Novel monosaccharides as potent inhibitors of cell proliferation

The effects of several novel monosaccharides upon thymidine incorporation into both normal and tumour cells were investigated. The monosaccharide 2-deoxy-3-[1-(R)-(ethoxycarbonyl)ethyl]-α-D -allo-pyranose had the most inhibitory effect on proliferation, with the (S)-enantiomer having less inhibitory effects. The chiral centre at carbon-7 was found to be an important part of the molecule, as 2-deoxy-3-[methoxycarbonyl methyl]-α-D -allo-pyranose had greatly decreased anti-proliferative properties in comparison with the parent compound. In addition, the 2-deoxy structure at carbon-2 was also found to be important, as 3-[1-(S)-(ethoxycarbonyl)ethyl]-α-D -allo-hexopyranose had greatly decreased inhibitory properties in comparison with the parent compound. The results indicate that these novel monosaccharides possess potent anti-proliferative properties, related to their chiral carbon-7 and 2-deoxy carbon-2 structure and suggest that further substitutions of the functional group at carbon-7 may improve these properties and possibly produce inhibitor selectivity for tumour cells in preference to normal cells. © 1997 John Wiley & Sons, Ltd.     

Plasma concentrations of progesterone and 13,14-dihydro-15-keto-prostaglandin F-2 alpha during regression of the corpora lutea of lactation in the bandicoot (Isoodon macrourus)

Plasma progesterone concentrations (mean +/- s.e.m.) declined from 7.5 +/- 1.2 ng/ml and 7.5 +/- 1.0 ng/ml to less than 1 ng/ml after removal of pouch young (RPY) from bandicoots at Days 24 and 30 of lactation respectively. In all 7 bandicoots, the corpora lutea of lactation showed signs of regression and, in 5 of these bandicoots, a premature ovulation had occurred 6-9 days after RPY. There was no change in the concentration of PGFM after RPY, and uterine prostaglandin F-2 alpha may not be involved in luteal regression in the bandicoot.     

Uterine oxytocin receptors in an Australian marsupial, the brushtail possum, Trichosurus vulpecula

1. Oxytocin receptors in the uterus of the brushtail possum (T. vulpecula) were characterized by radioreceptor assay and compared with those of the sheep and rat uterus. 2. A single oxytocin binding site was found with an affinity (Kd) and receptor concentration (Ro) of 3.0 +/- 0.8 nmol/l and 200 +/- 60 fmol/mg protein, respectively (SEM; n = 5). The receptor was stable at -20 degrees C; divalent ions were required for optimum binding. 3. Competitive displacement curves with related peptides showed the following order of specificity: vasotocin greater than oxytocin greater than mesotocin = arginine-vasopressin = [Thr4, Gly7]-oxytocin greater than lysine-vasopressin = isotocin much greater than [d(CH2)5, D-Phe2, Ile4, Ala9-NH2]-AVP. 4. It was concluded that oxytocin receptors in the possum have similar characteristics to those of placental mammals.