On the Measurement of Cholecystokinin

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A hormone is a chemical transmitter that is secreted from one part of the body and circulates in the bloodstream to reach a distant target in another part of the body where it exerts its biologic effect. At its inception, this was a revolutionary concept that gave birth to an entire physiological and, later, medical discipline. Early on, hormones were discovered by their biologic actions. However, the physiology of hormones could not be assessed without quantification. Fundamental to the study of hormones was the ability to measure concentrations in the blood. Although biological assays have been the cornerstone of endocrinologic measurements, the development of the radioimmunoassay (RIA) completely changed the field of endocrinology (1). The attractive features of RIA include (a) applicability to most hormones, (b) ease of performance, and (c) relatively low cost, as well as high degrees of (d) accuracy, (e) sensitivity, and (f) specificity.

Cholecystokinin (CCK) was discovered in 1928 on the basis of the ability of intestinal extracts to stimulate gallbladder contraction in dogs (2). Later it was recognized that CCK was a potent stimulant of pancreatic enzyme secretion (3). However, it was not until 1966, when CCK was purified, that the primary sequence was determined (4)(5). Early estimates of CCK-like activity in blood were based on biological assays such as pancreatic secretion or gallbladder contraction. However, these estimates were fraught with confounding problems that existed in whole animals, such as the effects of other hormones or neural influences. To circumvent these problems, a sensitive and specific in vitro bioassay was . . . [Full Text of this Article]

References

The following articles in journals at HighWire Press have cited this article:

				C. de Graaf, W. A. Blom, P. A. Smeets, A. Stafleu, and H. F. Hendriks Biomarkers of satiation and satiety Am. J. Clinical Nutrition, June 1, 2004; 79(6): 946 - 961. [Abstract] [Full Text] [PDF]