Pregnancy diagnosis in zoo animals by estrogen determination in feces

Estrogen concentration in feces was investigated in five different herbivorous species of zoo animals. Using a nonspecific estrogen radioimmunoassay, in four species (red buffalo, yak, Grevy's zebra, and Nubian ibex) pregnancy was revealed by measuring estrogen concentration in feces. In hippopotamus, the levels of fecal estrogens were not different between pregnant and nonpregnant animals.     

Detoxification of xenobiotics by plant cells: characterisation of vacuolar amphiphilic organic anion transporters

The transport activities of two primary ATP-dependent organic-anion transporters in the tonoplast of isolated barley (Hordeum vulgare L. cv. Klaxon) vacuoles have been characterised with N-ethylmaleimide glutathione (NEM-SG) and taurocholate as substrates. The transporters showed different sensitivities to organic anions and a variety of transport inhibitors and drugs. The vacuolar uptake of NEM-SG was inhibited by carbonylcyanide 4-trifluoromethoxyphenylhydrazone, 4,4-diisothiocyanatostilbene-2,2-disulfonic acid (DIDS), S-(2,4-dinitrophenyl)glutathione, alkyl-S-glutathione derivatives and taurocholate but stimulated by probenecid. The uptake of taurocholate was inhibited by vinblastine, DIDS and probenecid. Both transporters were unaffected by verapamil. The kinetic properties of the transporters indicate a general preference for amphiphilic anions with some substrate overlap. These characteristics of the transporters are similar to those displayed by the multidrug resistance protein of mammalian drug-resistant cells. We suggest that these vacuolar transporters be described as plant multispecific organic anion transporters (pMOATs).Abbreviations Bm-S bimane S-glutathione - DIDS 4,4-diisothiocyanatostilbene-2,2-disulfonic acid - DNP-SG S-(2,4-dinitrophenyl)glutathione - FCCP carbonylcyanide 4-trifluoromethoxyphenylhydrazone - LTC₄ cysteinyl leukotriene - MDR multidrug transporter - MRP multidrug resistance protein - NEM-SG N-ethylmaleimide glutathione We thank Prof E. Martinoia for technical advice on the uptake experiments and Prof J. Palmer for helpful discussions and suggestions. M.B.-K. was partially sponsored by a grant from Stichting VSB Fonds, The Netherlands. IACR receives grant-aided support from the Biotechnology and Biological Science Research Council of the United Kingdom     

Selected factors limiting the microbial degradation of recalcitrant compounds

Summary The focus of this review is to examine some of the reasons biodegradation may not take place in the environment even though its occurrence in the laboratory has been demonstrated. Some approaches for dealing with chemical persistence will be discussed. In addition, the potential of bioremediation as an in situ clean-up technology will be considered.     

The Photoperiodic Entrainment and Induction of Reproductive Rhythms in Male Blackheaded Buntings (Emberiza Melanocephala)

Groups of photosensitive, unstimulated or stimulated, male blackheaded buntings were subjected to photoregimes of 15 hr of green light of three intensities and 9 hr of dark per day. In some groups green light was interrupted with 90 min of bright fluorescent light at different times in the subjective day. While gonads did not develop or regressed in some groups, birds in others behaved as if exposed to long daylengths. The results besides suggesting the involvement of endogenous circadian rhythm during initiation and maintenance of gonadal growth indicate that the reproductive rhythms are entrained and induced by environmental photoperiod.     

环境雌激素的生殖毒性的分子机理研究进展

环境激素（environmental endocrines,EEs）是外源性激素,可模拟体内天然激素与机体内的受体以及相应靶点结合,导致内分泌系统以及生殖系统功能紊乱。环境激素所产生的效应十分复杂,因此,进一步明确其毒性机理将为环境激素所致危害的预防和治疗提供理论依据。就环境雌激素的生殖、发育等毒性机理作一综述。     

Effects of the aromatase inhibitor fadrozole on plasma sex steroid secretion,spermatogenesis and epididymis morphology in the lizard,Podarcis sicula

Recently, increasing importance has been attached to the role of estrogens and their receptors in male reproduction, since they have been found to be abundant in the male reproductive tract. In the lizard, Podarcis sicula, a seasonal breeder, estrogens seem to be involved in the regulation of testicular activity. Particularly, it has been hypothesized that the block of spermatogenesis and the complete regression of the epididymis and other secondary sexual characters (SSCs) in autumn might be due to high estrogen levels. To investigate the role of estrogens in the reproductive process of male lizards, we utilized Fadrozole ((AI) [4-(5,6,7,8-tetrahydroimidazole [1,5-a] pyridin-5-yl)-benzonitrile monohydrochloride] (CGS 16949A)), a nonsteroidal inhibitor of aromatase, the enzyme involved in the aromatization of androgens to estrogens, evaluating its effects on plasma sex-hormone release, spermatogenesis and epididymis morphology. For this purpose, adult male lizards, captured during the autumnal recrudescence, were intraperitoneally injected with 0.5 microg and 5 microg/g/body weight of AI for 15 and 30 days. In the animals treated with the higher AI dose, estrogen levels decreased if compared to the control groups, whereas androgen levels increased. Furthermore, histologic sections of testes and epididymes showed that the 30-day treatment with AI-induced spermatogenesis resumption with release of sperms into the large lumen of the seminiferous tubules, and the epididymes appeared more developed with moderately secreting columnar canal cells. Therefore, it is proposed that failure of spermatogenesis in autumn might be due to high estrogen levels.     

Estrogen mitogenic action. I. Demonstration of estrogen-dependent MTW9/PL2 carcinogen-induced rat mammary tumor cell growth in serum-supplemented culture and technical implications

Summary The MTW9/PL cell line was established by our laboratory in culture from the carcinogen-induced hormone-responsive MT-W9A rat mammary tumor of a Wistar-Furth (W/Fu) rat. This tumor formed estrogen, androgen, and progesterone responsive tumors in W/Fu rats (Sirbasku, D. A., Cancer Res. 38:1154–1165; 1978). It was later used to derive the MTW9/PL2 cell population which was also estrogen-responsive in vivo (Danielpour, D., et al., In Vitro Cell. Dev. Biol. 24∶42–52; 1988). In the study presented here, we describe serum-supplemented culture conditions in which the MTW9/PL2 cells demonstrate≥80-fold steroid hormone growth responses. All sera used were steroid hormone-depleted by charcoal-dextran treatment at 34°C. The studies were done with horse serum as well as serum from other mammalian species. The growth of the MTW9/PL2 cells was biphasic in response to hormone-depleted serum. Concentrations of ≤5% (v/v) promoted optimum growth. Above this concentration, serum was inhibitory. Concentrations ≥40% (v/v) inhibited growth altogether. Addition of 1.0×10⁻¹³−1.0×10⁻⁸ M 17β-estradiol (E₂) reversed the inhibition completely. At 1.0×10⁻⁸ M, estrone, estriol and diethylstilbestrol promoted growth as well as E₂. Testosterone and dihydrotestosterone promoted growth only at ≥10⁻⁷ M. Progesterone was effective only at≥10⁻⁶ M. Cortisol was ineffective. Labeled-hormone-binding analysis and Western immunoblotting documented that MTW9/PL2 cells had estrogen and progesterone receptors but not androgen or cortisol receptors. Estrogen treatment of MTW9/PL2 cells induced a concentration and time dependent increase in progesterone receptors. We conclude (1) the MTW9/PL2 population is the first highly steroid hormone-responsive rat mammary tumor cell line to be established in culture from a carcinogen-induced tumor, and (2) sera from a number of species including horse, rat and human contain an inhibitor which mediates estrogen sensitive MTW9/PL2 cell growth in culture.