The effects of injury and illness on haemoglobin mass

This study sought to quantify the effects of reduced training, surgery and changes in body mass on haemoglobin mass (Hbmass) in athletes. Hbmass of 15 athletes (6 males, 9 females) was measured 9±6 (mean±SD) times over 162±198 days, during reduced training following injury or illness. Additionally, body mass (n=15 athletes) and episodes of altitude training (n=2), iron supplementation (n=5), or surgery (n=3) were documented. Training was recorded and compared with pre-injury levels. Analysis used linear mixed models for ln(Hbmass), with Sex, Altitude, Surgery, Iron, Training and log(Body Mass) as fixed effects, and Athlete as a fixed and random effect. Reduced training and surgery led to 2.3% (p=0.02) and 2.7% (p=0.04) decreases in Hbmass, respectively. Altitude and iron increased Hbmass by 2.4% (p=0.03) and 4.2% (p=0.05), respectively. The effect of changes in body mass on Hbmass was not statistically significant (p=0.435).The estimates for the effects of surgery and altitude on Hbmass should be confirmed by future research using a larger sample of athletes. These estimates could be used to inform the judgements of experts examining athlete biological passports, improving their interpretation of Hbmass perturbations, which athletes claim are related to injury, thereby protecting innocent athletes from unfair sanctioning.

Spurious Hb mass increases following exercise

Sensitivity of the Athlete Blood Passport for blood doping could be improved by including total haemoglobin mass (Hb(mass)), but this measure may be unreliable immediately following strenuous exercise. We examined the stability of Hb(mass) following ultra-endurance triathlon (3.8 km swim, 180 km bike, 42.2 km run). 26 male sub-elite triathletes, 18 Racers and 8 Controls, were tested for Hb(mass) using CO re-breathing, twice 1-5 days apart. Racers were measured before and 1-3 h after the triathlon. Controls did no vigorous exercise on either test day. Serum haptoglobin concentration and urine haemoglobin concentration were measured to assess intravascular haemolysis. There was a 3.2% (p<0.01) increase in Racers' Hb(mass) from pre-race (976 g ± 14.6%, mean ±% coefficient of variation) to post-race (1 007 g ± 13.8%), as opposed to a - 0.5% decrease in Controls (pre-race 900 g ± 13.9%, post-race 896 g ± 12.4%). Haptoglobin was - 67% (p<0.01) reduced in Racers (pre-race 0.48 g / L ± 150%, post-race 0.16 g / L ± 432%), compared to - 6% reduced in Controls (pre-race 1.08 g / L ± 37%, post-race 1.02 g / L ± 37%). Decreased serum haptoglobin concentration in Racers, which is suggestive of mild intravascular blood loss, was contrary to the apparent Hb(mass) increase post-race. Ultra-endurance triathlon racing may confound the accuracy of post-exercise Hb(mass) measures, possibly due to splenic contraction or an increased rate of CO diffusion to intramuscular myoglobin.

Operant, open-field and tonic immobility behaviours in chickens with forebrain injections of cycloheximide or glutamate

Chickens that had received bilateral injections of cycloheximide or glutamate into the forebrain on day 2 of life and tested 4 weeks later showed no deficit in acquisition, performance or extinction of continuously reinforced appetitive key-pecking as compared to control birds injected with saline. However, chickens that had received injections of cycloheximide and were subsequently tested in an open-field apparatus took longer to leave the first square, defaecated more, and pecked, preened and moved about less than controls. They also showed longer durations of tonic immobility. Those injected with glutamate inhibited similar behaviour but were not significantly different from controls in the open field latency to leave the first square, defaecation, or tonic immobility tests. The above treatments have previously been described as producing permanent slowed learning in chickens on a pebble-floor task. Our results suggest that learning mechanisms may not be disrupted as shown by normal performance in a simple operant task but that enhanced emotionality or fear of novelty as revealed in the open field tests may interfere with the expression of learning behaviour in some situations.

Lateralisation of function in the chicken fore-brain

There is lateralisation of function in the chicken fore-brain. This was revealed by examining the behavioural modifications produced by administration of cycloheximide into the left or right hemisphere on Day 2 of post-hatched life. Visual discrimination learning of a task requiring a search for food was found to be performed either entirely or, at least, to a greater extent by the left hemisphere. Visual habituation learning was not found to be lateralised. The left hemisphere is more involved in auditory habituation than is the right; administration of cycloheximide to the left hemisphere slowed auditory habituation, as did bilateral administration, but treatment of the right hemisphere was ineffective. There are indications that the right hemisphere plays a more important role in response to novelty. A side-preference for response to stimuli seen by the left eye was demonstrated. These results are discussed with reference to head orientation during development in the egg.