320 



ANIMAL BIOCHEMISTRY 



The hormones thus far isolated from the anterior lobe of the pitui- 

 tary have all been proteins of medium molecular weight. All of them 

 exert a control effect on other glands with secondary effects on meta- 

 bolic reactions. Further research will undoubtedly show the existence 

 of additional control factors in this portion of the pituitary gland. 



POSTERIOR LOBE. Information on the control functions of the pos- 

 terior lobe is meager and is hard to obtain because of the difficulty in 

 removing that portion of the pituitary without seriously injuring the 

 anterior lobe. Present evidence on apparently successful operations 

 indicates a controlling action on urinary output and water intake and 

 on smooth muscles in general. On removal of this lobe both water 

 excretion and water intake increase in a manner similar to that en- 

 countered in diabetes insipidus. Many cases show improvement on 

 administration of posterior lobe extracts. 



Much of the information available on the action of the pituitary 

 gland has resulted from observations of the pharmacological effects of 

 injection of extracts or fractions thereof upon normal animals. Such 



tyrosine 



H 

 O 



r.^^^^ 



CH. 



isoleucine 



NH2 o 



CHo 



CH3 



CHo O 



CH 



CHo — CH — C — NH — CH — C — NH — CH 



cystine 



o 



c=o 



O CH2— C— NHo O NH 



O 



CH2— CH— NH— C— CH- 



-NH- 



c=o 



I 

 ■ N 



CHs 



asparagine 



o 



II 



-C— CH— CHo— CHo— C— NH2 



glutaniine 



o 



o 



-CH— C— NH— CH— C— NH— CH2— C— NH2 



glycinaniide 



CH2 CHo 



CHo 



proline 



CH 



CH3 CH3 



leucine 

 oxytocin 



