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A Komor

Publications and source records attributed to A Komor.

13 recordsLinked to original sources
PubMed1985

[Chromosome analysis of female baboons following treatment with STS 557 and levonorgestrel].

Adult, female baboons (Papio hamadryas) were administered orally once 18 h p.c., either 1.6 mg STS 557 (17 alpha-cyanomethyl-17 beta-hydroxy-estra-4;9(10)-dien-3-one) or 1.6 mg levonorgestrel. Investigations of the bone-marrow cells of these animals showed, compared to untreated controls, no signs of increased chromosome aberrations caused by the substances. The relative frequency of chromosome aberrations were estimated for controls: STS 557: levonorgestrel with 0.60 +/- 0.35 : 0.55 +/- 0.39 : 0.92 +/- 0.46%, respectively. The differences between the three groups investigated in the exact Fisher-test (2 alpha = 0.05) were not significant.

Animals↗
PubMed1983

Studies on pharmacokinetics of STS 557 in animal species and man.

Following oral and i.v. administration of [14 alpha, 15 alpha-3H]-STS 557 to beagle dogs, baboons, rats and female volunteers, plasma level courses of total radioactivity and STS 557, and radioactivity excretion in urine and feces have been investigated. Bioavailability of orally administered STS 557 was found to be 80--90% in man and beagle dog, 70--80% in baboon and rat. Concerning the systemic availability following oral administration of equivalent doses, the following order was established: beagle dog greater than man greater than baboon greater than rat. Equilibrium dialysis indicates species differences in plasma protein binding and a considerable part of STS 557 to be present in plasma unbound. STS 557 is rather rapidly eliminated from the plasma compartment of all species investigated with half lives less than or equal to 10 h. As an additional time parameter of pharmacokinetics the "mean residence time" was used. Urinary excretion of STS 557 metabolites is dominant in all species, including the rat. In contrast to the great part of STS 557 in plasma total radioactivity, only small amounts of unchanged STS 557 are excreted in urine. First results of current studies in rabbits are presented, too.

Animals↗
PubMed1983

STS 557 as an interceptive in baboons.

STS 557 (17 alpha-cyanomethyl-17 beta-hydroxy-estra-4, 9-dien-3-one) or levonorgestrel was given orally as a single dose of 0.4 mg per animal. Treatment was performed immediately after the 18 h or 6 h mating period. Regarding the 18 h mating period, in 30 control cycles (20 animals) 11 pregnancies (36.7%) and in 20 cycles (16 animals) with levonorgestrel treatment 2 pregnancies (10.0%) were observed. In 80 cycles (31 animals) with STS 557 treatment 7 pregnancies occurred (8.7%). With regard to the 6 h mating period, in 30 control cycles (18 animals) 9 pregnancies (30%) and in 26 cycles (17 animals) with levonorgestrel administration 3 pregnancies were recorded (11.5%). In 50 cycles (21 animals) with postcoital administration of STS 557 only two pregnancies occurred (4%). Therefore, after the 6 h mating period STS 557 showed high interceptive activities in this non-human primate model. In comparison with controls, STS 557 did not decrease the postovulatory rise of plasma progesterone. This finding demonstrates that postcoital STS 557 in the chosen dosage does not suppress ovulation. Repeated STS 557 administration starting early in the follicular phase was without marked influence on cycle characteristics. On the other hand, treatment start in the middle or at the end of the cycle caused cycle lengthening and reduced progesterone levels in some animals.

Animals↗
PubMed1982

Further report on the interceptive STS 557 in baboons.

STS 557 (17 alpha-cyanomethyl-17 beta-hydroxy-estra-4,9(10)-diene-3-one) or levonorgestrel was given orally as a single dose of 0.4 mg per animal. Treatment was performed immediately after the 6 h mating period. In 30 control cycles (18 animals) 9 pregnancies (30%) and in 26 cycles (17 animals) with levonorgestrel treatment 3 pregnancies (11.5%) were observed. In 46 cycles (21 animals) with STS 557 treatment only one pregnancy (2.2%) occurred (chi 2-test: P less than 0.01 as compared to control cycles). Therefore, STS 557 showed high interceptive activities in this nonhuman primate model. In contrast with levonorgestrel, STS 557 did not decrease the postovulatory rise of plasma progesterone.

Administration, Oral↗
PubMed1981

[Chromosomal analysis of baboons and their mothers, following application to mothers of potentially post-ovulation fertility-inhibiting steroids (author's transl)].

One single does of 0.4 mg of steroid compounds Levonorgestrel (13-ethyl-17alpha-ethinyl-17beta-hydroxy-gon-4-en-3-on) or STS 557 (17alpha-cyanomethyl-17beta-hydroxy-13beta-methylgona-4.9-dien-3-on) was administered to each of six baboon mothers, right after mating. No indication whatsoever to possible mutagenic action of the compounds applied under the given experimental conditions were recordable from the bone-marrow cells of the mothers nor from the lymphocytes of peripheral blood of their newborns. Chromosomal aberrations recorded from this species were within normal limits.

Animals↗
PubMed1980

STS 557 as an interceptive in rodents and baboons.

Studies with mice, rats, guinea pigs and baboons were undertaken to define the interceptive action of the new progestin STS 557 (17 alpha -cyanomethyl-17 beta-hydroxy-estra-4.9(10)-diene-3-one) and to compare it with other progestins used in oral contraceptives. STS 557, norethindrone and norethindrone acetate reduced deciduoma formation as well as the number of implantations in mice and rats. Chlormadinone acetate and levonorgestrel when administered at the appropriate dose could not prevent early pregnancy or deciduoma formation. But in contrast to STS 557, levonorgestrel maintained early pregnancy in ovariectomized rats. On the other hand, STS 557 was ineffective as a postcoital agent in guinea pigs. When 0.4 mg STS 557 was orally administered to 37 female baboons 3 or 6 h after the mating period, only one pregnancy occurred in a total of 60 cycles investigated (controls: 11 pregnancies in 12 cycles investigated). The results are discussed in view of the development of an interceptive method based on STS 557.

Animals↗
PubMed1978

[Postcoital contraception in primates. II. Examination of STS 153 and STS 287 as interceptives in the baboon (Papio hamadryas)].

The interceptive activity of 2 new synthesized steroid compounds: STS 153 (17 beta-Phenylaminocarbonyloxy-estra-1,3,5(10)-triene-3-methyl ether and STS 287 (16 alpha-Bromo-17 beta-[N',N'-dimethylhydrazino]-carbonyloxy-estra-1,3,5(10)-triene-3-methyl ether) and of 17 alpha-Ethynylestradiol was investigated in baboons.--Postcoital oral administration of 1--3 mg/kg b. w. STS 153 for 5--7 days and of 1 mg/kg b. w. STS 287 for 5 days resulted in a fertility inhibition of about 90% and 95% respectively. A dose of 2 mg/kg b. w. of ethynylestradiol was necessary to attain complete fertility inhibition. Following administration of STS 153 and STS 287, side effects were not observed. Pharmacokinetic aspects are discussed.

Animals↗
PubMed1978

[Characteristics of the ovarianc cycle in the baboon (Papio hamadryas)].

The dynamics of estradiol, estrone, 17 alpha-hydroxyprogesterone, progesterone and 20 alpha-dihydroprogesterone were investigated in the blood plasma of the pavian (papio, hamadryas) with regard to the menstrual cycle and in comparison with the human. Furthermore results were presented about the basal temperature, the fern phenomenon and the development of the sex-skin in the pavian.

Algestone↗
PubMed1978

[Postcoital contraception in primates. I. Action mechanism of a potential postovulatory fertility-inhibiting substance STS 456 in the baboon (Papio hamadryas)].

With the substance STS 456, an estrogenic active steroid, a high fertility inhibition could be obtained in the pavian, when administered p. o. over a 5 day period postcoital. The effectiveness and also the side effects were dose dependent. The antifertility mechanism is based on an luteolytic effect, demonstrated by analytical hormonal investigations. The inhibition of the synthesis of steroids in the ovary affected not only progesterone but also the estrogens.

Animals↗