Teratogenic and cytogenetic effects of ivermectin and its interaction with P-glycoprotein inhibitor     

Ibrahim M. El-Ashmawy  Abeer F. El-Nahas  Aida E. Bayad 《Research in veterinary science》2011,90(1):116-123

Experiments in animals proved that P-glycoprotein (Pgp) forms a functional barrier between maternal and fetal blood circulation in the placenta, thus protecting the fetus from exposure to xenobiotics during pregnancy. In this study we aimed to demonstrate the effects of administration of ivermectin (anthelmentic drug, Pgp substrates), either alone or simultaneously with verapamil (Pgp inhibitor) in Wister rats on fetal development, maternal bone marrow for detection of micronuclei (MN), chromosomal aberrations and mitotic index (MI) and embryonic liver cells for cellular proliferation indicated by MI, and bleeding from umbilical vessels for detection of embryonic micronuclei (MN). The results revealed that administration of ivermectin or verapamil at 6th through 15th day of gestation did not significantly altered fetal development. While, co-administration of ivermectin and verapamil clearly disturbed fetal development as indicated from abnormal feto-maternal attachment and a significant decrease in fetal weights and numbers. Furthermore, co-administration of both drugs induced a significant increase in resorption sites, post-implantation loss and external, visceral and skeletal abnormalities. They also induced genotoxicity in both dam and embryonic cells indicated by reduced mitotic index, increased number of micronucleated erythrocytes in both, and increased different types of chromosomal aberrations in dam cells, while ivermectin alone show some genotoxic effect on somatic cells of dams and the embryos. Verapamil induced reduction of embryonic mitotic index. We concluded combined treatment of ivermectin and verapamil severely affect fetal genetic material and development and induced genotoxic effect in somatic cells of the dams.  相似文献   

Foraging Behavior of Alberes Cattle in a Mediterranean Forest Ecosystem     

Jordi Bartolomé  Josefina Plaixats  Jesús Piedrafita  Marta Fina  Eduard Adrobau  Aida Aixàs  Marina Bonet  Jordi Grau  Lluis Polo 《Strength and Conditioning Journal》2011,64(3):319-324

The dietary composition of the semiferal cattle population in the Alberes Natural Park in northeastern Spain was determined four times per year, from June 2002 to February 2004, by microhistological analysis of a total of 120 fecal samples. Woody species, mainly the Quercus and Erica genera, formed the bulk of the diet, reaching 89% of it in winter. However, in spring and summer, the proportion of woody and herbaceous species varied between samples, depending on the habitat where they were collected. The forest samples contained 67% woody species in summer, whereas grassland samples only contained 44%. The results showed that the Alberes cattle population grazed actively in Mediterranean forests and consumed a high proportion of the most combustible species, such as the Erica genus (39% of the epidermal fragments in winter samples). Even when grassland habitat was utilized, in spring and summer, one-third of the diet was from woody species. Some bovines, such as the Alberes cattle breed, can therefore survive year-round in a forest habitat with little forage supplementation, and the consumption of a predominantly woody diet would be expected to reduce forest fire hazards.  相似文献   

Gonadotropin-releasing hormone and gonadotropin in goldfish and masu salmon   总被引：1，自引：0，他引：1  

M. Kobayashi  M. Amano  M.H. Kim  Y. Yoshiura  Y.C. Sohn  H. Suetake  K. Aida 《Fish physiology and biochemistry》1997,17(1-6):1-8

Reproductive activities in vertebrates are regulated by an endocrine system, consisting of the brain-pituitary-gonad axis. In teleosts, gonadotropin-releasing hormone (GnRH) in the brain stimulates gonadotropin (GTH) release in the pituitary gland, but because of lack of the portal vessel, it is not known when and how much GnRH is released for the regulation of GTH release. There are multiple molecular types of GnRH in teleosts and several distinct populations of GnRH neurons in the brain. However, we do not know which types and populations of GnRH neurons regulate reproductive activities. Here we summarize our recent studies on GnRH and GTH in masu salmon Oncorhynchus masou and goldfish Carassius auratus. Immunocytochemistry showed the location and molecular types of GnRH neurons. Salmon (sGnRH) and chicken-II GnRH (cGnRH-II) neuronal fibers were widely distributed in the brain of both masu salmon and goldfish. Only sGnRH fibers were observed in the pituitary of masu salmon, whereas both sGnRH and cGnRH-II fibers were observed in the goldfish pituitary, indicating that species specific GnRH profiles are involved in the regulation of pituitary function in teleosts. A series of experiments in masu salmon and goldfish suggest that among GnRH neuron populations GnRH neurons in the ventral telencephalon and the hypothalamus regulate GTH release, and that GnRH of the terminal nerve origin is not essential to gonadal maturation and ovulation. The biological function of other GnRH neurons remains unkown. Two GTHs appear to be characteristic of teleost; however, regulation of reproduction by these GTHs is a question that remains to be elucidated. In salmonid species, it is proposed that GTH I stimulates early gonadal development, whereas GTH II acts in later stages. When GTH expression was examined in goldfish, both GTH I and II mRNA levels in the pituitary gland showed increases in accordance with gonadal development, unlike the sequential expression of GTH subunits in salmonids. The expression of these GTH subunit mRNAs were affected by water temperature, starvation, and steroid hormones in goldfish, but in what manner these two GTHs regulate gonadal development remains to be clarified.  相似文献   

Stimulation of insulin-like growth factor-I production by recombinant bovine growth hormone in Mozambique tilapia, Oreochromis mossambicus     

S. Kajimura  K. Uchida  T. Yada  L.G. Riley  J.C. Byatt  R.J. Collier  K. Aida  T. Hirano  E.G. Grau 《Fish physiology and biochemistry》2001,25(3):221-230

We have previously reported growth-promoting effects of recombinant bovine growth hormone (rbGH) in Mozambique tilapia, Oreochromis mossambicus, after 4 weekly injections or a single injection of slow-releasing formulation (Posilac^®) (Leedom et al. 2002). In order to obtain further understanding of the role of the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis in growth in the tilapia, the effects of rbGH on plasma and mRNA levels of IGF-I were examined. Plasma IGF-I levels were significantly increased after rbGH and Posilac^® injections, and a significant correlation was observed between plasma IGF-I levels, body length and mass in both treatments. IGF-I mRNA levels in the liver and in the skeletal muscle were also significantly increased after rbGH and Posilac^® injections, indicating that IGF-I gene expression in these tissues is under control of circulating GH. IGF-I mRNA levels in the gill were not affected by treatment. Liver IGF-I mRNA levels were significantly correlated with body length and with body mass after rbGH and Posilac^® injections. These results indicate that the growth-promoting effect of rbGH in this species is mediated to a significant extent via its stimulation of hepatic production of IGF-I and the resulting increase in plasma IGF-I, and also possibly through locally produced IGF-I in the skeletal muscle, acting in a paracrine or autocrine fashion.  相似文献   

The expression and localization of corticotropin-releasing hormone and urotensin I transcripts in the Japanese eel, Anguilla japonica     

N. Kawaguchi  K. Okubo  K. Aida 《Fish physiology and biochemistry》2003,28(1-4):43-44

  相似文献   

Androgen secretion activity of recombinant follicle-stimulating hormone of Japanese eel, Anguilla japonica in immature and maturing eel testes     

H. Kamei  T. Oshira  Y. Yoshiura  N. Uchida  K. Aida 《Fish physiology and biochemistry》2003,28(1-4):97-98

The androgen secretion activities of recombinant Japanese eel follicle-stimulating hormone (rjeFSH) were investigated in immature and maturing eel testes. The rjeFSH stimulated testosterone (T) and 11-ketotestosterone (11-KT) secretion in immature testis but not in maturing testis. This result suggests that eel FSH plays an important role through the sex steroid secretion in immature testis rather than in maturing testis.  相似文献   

Incidental captures of sea turtles by swordfish and albacore longlines in the Ionian sea   总被引：2，自引：0，他引：2  

Michele?Deflorio  Aida?Aprea  Aldo?Corriero  Nicoletta?Santamaria  Gregorio?De?MetrioEmail author 《Fisheries Science》2005,71(5):1010-1018

ABSTRACT:   Incidental catches in pelagic longline fishing pose a serious threat to sea turtle populations throughout the world's seas and oceans. In this work, carried out in the framework of the EC-DG-Fisheries 98/008 project, information on sea turtle catch rates from swordfish and albacore longline fishing activities observed in Italian waters off the Ionian Sea during 1999 and 2000, are reported. In addition, biometric data, health status, and tagging return rate of sea turtles captured are provided. A total of 200 sea turtles were caught (198 loggerhead turtles and 2 green turtles), comprising 0.5–15.7% of the total catch in number of individuals. The estimates of the sea turtles caught by the total fishing effort of both longlines in the whole study area were 1084 specimens in 1999 (95% CI = 667–1502) and 4447 specimens in 2000 (95% CI = 3189–5705). Although all sea turtles were released alive, nearly half of them had hooks that could not be removed and remained deeply embedded in the digestive tract.  相似文献   

Development of an emulsion prepared with lipophilized gelatin and its application for hormone administration in the Japanese eel Anguilla japonica     

N. Sato  I. Kawazoe  Y. Suzuki  K. Aida 《Fish physiology and biochemistry》1997,17(1-6):171-178

A new water-in-oil-in-water (W/O/W) type emulsion using lipophilized gelatin (LG) and cotton-seed oil was developed for a novel method of hormone administration in fishes. LG was prepared by attaching palmitic anhydride to gelatin. The best conditions for preparing stable emulsions were determined where the final concentrations of LG in the emulsion and the volume ratio of LG solution to cotton-seed oil were 2% and 1:2, respectively. Hormone releasing properties of LG emulsion were compared with a water-in-oil (W/O) type emulsion prepared with Freund's incomplete adjuvant (FIA) and saline solution by monitoring plasma profiles of salmon gonadotropin (sGtH) II in the Japanese eel. sGtH II is gradually released from the LG emulsion. LG emulsion had hormone-releasing properties different from those of the saline solution and the FIA emulsion. Immature female Japanese eel (BW, 566 to 1017 g) received a weekly intramuscular injections (total of 10 injections) of the LG emulsion, the FIA emulsion or the saline solution, each of which contained sGtH fraction. The LG emulsion was found to be more effective in inducing ovarian maturation. In mature eel, final maturation and ovulation could be induced by simultaneous administration of sGtH fraction and 17-hydroxyprogesterone using LG W/O/W emulsion.  相似文献   

Large-area three-dimensional molecular ordering of a polymer brush by one-step processing     

Hosono N  Kajitani T  Fukushima T  Ito K  Sasaki S  Takata M  Aida T 《Science (New York, N.Y.)》2010,330(6005):808-811

Rational molecular design and processing, enabling large-area molecular ordering, are important for creating high-performance organic materials and devices. We show that, upon one-step hot-pressing with uniaxially stretched Teflon sheets, a polymer brush carrying azobenzene-containing mesogenic side chains self-assembles into a freestanding film, where the polymer backbone aligns homeotropically to the film plane and the side chains align horizontally. Such an ordered structure forms through translation of a one-dimensional molecular order of the Teflon sheet and propagates from the interface macroscopically on both sides of the film. The resultant wide-area bimorph configuration allows the polymer film to bend rapidly and reversibly when the azobenzene units are photoisomerized. The combination of polymer brushes with hot-pressing and Teflon sheets provides many possibilities in designing functional soft materials.  相似文献   

Involvement of sex steroids,luteinizing hormone and thyroid hormones in upstream and downstream swimming behavior of land-locked sockeye salmon <Emphasis Type="Italic">Oncorhynchus nerka</Emphasis>     

Arimune Munakata  Masafumi Amano  Kazumasa Ikuta  Shoji Kitamura  Katsumi Aida 《Fisheries Science》2012,78(1):81-90

The involvement of testosterone (T), estradiol-17β (E₂), 11-ketotestosterone (11-KT), 17,20β-dihydroxy-4-pregnene-3-one (DHP), luteinizing hormone (LH), thyroxine (T₄), and triiodothyronine (T₃) in the regulation of downstream and upstream movement (swimming behavior) was investigated in land-locked sockeye salmon Oncorhynchus nerka, using an artificial raceway. During the downstream migratory period, T implant resulted in high plasma T levels and inhibited the occurrence of downstream swimming behavior (negative rheotaxis) in yearling (1+) immature smolts. In terms of upstream behavior, 2-year-old (2+) males exhibited high plasma T and 11-KT levels, while 2+ females had elevated T and DHP levels. In 1+ immature fish, a T implant induced upstream swimming behavior (positive rheotaxis). In experiments 1 and 3, the plasma T₄ and T₃ levels of non-migrants tended to be higher than those of migrants. In contrast, no marked changes in plasma and pituitary LH were found in both downstream and upstream migrants. These results suggest that sex steroids, such as T, play significant roles in the regulation of downstream and upstream swimming behaviors in land-locked sockeye salmon.  相似文献