The effect of a six-day ski-hike on plasma catecholamine concentrations and on their response to submaximal exercise

Plasma catecholamine concentrations and dopamine-beta-hydroxylase activities were studied in 29 participants of a six-day cross-country ski-hike (260 km) to elucidate the adaptive responses of the sympatho-adrenal system to prolonged heavy exercise. Immediately after skiing on the first skiing day plasma noradrenaline concentrations appeared to be over twice as high as in the morning. On the morning of the fourth day noradrenaline levels had increased significantly when compared to those of the first morning. Concentrations after skiing on the fourth day were, however, about the same as in the first evening. After a submaximal ergometer test performed immediately after the skiing concentrations were still raised and the relative enhancement by this short-term exercise was about the same magnitude (40--60 %) on every test day. On the sixth day noradrenaline concentrations were about the same level as on the fourth day. Eleven days after the hike the basal noradrenaline levels were still about 25 % higher than before it. The changes of plasma adrenaline concentrations were in the same direction although not as striking as those of noradrenaline. Dopamine alterations were negligible. A significant but reversible decrease in plasma dopamine-beta-hydroxylase activities and cholesterol concentrations was found during the hike. The present results show that the sympatho-adrenal system is activated during the first few days of a ski-hike type prolonged exercise. A plateau developed in about four days. There were no signs of a decreased sympatho-adrenal response to a short-term heavy load.     

Acidocillin concentration in middle ear exudate]

Acidocillin levels were determined in the middle ear exudates and serum of patients with acute exudative otitis media after oral administration of the drug. Acidocillin rapidly diffused exudate into the ear and its level in the exudate in 1 hour was 0-1.7 gamma/ml. At the same time the serum levels ranges within 4 to 25 gamma/ml. acidocillin remained longer in the ear exudate than in the serum. In 12 hours 0.2 to 1.3 gamma/ml of acidocillin was still found in the exudates, while there was no antibiotic in the serum.     

Stock‐specific variation of trophic position,diet and environmental stress markers in Atlantic salmon Salmo salar during feeding migrations in the Baltic Sea

This study investigated stock‐specific variation in selected ecophysiological variables during the feeding migrations of Atlantic salmon Salmo salar in the Baltic Sea. Oxidative stress biomarkers and EROD (ethoxyresorufin‐O‐deethylase, Cyp1A enzyme) activity were used as indicators of possible environmental stress and stable isotopes as determinants of diet and trophic position. Latvian S. salar stocks Daugava and Gauja had distinct stable‐isotope signatures compared to the other stocks, indicating differences in migration patterns, residency or arrival times, or dietary specialization among stocks. Salmo salar originating from Daugava and Gauja also had lower catalase enzyme activity than the other stocks. Post‐smolts originating from rivers of the Gulf of Finland had elevated EROD activities compared to fish of the same age from Bothnian Bay rivers, which could indicate exposure to organochlorine pollutants. No other stock‐specific differences in oxidative stress biomarkers were found. The study demonstrates how genetic, oxidative stress biomarker, EROD and stable‐isotope data may be combined to study trophic position, prey prevalence and environmental stress of mixed S. salar stocks foraging in the sea.