Progesterone potentiating effect of Dipsacus mitis D. Don for its contraceptive action in hamster.

A pure compound, isolated from ethyl acetate extract (root) of D. mitis D. Don, prevented pregnancy by 100% in adult female hamster but partially in rat when administered orally on Days 1-7 and 1-10 post-coitum respectively. The effective dose in both species was 150 mg/kg. Using uterine wet weight in ovariectomized immature rat as bioassay method, the compound was found to be devoid of estrogenic and antiestrogenic property. On examination for progestational and antiprogestational activity, using trauma-induced deciduoma formation in immature rat uterus as end points, the compound (per se) did not show the former activity but in a conjoint treatment with progesterone it augmented the action of latter. The compound was assumed to act by potentiating progesterone biosynthesis, the excess of which might be the cause for interruption of pregnancy in hamster. This is the first study to report contraceptive efficacy and mode of its action at the uterine level.

Relative potentiality of some contragestational agents on trauma induced deciduoma formation in immature rats.

Relative progestational and antiprogestational profile of four contragestational agents, viz. RMI-12,936, RU-38,486, STS-557 and WIN-32,729, known to possess either or both the properties in other test systems, was determined in immature rats using deciduoma induction as marker. The deciduoma was produced by needle traumatization in one of the uterine horn, and the extent of stimulation was analysed, both macro and microscopically, against the control nontraumatized horn. The results indicated that the agents which demonstrated better potentiality(ies) as progestational and/or antiprogestational in this bioassay exhibit contraceptive efficacy at relatively lower doses as compared to those that showed mild to moderate potentiality.

Easy criterion for detection of mating in guinea pig.

Existing criteria for determining receptivity to mating in female guinea pig has been redefined on the basis of kind of cells present in vaginal smear following its opening. The animals that showed not only cornified but also predominantly cornified cells over the leucocytes show higher sperm positivity rate. It is inferred that continuous cohabitation of these animals invariably leads to successful mating.

Decidual cell reaction: relative response to traumatization in uterus of rat, hamster and guinea pig.

Relative decidual cell response to traumatization was studied in the uterus of immature rat, hamster and guinea pig. A single dose of progesterone (1.0 mg/animal) caused 285 +/- 41 and 459 +/- 58% uterotrophy in traumatized horn of rat and hamster respectively, while in guinea pig increasing doses of progesterone (1, 2 and 5 mg/animal), several combinations of estrogen and progesterone or alteration in treatment schedule of the two hormones as well as extending the day of traumatization failed to elicit comparable uterotrophic response. Uterus of immature hamster was found to be most responsive to traumatization and that of guinea pig the least.