More than just the numbers-contrasting response of snake erythrocytes to thermal acclimation.

Acclimation to lower temperatures decreases energy expenditure in ectotherms but increases oxygen consumption in most endotherms, when dropped below thermoneutrality. Such differences should be met by adjustments in oxygen transport through blood. Changes in hematological variables in correspondence to that in metabolic rates are, however, not fully understood, particularly in non-avian reptiles. We investigated the effect of thermal acclimation on a snake model, the grass snakes (Natrix natrix). After 6 months of acclimation to either 18 °C or 32 °C hematocrit, hemoglobin concentration, erythrocyte number, and size were assessed. All variables revealed significantly lower values under warm compared to cold ambient temperature. Our data suggest that non-avian reptiles, similarly as birds, reduce erythrocyte fraction under energy-demanding temperatures. Due to low deformability of nucleated erythrocytes in sauropsids, such reduced fraction may be important in decreasing blood viscosity to optimize blood flow. Novel findings on flexible erythrocyte size provide an important contribution to this optimization process.

Contrasting response of haematological variables between long-term training and short exercise bouts in zebra finches (Taeniopygia guttata).

Physical aerobic activity is oxygen demanding, but - particularly for birds - there is still little understanding of how blood contributes to oxygen supply under various activity levels. In a two-factorial experimental design, we investigated the long-term effect of daily flight training and the immediate effect of a short exercise bout on a set of haematological variables: haemoglobin (Hb) content, haematocrit (Hct), and red blood cell number (RBCcount) and size (RBCarea) in zebra finches (Taeniopygia guttata). For a period of 6 weeks, birds were either trained daily for 3 h in a flight arena or remained untrained. Subsequently, half of each group was blood sampled either in the resting condition or after a 5 min exercise bout in a flight-hover wheel. We found significantly lower Hb content, Hct and RBCcount compared with that in untrained controls in response to training, while RBCarea did not differ between treatments. Response to an exercise bout revealed the opposite pattern, with significantly higher Hb content and Hct compared with that in non-exercised birds. Additionally, RBCarea was significantly smaller immediately after exercise compared with that in non-exercised birds, and such short-term flexibility represents a novel finding for birds. This contrasting response in erythrocyte characteristics with respect to long-term training and short exercise bouts appears as a clear pattern, presumably underlain by changes in water balance. We infer alterations of blood flow to be involved in adequate oxygen supply. During an exercise bout, RBCarea flexibility may not only enhance oxygen delivery through improved erythrocyte surface area to volume ratio but also improve blood flow through a compensatory effect on blood viscosity.

[Active and passive exposure to tobacco smoke of pregnant women: two-center study]. / Czynne i bierne narazenie kobiet ciezarnych na dym tytoniowy--badanie dwuosrodkowe.

According to the current data over 12 million Polish citizens smoke tobacco, 40% of them are women. Maternal smoking in pregnancy significantly increases the rate of having a low-birthweight baby, the rate of perinatal mortality and several other adverse pregnancy outcomes. The aim of the study was to estimate the rate of smoking women during pregnancy and those who are exposed to secondhand smoke. 219 women hospitalized at Gynecology and Obstetrics Department of Wroclaw Medical University and Gynecology and Obstetrics Department in Opole have undergone the examination. The pregnant women have been interviewed and the results of questionnaire have been checked by the exhaled carbon monoxide (ExhCO) measurement. CO expresses the percentage of carboxyhemoglobin (HbCO) and is used for objective monitoring tobacco smoking. The results of the study suggest that regular exposure to secondhand smoke becomes a serious problem. 25.5% patients from Wroclaw and 16.4% patients from Opole have declared passive smoking. The mean value of ExhCO in this group of women obtained the level of 3.3 ppm vs 1.95 ppm in the group of patients who have denied both active and passive exposure.