1. The daily torpor was measured by oxygen uptake in Djungarian hamsters during adaptation to a short photoperiod (SP: 10L, 14D) at 20 degrees C. In these constant conditions the torpor presented metabolic characteristics and a daily time course independent of the duration of adaptations to SP. 2. The frequency of torpor bouts increased during SP exposure and its maximum was reached after about 130 days. The frequency of torpor was greater in males than in females. 3. The incidence of torpor was increased by constant dark exposure and this is discussed as a protective mechanism for the individual animal's ability to survive. 4. The temporal organization of daily torpor was demonstrated to be directly synchronized by the day-night cycle and to be controlled by an endogenous circadian function.

No abstract

IntroductionNumerous biological parameters are physiologically modified during normal pregnancy, in particular hematology. The knowledge of these modifications of the maternal body by biologists and clinicians allows the screening of possible anomalies. In Morocco, the reference values of the complete blood count test for pregnant woman are missing, as are those specific to different trimesters of pregnancy. The aim of this study is to look for the reference values for healthy pregnant women of the Northwest region of Morocco, to compare them to those of non-pregnant women (control) and to those of the literature.MethodsBlood samples were taken voluntarily from 3898 healthy pregnant women from 18 to 46 years old who presented themselves at the center of health Kalaa and at the service of gynecology obstetrics of the Provincial Hospital Center of M'diq (Morocco), for prenatal care. To establish the reference intervals of the CBC for non-pregnant women, a control group was constituted by 7035 healthy women from 18 to 50 years old selected according to the Moroccan law of blood donation. The CBC was measured on a Sysmex KX21N® analyzer. For each sample a systematic blood smear was done to determine the leukocyte differential.ResultsA statistically significant difference between the pregnant women and control group was noted (p < 0.05) for all the hematological parameters: red blood cells, hematocrit, hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, leukocytes, neutrophils, basophils, eosinophils, lymphocytes, monocytes, platelets and mean platelet volume. So, the comparison of the averages established between the first, second and third trimester of pregnancy showed the existence of a significant variation with regard to all the parameters of the CBC test looked for (p < 0.001).ConclusionThe present study provides additional baseline data for basic hematological parameters in healthy pregnant Moroccan women and concluded that pregnancy in women has the tendency to alter some hematological indices. For these reasons, there is an interest to take these modifications into account for optimal maternal and fetal medical care.

Nocturnal secretion of melatonin from the pineal gland may affect central and peripheral timing, in addition to its well-known involvement in the control of seasonal physiology. The Syrian hamster is a photoperiodic species, which displays gonadal atrophy and increased adiposity when adapted to short (winter-like) photoperiods. Here we investigated whether pineal melatonin secreted at night can impact daily rhythmicity of metabolic hormones and glucose in that seasonal species. For that purpose, daily variations of plasma leptin, cortisol, insulin and glucose were analyzed in pinealectomized hamsters, as compared to sham-operated controls kept under very long (16 h light/08 h dark) or short photoperiods (08 h light/16 h dark). Daily rhythms of leptin under both long and short photoperiods were blunted by pinealectomy. Furthermore, the phase of cortisol rhythm under a short photoperiod was advanced by 5.6 h after pinealectomy. Neither plasma insulin, nor blood glucose displays robust daily rhythmicity, even in sham-operated hamsters. Pinealectomy, however, totally reversed the decreased levels of insulin under short days and the photoperiodic variations in mean levels of blood glucose (i.e., reduction and increase in long and short days, respectively). Together, these findings in Syrian hamsters show that circulating melatonin at night drives the daily rhythmicity of plasma leptin, participates in the phase control of cortisol rhythm and modulates glucose homeostasis according to photoperiod-dependent metabolic state.

No abstract