Pregnancy associated glyciprotein and progesterone concentrations in plasma of sheep during gestation and post-partum period

Contributed to: 109th meeting of the British Society of Animal Production (Scarborough, UK, Mar 21-23, 1994).Peer reviewe

Prediction of cortisol response to dexamethasone from age and basal cortisol in normal volunteers: A negative study

The dexamethasone suppression test (1 mg at 23 h and 4 P.M. blood collection) was performed in 22 normal subjects. In contrast to a previous study using 0.5 mg dexamethasone and a 8-9 A.M. post-dexamethasone blood sample, age and basal cortisol level did not significantly predict postdexamethasone cortisol levels. © 1986 Springer-Verlag

Diurnal variations of sexual receptivity in the female Japanese quail (Coturnix coturnix japonica).

A series of experiments was performed to study the changes during the day of female receptivity in Japanese quail. In each experiment, the frequency of squatting and the percentage of male approaches which were followed by squatting increased at the end of the day, approximately 11 to 13 hr after lights on (in a photoperiod of 16L:8D). In some cases this increased receptivity was associated with a significant decrease of the long-avoid frequency. Analyses are presented which demonstrate that the increased receptivity at the end of the day is not directly caused by the oviposition and does not result directly from changes in the behavior of the male stimuli. This is strongly supported by the observation that the increase in receptivity was observed at the same time after lights on (but different clock times) in two groups of females which were raised in two different photoperiods shifted by 6 hr and tested with the same group of males raised in one of the two photoperiods. The increase in receptivity coincides with an increase in plasma estradiol and progesterone. Considering that this behavior is suppressed by ovariectomy, it is argued that the daily changes in receptivity could be controlled by the hormonal changes associated with the ovulatory cycle

Hormonal correlates of gonadal regression and spontaneous recovery in Japanese quail exposed to short day-lengths.

Adult male Japanese quail were transferred from long to short days. Plasma testosterone and dihydrotestosterone quickly decreased and this endocrine response was followed by a regression of the cloacal gland, an androgen-target organ. After about a month, a spontaneous recovery of gonadal activity was observed in some but not all birds. It was not associated with obvious shifts in the circadian system. The physiological bases of this spontaneous recovery are discussed as well as the detailed relationships between plasma testosterone and cloacal gland size

Coping style, trait anxiety and cortisol reactivity during mental stress

The present study examined whether salivary cortisol secretion as an index of stress reactivity to continuous mental task performance reflected individual differences in coping styles. During 4 hr of continuous mental tasks significantly higher cortisol levels were found in comparison with a control session. However, individual variability in the cortisol response was high. Correlational data indicate a significant negative relationship between the coping style ‘comforting cognitions’ and the individual cortisol response during mental stress. During this particular type of cognitive stress, where the subject has no control over the experimental situation, comforting and emotion-focused coping may be effective because of the subject's efforts of trying to reframe the inevitable situation in a positive and self-encouraging way. In contrast, there was no significant relationship between trait anxiety and individual glucocorticoid susceptibility to mental stress

Evolución de las concentraciones plasmáticas de PAG (Pregnancy-Associated Glycoprotein) y progesterona en ovejas de raza Assaf durante la gestacion y el post-parto

3 páginas, 1 figura.-- Ponencia presentada a las VI Jornadas sobre Producción Animal (AIDA) (Zaragoza, 25 a 27 de abril de 1995). Publicada en un número especial de la revista ITEA.En el transcurso de la gestación de diferentes especies animales diversas proteínas y hormonas aparecen por primera vez en la circulación materna o aumentan su concentración. Una de estas proteínas es la PAG (pregnancy-associated glycoprotein), que es secretada por las células binucleadas de la placenta de los rumiantes, y ha sido aislada en la vaca, la oveja y la cabra (Benítez-Ortiz, 1992). La PAG ha sido utilizada como método de diagnóstico de la gestación y como parámetro indicativo de la mortalidad embrionaria. La evolución de las concentraciones de PAG durante la gestación simple de ovejas de raza Churra y Merina ha sido descrita recientemente (Ranilla, et al, 1994), poniéndose de manifiesto la existencia de diferencias interraciales. Otros estudios (Benítez-Ortiz, 1992) sugieren que el número de fetos puede también afectar a las concentraciones plasmáticas de PAG. En el presente trabajo se describen los perfiles plasmáticos de PAG y progesterona en los últimos meses de la gestación y el postparto de ovejas Assaff con gestación simple y doble.Peer reviewe