18 research outputs found

    Histological and immunohistological aspects of the ovarian cycle of the algerian wild sand rat, Psammomys obesus Cretzschmar, 1828.

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    The sand rat, Psammomys obesus, is largely used as a model for studying several metabolic disorders. In order to perform breeding laboratory conditions, the reproductive function of this species was investigated. Using histological and immunohistochemical techniques, several aspects of the ovaries were studied throughout the sexual cycle. During the ovarian cycle, the different stages of folliculogenesis, from primordial to Graafian follicle, have been shown; the differentiation of both granulosa and theca cells, the formation of the antrum, cumulus oophorus and corona radiate were described. Broken follicles and corpora lutea have been observed, confirming a spontaneous ovulation in isolated females. Steroid activities were analysed using immunohistochemical techniques. Estrogen, androgen and progesterone hormones were visualized in the different compartments of the ovary

    Morphometry and immunohistochemistry of follicles growth and steroidogenesis in saharian wild sand rat, Psammomys obesus, ovary.

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    The sand rat (Psammomys obesus) constitutes a model to study seasonal changes and several metabolic disorders. In order to perform breeding laboratory conditions, the reproductive function of this species living in North Occidental Algerian Sahara was studied. The aim of this work was to investigate the follicular growth changes and the steroidogenic associated aspects. The study was performed using morphometrical and immunohistochemical methods. From primordial to preantral states, the follicle diameter increased progressively from 17-20 mum to 192-225 mum. The preovulatory follicles reached about 500 mum in diameter. Immunoreactivity to progesterone, androstenediol and estradiol, varied in the different parts of the ovary and follicular cells. The progesterone antibody appeared clearly labelled in the theca interna of the growing follicle and increased in the granulosa; the androgen antibody was continuously weak and diffuses in all follicles; the estradiol labelling appeared weak and diffuse in preantral follicles then increased in antral follicles in both theca and granulosa or only in granulosa. In antral follicles, estradiol label was clearly localized in granulosa cells and totally devoid in theca cells. In Psammomys ovary, labels of hormone were diffuse or localized, weak or intense in the theca and or in the granulosa according to the follicle size

    Postnatal changes in testicular development and androgen receptors immunolocalization in D’Man ram lambs

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    The purpose of this study was to characterize testicular development in D’Man ram lambs, focusing primarily on androgen receptors (ARs) immunolocalization in the adenohypophysis and testis that is not still known in the D’Man ram lamb. Lambs (n = 12) were divided into four groups (three lambs per group). Adenohypophysis and testis were fixed and paraffin embedded; cross-section (3 μm) were stained and evaluated with immunohistochemistry. Testis weight increased at a greater rate between two and five months after birth, which was associated with remarkable changes in testicular histology, including significant increases in the diameter of seminiferous tubules. Spermatogenesis started between three and five months after birth; lumen and elongated spermatids were observed for the first time in three and four months-old animals respectively. ARs detected with immunohistochemistry were located in the nuclei and cytoplasm of adenohypophysis cells, and only in nuclei of testis cells (Leydig, Sertoli, peritubular myoid and germ cells)

    An overview of the welfare of animals used for scientific and educational purposes in Algeria

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    This study describes the welfare and animals used for scientific and educational purposes in the field of laboratory animal sciences in Algeria. The aim of this study is to provide an overview of the status of the care and use of animals and to improve implementing plans and animal welfare measures. A literature review was performed using online databases and reference lists of the US National Library of Medicine to assess the prevalence of animal use for research in Algeria between 2013 and 2017. Also a retrospective study was conducted using the Pasteur Institute of Algeria report for 2015 to assess the prevalence of animal use in both teaching and research. The first workshop on animal experimentation was organized in 2013 in collaboration with international animal laboratory organizations (ICLAS and OIE) and involving the participation of universities, research centers, veterinary schools and the Pasteur Institute of Algeria. In addition, after accreditation of the Algerian Association of Experimental Animal Sciences, a number of training workshops and courses relating to laboratory animal sciences were organized. In Algeria the use of laboratory animals in research and education is a subject of debate regarding the need to establish regulations and to propose an appropriate ethical framework for the use of animals. Finally, some actions have been already taken in Algeria to promote the ethical use of animals but many more sustainable actions are needed and require cooperation, harmonization of policies and establishment of regional and international networks for experience exchange

    Assessment of Testicular Lhcgr mRNA Expression Correlated with Testis and Seminal Vesicle Activities in the Libyan jird (Meriones libycus, Rodentia: Muridae) during Breeding Season Compared with Nonbreeding Season

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    The Libyan jird (Meriones libycus, 1823) is a wild desert rodent that is a seasonal breeder species adapted to breed when the environmental conditions can satisfy the energy and hydrous requirements of pregnant and nursing females to ensure that births occur at the most favorable time of the year. We assessed gene expression of testicular luteinizing hormone receptor (Lhcgr) correlated to testis activity. The expression of Lhcgr was evaluated using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR and the testis activity by a histological method in adult male Libyan jirds during the nonbreeding and breeding seasons. Our results showed that Lhcgr mRNA expression increased in autumn during the nonbreeding season and decreased in spring during the breeding season. This expression varied in contrast to testicular structure or function and plasma testosterone levels. These results help to elucidate this desert rodent’s seasonal sexual activity, which is correlated with central regulation

    Histological and immunohistological aspects of the ovarian cycle of the algerian wild sand rat, Psammomys obesus Cretzschmar, 1828.

    No full text
    The sand rat, Psammomys obesus, is largely used as a model for studying several metabolic disorders. In order to perform breeding laboratory conditions, the reproductive function of this species was investigated. Using histological and immunohistochemical techniques, several aspects of the ovaries were studied throughout the sexual cycle. During the ovarian cycle, the different stages of folliculogenesis, from primordial to Graafian follicle, have been shown; the differentiation of both granulosa and theca cells, the formation of the antrum, cumulus oophorus and corona radiate were described. Broken follicles and corpora lutea have been observed, confirming a spontaneous ovulation in isolated females. Steroid activities were analysed using immunohistochemical techniques. Estrogen, androgen and progesterone hormones were visualized in the different compartments of the ovary

    Ovarian function of the algerian wild Libyan jird, Meriones libycus during seasonal reproductive cycle: histological and immunohistochemical expression

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    Meriones libycus (Libyan jird), a nocturnal Saharan rodent, is characterized by a seasonal reproductive cycle with a short active phase (spring and early summer) and a long resting period (late summer, autumn, winter). Histological and immunohistochemical techniques were performed in order to study the seasonal variations in mature ovaries. During the breeding season, the ovary showed a continuous cyclical activity, the various stages of folliculogenesis from primordial to preovulatory follicles were observed; broken follicles and corpora lutea were also observed. During sexual quiescence, the ovarian cycle was interrupted; anovulation was observed without any corpus luteum. Non mature antral follicles entered the atretic process. Steroid and steroidogenic enzyme activities were studied using indirect immunohistochemistry. 17Ăź-estradiol, progesterone, testosterone hormones and P450 aromatase (P450 arom) were detected in the different components of the ovary and in various stages of healthy and atretic follicles during the seasonal reproductive cycle. Our results indicate that during ovarian folliculogenesis in breeding season steroids hormone and P450 arom present important activities. In comparison with the resting period, steroidogenesis and steroidogenic enzyme activity became less pronounced in the healthy preantral follicle; it seemed that steroid biosynthesis was reduced and could be involved in the stimulation and maintenance of the ovarian structural integrity in early follicle development. In conclusion, the histological and immunohistochemical seasonal variations of ovaries in Meriones libycus support the hypothesis that seasonal fluctuations are indirectly involved in regulating reproduction, inducing significant changes in both ovarian morphology and its hormonal function

    Valeurs implicites dans l'enseignement de la génétique humaine dans les manuels scolaires de cinq pays riverains de la Méditerranée

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    The present study aims to see up to which point national specificities are found in the chapters of the textbooks related to human genetics, among five countries around the Mediterranean Sea. Inside the scientific community, the era of "all-genetic" is now replaced by a new paradigm : the epigenetics, focused on interaction between the genes and their environment. The comparative analysis of textbooks shows a certain persistence of innatism in the five countries but in different ways. We never found a link between this innatism and some sexism or racism. The textbooks can be efficient to promote citizenship valuesDans la communauté scientifique, l'ère du "tout-génétique" est remplacée par le paradigme de l'épigénétique qui met l'accent sur l'interaction entre génome et environnement. Existet- il dans les manuels scolaires des traces d'innéisme et éventuellement de sexisme ou de racisme associés à l'innéisme ? L'analyse comparative des chapitres qui traitent de la génétique humaine de cinq pays méditerranéens permet de dire qu'il y a une certaine survivance de conceptions innéistes dans ces manuels, plus ou moins marquée selon les pays, mais sans trace de représentations sexistes ou racistes. Les manuels peuvent être un moyen essentiel de promotion de valeurs citoyennes

    Endocrine, energy, and lipid status during parturition and early lactation in indigenous goats native to the Algerian Sahara

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    International audienceBackground and Aim: Goats are widely distributed in southwest Algeria. The Saharan goat is perfectly adapted to the harsh conditions of arid areas, and it is characterized by resistance to long photoperiod and reduced metabolic needs, allowing the survival of its offspring by maintaining lactation. Several studies have demonstrated that parturition and lactation are critical periods that induce hormone, energy, and lipid status changes in mammals. However, the relationship between the blood biochemical parameters of parturition control and lactation functions in the Algerian Saharan goat has not been thoroughly documented. Therefore, this study assesses hormone and metabolite levels during parturition and early lactation in Saharan goats reared in arid areas. Materials and Methods: Experiments were performed on 14 multiparous female goats, and blood samples were collected during parturition, 4 days postpartum (D1PP-D4PP), and during the first 12 weeks of lactation (W1-W12) to analyze prolactin, cortisol, glucose (GLU), total proteins (TP), cholesterol (CHO), triglycerides (TGs), total lipids (TL), low-density lipoproteins (LDLs), high-density lipoproteins (HDLs), and very LDLs (VLDLs). Results: Statistical data analysis revealed a significant (p<0.05) increase in plasma prolactin concentrations at W1 after parturition, reaching maximum values at W3 and W9, and remained high until W12 of lactation. Plasma cortisol levels were high at parturition, reaching two peaks at W3 and W9, and then decreased at W5, W7, and W12 of lactation. No significant changes were found in serum GLU levels during the first 7 weeks of lactation compared with parturition day; then, the levels became significantly (p<0.05) lower at W8, W11, and W12 of lactation. Plasma TP increased significantly (p<0.05) at D3PP, W1, and W4, then decreased significantly (p<0.05) at W8. In addition, this decrease coincided with that of GLU production. Serum CHO, TGs, TL, LDLs, and VLDLs, were low at parturition and high at D4PP and during the first 3 months of lactation. Furthermore, HDL levels were low at D3PP, 1st, and 3rd months and high at the 2nd month of lactation. Conclusion: This study emphasized the impact of parturition and the 1st weeks of lactation on endocrine and metabolic changes in indigenous goats living in the Algerian Sahara Desert. These results can be used to monitor and improve farming management and understand physiological adaptive strategies, mainly lactation function sustainability, of this goat living in marginal zones
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