Effect of pregnant mare serum gonadotropin on the induction and degradation of FSH and LH receptors in the granulosa cell of the immature rat

The relative induction of FSH and LH receptors in the granulosa cells of immature rat ovary by pregnant mare serum gonadotropin (PMSG) has been studied. A single injection of PMSG (15 IU) brought about a 3- and 12-fold increase in FSH and LH receptor concentration,respectively, in the granulosa cells. Maximal concentration was reached by 72 h but the receptor levels showed a sharp decline during the next 24–48 h. The kinetic properties of the newly formed FSH receptors were indistinguishable from the pre-existing ones. The induced FSH receptors were functional as demonstrated by an increase in the in vitro responsiveness of the cells to exogenous FSH in terms of progesterone production. Treatment of immature rats with cyanoketone, an inhibitor of Δ5,3β-hydroxysteroid dehydrogenase, prior to PMSG injection effectively reduced the PMSG-stimulated increase in the serum estradiol, uterine weight and LH receptors but had no effect on the FSH receptor induction. The ability of PMSG to induce gonadotropin receptors can be arrested at any given time by injecting its antibody, thereby suggesting a continuous need for the hormonal inducer. Estrogen in the absence of the primary inducer was unable to maintain the induced LH and FSH receptor concentration. Inhibition of prostaglandin synthesis using indomethacin also had no effect on either the induction or degradation of gonadotropin receptors. Administration of PMSG antiserum, 48 h after PMSG injection, brought about a rapid decline in the induced receptors over the next 24 h, with a rate constant and \iota 1/2 of 0.078 h−1 and 8.9 h for FSH receptors and 0.086 h−1 and 8.0 h for the LH receptors, respectively.

Effect of blocking oestrogen synthesis with a new generation aromatase inhibitor CGS 16949A on follicular maturation induced by pregnant mare serum gonadotrophin in the immature rat

While the endocrine role of oestrogen is well established, its function in follicular maturation as an autocrine or paracrine regulator is less well understood. This study was designed to delineate the requirement of oestrogen for follicular development in immature rats. Exogenous gonadotrophin (25 IU pregnant mare serum gonadotrophin (PMSG) per rat) was administered to 21- to 23-day old female rats to induce follicular growth and development. In the experimental animals, synthesis of oestrogen was blocked by implanting an Alzet pump containing the aromatase inhibitor (AI) CGS 16949A (fadrozole hydrochloride; 50 mu g/rat per day). The treatment resulted in blockade of the PMSG induced increase in both serum and intrafollicular oestrogen (>95%), thus leading to an inhibition in uterine weight increment. Compared with the controls, ovarian weight increased markedly in both the PMSG (295%)- and PMSG+AI (216%)-primed animals. There was no significant difference in either the proliferative capabilities of the ovarian granulosa cells or their responsiveness to human chorionic gonadotrophin (hCG; 200 pg/ml) and ovine FSH (20 ng/ml) between the PMSG- and PMSG+AI-treated groups. Histological examination of the ovary, however, indicated a decrease in the number of healthy antral follicles in the Al-treated group compared with the PMSG-primed animals but both the groups showed a percentage increase over the controls (PMSG, 225; PMSG+AI, 158). The responsiveness of the animals to an ovulatory dose of hCG was drastically reduced (>80% inhibition of ovulation) in the oestrogen-deprived animals; this could be overriden by exogenous administration of oestrogen. In conclusion, although blocking oestrogen synthesis in the PMSG-primed rat does not seem to alter the functional properties of the isolated granulosa cells in vitro there appears to be an effect on the number of follicles which complete maturation and are able to ovulate in vivo.

Mare Balticum. Amstelodami, Apud. F. de Wit. ; Nieuwe pascaert van de Oost Zee t Amsterdam Gedruckt by F. de Wit

Pahville liimattu

Napoli da Mare : [vue générale de Naples depuis la mer] : [peinture]

Collectionneur : Lesouëf, Auguste (1829-1906)

Napoli da Mare : [vue générale nocturne de Naples depuis la mer et Vésuve en éruption à l'arrière-plan] : [peinture]

Collectionneur : Lesouëf, Auguste (1829-1906)

Landulfi de Columna, Canonici Carnotensis, breviarium historiarum à creatione mundi ad annum Christi 1250. suppletum est chronicum non uno in loco ex libro Joannis de Columna, qui inscribitur : Mare historiarum.

Mazarinaeus

Quan neix una mare? Xerrada per a mares gestants : la vinculació. 'Cuando nace una madre? Charla para madres gestantes : la vinculación'.

Resumen tomado del autor

Ai, mare de déu senyor! la nova àrea de societat, cultura i religió a la LOCE. '­Ay, Virgen María! la nueva área de sociedad, cultura y religión en la LOCE'.

Resumen tomado de la publicación en catalán. Este artículo forma parte del monográfico 'Nous currículums. Torna el Cid!'

Joan Fuster mestre aforismaire : l'aforisme de mare did??ctica i pare raonable. 'Joan Fuster maestro aforismador : el aforismo de madre did??ctica y padre razonable'

Resumen en catal??n del autor

Ma mare és..., un programa infantil de televisió farcit de mares treballadores. 'Mi madre es... un programa infantil de televisión lleno de madres trabajadoras'.

Presentación de un programa de la Televisión Autonómica de Valencia sobre las profesiones de las madres. En él los niños tienen un papel muy importante ya que son éstos los que hablan sobre las profesiones de sus madres. Para ello el programa cuenta con la colaboración de diferentes centros escolares del País Valenciano.

Quan la mare torna a casa per Nadal. 'Cuando mamá vuelve a casa por Navidad'.

Resumen del vídeo en catalán

Crucero Mare Nostrum : (22 julio -7 agosto 1967).

La Dirección General de Enseñanza Media organiza viajes de estudios por el extranjero desde 1962, con el fin de potenciar el conocimiento de otros sistemas educativos entre profesionales de la enseñanza media españoles. En el año 1967 el viaje proyectado se tituló Mare Nostrum, y tenía previsto visitar Egipto, Tierra Santa y Grecia. Pero el estallido del conflicto entre árabes y judíos conllevó la suspensión de la visita a Egipto y algunos de los países árabes, excepto Tierra Santa y Turquía. Se describe la ruta seguida, la rutina diaria, con las actividades realizadas, como conciertos, fiestas, conferencias culturales, visitas a bibliotecas etc. También se describen los lugares visitados, como el puerto de Haifa, Tierra Santa, Turquía y Grecia, y el regreso a Barcelona. Se trata de la descripción de un viaje y de los lugares visitados, y no hay referencias a los sistemas educativos de los países visitados.

Programa de inmersión cultural : ¡Mare! A chupar china en Yucatán : un modelo de adquisición de una segunda lengua dirigido a estudiantes anglófonos monolingües.

Memoria de máster (Universidad Antonio de Nebrija, 2010). Incluye anexos. Resumen basado en el de la publicación