COORDINATION 



449 



from the pituitary called adreno-cortico- 

 tropic-hormone or ACTH, for short. This 

 substance has only recently been isolated 

 in sufficiently pure form so that it can be 

 used in treatment of patients. Its action 

 parallels cortisone in every respect, which 

 proves that its action is through the adrenal 

 cortical hormone. Therefore, ACTH must 

 control the cortisone output. By increasing 

 the ACTH, cortisone is also increased. 



An interesting sidelight on the discovery 

 of ACTH came from a common observa- 

 tion, namely, that during pregnancy ar- 

 thritic women recover from their rheuma- 

 tism. Shortly after the child is delivered the 

 disease returns. Both cortisone and ACTH 

 have the same remitting effect as preg- 

 nancy. Apparently, the added burden of 

 child-bearing stimulates a greater output of 

 ACTH whic'ii, in turn, stimulates a greater 

 production of cortisone, the combined ac- 

 tion of which improves the arthritis. Just 

 what the specific action is on the disease 

 itself is not known. 



Both of these hormones have proven 

 beneficial in cases of extensive body injury 

 such as that caused by severe lacerations or 

 burns. They serve to muster all the body's 

 potentials toward regenerating new tissue 

 as well as preventing shock and the other 

 symptoms associated with severe trauma. 



Gonadotrophin effects. A young hypoph- 

 ysectomized animal never becomes sexu- 

 ally mature, and if the operation occurs 

 after maturity there is prompt atrophy of 

 the sex organs. There is thus a close and 

 important relationship between the pitui- 

 tary and the sex glands. There are at least 

 two gonad-stimulating hormones produced 

 by the anterior lobe of the pituitary gland: 

 one is called FSH ( follicle-stimulating hor- 

 mone) and the other LH (luteinizing hor- 

 mone ) . Both are complex proteins and have 

 only recently been isolated in pure form. If 

 no FSH is produced, Graafian follicles fail 

 to form in the female and seminiferous tu- 

 bules cease to function in the male. With- 

 out LH none of the Graafian follicles will 



release their eggs, nor will the interstitial 

 tissue of the testis produce testosterone. 

 Restoration of these two hormones to a 

 hypophysectomized animal allows normal 

 development of the sexual organs and in 

 the female insures normal functioning all 

 the way to pregnancy and full term devel- 

 opment of the fetus. 



It should be pointed out here that the 

 placenta, in addition to secreting hormones 

 that supplement those of the ovary, also 

 produces a gonotrophic hormone resem- 

 bling LH. This is produced in such large 

 quantities early in pregnancy that it ap- 

 pears in the urine. Some enterprising endo- 

 crinologists have taken advantage of this 

 fact by developing a pregnancy test which 

 is quite accurate. It consists of injecting 

 small quantities of concentrated urine un- 

 der the skin of a male frog. If LH is pres- 

 ent in the urine — as it will be even in a 

 pregnancy no more than two weeks old — 

 sperm will be shed by the frog. Similar but 

 not so simple tests have been devised using 

 rats and rabbits. 



As was pointed out in an earlier section 

 on the gonadal hormones, the mammary 

 glands develop under the impetus given 

 them by estrogen, progesterone, and pos- 

 sibly another hormone. Even after they are 

 fully formed, lactation (secretion of' milk) 

 will not occur unless still another hormone, 

 lactogen, is produced by the pituitary. This 

 is sometimes referred to as the "maternal 

 instinct" hormone, because it will produce 

 certain mothering behavior in animals 

 which normally do not possess such in- 

 stincts, an old male dog, for example. If 

 such an animal is given this hormone in suf- 

 ficient quantities over a period of time it 

 will not only mother pups but will also 

 produce milk to feed them. 



The posterior lobe. The posterior lobe 

 functions in maintaining the proper water 

 balance in the body, among other things. 

 If it is damaged or removed, water is not 

 reabsorbed in the kidney tubules. This re- 

 sults in a great urine flow (from 3 to 10 



