Serum enzyme activities in reindeer

The enzyme activities of CK, A L D , L D H , H B D H , M D H , G L D H , GGT, L A P , A P , C H E and GSHPx were measured by standard methods in reindeer serum during autumn 1986. No significant sex differences in enzyme activities were detected in calves. Young and adult reindeer of both sexes had slightly lower A L D , L D H , H B D H , M D H and significantly lower A P values than calves.


Introduction
The heamatology and blood chemistry of domestic animals with respect to age, breed, nutrition and season have been thoroughly investigated.Much attention, moreover, has been paid to the problem of measuring physiological condition in freely grazing wild ungulates.In Finland, semi-domesticated reindeer still graze almost like their wild ancestors, roaming freely in forests or subarctic mountain areas north of latitude 65°N.They show many adaptations to these conditions (e.g.Nieminen 1980).Reindeer eat mainly green vegetation in summer and carbohydrate rich lichens during the long winter.Serum concentrations of protein, lipid and mineral are highest during autumn when the reindeer are in the best condition.In freely grazing hinds and calves concentrations fall during winter; lowest values are usually found in starving hinds and calves during early spring (Nieminen andTimisjarvi 1981,1983).

Material and methods
The study was carried out in Kaamanen reindeer research station in Northern Finland in November 1986.Fifty-two semi-domesticated reindeer {Rangifer tarandus tarandus L.) aged from 5 months to over 3 years were divided into 6 groups according to sex and age.All the animals grazed freely on good pastures for six months before sampling.They were captured by hand one at a time during the regular autumn round-up.No immobilizing or sedative drugs were used.

Results and discussion
The results are given in Table 1.There where no significant sex differences in serum enzyme activities of 5 months old calves or young reindeer (age 17 months) (Student's t-test).Young and adult females had slightly lower ALD, LDH, HBDH, MDH and significantly lower (P<0.001)AP values than female calves.Yaung and adult males had also lower enzyme activities than male calves during autumn.
Alkaline phosphatase (AP) is concentrated intracellularly in osteoblasts, renal tubules and the intestinal mucosa.An increase in serum AP activity is observed in bone with an increased activity of the osteoblasts during growth and pregnancy.Lowered levels can indicate malnut-rition.Serum AP was high in calves during autumn, but the activity was slightly lower than in the previous studies (see Nieminen 1980, Nieminen andTimisjärvi 1983).
Creatine kinase (CK) is present in skeletal muscle, heart and brain, and it is a potential indicator of physical stress, trauma and perhaps malnutrition.Elevated CK levels have been recorded associated with the capture of game animals and reindeer (e.g.Hyvärinen et al 1976, Gericke et al 1978) and in cattle with paratuberculosis, in selenium (Se) deficiency, or in stress (Szilägyi et al 1982(Szilägyi et al , 1986)).Serum CK activities of reindeer calves and females were in physiologic range in present study indicating neither severe handling stress during sampling nor other cell membran damages in individuals.However, the CK levels in reindeer appear to be higher than in domestic animals (Szihägyi et al 1986(Szihägyi et al ,1987)).The activity of lactate dehydrogenase (LDH) of calves and adult reindeer was also low in present study.High levels of LDH are usually associated with tissue breakdown.High serum urea and CK, LDH and AP activities have been found in undernourished reindeer hinds during late winter and spring (Nieminen 1980).
Activities of ALD, HBDH, MDH, GLDH, GGT, CHE and GSHPx have not been measured previously in reindeer.Aldolase (ALD) takes part in glycolytic process.It is present in many organs such as the liver and heart but the Gamma glutamyl-transpeptidase (GGT) catalyzes the hydrolysis of peptides and the simultaneous transfer of the glutamyl group.It is present in liver, pancreas, and kidneys, and hepatobiliary and pancreatic disease is the usual cause for serum enzyme increase.Cholinesterase (CHE) is formed in the liver.It hydrolyzes acetylcholine to choline and acetic acid.Cholinesterase activity is another diagnostic test for liver disease.It is very useful in detecting poisoning by organic phosphate insecticides or some drugs as in anesthesia.Leucine aminopeptidase (LAP) hydrolyzies amino acids containing alpha amino groups.The highest concentration of leucine aminopeptidase is usually found in the pancreas and liver.The activity of serum glutathione peroxidase (GSHPx) in present study was rather high and may be associated with the high concentration of selenium in reindeer meat (mean 1.02 mg/kg dry weight in adult hinds).This value is about 20 times higher than in Finnish cows (see Niemi¬ nen et al. 1986).The nutritional importance of selenium and its relation to vitamin E is well known.Its specific biochemical role 7 however, is uncertain (see Rotruck et al. 1973).Selenium acts at the active site of GSHPx, which catalyses the conversion of peroxidized fatty acids to hydroxy fatty acids, thereby preventing lipid free radical chain reactions (Hafeman et al. 1974).