Jouni Timisjärvi

The structure and insulation properties of the reindeer fur

The structure of the fur of the reindeer (6 adults, 4 calves) was studied with light and scanning electron microscopy and skin and rectal temperatures were measured in 216 living animals at varying ambient temperatures (-28 to +15 degrees C) and also on excised skin samples in the laboratory (temperature range -20 to +20 degrees C, wind 0 or 10 m/sec, 5 different directions). Guard hair count and length varied according to the site of excision and were on average 2000/cm2 and 12 mm on the foreleg, 1000/cm2 and 30 mm on the abdomen and 1700/cm2 and 30 mm on the back. The corresponding counts in the calves were higher but the hairs were shorter. The rectal temperatures ranged from 38 to 40 degrees C independently of the ambient temperature. The dependence of the skin temperature on the ambient temperature was complex in living animals. The dependence was strongest in the legs. The skin temperature of the excised samples depended rather linearly on the ambient temperature. It is concluded that the reindeer can maintain its body temperature also in severe cold although the extremities show characteristics of heterothermia.

Serum lipids, thyroxine and catecholamine levels in the reindeer with reference to the annual climatic cycle

Abstract 1. 1. Blood glucose and lactate, serum total lipid and triglyceride, thyroxine (T 4 ), epinephrine and norepinephrine concentrations and serum dopamine-β-hydroxylase activity were studied in 76 reindeer hinds and 127 calves with reference to the seasons. 2. 2. Blood glucose level tended to be lowest in Autumn, and blood lactate highest in Summer. 3. 3. Serum total lipids were smallest in Spring (2.8 g/l) and greatest in Autumn (5.3 g/l). Triglycerides were smallest in Winter (0.18 mmol/l) and highest in Autumn (0.32 mmol/l). In calves the total lipids increased during the neonatal period. 4. 4. Serum epinephrine correlated with the weight, age, blood glucose and total lipids of the animals. In adult animals the lowest serum epinephrine level was found in Spring and the highest in Autumn (55 vs 190 ng/ml). 5. 5. Serum norepinephrine concentration and dopamine-β-hydroxylase activity were highest in Spring and decreased towards Autumn. Parturition affected these parameters significantly. 6. 6. The preponderance of high levels of some blood constituents in Autumn may be attributable to the replenishment of energy supplies for Winter time and also to the rutting season. 7. 7. T 4 was smallest in Spring and highest in Summer. It was slightly greater in Winter than in Autumn. This suggests that the metabolic rate is tower in Winter than in Summer. Thus, the adaptation of the reindeer to a cold climate mainly utilizes insulation.

The acute dose-related effects of ethanol on right ventricular function in anesthetized dogs

The acute dose-related effects of small to moderate doses of ethanol on right ventricular functioning were studied on 18 anesthetized, artificially ventilated dogs in 39 sessions. Diluted ethanol (from 25-37.5%) was infused during 40 minutes, yielding total doses of 1.0 g/kg (n = 15), and 1.5 g/kg (n = 12) with corresponding venous blood ethanol peak concentrations of 1.38 +/- 0.25 and 2.41 +/- 0.31 mg/ml, respectively. Heart rate increased up to 16% in groups receiving ethanol. In the control group receiving the equivalent volume of saline (n = 12) heart rate decreased 14%. Pulmonary arterial systolic pressure increased from 24 +/- 3 to 27 +/- 3 mmHg and diastolic pressure from 11 +/- 2 to 14 +/- 4 mmHg (p less than 0.05) when the ethanol dose was 1.0 g/kg. The pulmonary arterial resistance increased from 620 +/- 135 to 805 +/- 185 dyn.s.cm-5 (p less than 0.01). The peak dP/dt decreased maximally by 20% with increasing ethanol doses. Stroke volume decreased maximally by 14% but due to the increase in heart rate, cardiac output even increased. The changes in end-diastolic volume and pressure were not significant. Hence, the ethanol increased heart rate and afterload of the right ventricle but depressed the myocardium.

Electromechanical delay in the intact dog heart

A computer method was developed for the determination of electromechanical delay defined as the time between the onset of Q-wave and the onset of the left ventricular systolic pressure rise. It was validated for heart catheterization studies on 56 intact anaesthetized beagle dogs in 86 sessions. The mean basal value of the electromechanical delay was 22 +/- 4 msec. Heart rate, contractility, preload and afterload were changed by atrial pacing and by infusions of calcium chloride, isoproterenol, propranolol, dextran and phenylephrine. Increase of heart rate by pacing from the spontaneous rate of 90 per min to 240 per min prolonged the electromechanical delay from 21 +/- 5 to 33 +/- 14 msec (P less than 0.001). Otherwise the duration of electromechanical delay changed independently of the heart rate. If it changed, the direction of the change followed that of the pre-ejection period. Its proportion of the pre-ejection period varied from 26 to 52%. The electromechanical delay shortened when a positive inotropic effect was noticed or the presystolic fibre length increased.

Electrophoretical and immunoelectrophoretical studies on serum proteins in growing and fully-grown reindeer (Rangifer tarandus tarandus L.)

Abstract 1. 1. The age (1 day to 10 yr) and sex-related growth and electro- and immunoelectrophoretical serum protein changes are described for 167 reindeer (Rangifer tarandus tarandus L.) in Finland. 2. 2. The mathematical presentation of the rapid weight gain, maximally about 400 g/day at an age of 4–8 wk, uses two separate functions since the experience of the calfs first winter stops growth. 3. 3. About 15 distinct protein bands were discernible in the reindeer serum showing wider distribution of the proteins in alpha region and IgG and more cathodic mobility of IgA than in normal human serum. 4. 4. The total serum protein concentration was low in the 20-day-old calf but high in the adult hind and the difference was caused by changes in globulins. The mating season decreased the protein levels of stags as compared with those of hinds. 5. 5. The gamma globulin level was high in the newborn calf but low at the age of 20 days. The highest levels of gamma globulin were found in the adult hind. 6. 6. The results suggest that the reindeer calf acquires its passive immunity soon after birth by intestinal absorption of immunoglobulins and also that the endogenous synthesis of immunoglobulins begins in the 4th wk of life.

Anabolic steroids alter the haemodynamic effects of endurance training on the canine left ventricle

The effects of six week, high-dose anabolic steroid treatment (methandienone, 1.5 mg/kg/day) on the changes in left vetricular function induced in dogs by endurance training were studied by a catheterization technique under anaesthesia. Pacing, isoproterenol and dextran infusions were used as loading tests (respectively). Dogs were randomized into an exercise group (EG,n=7) and an exercise-steroid group (ESG,n=7), the latter receiving anabolic steroids as well as participating in the training program. In a standardized submaximal exercise test, the heart rate of unanaesthetized dogs was lower both in the EG (p<0.001) and in the ESG (p<0.01) after the training period than before it. In the EG the resting systemic vascular resistance (SVR) before haemodynamic interventions was lower (p<0.05) and left ventricular stroke work (SW) was higher (p<0.05) after the training period than before. In the ESG, left ventricular ejection fraction (EF) decreased with training and anabolic steroid treatment (p<0.05). After the training period isoproterenol increased the maximum velocity of the cardiac contractile element significantly more (p<0.05) in the EG than in the ESG. Also SW increased in the EG (29%,p<0.001), but not in the ESG (−11%, NS). Endurance training increased the left ventricular end-diastolic and stroke volumes during isoproternol infusion, but this training effect was attenuated by simultaneous anabolic steroid treatment (p<0.05 between the groups in both case). During the isoproterenol test SVR decreased less in ESG than in EG (p<0.05 between). In volume loading tests, the ESG worked on a higher level of stroke work at a given end-diastolic volume when compared to the EG (p<0.001). This was related to a higher mean aortic ejection pressure and systemic vascular resistance measured in the ESG. In conclusion, the improved cardiac performance and peripheral adaptation after endurance training are partly attenuated by the simultaneous use of anabolic steroids in dogs.

Blood composition of the reindeer . II. Blood chemistry

The blood chemical composition of 578 semi-domestic reindeer were investigated in respect to age, season, calving and nutrition in Northern Finland during 1973-79. The weight gain was maximally 400 g/day at an age of 4-8 weeks as also reflected by high serum thyroxine (T4), alkaline phosphatase (SAP), creatine phosphokinase (CPK) and blood glucose values. Low SAP activity in winter indicated a cessation of growth. The pH of the venous blood was 7.35 and the clotting activity very high (21 sec, 100 %) in summer and autumn. 15 protein bands and 15 fatty acids were discernible in reindeer serum. The total serum protein was 58 g/1 in the 20-day-old calf and 87 g/1 in adult hind in the autumn, the difference being caused by changes in globulins. The neonatal fluctuation of immunoglobulins suggests that the calf acquires its passive immunity soon after birth by the intestinal absorption of proteins and that its endogenous synthesis of gamma globulins begins in the 4th week of life. The serum total lipids (2.9 g/1), triglycerides (0.29 mmol/1) and cholesterol (1.6 mmol/1) were low in newborn calves and reached their adult levels at the age of 5 months (average 5.1 g/1, 0.4 mmol/1, 2.7 mmol/1, respectively). The young calves had higher serum cholesterol, total and free fatty acid, myristic acid and palmitic acid, but lower stearic and oleic acid values than adult hinds. The reindeer calf liberates considerable amounts of catecholamines during the first days after birth, but the postpartum dopamine-B-hydroxylase activity was rather low. The means of blood glucose (3.4-4.6 mmol/1), total serum proteins (63 - 87 g/1), albumin (39 - 43 g/1), total globulins (23 - 44 g/1), urea (5.7-9 mmol/1), total lipids (2.7 - 5.2 g/1), triglycerides (0.17 - 0.33 mmol/1), total fatty acids (0.89 - 1.54 g/1), calcium (2.2 - 2.6 mmol/1), inorganic phosphorus (1.6 - 2.2 mmol/1), magnesium (0.8 - 1.2 mmol/1) and copper (6.7 - 18 |Jmol/l) of free-grazing adult hinds were highest in summer and autumn and decreased during winter. The lowest means were measured for the starved hinds in early spring. The high serum urea and CPK, LDH and SAP activities reflected catabolism of the body proteins and tissue breakdown during starvation. Season and nutrition did not affect serum T4, creatinine, sodium and chloride values. High body weight and blood chemical values were measured for the hinds fed on silage and molasses in winter. Poron veri. II. Veren kemia. Abstract in Finnish / Yhteenveto: 578 puolivillin poron veren kemiallista koostumusta tutkittiin ian, vuodenajan, vasonnan ja ravitsemustilan suhteen vuosina 1973-79. Painon lisays oli suurimmillaan 400 g/vrk 4-8 viikon iassa ja sita kuvastivat myos korkeat seerumin tyroksiinin (T4), alkaalisen fosfataasin (SAP), kreatiinifosfokinaasin (CPK) ja veren sokerin arvot. Alhainen SAP aktiivisuus talvella osoitti kasvun pysahtymista. Laskimoveren pH oli 7.35 ja veren hyytymiskyky (21 sek, 100 %) erittain hyva kesalla ja syksylla. Seerumista erotettiin 15 eri valkuaista ja 15 rasvahappoa. Seerumin valkuaisainepitoisuus oli 58 g/l 20 vrk:n iassa ja vaatimilla 87 g/l syksylla. Ero johtui globuliinien maaran muutoksesta. Immunoglobuliinien muutokset osoittavat, etta syntymanjalkeisen vastustuskykynsa vasa saa ilmeisesti eman maidosta ja etta oma gammaglobuliinien tuotanto alkaa vasta 4 viikon iassa. Vastasyntyneen vasan seerumin lipidit (2,9 g/l), triglyseridit (0,29 mmol/1) ja kolesteroli (1,6 mmol/1) olivat melko alhaiset ja saavuttivat aikuisen tason 5 kuukauden iassa (keskimaarin 5,1 g/l, 0,4 mmol/1, 2,7 mmol/1, vastaavasti). Vasojen seerumin kolesteroli-, kokonaisrasvahappo-, myristiinihappo- ja palmitiinihappopitoisuudet olivat korkeammat, mutta steariinihappo- ja oljyhappopitoisuudet alhaisemmat kuin vaatimilla. Ensimmaisina vuorokausina vasa tuottaa runsaasti katekolamiineja, mutta seerumin dopamiini-B-hydroksylaasin aktiivisuus on melko alhainen. Vapaana laiduntavan vaatimen veren sokeri (3,4 - 4,6 mmol/1), seerumin kokonaisvalkuainen (63 - 87 g/l), albumiini (39 - 43 g/l), globuliinit (23 - 44 g/l), urea (5,7 - 9 mmol/1), kokonaislipidit (2,7 - 5,2 g/l), triglyseridit (0,17 - 0.33 mmol/1), rasvahapot (0,89 - 1,54 g/l), kalsium (2,2 - 2,6 mmol/1), fosfori (1,6 - 2,2 mmol/I), magnesium (0,8 - 1,2 mmol/1) ja kupari (6,7-18 (Jmol/l) olivat korkeimmillaan kesalla ja syksylla ja laskivat talvella. Alhaisimmat pitoisuudet mitattiin nalkiintyneille vaatimille kevaalla. Seerumin korkeat ureapitoisuudet ja CPK, LDH ja SAP aktiivisuudet kuvastivat kehon valkuaisten ja kudosten hajoamista nalkiintymisen aikana. Vuodenajoilla ja ravinnolla ei ollut vaikutusta seerumin T4-, kreatiniini-, natrium- ja kloridipitoisuuksiin. Korkeat ruumiinpainot ja veren kemialliset arvot mitattiin vaatimille, joita ruokittiin sailorehulla ja melassileikkeella talvella. Renblod. II. Blodkemi. Abstract in Swedish / Sammandrag: Den kemiska sammansattningen av blodet hos 578 halvvilda vajor undesoktes under ar 1973 — 1979 med hanvisning till alder, arstid, kalvning och naringstillstand. Viktokningen var storst, 400 g/dygn, vid en alder av 4 — 8 veckor. Detta aterspeglades aven i de hoga varden av serumthyroxin (TV), alkalfosfatas (SAP), kreatininfosfokinas (CPK) och i blodsockerhalten. Den laga SAP-aktiviteten under vintern var ett tecken pa att tillvaxten stannat. Vardet av pH i venblodet var 7,46 och koagulationskapaciteten (21 sek, 100%) var mycket hog under sommaren och hosten. 15 olika aggviteamnen och 15 fettsyror skiljdes ur serum. Halten av aggviteamnen i serum var 58 g/1 vid en alder av 20 dygn och 87 g/1 hos vajorna pa hosten. Skillnaden berodde pa forandringen i globulinmangden. Forandringarna hos immunoglobulinerna pavisar, att kalven far sin motstandsformaga efter fodseln ur vajans mjolk och att kalven sjalv borjar producera gammaglobuliner forst da den natt en alder av 4 veckor. Den nyfodda kalvens serumlipider (2,9 g/1), triglycerider (0,29 mmol/1), och kolesterol (1,6 mmol/1) var tamligen laga och uppnadde nivan hos en vuxen ren vid 5 manaders alder (respektive medeltal 5,1 g/1, 0,4 mmol/1, 2,7 mmol). Halterna av kolesterol, fettsyra, myristinsyra och palmitinsyra var hogre i kalvarnas serum, emedan halterna av stearinsyra och oljesyra var lagre an hos vajor. Under de forsta levnadsdygnen producerar kalven katekolaminer i rikliga mangder. Daremot ar serumdopamid - B - hydroxylas-aktiviteten ganska lag. En fritt betande vajas blodsockerhalt (3,4 - 4,6 mmol/1), totalaggvitehalt i serum (63 - 87 g/1), albuminhalt (39 - 43 g/1), globulinhalt (23 - 44 g/1), urea (5,7- 9 mmol/1), totala lipidhalt (2,7 - 5,2 g/1), triglyceridhalt (0,17-0,33 mmol/1), fettsyrehalt (0,89 - 1,54 g/1), kalciumhalt (2,2 - 2,6 mmol/1), fosforhalt (1,6 - 2,2 mmol/1), magnesiumhalt (0,8 - 1,2 mmol/1) och kopparhalt (6,7 - 17 )Jmol/l) var hogst under sommaren och hosten emedan de sjonk under vintern. De lagsta halterna mattes hos u-tsvultna vajor pa varen. Den hoga ureahalten i serum samt CPK-, LDH- och SAP-aktiviteterna aterspeglar aggviteamnens och vavnaders upplosning i kroppen. Arstiderna och naringen inverkade varken pa halterna av T4 kreatinin, natrium eller klorid i serum. De hoga siffrorna for kroppsvikt och blodets kemiska varden mattes hos vajor som under vintersasongen matats med pressfoder och melassflis.

Thermoregulation in reindeer

Thermoregulation was studied in Finnish reindeer (Rangifer tarandus L) on captive and herded individuals during 1977-85. Newborn calves maintained a high rectal temperature (Tre) (+39 to +41°C) even at —23°C by increasing heat production 5- to 6-fold through non-shivering thermogenesis, stimulated by cold-induced noradrenaline (NA). Plasma NA and thyroxine (T4) were high (18 ng/ml and 459 nmol/1) in neonatal reindeer. Sensitivity to exogenous NA was lost during the first 3-4 weeks of life. At +20°C and above, calves increased Tre (ca 1°C), oxygen consumption and heart rate, thereby showing poor heat tolerance. Thermal conductance was low in a cold environment, but rose sharply as ambient temperature (Ta) increased above + 10°C. The Tre of adults (+ 38 to +39°C) was independent of Ta (—28 to +15°C). Coarse (hollow) hair density and length in adults averaged 2000/cm2 and 12 mm on the legs, 1000/cm3 and 30 mm on the abdomen and 1700/cm2 and 30 mm on the back (calves 3200/cm2, 10 mm), respectively. The dependence of skin temperature on the Ta was linear in excised fur samples, but complex in living animals being strongest in the legs. Serum adrenaline correlated with the weight, age and total lipids. Serum NA and dopamine-fi-hydroxylase were highest in spring and decreased by autumn. Serum T4 was highest in summer and lowest in spring.

Left ventricular volumes and functioning of the reindeer heart

SummaryLeft ventricular volumes were measured by cineangiocardiography in 56 sessions on 25 reindeer, together with determinations of arterial pressure and blood oxygen saturation.The heart rate with the animal kept lying on the sternum at rest was 50 b/ min the aortic blood oxygen saturation 94 to 98% and the aortic blood pressure 153/130/115 mm Hg. The left ventricular end-diastolic volume was 3.4 ml/kg of b.w., stroke volume 2.6 ml/kg, cardiac output 133 ml/kg·min, and ejection fraction 76%. If the animal was placed on its side the aortic blood oxygen saturation decreased by 2 to 3 per cent, end-diastolic volume rose 10%, stroke volume 25%, cardiac output nearly 30% and ejection fraction 14%.The heart rate and cardiac output increased in hypoxemia, but the enddiastolic and stroke volumes simultaneously decreased. If the aortic blood pressure rose during hypoxia, the end-diastolic and stroke volumes increased, while the ejection fraction first increased and then decreased again.In normoxia a rise in aortic blood pressure was associated with decreased end-diastolic and stroke volumes and ejection fraction. An increased heart rate at rest was followed by increased cardiac output, but decreased end-diastolic and stroke volumes and ejection fraction.ZusammenfassungBei 25 Rentieren wurde das Innenvolumen des linken Ventrikels mit Hilfe einer kineangiokardiographischen Methode in 56 Sitzungen gemessen. Gleichzeitig wurden der arterielle Blutdruck und die Sauerstoffsättigung des Blutes bestimmt.Beim ruhenden, auf dem Sternum liegenden Tier betrug die Herzfrequenz 50 Schläge/min, die Sauerstoffsättigung der Aorta 94 bis 98% und der Aortendruck 153/130/115 mm Hg. Das enddiastolische Volumen betrug 3,4 ml/kg, das Schlagvolumen 2,6 ml/kg, das Herzminutenvolumen 133 ml/kg und die Austreibungsfraktion 76%. Beim Tier in Seitenlage war die Sauerstoffsättigung der Aorta um 2 bis 3% vermindert, das enddiastolische Volumen um 10%, das Schlagvolumen um 25%, das Herzminutenvolumen beinahe um 30% und die Austreibungsfraktion um 14% erhöht.Bei gesteigertem Aortendruck waren Schlagvolumen, enddiastolisches Volumen und Austreibungsfraktion bei Normoxie vermindert, während unter Hypoxie das enddiastolische Volumen und das Schlagvolumen erhöht, die Austreibungsfraktion zunächst erhöht und danach vermindert waren. Unter Hypoxie nahmen Herzfrequenz und Herzminutenvolumen zu bei gleichzeitigem Rückgang von enddiastolischem Volumen und Schlagvolumen. Eine erhöhte Herzfrequenz ohne Muskelarbeit führte zu einer Steigerung des Herzminutenvolumens, während enddiastolisches Ventrikelvolumen, Schlagvolumen und Austrebungsfraktion gleichzeitig vermindert waren.

Mean outflow resistance as a marker of left ventricular afterload

SummaryThe changes of mean outflow resistance (MOR) (defined as the ratio between mean aortic ejection pressure and mean ejection rate) and of total peripheral resistance (TPR) together with their relations to some circulatory parameters and to each other were studied under control (NaCl) and six different loading conditions on anesthetized closed chest dogs. Phenylephrine increased both MOR and TPR (ca. 160%, max), pacing increased MOR (p<0.01) but not TPR. Isoproterenol and dextran infusion decreased TPR (p<0.001) but not MOR. Calcium chloride decreased MOR (p<0.05) but increased TPR (NS). The relationship between MOR and TPR was linear in each case (r from 0.63 to 0.91). Both MOR and TPR showed either positive or negative linear correlations with volume and pressure parameters although MOR appeared to be more sensitive to the administered interventions. The present results suggest that, when referring to the pulsatile and discrete nature of the blood-flow-pressure output from the left ventricle, MOR seems to be a more useful measure than TPR in the assessment of the left ventricular afterload.