Harness H R, Anderson R R
Proc Soc Exp Biol Med. 1975 Mar;148(3):933-6. doi: 10.3181/00379727-148-38663.
Mammary DNA, RNA and RNA/DNA were measured in groups of 10 ovariectomized rats treated for 20 days with relaxin (R) in doses of 20 and 90 guinea pig units (GPU) alone or in combination with 1 mug estradiol benzoate (EB) or EB plus 3 mg progsterone (P). No treatment, EB only, and EB plus P served as control groups. Twenty GPU R alone significantly increased DNA over the no treatment group while 90 GPU did not increase DNA any higher. Although DNA values for the EB group were higher than no treatment and EB plus P higher than EB, R was not effective in increasing DNA in combination with either EB or EB plus P.R alone at either level did not change RNA from the no treatment group, but 90 GPU R in association with EB and both levels of R in association with EB plus P significantly reduced RNA in relation to the approiate control groups. Relaxin acts synergistically with estrogen and progesterone to develop the mammary apparatus and at the same time to suppress lactation. Removing the inhibitory effects of relaxin at parturition may be an important prelude to lactogenesis.
对10只去卵巢大鼠为一组进行实验，用剂量为20和90豚鼠单位（GPU）的松弛素（R）单独处理，或与1微克苯甲酸雌二醇（EB）或EB加3毫克孕酮（P）联合处理20天，然后测定乳腺中的DNA、RNA和RNA/DNA。未处理组、仅用EB处理组以及EB加P处理组作为对照组。单独使用20 GPU的R组DNA含量相比未处理组显著增加，而90 GPU的R组DNA含量未进一步升高。虽然EB组的DNA值高于未处理组，EB加P组高于EB组，但R与EB或EB加P联合使用时对增加DNA无效。单独使用任一剂量的R组RNA含量与未处理组相比无变化，但90 GPU的R与EB联合使用以及两种剂量的R与EB加P联合使用时，与相应对照组相比RNA含量显著降低。松弛素与雌激素和孕酮协同作用，促进乳腺组织发育，同时抑制泌乳。分娩时消除松弛素的抑制作用可能是泌乳发生的重要前奏。
