EFFECT OF VARIOUS BLOOD SAMPLING TECHNIQUES ON SERUM LEVELS OF PITUITARY AND THYROID HORMONES IN THE RAT

Abstract

Section of Clinical Endocrinology, Department of Medicine, and Zentrales Tierlabor, Medizinische Hochschule Hannover, 3000 Hannover 61, Germany (Received 23 March 1977) The laboratory rat has served many researchers as an excellent model in the study of endocrine mechanisms. However, the great disadvantage of this animal, especially for the endocrinologist, is its sensitivity toward many types of stress (Ducommun, Sakiz & Guillemin, 1966; Neill, 1970; Ajika, Kalra, Fawcett, Krulich & McCann, 1972; Harms, Langlier & McCann 1975). It has been shown that mild stimuli such as handling or cage transport may have significant effects on the release of pituitary, adrenal and thyroid hormones in the male rat (Baldwin, Colombo & Sawyer, 1974; Euker, Meites & Riegle, 1975; Döhler, Gärtner, von zur Mühlen & Döhler, 1977). To obtain accurate information about the genuine state of endogenous hormone circulation, it is of great importance to select blood sampling procedures which have little or