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Biomedical subjects

M Oettel

Publications and source records attributed to M Oettel.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1982

Further report on the endocrinological profile of 17 alpha-cyanomethyl-17 beta-hydroxy-estra-4,9(10)-diene-3-one (STS 557) in rodents.

STS 557, a new orally active progestin with antifertility properties has been tested for uterotrophic, antiuterotrophic, vaginotrophic, and antiovulatory effects. Further, maintenance of pregnancy in ovariectomized mice, influence on pregnancy in mice and rats, and conditioning of the immature rat uterus for decidual response were investigated. Both estrogenic and anti-estrogenic activities in mice and rats were found to be very low. STS 557 fails to maintain pregnancy in ovariectomized animals but does not interfere with pregnancy in intact mice if implantation already took place. Moreover, no effects have been found regarding the influence on the first ovulation in prepuberal rats. The biological profile of STS 557 in animals seems to make this compound suitable for use as a post-coital contraceptive.

Animals↗
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

Induction of pituitary tumours and hyperprolactinemia in female rats by estrogens. The effect of apomorphine, reserpine and L-dopa.

Prolonged estrogen treatment induced an enlargement of the anterior pituitary gland and finally resulted in irreversible pituitary tumours. Using continuous estrogen delivery [subcutaneous (s.c.) cholesterol-estrogen implants], the effects of ethinyl estradiol and the likewise synthetic estrogens STS 153 and STS 456 have been studied with or without concomitant administration of a progestogen without anti-estrogenic activities (STS 557). There was a dose-dependent prolactin cell-stimulating effect of all these estrogens. Ethinyl estradiol (EE2) had the most marked effect followed by STS 456 which coincides with the relative uterotrophic activity found in rats and mice. The elevated serum prolactin levels in rats with an EE2 implant for 6 months could be reduced slightly but not significantly by apomorphine and reserpine at a daily dose of 100 micrograms/animal and 5 micrograms/animal, respectively. Daily administration of 300 micrograms L-dopa led to a slight but insignificant increase of serum prolactin. The high pituitary weight and serum prolactin levels induced by long-term EE2 treatment were partially reversible after implant withdrawal.

Animals↗
PubMed1980

Lysozyme (muramidase) and hemolytic complement (CH50U) in sera of beagle dogs and minipigs after longterm application of different preparations of estrogens and gestagens.

In studies for the chronic toxicity of estrogens and gestagens, lysozyme and hemolytic complement (CH50U) in sera of beagle dogs and minipigs were measured. Various doses of the sexsteroids were given: 0.01 mg, 0.1 mg and 1.0 mg/kg respectively. The influence of the steroids on the tested parameters after an application for 6 months was not significant, only in a single series with unphysiologically, high dosages of the preparations were some values changed significantly.

Animals↗
PubMed1980

Embryotoxic effects of post-coital fertility inhibiting steroids.

In mice post-coital estrogens caused retardation of tubal egg cleavage, whereas post-coital progestins stimulated egg division. In rats the situation was reversed. In this species estrogens accelerated the tubal embryo development and vice versa; the progestin STS 557 arrested division of embryos resting in the tube. Normal implantation occured following transfer of early blastocysts from estrogen-treated mice to untreated mice, but not following transfer of blastocysts from untreated animals to estrogen-treated animals. This shows that post-coital estrogens do not affect the embryos directly but they disturb the physiological integrity of the endometrium required for proper implantation.

Abnormalities, Drug-Induced↗
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↗
PubMed1980

Effect of STS 557 on semen composition, fertility and sexual behaviour of male rabbits.

Fertility control of male rabbits was achieved by daily oral administration of STS 557 (17 alpha-cyanomethyl-17 beta-hydroxy-estra-4.9(10)-diene-3-one) over a period of 8 weeks. In doses of 10 and 20 mg STS 557 per animal per day, fertility inhibition was accompanied by a decrease of mean number of mounts and ejaculations. Furthermore, semen volume, number of sperm per ejaculate, and sperm motility were reduced. At a dose of 5 mg STS 557 per day, male sterility was associated with reduction of sperm motility and semen fructose content. Libido, semen volume, sperm number, and sialic acid content in semen remained unaffected. Development of male contraceptives on the basis of chronic progestin treatment without concomitant androgen supplement may thus be possible.

Animals↗
PubMed1980

STS 557, a new orally active progestin with antiprogestational and contragestational properties in rabbits.

STS 557 (17 alpha-cyanomethyl-17 beta-hydroxy-estra-4.9(10)-diene-3-one) is a potent progestin. This compound was 10 times as potent as the standard levonorgestrel as judged by the classic Clauberg-McPhail Assay. The antiprogestational response is significant when STS 557 treatment starts 2 days before progesterone administration. It does not disturb the priming activity of estradiol. This compound alone is adequate for endometrial priming. Early pregnancy is maintained in ovariectomized does. Administration on day 1 of pregnancy reduces the number of implantations. In comparison with chlormadinone acetate and d-norgestrel, only STS 557 treatment causes complete inhibition of egg fertilization.

Animals↗
PubMed1980

Effects of levonorgestrel and STS 557 on testis in rodents.

In immature male Wistar rats levonorgestrel and STS 557 (17 alpha-cyanomethyl-17 beta-hydroxyestra-4,9(10)-diene-3-one) reduced testicular growth, testicular DNA contents and plane of tubular cross-section in a dose dependent manner. In this respect, STS was less active than levonorgestrel. In immature castrated male rats the LH-suppressing effect of STS 557 was about 15 times lower than that of levonorgestrel. The results suggested that peripheral inhibitory effect of the two progestins was coupled with central LH suppression. On the other hand, in mating tests with male hybrid mice STS 557 possessed high fertility inhibiting activities in comparison to levonorgestrel and chlormadinone acetate. Limited dissociation has been shown between fertility inhibition and mating rate. All changes were reversible. Findings are discussed in view of development of male contraceptives.

Animals↗
PubMed1980

[A new class of highly active progestagens: 17 alpha-CH2X-substituted gona-4,9(10)-dienes. 58. Steroids].

The synthesis of new gona-4,9(10)-dienes with a 17 alpha-CH2X-substituent (X = CN, N3, Cl or Br) is described. The progestagenic activity of these substances was studied in the McPhail assay using immature rabbits. The compound XVI (X = CN, STS 557) is the most potent one, showing an activity about ten times higher than D-norgestrel. Differences in the activity caused by different routes of application are discussed.

Animals↗
PubMed1979

Direct evidence for the involvement of prostaglandin F2 alpha in the first step of estrone-induced blastocyst implantation in the spayed rat.

The effect of prostaglandin F2 alpha (PGF2 alpha) on blastocyst implantation in spayed rats has been studied. In preliminary experiments, the first implantation sites were observed 8 - 12 hours after a single injection of estrone in ovariectomized and progesterone-conditioned rats. Intraluminal instillation of PGF2 alpha into the right uterine horn 8 - 10 h after the estrone injection increased the number of implantation sites. Even treatment with PGF2 alpha without previous estrone injection induced the first step of blastocyst implantation as shown by uterine dye site reaction (Niagara-blue test). The results are discussed with regard to the possible role of PGF2 alpha in the regulation of the blastocyst implantation processes in the rat.

Animals↗
PubMed1979

[Postovulatory and post-implantation inhibition of fertility--general account (author's transl)].

Latest knowledge about interception and induced menstruation is discussed. Interception (postovulatory inhibition of fertility) can be undertaken by using oestrogens, anti-oestrogens and gestagens as well as non-steroid compounds. Induced menstruation is discussed as a method of post-implantation inhibition of fertility. Induction of menstruation, that is post-implantation contraception, will be feasible by means of anti-gestagens or inhibitors ov ovarian steroid biosynthesis. While most various research efforts have been undertaken, no practicable procedure has become available as yet.

Animals↗
PubMed1979

Morphometric investigations on endocrine glands. V. Changes in the testes of Wistar rats after application of chlormadinone acetate and norethisterone acetate.

In growth inhibiting tests of rat testes the tubular diameter and, somewhat less sensitive, the nuclear volume of the Leydig cell follow the weight changes. Chlormadinone acetate shows antigonadotropic activity only at high doses and a dose-dependent antiandrogenic activity. The dose-weight curve under norethisterone acetate has a minimum at 4.2 mg/rat/14 days; higher doses seem to be accompanied by androgenic efficiency.

Animals↗
PubMed1978

Relationship between uterotrophic and interceptive activities of steroidal estrogens.

The steroidal estrogens ethinylestradiol, mestranol and the synthetic "impeded" estrogen derivatives STS 456, STS 593 and J 628 were studied for their postcoital antifertility activity and estrogenicity in mice, rats and rabbits. Results of these studies suggest a positive relationship between these two biological endpoints with the exception of the findings in rats. As seen in uterotrophic--anti-implantation ratio, in view of only one species it is possible to dissociate the interceptive and the unwanted uterotrophic activities. The profound species differences in the effects of exogenous estrogens on the nidation phase are discussed.

Animals↗