MAMMARY GLAND UPTAKE OF SODIUM TC-PERTECHNETATE IN A CAT WITH A DRUG-INDUCED GYNECOMASTIA

Sodium Tc-pertechnetate accumulated in the mammary glands of a male cat. It was determined that the uptake was attributable to gynecomastia induced by medroxyprogesterone acetate injections. Gynecomastia and pertechnetate uptake resolved following cessation of medroxyprogesterone acetate treatment.     

Histologic evaluation of gallbladder in progestogen-treated bitches.

Adverse histologic effects were not observed in the gallbladder mucosa of selected bitches with endometrial hyperplasia experimentally induced by administration of exogenous medroxyprogesterone acetate.     

醋酸甲孕酮单克隆抗体的制备与鉴定

用人工合成的醋酸甲孕酮-牛血清白蛋白(MPA-BSA)作为抗原免疫BALB/c小鼠,利用杂交瘤技术筛选得到1株稳定分泌醋酸甲孕酮单克隆抗体的杂交瘤细胞株4C11A3B6,该细胞株经体外传代和冻存复苏后抗体分泌稳定。间接ELISA测定培养上清效价为1∶640,诱生腹水效价为1∶2.56×106。经鉴定:杂交瘤细胞分泌的抗体亚型为IgG2а。竞争抑制ELISA(ciELISA)检测显示其IC50为22 ng/mL,与常见抗生素及结构类似物的交叉反应小,表明该单抗具有较好的敏感性和特异性。     

MEDROXYPROGESTERONE ACETATE AND REPRODUCTIVE PROCESSES IN MALE DOGS

The treatment of normal male dogs with a depot preparation of medroxyprogesterone acetate (4 mg/kg) for 7 weeks reduced peripheral testosterone levels by 58%. No effects on testicular size and consistency, semen quality or libido were found.     

The use of medroxyprogesterone acetate to induce molting in chinstrap penguins (Pygoscelis antarctica).

Molt was successfully induced with a progestational compound, medroxyprogesterone acetate (Depo-Provera), in six of six previously nonmolting chinstrap penguins (Pygoscelis antarctica). The initial treatment consisted of five sequential weekly injections of 30 mg/kg Depo-Provera beginning in early September. Four weeks after completing the injections, the penguins had gained an average of 23% body weight, but none had molted. Beginning early November, five weekly injections were resumed, which initiated molt in all individuals within 34 days following the last injection. Molt was completed by mid-January, nearly 2 wk later. In the following years, nonmolting chinstrap penguins were given a single series of five weekly injections beginning in early November, 2 mo prior to the normal molting period.     

Postnatal exposure to a progestin does not prevent uterine adenogenesis in domestic dogs

To assess the effects of a single supraphysiological postnatal administration of a progestogen on uterine glands in dogs, 10 females were randomly assigned to a medroxyprogesterone acetate 35 mg (MPA; n = 6) or placebo (n = 4) group within the first 24 h of birth. The safety of the treatment was also evaluated. A transient mild clitoris enlargement appeared in MPA-treated females. Microscopic postpubertal uterine assessment revealed the presence of uterine glands in all cases without significant differences in the area occupied by the glands per µm² of endometrium nor in the height of the uterine epithelium.     

Estrous synchronization in ewes: The use of progestogens and prostaglandins

ABSTRACT

This review summarizes the first principles, hormone types, and applied research related to the synchronization of estrus in ewes. The hormones used to induce synchronization include progestogens, such as medroxyprogesterone acetate (MAP), fluorogestone acetate (FGA), a controlled internal drug-releasing (CIDR) device, progesterone (P₄), norgestomet, and prostaglandins. These are usually combined with gonadotropins. Research on these hormones indicates that CIDR, MAP, and FGA can be regarded as equally effective for induction of estrus in ewes. Prostaglandins are a suitable alternative for estrous synchronization especially considering that progestogens may have negative effects on the functionality of ovulatory follicles. Artificial insemination, embryo transfer, and the acceleration of herd genetic trait improvement are among the potential practical applications of synchronous estrus in ewes.     

Clinical, pathological and immunohistochemical study of feline mammary fibroepithelial hyperplasia following a single injection of depot medroxyprogesterone acetate

Feline mammary fibroepithelial hyperplasia (FMFH) following a single injection of depot medroxyprogesterone acetate (MPA) was observed in eight intact young queens. The repository compound is marketed as a veterinary product by a local pharmaceutical company with an indication for contraception in cats. The drug was administered according to the recommended doses and injection frequencies. Serum hormone assays performed immediately before neutering and 3 weeks after neutering detected persistently high levels of progesterone suggesting that depot MPA was still exerting its influence. No corpora lutea were found in those cases ruling out ovaries as the main site of progesterone. Immunohistochemistry performed on the hyperplastic mammary glands detected progesterone receptors in the nuclei of ductal cells, and growth hormone (GH) and insulin-like growth factor-I (IGF-I) in the cytoplasm of ductal epithelium. Overdosing should be considered here as the animals received at least 10 mg/kg of depot MPA in a single injection. Progestin-induced local synthesis of GH and IGF-I in mammary epithelial cells is suggested as one of the pathogenic mechanisms involved in the development of FMFH.     

Modulation of anthracycline activity in canine mammary tumour cells in vitro by medroxyprogesterone acetate

Failure of chemotherapy with anthracyclines as a result of drug resistance and toxicity is a major problem in the clinical management of neoplasia. The aim of the present study was to evaluate the activity of medroxyprogesterone acetate (MPA) as a chemosensitiser on anthracycline cytotoxicity. The study investigated whether such an effect could be related to an increase in lipid peroxidation, nitric oxide production, membrane fluidity and intracellular anthracycline concentration. The results showed that anthracyclines decreased nitric oxide production but increased membrane viscosity (polarisation constant) and lipid hydroperoxide formation in canine mammary tumour cells. Moreover, it was found that both drug-induced cytotoxicity and membrane viscosity increased in the presence of MPA. Conversely, lipid hydroperoxides decreased in MPA-supplemented cells. Medroxyprogesterone acetate did not show any effect on nitric oxide production. The two anthracyclines used (doxorubicin and idarubicin) showed differential intranuclear accumulation in canine mammary tumour cells, and MPA significantly modified intracellular concentration of anthracyclines.     

Vaginal Histological Changes after Using Intravaginal Sponges for Oestrous Synchronization in Anoestrous Ewes

To characterize the histological and cytological vaginal changes generated by the use of intravaginal sponge (IS) applied in oestrous synchronization treatments in ewes during mid‐non‐breeding season. Thirty‐five multiparous ewes were allocated to three experimental groups according to the moment in which the samples were taken: (i) ewes treated with IS containing 60 mg of medroxyprogesterone acetate for 14 days, sampled the day of IS removal (group ISR; n = 10), (ii) or after sponge removal at time of oestrus or 72 h after removal (group AR; n = 14) and (iii) ewes without sponge treatment that were sampled at the day of IS removal of the other groups (group CG; n = 11). Vaginal biopsies and cytological samples were taken from the anterior vaginal fornix area. The vagina of the CG group had a stratified squamous epithelium with a moderate degree of cellular infiltration with lymphocytes and plasma cells in the lamina propia. Treated ewes (ISR and AR) had epithelial hyperplasia and hypertrophy. ISR ewes had haemorrhage and perivascular infiltrate and an increased number of epithelial cells, neutrophils, macrophages and erythrocytes at IS removal. The use of IS generated histological and cytological alterations in the vaginal wall when used for oestrous synchronization in anoestrous ewes.     

Treatment of fibroepithelial hyperplasia (FEH) of the mammary gland in the cat with the progesterone antagonist Aglépristone (Alizine)

Three cases of fibroepithelial hyperplasia (FEH) of the mammary gland in the cat are reported. A one year old female cat had a distinct enlargement of the middle mammary glands, one on each side, 5 days after the first estrus. One week later the cat was treated with medroxyprogesterone acetate (Depo-Promone). The affected glands, along with the remaining glands, increased further in size. A five year old female cat was treated with Proligeston (Covinan) for the suppression of estrus. Two weeks later fibroepithelial hyperplasia occurred in two glands, one with a well demarcated ulceration. A seven months old male cat was treated with delmadinon acetate (Tarden) because of urine spraying. Two months later he had enlargement of all mammary glands. All three cats were treated with the progesterone antagonist Aglépristone (Alizine). Within 5 to 11 weeks the mammary glands had regressed to normal.     

Effect of naloxone, nalbuphine, progesterone and pregnant mare's serum gonadotrophin on the sexual behaviour of ewes

Sheep were medicated with progestogen sponges, pregnant mare's serum gonadotrophin, naloxone or nalbuphine during April, May, June or September 1986. It was observed that when suckling ewes were treated three or five weeks post partum with 45 mg medroxyprogesterone acetate (incorporated on an intravaginal sponge) for 12 days followed by 500 iu of pregnant mare's serum gonadotrophin and 0.4 mg naloxone administered intramuscularly after the withdrawal of the sponge, oestrus became evident 24 to 48 hours after the sponges were withdrawn. However, when the naloxone was replaced by 10 mg nalbuphine administered intramuscularly, oestrus was not shown. When the ewes were medicated with the same combination of drugs during anoestrus, the result was similar to that observed during lactation and oestrus was displayed only in the ewes that received naloxone. Thus the opioid antagonist naloxone facilitates the expression of oestrus in the ewe during anoestrus and lactation.     

Evaluation of melengestrol acetate and equine chorionic gonadotropin for out-of-season breeding in sheep on Prince Edward Island

The purpose of this study was to compare the efficacy of a recommended protocol of oral melengestrol acetate (MGA) to intravaginal medroxyprogesterone acetate (MPA), with or without equine chorionic gonadotropin (eCG), for out-of-season breeding of sheep on Prince Edward Island. One hundred and twenty ewes were assigned to 1 of 4 groups in a factorial design and were treated with either an intravaginal MPA sponge or oral MGA. Ewes received either an intramuscular injection of eCG or a saline placebo at cessation of progestogen treatment. The reproductive performance was best for the MPA-eCG group, followed by the MGA-eCG, MGA-saline, and MPA-saline. Pregnancy rates of 66.7%, 43.3%, 31.0%, and 16.7%, respectively, and ratios of lambs born to ewes exposed to the ram of 1.17, 0.63, 0.52, and 0.23, respectively, were recorded for these groups. We concluded that, under the conditions of this study, the use of oral MGA resulted in fewer lambs than did the use of MPA sponges with eCG. Nonetheless, the use of MGA may be attractive to producers because it is less expensive and more convenient than the use of sponges.     

Oestrus control and the incidence of mammary nodules in bitches, a clinical study with two progestogens

The incidence, size and location of mammary nodules were established in 10 practices in The Netherlands by the clinical examination of bitches in which oestrus was controlled with proligestone (P), 331 animals, or medroxyprogesterone acetate (MAP), 341 animals and in 339 animals never medicated with such compounds. In comparison with the unmedicated control and the P-medicated animals of comparable age the incidence of mammary nodules of all sizes was significantly increased in the MAP-medicated animals. There was no significant difference in nodule incidence between the P-medicated animals and the control animals. Based on the assumption that nodules above a certain size are most likely tumours, these results indicate that oestrus control with MAP stimulates tumour development even in animals medicated for less than four years. The practical value of the reported differences, especially in relation to the subsequent requirement for surgical removal of tumours in bitches, medicated for oestrus control, is discussed.     

Growth of several strains of Chlamydia psittaci in Vero and McCoy cells in the presence of cytochalasin and cortisone.

Chlamydia psittaci of avian and mammalian origin were grown in McCoy and Vero cells in the presence of cytochalasin B with cortisone acetate. Six turkey strains, one parrot strain, one human strain, one ovine strain and one bovine strain were used in this study. All strains, except the turkey strain NJ-1, grew to higher titers in Vero cells than in McCoy cells. Five of the six turkey strains could be grouped together because they induced cytopathic changes rapidly. The other turkey strain, along with the parrot, human and ovine strain, induced cytopathic changes more slowly and the bovine strain failed to cause cytopathic changes, but it did replicate in the cell culture system.     

Effects of anabolic steroids on liver cell ultrastructure in sheep.

Castrated male sheep were sham inplanted or implanted with estradiol, trenbolone acetate or trenbolone acetate in combination with estradiol, and slaughtered after 56 days. Ultrastructural and morphometric examination of the livers of steroid-treated sheep showed an increase in the volume density of the cell occupied by rough endoplasmic reticulum and microbodies. In four of the eight sheep treated with trenbolone acetate, either alone or in combination with estradiol, enlarged mitochondria with crystalline inclusions were seen. The increase in hepatic rough endoplasmic reticulum may be of benefit to the sheep whereas the mitochondrial changes after anabolic steroid use indicate a cellular lesion of unknown significance for health.     

Early Breeding and Pregnancy Diagnosis in Syrian Awassi Sheep Yearlings

Contents
Fifty-nine female yearlings of local Awassi sheep were randomly divided into two groups. Animals in group T (treated) were fitted with intravaginal sponges containing 60 mg of medroxyprogesterone acetate for 14 days followed by 400 IU of pregnant mare's serum gonadotrophin (PMSG) at sponge withdrawal, whereas group C (control) received no treatment. Oestrus rate was 92.7 and 11.2% for groups T and C, respectively. Lambing rate was 78 and 5.6% for groups T and C, respectively. Twinning rate was 31.3% in group T compared to zero in group C. Average birth weight for single born lambs (4.7 ± 0.6 kg) was significantly (p < 0.05) higher than twin born lambs (3.0 ± 0.5 kg) in group T. The average concentration of blood progesterone collected between days 17–19 after mating was 19.30 nmol/l and the accuracy of early pregnancy diagnosis was 100%. It was concluded that, it is possible to induce synchronized oestrus, and to increase the twinning rate in Syrian Awassi sheep yearlings outside the breeding season, using intravaginal sponges and PMSG. In addition, early pregnancy diagnosis could be successfully determined in female Awassi sheep yearlings between days 17–19 after mating.     

Response of Corriedale ewes to the "ram effect" after priming with medroxyprogesterone, fluorogestone, or progesterone in the non-breeding season

One hundred eighty-nine Corriedale ewes were used during the non-breeding season to study the "ram effect" stimulus after priming with progestogens. Intravaginal sponges containing either medroxyprogesterone acetate (MAP group, n = 49), fluorogestone acetate (FGA group, n = 49), or progesterone devices (CIDR group, n = 46) were inserted on Day-6 (Day 0 = introduction of the rams). Forty-five ewes were untreated and kept as a control group. On Day 0 the sponges were removed and rams provided with marking harnesses for oestrous detection were placed with the ewes. Onset of estrus was monitored until Day 25, and conception was determined by transrectal ultrasonography. Ewes came into heat during 4 periods: Days 0-3, 5-7, 17-20, and 21-23. The overall number of oestrus ewes were 29%, 53%, 35%, and 50% for the control, MAP, FGA, and CIDR groups, respectively (MAP and CIDR > control, p < 0.05). Control ewes presented oestrus only on Days 17-20 and 21-23. Oestrus in the progestogen-primed ewes was concentrated during Days 0-3 and 17-20, and some ewes came into oestrus on Days 5-7. There were no differences between different primings neither in oestrous response nor in conception rate. The conception rate from matings occurring on Days 0-3 was higher than on those occurring on Days 17-20. We conclude that MAP, FGA, and CIDR is equally effective in improving the response to the ram effect, and the pattern of oestrus in primed ewes was different than previously reported.     

Progestin-induced growth hormone (GH) production in the treatment of dogs with congenital GH deficiency

The recent demonstration of the ability of progestins to induce the expression of the growth hormone (GH) gene in the mammary gland of dogs and cats opens possibilities for the treatment of some forms of GH deficiency with progestins. Therefore, one male and one female German shepherd dog with congenital dwarfism because of a pituitary anomaly were treated with subcutaneous injections of medroxyprogesterone acetate (MPA) in doses of 2.5–5.0 mg per kg body weight, initially at 3-wk intervals and subsequently at 6-wk intervals. In both dogs, body sizes increased and a complete adult hair coat developed. Undesirable side-effects were recurrent periods of pruritic pyoderma in both dogs and cystic endometrial hyperplasia with mucometra in the female dog. Parallel with the physical improvements, plasma insulin-like growth factor I concentrations rose sharply. Plasma GH concentrations tended to rise, but never exceeded the upper limit of the reference range. Nevertheless, one of the dogs developed slight acromegalic features, possibly because mammary GH, unlike pituitary GH, is released evenly throughout the day. Even moderate increases in circulating GH concentration may, therefore, give rise to overexposure. It is concluded that long-term treatment with MPA can be used as an alternative for heterologous GH in the treatment of congenital GH deficiency in the dog.     

Serum progesterone determination as an aid for pregnancy diagnosis in goats bred out of season

Nubian does (n = 12) were bred by artificial insemination after induction of estrus with medroxyprogesterone acetate impregnated vaginal sponges and pregnant mare serum gonadotrophin injections during the anestrous season. Pregnancy status was predicted from serum samples collected 21 days following the last breeding and analyzed using 1) a commercial bovine milk progesterone enzyme immunoassay test (EIA), and 2) a radioimmunoassay progesterone (RIA) test. Both tests detected nonpregnancy (EIA 100%, RIA 80%) more accurately than pregnancy (EIA 66%, RIA 75%). Commercial bovine progesterone EIA kits have potential as rapid, inexpensive screening tests for nonpregnant does bred out of season.