC is often taken to represent the control curve for the analysis of drugs.