The Application of Newer Histochemical and Isotope Techniques for the Localisation of Protein-bound Cystine or Cysteine to the Study of Hypothalamic Neurosecretion in Normal and Pathological Conditions

Abstract

It is probable that the elaboration of the posterior pituitary principles is elosely related to the secretion and Storage of a hypothalamo-neurohypophysial neurose ere tory material. It is suggested that histochemical techniques for the demonstration of this neurosecretory material should fulfill certain criteria which stem from the ad vances made by Bargmann (1954) and his colleagues in the field of neurosecretion. Thus such histochemical techniques should be at least as sélective as the Gomori chrome-alum-haematoxylin (CAH) staining method. Further the substances thus demonstrated should behave like material staining with CAH, both in the hypophysectomised animal, and in animais exposed to osmotic stress. The only histochemical techniques which satisfy these criteria demonstrate substances rieh in protein-bound cystine or cysteine. Because of their selectivity and known histochemical basis thcy have a number of applications, in particular in comparative morphology and pathology. Their suecess has recently led us [Arnott and Sloper (1957)] to attempt to study the dynamics of neurosecretion with the aid of radioactive (S³⁵) labelled cysteine.