HORMONES 



309 



constitution is therefore not known. However, it tends to follow secre- 

 tin in extraction and purification procedures and may be a peptide. 



Entcrogastrone. This hormone is also secreted by the duodenal mucosa, 

 but it has the effect of inhibiting the movements of the stomach, as well 

 as the stomach's secretion of hydrochloric acid. Secretion of entero- 

 gastrin into the blood stream is brought ab(jut by the presence in the 

 small intestine of fatty acids, especially oleic acid, soaps, neutral fat, 

 or relatively concentrated solutions of sucrose, glucose, or lactose. The 

 hormone has not been isolated in pure form, but the best preparations 

 contain amino acids and have the properties of peptides. If sufficiently 

 pure preparations to avoid undesirable side effects were available, entcro- 

 gastrone would be of value for the treatment of gastric ulcers in human 

 patients. 



REVIEW QUESTIONS ON HORMONES 



1. Distinguish between hormones and vitamins. 



2. Name two hormones which are derived from amino acids in the animal body, 

 and outline the process by which this conversion takes place. 



3. Define the terms: vasoconstrictor, secretogogue, androgen, estrogen, endocrine 

 organ, gastrin, oxj'tocin. 



4. Point out the similarities and differences between the types of diabetes caused 

 by alloxan, phlorhizin, pancreatic deficiency, and posterior pituitary deficiency. 



5. Gi\-e examples to illustrate three different ways in which the quantity of hor- 

 mones secreted by various glands is controlled in the body. 



6. Make a list of hormones known to participate in the process of reproduction 

 in mammals. Indicate briefly the function oi each. 



7. Outline the mechanisms by which the blood calcium level is controlled, explain- 

 ing the influence of each factor. What are the consequences of abnormal blood 

 calcium levels? 



8. To which chemical classes do the majority of hormones belong? Give examples. 



9. List diseases caused by abnormal hormone production in animals, and name 

 the hormone associated with each. 



10. Why is the pituitary sometimes called the "master gland" of the animal or 

 human body? 



REFERENCES AND SUGGESTED READINGS 



Abel, J. J., Ceiling, E. M. K., Rouiller, C. A., Bell, F. K., and Wintersteiner, O., 

 "Ciystalline Insulin," J. PharmacuL, 31, 65 (1927). 



Banting, F. G., Best, C. H., Collip, J. B., and MacLeod, J. J. R., "Preparation of 

 Pancreatic Extracts Containing Insulin," Trans. Roy. Soc. Canada, 16, Sect. V, 1 

 (1922). 



Colowick, S. P., Coi-i, G. T., and Slein, M. W., "The Effect of Adrenal Cortex and 

 Anterior Pituitaiy Extracts and In.sulin on the Hexokinase Reaction," J. Biol. 

 Chem., 168, 583 (1947). 



Cori, C. F., "Enzymatic Reactions in Carbohydrate Metabolism," The Harvey Lec- 

 tures (1945-46), p. 253. 



