MAMMARY C5LAND AND LACTATION 



603 



Fig. 10.6. Typical areas of whole mounts of the abdominal mammary gland of rat.s after 

 the following treatments: A. Untreated rat on day 31, 14 days after hypophysectomy. The 

 gland has regressed to a bare duct system. B. Rat hypophysectomized and ovariectomized on 

 day 30 and injected daily with 2 mg. somatotrophin (STH) for 7 days. Note the presence 

 of end clubs, r. Rat treated as in B but which received, in addition to the STH, 1 ^g. estrone. 

 Note profuse eiid-rhil' ] iroliferatiou. D. Rat li.\|M)]ili\s(>ctomized on day 30. ovariectomized 

 and adri'nali^ctoinized on day 60, and injected daily from days 60 to 69 with 1 mg. STH + 

 0.1 mg. DCA + 1 fig. estrone. Note again the profuse number of end buds indicative of 

 duct proliferation. E. Same treatment as in D followed by 10 days treatment with 5 mg. 

 prolactin + 2 mg. STH + 1 /xg. estrone + 2 mg. progesterone + 0.1 mg. DCA + 0.05 mg. 

 prednisolone acetate. Note excellent lobule-alveolar growth. F. Same treatment as in D 

 followed by 20 days treatment with 5 mg. prolactin + 2 mg. STH + 1 fig. estrone + 2 mg. 

 progesterone + 0.1 mg. DCA + 0.05 mg. prednisolone acetate; thereafter given 0.1 mg. pro- 

 lactin locally over this gland and 0.1 mg. DCA + 0.1 mg. prednisolone acetate systemically for 

 6 days. Note fully developed lobules with ah'eoli filled with milk. (All glands at the same 

 magnification.) (From W. R. Lyons. C. H. Li and R. E. Johnson, Recent Progr. Hormone 

 Res., 14, 219-254, 1958.) 



