A comparison of the isomers of warfarin

The Principles of Biological Assay

Physiology and chemistry of parathyroid hormone

http://science.sciencemag.org/content/sci/105/2727/368.full.pdf

Detection of Hypoglycemic Reactions in the Mouse Assay for Insulin.

Many attempts have been made to work out a convenient method for the assay of parathyroid hormone. That this, however, is still to be achieved is indicated by the fact that most investigators who have attempted to purify the hormone have tested their preparations by measuring the increase of serum calcium in dogs as originally described by Collip & Clark (1925). A partially successful attempt to break away from this tradition was made by Tepperman, L'Heureux & Wilhelmi (1947), who utilized the fall in serum phosphate of normal rats as a measure of parathyroid activity. However, the recent preparation by Stewart & Bowen (1952) and Davies & Gordon (1953b) of gland extracts devoid of effect on plasma calcium, but still capable of stimulating the renal excretion of inorganic phosphate, demonstrates the need for separate methods, dependent on changes in either calcium or phosphate, to measure the two types of activity. The present paper reports an attempt to work out a test based on changes in the plasma calcium level of parathyroidectomized rats. Unfortunately, the normal rat is known to be relatively resistant to injected parathyroid hormone. Thus Biering (1950), who described a method in which serum calcium changes in normal rats were measured, found it necessary to use approximately 1000 u.s.p. units of hormone to secure an increase of 3 mg Ca%. Rather large amounts of hormone were also employed by Pugsley (1932), Dyer (1933), Olsen (1934), Truszkowski, Blauth-Opienska & Iwanowska (1939), who all measured increases in the urine calcium of normal rats. Fortunately, Tweedy & Chandler (1929) observed a noticeable increase in the sensitivity of the plasma calcium response in rats after parathyroidectomy, and this has been taken advantage of in the present work. Such animals, unless kept on a low calcium high phosphate diet, rarely show signs of tetany (Shelling, 1932) and

https://physoc.onlinelibrary.wiley.com/doi/pdf/10.1113/jphysiol.1954.sp005166

Lloyd C. Miller

Papers

The Assay of Digitalis *:I. Criteria for evaluating various methods using frogs

The Dose-Response Relationship in the U. S. P. XI Parathyroid Assay