Mammary gland differentiation in hypophysectomized, pregnant mice treated with corticosterone and thyroxine.

Swiss Webster mice were hypophysectomized or sham-operated on Day 11 of pregnancy. The animals were fitted s.c. with osmotic minipumps containing either corticosterone (B) dissolved in Molecusol (Pharmatec, Alachua, FL) or the vehicle alone immediately after they were hypophysectomized. Animals in some of the experimental groups also received thyroxine (T4) in their drinking water. The mice were killed on Day 18 of gestation, and mammary tissue was homogenized and extracted for assessment of DNA, RNA, alpha-lactalbumin, and alpha-casein. Serum was assayed for placental lactogen-I (PL-I), and placental lactogen-II (PL-II), B, and T4. The concentration of PL-II in serum was elevated in the hypophysectomized mice, whereas the PL-I concentration did not differ among experimental groups. Hypophysectomy decreased both T4 and B concentrations in serum, and administration of these hormones restored their serum concentrations to normal or, in some cases, somewhat higher than normal levels. Hypophysectomy reduced the total RNA content and RNA/DNA ratio of the mammary gland, but treatment with B alone or with B and T4 restored RNA levels to those of sham-operated animals. T4 alone was ineffective in restoring RNA levels. Sham-operated animals that received hormonal treatment (B and T4) had the highest levels of RNA in the mammary tissue. Hypophysectomized animals had reduced content and concentration of alpha-lactalbumin in the mammary gland as compared to all other experimental groups.(ABSTRACT TRUNCATED AT 250 WORDS)     

Lawsone accumulation in normal and transformed cultures of henna,Lawsonia inermis

The improvement of axillary shoot formation of Lawsonia inermis L. cultured in vitro depended on the iron concentration in the culture medium. Regenerated shoots were rooted on a hormone-free half-strength Murashige and Skoog medium (1/2 MS) before transfer to greenhouse conditions. Determination of lawsone in the plant material was investigated using a new HPLC method. The results showed that lawsone accumulation in vivo is restricted to the aerial part of the plant. In addition, the possibility of inducing lawsone biosynthesis in root cultures was studied. Hairy root cultures were established by a co-culture method using leaf segments of L. inermis and Agrobacterium rhizogenes NCIB 8196. Of several basal media tested, the production of lawsone (0.13% dry weight) was only observed in hairy roots tissues incubated in the dark and cultured in 1/2 MS or MS media. This revised version was published online in June 2006 with corrections to the Cover Date.