Bayer (1) first synthesized acetylcholine but for a long time this substance attracted little pharmacological interest. In 1901, Hunt (2) suggested that an ester of choline might be the active material released by parasympathetic nerve endings. Five years later, Hunt and Taveau (3) reported that the acetate ester of choline was one thousand times more potent in its depressor action than choline itself. [...]

It was known since ancient times that one generally becomes immune to certain disease, such as smallpox after the recovery from that disease. The method of artificial immunization was however not known until the end of the 18th century when Jenner showed that the artificial immunity against smallpox could be conferred upon an individual by vaccination with cowpox virus. [...]

The problem of sulfate and glucuronide conjugation of naturally occurring compounds, specifically steroids, has intrigued investigators for many years. The early workers regarded conjugation as only a form of detoxification. It was not until much later that a wider significance was applied to this phenomenon, as that of an important process in the activity or metabolism of these compounds. [...]

At the end of the 19th century, horse serum was introduced as a source of antitoxin in the treatment of human diseases. This event marked the beginning of an interest in the properties of equine antiserum. [...]

The research presented in this thesis is part of a larger undertaking concerning the site, mode of synthesis and secretion or serum lipoproteine and their constituants, which is being carried out under the direction or Dr. D. Rubinstein,in the Department or Biochemistry, McGill University. [...]

In 1811, Nicolas Vauquelin reported the presence of potassium in brain (408). Ana1yzing the ash residues of muscle, Liebig found more potassium than sodium (cited by Kaunitz,211). He suggested that potassium occupies an intracellular position and sodium, an extracellular position, in muscle tissues (see Tower,392). Since that timea long series of analytical studies have shown that an analogous distribution of the two elements exist almost universa1ly in bacterial, plant and animal cells (see Reinberg,J27). Fenn has defined this phenomenon, writing: "As is well known, potassium is of the soi1 and not the sea; it is of the cell but not the sap" (122). [...]

The occurrence of neutral 16-hydroxylated steroids in biological materials has been recognized for many years. In 1940, Marker and Turner (1) demonstrated the presence of a 16-hydroxy group in a steroid isolated 7 years previously by Smith et al from pregnant mares urine (2). It was not until 1945 however that Hirschmann (3) showed the compound to be 5α-pregnan-3ß,l6α,208-triol. [...]

The phenomenon of regeneration in various animals as a distinct form of growth has interested classical biologists for over two centuries and it has been viewed as a particular case of a general phenomenon of growth. The literature pertaining to this historical era of development in morphological thought has been adequately reviewed by D'Arcy Thompson (1). [...]

The fundamental discovery by investigators at the Worcester Foundation that perfused bovine adrenals can hydroxylate steroids (1, 2) opened the way for numerous studies concerning the biosynthesis of steroids in endocrine tissue. To catalogue the reported findings which have since been published would not be possible in a thesis. As a result, the survey of the literature in this section will be confined to those reports which are most relevant to the investigations to be described. A number of comprehensive reviews and chapters are referred to which have discussed the biosynthesis of steroids fully (3-12). In addition, this author would like to refer to the excellent review of cholesterol biosynthesis by Tchen (13) and to a survey of the literature on adrenal androgens by Dorfman (5) . [...]

A neurohumoral transmitter is a substance which not only is released when a nerve is stimulated but which also is capable of exhibiting effects like those of nervous stimulation. There is no reason to doubt that such substances play an important part in transmitting impulses from the nerve to its effector organ (1). [...]