bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects from the Sensorimotor Cortex on Ascending Spinal Pathways
Authors: Lundberg A. , Norrsell U. , Voorhove P.
Published: December 2008

The effect of stimulation of the sensorimotor cortex on ascending spinal pathways was investigated in cats with recording of mass discharges, with intracellular recording from the cell bodies and with unit recording from the axons. Apart from effects caused by primary afferent depolarization there are marked effects from the sensorimotor cortex only on pathways influenced from the flevor reflex afferents (FKA). This holds true for the ventral spinocercbellar tract which is inhibited from the FRA and from cortex and for the ventral spinobulbar tract which is excited from the FRA and from cortex. The same parallelism betwerri actions from cortex and the FKA was found for the dorsal spinocerrbellar tract but not for the spinocervical tract which have FRA activated neurones that are not excited from the sensorimotor cortex.
Liver Catalase Activity during Complete Extra‐Hepatic Biliary Stasis in Rabbits and Dogs
Authors: Aronsen Karl‐Fredrik , Haeger‐Aronse Birgitta
Published: December 2008

The liver catalase activity has been studied in rabbits and dogs during and after different periods of complete extra‐hepatic hiliary obstruction. In both animals biliary stasis caused a decrease in enzyme activity. This decrease was most pronounced in the rabbits. After release of the biliary obstruction in the dogs the reduced activity of the liver catalase returned to normal level indicating a rcversible phenomenon. The species difference and the cause of the decrease of the catalase activity in association with biliary stasis has been discussed.
Time Courses of Blood Gas Changes Provoked by Light and Moderate Exercise in Man
Authors: Barr P.‐O. , Beckman M. , Bjurstedt H. , Brismar J. , Hesser C. M. , Matell G.
Published: December 2008

Changes in arterial gas levels in response to constant‐load, dynamic exercise (400 and 700 kpm/min for 6 min) were studied in 8 healthy male subjects by continuous analyses of arterial pH and O2saturation. During pre‐exercise rest, spontaneous time‐variations in these variables occurred in all individuals at half‐minute intervals or longer. These cyclic fluctuations, which were quite marked in some individuals, probably in part explain differences reported as to the magnitude and direction of changes occurring in response to exercise. To eliminate most of such influences on the observed deviations following the onset of exercise, the time‐averages over the preceding 3 min were chosen as reference levels. Both pH and O2saturation, when referred to the blood passing through the left heart, remained essentially constant during the first 20–30 sec following the transitions from rest to exercise and from exercise to rest at both work loads. The arterial [H+] rose to reach a plateau during the 3rd and 4th min (average decrease in pH = 0.022 at 400 kpm/min and 0.036 at 700 kpm/min). Calculated arterial PO2, after a transient drop during early exercise, was increased by about 5 mm Hg during the last 3 min of exercise at both loads. About 30 sec after cessation of work, arterial [H+] fell rapidly towards pre‐exercise level, whereas arterial PO2rose markedly to reach its maximal deviation after about 1.5 min. The shift towards acidosis during exercise was roughly proportional to the relative intensity of work, whereas no such relationship was observed on the part of the concomitant increment in arterial PO2.
Influence of Some Local Anesthetics upon the Adrenaline Contraction of Isolated Strips of Rabbit Aorta
Authors: ÅStröm A.
Published: December 2008

Several local anesthetic agents have been tested for their ability to counteract adrenaline‐and noradrenaline‐induced contractions of the spirally cut strip of rabbit aorta. The method used includes a calibrated spiral spring arrangement attached to a conventional strain gauge transducer. This device which is very useful also for several other isolated organs, is described in detail. All the local anesthetics tested possess anti‐adrenaline activity in appropropiate concentrations (1–3 mM), but procaine, mepivacaine and o‐methyl‐α‐propylamino‐propionanilide (L 67) are about 5 times more active than lidocaine and cocaine in this respect. The antagonism is non‐specific in nature and contractions induced by histamine are counteracted in a similar manner. The results are discussed in relation to the known anesthetic properties of the agents. The conclusion is drawn that the non‐specific anti‐adrenaline action varies independently of the local anesthetic effect as measuredin vitroon the isolated nerve preparation.
Zur Methodik der venösen Okklusionsplethysmografie. Die Wirkung distaler Gefässokklusion auf die Durchblutung im Unterarm
Authors: Graf Klaus
Published: December 2008

Observations were made on the circulatory effects of an occlusion cuff applied distally to a forearm segmental plethysmograph. Measurements of the forearm blood flow (plethysmographically and with thermal conductivity recorders) and the pressure in the brachial artery, were performed. The plethysmographic registration of blood flow (arterial inflow) in a forearm segment necessitates a temporary blockade of the more peripheral venous return. The commonly used arterial occlusion was shown to be only partially adequate; besides other disadvantages, it was regularly accompanied during the first 1–2 min by a gradual increase of the blood flow in forearm muscle and skin, and there was also an immediate rise of the local arterial blood pressure. The distal occlusion cuff had to be kept in a constant position as a displacement in the distal direction of only 1–2 cm frequently gave rise to a considerable increase of the plethysmographically measured blood flow values, especially when the forearm or hand circulation was high. A cuff position directly distal to the plethysmograph should be avoided as it causes proximal tissue displacement and probably vessel compression. Every mode of application of the distal occlusion cuff is a compromise between different disadvantages. For venous occlusion plethysmography this means that it is impossible to measure accurately the true blood flow (arterial inflow) in limb segments. On forearm the optimal results were frequently obtained with the cuff 1–2 cm distal to the plethysmograph, and with simultaneous inflation of the distal occlusion and proximal collecting cuff to the same venous occlusion pressure (i. e. about 50–80 mm Hg under normal conditions).
Auswertung und Messfehler okklusions‐plethysmografischer Durchblutungsregistrierungen
Authors: Graf Klaus
Published: December 2008

Investigations were made on the evaluation and interpretation of blood flow measurements performed by venous occlusion plethysmography on human arms and legs. The different types of inflow curves and the criteria for application of the tangents to them are discussed. The arm position which least influences the circulation in the forearm and hand was determined. An investigation was made of the errors of measurement for the determination of the tissue volume enclosed in the plethysmograph as well as for the recording device including the plethysmographs. It is suggested that values for the apparent rate of arterial inflow of between 0.5 and 20–40 ml/100 ml·min can be measured by venous occlusion plethysmography with sufficient accuracy.
The Influence of Chlorpromazine on the Catecholamine Excretion of Normal and Gold Acclimated Rats
Authors: JOHNSON G. E.
Published: December 2008

Abstract

Chlorpromazine was administered to normal rats placed at 30° and 20° C and to cold acclimated rats exposed to 30° and 2°. Treatment of the animals at 30° produced no increase in catecholamine excretion. However, rats placed at either 20° or 2° significantly increased their noradrenaline excretion, and to a lesser extent their adrenaline excretion, following chlorpromazine. These increases, also noted in adrenalectomized rats and associated with hypothermia, could be prevented by pretreatment with a ganglionic blocker. It is concluded that the increase in noradrenaline excretion is a result of a temporary hypothermia produced by chlorpromazine and originates from sympathetic nerve endings.
Heart Rate, Arterial Lactate Concentration and Oxygen Uptake During Exercise in Old Men Compared with Young Men
Authors: Strandell T.
Published: December 2008

In 121 healthy men aged 30–83 years heart rate, oxygen uptake, arterial lactate and pyruvate concentrations were studied during stepwise increased work loads on a bicycle ergometer. The relationship between heart rate and work load was not affected by age but the final heart rate and work load decreased with age. In the younger ages the most usual reason for breaking off the test was fatigue in the legs, in the higher ages dyspnoea. The regression line for log lactate on heart rate during exercise was on a higher level in old men than in young. Blood lactate during exercise was correlated both to the degree of circulatory steady state, the heart rate, and the final work load irrespective of age. The relationship between lactate and excess lactate during exercise was similar in old and young men, excess lactate being equivalent to lactate reduced by 2 mM/1. In 20 men aged 60–83 years there was at 600 kpm/min a negative correlation between mechanical efficiency and heart rate and a positive between oxygen uptake and weight or heart rate. No correlation was found between oxygen uptake or mechanical efficiency and age, degree of circulatory steady state or blood lactate concentration.
Iron Metabolism and Erythrocyte Formation in Fish
Authors: Hevesy G. , Lockner D. , Sletten K.
Published: December 2008

Iron metabolism in tench was studied. At 18° up to 70 per cent of injected Fe59 was taken up by the erythrocytes. In the first days of the experiment an appreciable part, up to 20 per cent, of the Fe59 is present in the erythrocytes as non‐hemoglobin iron, the latter decreases with time. Hemoglobin (Hb) concentration amounted to 5.4 g%, erythrocyte number 1.04×106 per mm3. Serum iron was found to be 61 ü g% and iron binding capacity 250 üg%. Plasma iron half disappearance rate is 4 hours. In fish kept at 5° iron taken up by erythrocytes amounts to 4 per cent only. Both in at 18° and 5° kept fish one Hb fraction and one transferrin fraction was found only. At high oxygen concentration or in nitrogen atmosphere less Fe59 is incorporated in in vitro experiments into erythrocyte hemin than in air. The life time of about 60 per cent of erythrocytes amounts to about 150 days at 18°, indications of longer‐living erythrocytes were found.
Flow and Protein Content of Lymph in Resting and Exercising Skeletal Muscle
Authors: Jacobsson S. , Kjellmer I.
Published: December 2008

The study was undertaken to evaluate the rôle of the lymphatic drainage of the calf muscles of cats in the transport of fluid and proteins from exercising muscle. Pure muscle lymph was obtained from a deep lymph vessel above the knee after exclusion of the paw which otherwise contributes substantially to the flow of lymph in the deep vessels. During exercise the lymph flow in skeletal muscles increases but even then accounts for only some 10 per cent of the simultaneously produced capillary filtrate. The protein content of lymph from muscle was about the same as that of lymph from skin. The albumin fraction in muscle lymph was moderately raised compared with that of plasma and did not change during exercise. The lymph can probably drain the entire protein content of the capillary filtrate produced during exercise.
Acid‐Labile Carbon Dioxide of Rat Brain After Freezing the Tissue in Situ
Authors: Pontén U. , Siesjö B. K.
Published: December 2008

A new method for the determination of the acid‐labile carbon dioxide of frozen tissue samples (Pontén and Siesjö 1963 b) has been used in a study of the relation between the arterial carbon dioxide tension and the total carbon dioxide content of brain tissue in rats, employing either freezing of the tissue in situ with liquid nitrogen, or decapitation of the animals with excision of the tissue and subsequent immersion in liquid nitrogen. It was found that failure to freeze the tissue in situ leads to values for the total carbon dioxide content which spread unduly, and which are related to the lag between the decapitation and the inhibition of the tissue metabolism. During the first minutes after decapitation, the total acid‐labile CO2 of the tissue is usually higher than that obtained after freezing the tissue in situ, whereas longer delays lead to losses of carbon dioxide from the tissue. The values obtained after in situ freezing are lower than those given previously in the literature. Thus, in a group of 12 experiments in which the arterial carbon dioxide tension varied between 35 and 45 mm Hg, the total carbon dioxide content of the brain was determined to 13.31 ± 0.07 ümoles/g. Assuming a 16 per cent extracellular space, the average bicarbonate concentration in the cell phase of the tissue could be calculated to about 9.8 ümoles/g.
Neural and Humoral Control of the Gallbladder‐Emptying Mechanism in the Gat
Authors: Pallin Bengt , Skoglund Sten
Published: December 2008

The neural and humoral control of the gallbladder‐emptying mechanism was investigated in cats. It was found that vagal stimulation facilitates the effect on the gallbladder‐tone set up by cholecystokinin and further that stimulation of the right splanchnic nerve inhibits the effect of cholecystokinin just as it inhibits the effect of vagal stimulation, as shown earlier. The results show that neural and humoral control of the gallbladder are interlocked. It is concluded that the inhibition cannot be directed on a possible endogenous liberation of cholecystokinin caused by vagal stimulation. The reason for this is that it can be demonstrated on the effect of intravenously administered hormone in the abscence of any vagal influence. The inhibitory mechanism is not affected by the hormone since the inhibition is the same independent of whether the gallbladder‐tone has been set up by neural or humoral means.
Intracellular Slow Wave Potentials in the Somatosensory Area of Cat
Authors: Andersson S. A. , Lundberg A. , Wolpow E. R.
Published: December 2008

Intracellular recordings from cells in the first somatosensory area of the cerebral cortex have been made in cats in which the spinal pathways projecting to this area have been transected. There are large rhythmic membrane potential changes which correspond to the extracellularly recorded slow waves.
Cortical Synchronization and Desynchronization via Spinal Pathways
Authors: Andersson S. A. , Norrsell U. , Wolpow E. R.
Published: December 2008

The regular slow waves found in the somatosensory cortex after transection of the specific projection spinal pathways can be enhanced by strong peripheral stimuli applied to receptive fields below the level of the spinal lesion. In cortical areas where no changes in the basic slow wave activity are induced by the lesion the same stimulation gives a longlasting cortical arousal reaction. These effects are mediated via the bilateral ventral flexor reflex tract (bVFRT). Via this pathway the activity of cells in the somatosensory, auditory and association cortices can be excited. Many cortical cells are influenced via the specific projection pathways as well as via pathways in the ventral cord.

It is suggested that the activity in the specific projection pathways prevents the appearance of cortical waves within the range of the alpha frequency by inhibition of a pacemaker mechanism.
Vasoconstrictor Action of Acetylcholine on Kidney Blood Vessels
Authors: ÅStröm A. , Crafoord J. , Samelius‐Broberg U.
Published: December 2008

Changes in the renal vascular resistance of cats and dogs have been studied employing a constant flow perfusion technique. Close intraarterial injections of acetylcholine, in large doses, usually greatly increase resistance. This effect is enhanced by neostigmine and abolished by atropine. It is not abolished by ganglionic blockade, adrenolytic agents or pretreatment of the animals with reserpine. The effect has been observed in kidneys with intact nerve supply as well as after denervation. When the action of acetylcholine is tested during an infusion of lidocaine into the renal artery, the response is slightly reduced. The mechanism of action is discussed and it is concluded that in this preparation the vasoconstrictor action of acetylcholine is due to a direct action on the vascular smooth muscle.
Electric Fish (Gymnotus carapo) as a Tool for Bioassay of Methylphenidate and Chlorpromazine
Authors: Holmstedt B. , Krivoy W. , Kroeger D.
Published: December 2008

Gymnotus carapo, an electric knife fish, produces a continuous spontaneous discharge, the rate of which is subject to modulation, when the fish is disturbed. Free swimming knife fish of this species were subjected to the action of chlorpromazine and methylphenidate, while the discharge was detected by electrodes in the corners of the aquarium and recorded on magnetic tape. Methylphenidate increased and chlorpromazine decreased the frequency. The log dose response curves for both compounds presented a straight line relationship. The usefulness of the technique for bioassay of compounds acting on the central nervous system is discussed briefly.
An Attempt to Measure the Two‐Way Permeability in the Blood‐Brain‐CSF System
Authors: Edström Ricardo
Published: December 2008

Perfusion of various CSF (cerebrospinal fluid) spaces with an artificial fluid opens the way to a quantitative analysis of transport rates and permeability in the blood‐CSF interphase. Several approaches have been reported recently; two of the most successful ones are the reports of Heisey et al. (1962) and Pollay and Davson (1963). In these studies the CSF‐blood transfer has been calculated from measured losses of indicator material from the perfusion fluid. The present paper will report on an attempt to amplify this approach by a determination also of the appearance rate of the indicator material in the blood, and by a simultaneous measurement of the transport rate in the opposite direction: blood‐CSF.

Various equations for use in this system are given, and practical experiments with sodium and iodide transfer are reported. They do not permit a conclusion of any preferential direction of sodium transport, but iodide seems to be transported about 10 times faster out of the cerebral ventricles than in the opposite direction.
Further Studies on the Effect of Radio Frequency Hypothalamic Lesions on Lactation and Water Metabolism
Authors: Gale Charles C.
Published: December 2008

In two lactating goats production of median eminence lesions by radio frequency heating blocked milk synthesis and evoked diabetes insipidus (D I). After administration of hormonal therapy (ACTH, STH, T 3, and insulin) had restored milk production, withdrawal of STH from the regimen was associated with a decline in milk yield. The acute polyuria elicited by median eminence lesions in two unanesthetized goats preceded by several hours an increase in water intake (polydipsia). Similarly, the onset of the permanent phase of D I in one goat studied was occasioned by a primary polyuria. Intravenous injection of a blocking dose of thyroxine two hours before lesioning of the median eminence failed to prevent the thyroid activation which acutely follows such hypothalamic injury.
Mechanical Systole at Rest, During and After Exercise in Supine and Sitting Position in Young and Old Men
Authors: Strandell T.
Published: December 2008

In 12 healthy men aged 20–25 years and 20 aged 61–83 years mechanical systole was measured by phonocardiography as the time interval between the 1st and the 2nd sound. During exercise with stepwise increased work loads mechanical systole at first decreased approximately linearly with increasing heart rate, but at high heart rates a significant curvilinearity was recorded with successively lesser decrease of mechanical systole. At low heart rates mechanical systole was shorter in sitting than in supine position, but at high heart rates it was of the same duration in both positions. At rapidly increasing or decreasing heart rates the changes in duration of systole were slower than the changes in diastole. The regression line of mechanical systole on heart rate was at a slightly but significantly higher level in the old than in the young men, whereas the slope was similar. The lower maximal heart rates during exercise in the old men were thus not accompanied by comparable changes in the mechanical events of the heart cycle. However, in the old men the maximal heart rate was probably significantly correlated to the slope of mechanical systole on heart rate. The slope was also negatively correlated to the cardiac index at rest in the old men, and the level of the line was negatively correlated to the systolic pressure increase in the brachial artery during exercise.
Angiocardiography of the Duck during Submersion Asphyxia
Authors: Aakhus Trygve , Johansen1 Kjell
Published: December 2008

Angiocardiography with simultaneous recording of arterial blood pressure has been done on unanesthetized ducks during submersion.

The contrast density was increased in the inflow veins to the right atrium during submersion. Variable degrees of reflux and a delayed passage were commonly observed in the veins. The circulation time through the lungs was prolonged by a factor of 4–5 depending on the degree of bradycardia developed during submersion. The duration of the capillary phase was similarly 7 times longer during submersion. A smaller number of heart beats sufficed to propagate the contrast through the pulmonary circuit during submersion. The total size of the heart was always increased in corresponding phases of the cardiac cycle during submersion. The increase of the heart contour was most prominent on the right side of the heart. The changes in size of the left ventricle were more moderate, but disclosed a tendency towards an increased volume and a larger systolic residue during submersion. The pulmonary arteries showed far smaller vessel diameters in the submerged condition. The diameter reduction was most marked before the vessels entered the pulmonary parenchyma. The larger systemic arteries showed no apparent dimensional changes going from presubmerged to submerged condition.

The results indicate an increased resistance to flow in the pulmonary vascular bed. The large increase in the size of the heart and an increased central venous pressure in the presence of an unaltered arterial pressure are strongly suggestive that neural and/or humoral factors are playing an important part in the instantaneous regulation of stroke volume during submersion.
An Indirect Method for Estimating Tissue Pressure with Special Reference to Tissue Pressure in Muscle during Exercise1
Authors: Kjellmer Ingemar
Published: December 2008

Tissue pressure is one of the determinants of capillary filtration and appears to be a major limiting factor of filtration exchange during muscular exercise. Since direct measurement of tissue pressure through a needle was considered impossible, an indirect method was developed to record tissue pressure in skeletal muscle during rest and exercise. This method is based on the fact that veins are normally collapsible and that the pressure inside patent veins can never be less than the extramural pressure i. e. tissue pressure. When the tissue pressure exceeds the central venous pressure, the pressure in the local veins is dictated by, and becomes a measure of the tissue pressure. Instead of measuring this pressure the changes in volume of the muscle were recorded plethysmographical‐ly and the pressure below which changes of central venous pressure did not influence volume was noted. This pressure was regarded as corresponding to the minimum tissue pressure. The maximum tissue pressure was obtained from distensibility curves for the veins. The accuracy of the method is about 2 cm H2O. During rest the tissue pressure was only little above zero and rose during exercise in relation to the amount of filtrate accumulated in the muscle.
The Effect of Oxygen at High Pressure on Thyroid Function in the Rat
Authors: Sjöstrand J.
Published: December 2008

Rats were exposed to oxygen at 6 atm daily for 4–5 days and killed on the sixth day. The animals showed a very low incidence of convulsions. The thyroid weight was decreased (p < 0.05) but the uptake of I“‘ in the thyroid was increased (p < 0.05). The increase of I131 uptake of the thyroid per 100 g body weight per mg thyroid weight was highly significant (p < 0.001) in the OHP exposed rats. A group of rats subjected to stress by formalin injections were investigated for comparison. The thyroid I131 uptake was significantly higher in rats exposed to oxygen at high pressure (OHP) than in rats treated with formalin injections (p < 0.01). There was thus an increase in the total amount of I131 24 hours after injection in the thyroid associated with the OHP and it seems probable that this was a specific reaction, different from the well‐known response to non‐specific stress.
Short Term Effects of Reserpine on Noradrenaline Levels in Skeletal Muscle1
Authors: Sedvall Göran
Published: December 2008

In the skeletal muscle from the hindlimb of cat noradrenaline disappeared almost completely within 5 to 10 hours after reserpine (5 mg/kg i.v.). When the sympathetic nerve supply to the muscles was cut at a preganglionic level before reserpine was given, about 15% of the noradrenaline was still present after 5 hours. This remaining amount then disappeared more slowly during 24 to 48 hours, and its rate of disappearance was not influenced by a second dose of reserpine. When the preganglionic section of the sympathetic supply was performed 3 hours after reserpine administration it prevented the rapid disappearance of the remaining noradrenaline only to a small extent. It is known from previous investigations that the noradrenaline in skeletal muscle is stored almost exclusively in the adrenergic nerves. The effects of preganglionic section of the sympathetic nerve supply are presumably due to an interruption of the normal impulse discharge in these nerves. The data from the present investigation seem to indicate that noradrenaline in the adrenergic nerves of skeletal muscle is stored in two different compartments. One larger fraction disappears within a relatively short time after reserpine. Another smaller fraction disappears more slowly but this fraction is rapidly released during impulse activity.
Identification of a Spinocerebellar Tract Activated from Forelimb Afferents in the Cat
Authors: Osgarsson O. , Uddenberg N.
Published: December 2008

A spinocerebellar tract activated from ipsilateral forelimb nerves has been identified by antidromic activation from the cerebellar cortex. This tract has been denoted the rostral spinocerebellar tract (RSCT). It originates from cell bodies at, or slightly above, the level of the dorsal roots supplying excitation. The RSCT ascends in the middle third of the lateral funiculus where it has a more ventral position than the ventral spinocerebellar tract (VSCT) which it partly overlaps. About two thirds of the RSCT enter cerebellum together with the VSCT through the brachium conjunctivum. About one third of the RSCT shifts dorsally, becomes contiguous to the dorsal spinocerebellar tract (DSCT), and enters cerebellum through the restiform body. The RSCT terminates mainly in the anterior lobe but some fibres send branches also to the pyramis and the ipsilateral paramedian lobule. In the anterior lobe the RSCT terminates in bilateral zones consisting of a medial strip of the intermediate cortex and a lateral strip of the vermal cortex. The termination is more intense ipsilaterally and the fibres reach equally often the “hindlimb” as the “forelimb area”. — The RSCT receives monosynaptic excitation from high threshold group I muscle afferents and polysynaptic excitation from the flexor reflex afferents. The functional organization and the characteristic cerebellar termination suggest that the RSCT is a forelimb equivalent of the VSCT.
The Distribution of Noradrenaline and Adrenaline in the Fallopian Tube of the Rabbit
Authors: Brundin Jan
Published: December 2008

The present study was undertaken in an attempt to explain the functional difference between the isthmic and ampullary regions of the oviduct in the rabbit by a difference in the distribution of their adrenergic nerve supply. The isthmus contains considerable amounts of noradrenaline (NA), while the NA contents of the ampulla and uterus are low. Adrenaline (A) was found in low concentrations in all of the preparations studied. Some implications of the distribution of NA in the different regions are discussed.
Rigidity Produced by Deafferentation
Authors: Wiesendanger M.
Published: December 2008

Posture, locomotion and evoked activity was investigated clinically and electromyographically in cats with intradurally (6 cats) or extradurally (7 cats) deafferented hind legs. Within 3–4 weeks after the deafferentation an overaction of extensor muscles developed characterized by an extension posture of the deafferented extremity when the cats were sitting, standing, walking or jumping. Reciprocal innervation was disturbed during stepping. Only intradurally operated cats showed rigidity as evidenced by increased resistance to passive flexion of the limb and persistent electrical activity in the extensor muscles when investigated in a standardized position (sling). The hind limb of extradurally operated cats hung loosely without resistance to passive flexion and without spontaneous electrical activity. Crossed extensor reflexes were elicited in intradurally deafferented cats only. Damage to the spinal cord by the intradural operation was evidenced by a disturbance in bladder function as well as by the anatomic findings on the operated side: tissue defects, signs of degeneration in the lateral funiculi and a decrease in interneurones. Similarly as in an asphyxiated cord (Gelfan and Tarlow 1959) the rigidity in intradurally operated cats might be due to hypersensitivity of partially denervated motoneurones. A slight reduction of synaptic connections to motoneurones is likely to occur in extradurally deafferented cords as well. This might explain that also in these cats the deafferented hind leg was often in the posture of extension.
Effect of Resection of Gastrin Releasing Regions on Acid Response to Sham Feeding and Insulin Hypoglycemia in Pavlov Pouch Dogs
Authors: Olbe Lars
Published: December 2008

In 9 Pavlov pouch dogs, in which antrum‐duodenum had previously been excluded from gastrointestinal continuity, the antrum was resected. Additional resections of the duodenal bulb and distal 3–4 cm of corpus were performed in 5 of the dogs. Following these resections the acid response to sham feeding was reduced to extremely low values in all animals. The post‐resection sham feeding response was markedly increased upon injection of subthreshold amounts of gastrin suggesting that physiological vagal excitation of the HC1 glands by sham feeding requires the presence of gastrin to produce significant acid secretion in these preparations. In contrast a substantial post‐resection acid response to 0.4–0.6 I.U. of insulin per kg b.w. was still obtained in 6 of 7 dogs. The present results show that the excitations of the HC1 glands by sham feeding and relatively high doses of insulin are incommensurable, and suggest that vagal activation by these doses of insulin produces acid secretion independent of the gastrin mechanism.
Proprioceptive Impulse Patterns during Contraction of Irtrinsic Laryngeal Muscles
Authors: Mårtensson A.
Published: December 2008

In histological serial sections of four different laryngeal muscles in the dog no spindles were found. — Evidence of proprioceptive reflexes induced by displacement of laryngeal cartilages and mediated by afferent inflow via the internal laryngeal nerve prompted an analysis of the proprioceptive impulse discharges in this nerve. Twitch and tetanic contractions of slow and fast laryngeal muscles were used to induce ieproducible movement patterns in the larynx. Comparison with manually applied pressure stimulation indicated that the receptors activated during muscle contraction are located outside the muscles, mainly in ligament structures and around joints. During twitch contraction receptor activation was observed in the form of an acceleration of spontaneously active units or an initiation of discharges in initially silent units, and receptor inhibition in the form of a pause of pre‐existent activity. The duration of both types of responses could be related to the time course of contraction. The same types of effect were induced by tetanic contraction. Typical and atypical responses obtained during the dynamic and static phases of tetanic contraction of varying amplitude are described. Most units responded to contractions of two or three muscles, and some common combinations of excitatoiy and inhibitory effects in one and the same unit are presented. It is concluded that the impulse patterns of the receptors studied are differentiated enough to serve a proprioceptive control mechanism.
Studies on Heart Lymph
Authors: Areskog N.‐H. , Arturson G. , Grotte G. , Wallenius G.
Published: December 2008

Areskog, N.‐H., G. Arturson, G. Grotte and G. Wallenius. Studies on heart lymph. II. Capillary permeability of the dog's heart, using Dextran as a test substance. Acta physiol. scand. 1964. 62. 218–223.— The capillary permeability of the normal heart has been studied in ten dogs, using dextran as a test substance. The capillary permeability has been determined as the ratio of the concentration of dextran of various molecular weights present in lymph and plasma under “steady state conditions”. The results show a pattern similar to those of earlier investigations, where lymph from the leg and the cervical region was collected, i.e., capillary pores (pore radii 40–60 Å) and capillary “leaks” (120–300 Å), the only difference being an increased number of “leaks” in the heart capillaries compared with the other two regions.
The Metabolism of Fatty Acids in the Rat
Authors: Göranssn Göran , Olivecrona Thomas
Published: December 2008

Göransson, G. and T. Olivecrona. The metabolism of fatty acids in the rat. I. Palmitic acid. Acta physiol. scand. 1964. 62. 224–239. — Data on the concentration and the fatty acid composition of neutral lipid fatty acids and of phospholipid fatty acids in blood, liver, heart, kidney, lung, spleen and muscle from fasted and refed male rats are reported. Data are also given on the radioactivity in these tissue lipid fractions at several time intervals after the intrevenous injection of 9–10‐H3‐labeled palmitic acid in rat serum. These data are intended as a reference for further studies on the metabolism of other long‐chain fatty acids. The data are discussed with reference to a general picture of the metabolism of the plasma FFA after their removal from the plasma. After entering the tissues the FFA are oxidized, converted to other long‐chain fatty acids, esterified or transferred back to the plasma. The fractions diverted into the different pathways depend upon the nutritional state. The fraction oxidized is larger in the fasted than in the refed rats. The diversion into one or the other of the possible pathways occurs almost immediately after the FFA have entered the tissue. Subsequently, the remaining labeled fatty acids are metabolized at considerably lower fractional rates since they have entered larger fatty acid pools, than the plasma FFA pool.
Circulatory and Respiratory Adaptation, during Long‐Term, Non‐Steady State Exercise, in the Sitting Position1
Authors: Ekelund L. G. , Holmgren A.
Published: December 2008

Ekelund, L. G. and A. Holmgren.Circulatory and respiratory adaptation during lone‐term, non‐steady state exercise in the sitting position. Acta physiol. scand. 1964.62. 240–255. — Circulatory and respiratory changes during long‐term, non‐steady state exercise in the sitting position was studied with heart catheterization technique in six healthy young men with average training. The work load was chosen individually to increase the heart rate to about 140–150 beats per minute after 10 min work and to 170–180 beats per min after 60 min work.The circulatory changesduring these experimental conditions were characterized by continuously falling systemic arterial blood pressure, constant cardiac output, and increasing heart rate, indicating a continuously fallinn stroke volume. The blood volume was lower during exercise than at rest in the supine position but remained unchanged between 10 and 50 min work. Theacid‐basestatus was characterized as a compensated metabolic acidosis, which remained essentially constant throughout the test. Therespiratory responsewas characterized by a successively increasing total ventilation, a moderate increase in alveolar ventilation and a marked increase in dead‐space ventilation. The increase in total ventilation was effectuated by an increase of both the respiratory rate and the tidal volume. The overallventilation‐perfusion relationshipshowed a slight continuous increase. Both circulatory and respiratory changes may be explained in the light of a gravitational shift in the distribution of the blood volume.
The Effect of Graded Stimulation of Efferent Vagal Nerve Fibres on Gastric Motility
Authors: Martinson Jan
Published: December 2008

Martinson, J. The effect of graded stimulation of efferent vagal nerve fibres on gastric motility. Acta physiol. scand. 1964. 62. 256–262. — The gastric motor responses to efferent vagal stimulation of varying frequency and impulse duration were studied in cats. The efferent fibres, both excitatory and inhibitory, exert their maximum effect on stimulation by an impulse rate of about 10 imp/sec. Higher frequencies producing little, if any, further effect. The stimulation thresholds of the excitatory and inhibitory fibres depend only on the strength and duration of stimulation pulses and not on their frequency, so that high frequency‐stimulation is not equivalent to high‐intensity stimulation, i. e. stimulation with long‐duration pulses, regarding its ability to produce gastric motor inhibition. The findings argue against the inhibition observed being produced by overflowing transmitter substance from aberrant sympathetic vasomotor nerve fibres running in the vagal supply to the stomach.
Collateral Blood Flow in the Myocardium of Dogs Measured with Krypton85
Authors: Johansson Borje , Linder Erland , Seeman Torsten
Published: December 2008

Johansson, B., E. Linder and T. Seeman.Collateral blood flow in the myocardium of dogs measured with Krypton85. Acta physiol. scand. 1964.62. 263–270. — Methods have recently been developed for determination of regional blood flows from wash‐out curves recorded externally after close‐arterial injection of radioactive Krypton (Kr85). In the present study this technique has been applied to measurement of collateral capillary blood flow in the myocardium of dogs during acute occlusions of coronary arteries. A monoexponential fall in activity was found during elimination of Krypton from the normal myocardium indicating a homogeneous distribution of blood flow. The wash‐out curves recorded during coronary occlusions could be dissolved into two separate components. There was a rapid phase related to the elimination of Krypton from normally perfused regions of the myocardium and a slow phase due to the de‐saturation of the ischemic portion. The magnitude of the collateral capillary blood flow was determined from the decay rate of the slow component. The relative size of the ischemic region could be estimated from the zero time values of the two phases. Collateral blood flow seemed to be fairly homogeneously distributed within the ischemic part of the myocardium. Release of an occlusion was followed by a rapid fall in activity in association with the reactive hyperemia.
Iron Exchange between Transferrin and the Placenta in the Rat
Authors: Laurell Carl‐Bertil , Morgan Evan
Published: December 2008

Laurell, C.‐B. and E. Morgan. Iron exchange between transferrin and the placenta in the rat. Acta physiol. scand. 1964. 62. 271–279. — The process of iron exchange between transferrin and the placenta was studied in vitro using 59Fe, rat serum or purified rat transferrin labelled with 131I and placental tissue. The yolk sac placenta bound more transferrin and took up iron more rapidly than did the allantoic placenta. The amount of transferrin bound increased rapidly for the first 15 minutes but thereafter showed little further increase: the amount bound increased as the transferrin concentration was increased but was unaffected by the degree of its saturation with iron. Iron uptake increased steadily during incubation, was greater when the iron concentration was increased, but was unaffected by increasing the transferrin concentration with a constant iron concentration. The release of iron from placenta was slower than that of transferrin and was less into a transferrin‐free solution than into plasma. The intravenous injection of rat transferrin in amounts sufficient to approximately double the plasma concentration did not alter the subsequent transfer of 59Fe from maternal plasma to the fetuses. The results show that the mechanism of iron exchange between transferrin and rat placenta is very similar to that between transferrin and reticulocytes.
Reflex Influence of “Somatic Pressor and Depressor Afferents” on Resistance and Capacitance Vessels and on Transcapillary Fluid Exchange
Authors: Johansson Börje , Lundgren Ove , Mellander Stefan
Published: December 2008

Johansson, B., O. Lundgren and S. Mellander. Reflex influence of “somatic pressor and depressor afferents” on resistance and capacitance vessels and on Tran capillary fluid exchange. Acta physiol. scand. 1964. 62. 280–286. — The reflex circulatory effects of afferent somatic nerve stimulation were studied in the different consecutive vascular sections in skeletal muscle and intestine. In skeletal muscle the “somatic pressor reflex” elicited constriction of resistance and capacitance vessels and increased the pre‐/postcapillary resistance ratio while precapillary sphincter tone was unchanged. In the intestine there was reflex constriction of capacitance and precapillary sphincter vessels but only transient changes in the resistance function. In a situation of increased vasoconstrictor fiber activity produced by carotid occlusion stimulation of “somatic depressor afferents” elicited dilatation of resistance and capacitance vessels in both skeletal muscle and intestine. Carotid occlusion produced continuous absorption of fluid from the extravascular space in skeletal muscle due to a fall in capillary pressure. A superimposed stimulation of somatic depressor afferents was able to restore capillary pressure to the control level despite incomplete restoration of total resistance and capacitance functions. A dilatation of precapillary sphincters occurred in intestine but apparently not in skeletal muscle during the somatic depressor reflex.
STUDIES ON 5‐HYDROXYTRYPTAMINE STORES IN PINEAL GLAND OF RAT
Authors: BERTLER ÅKE , FALCK BENGT , OWMAN CHRISTER
Published: December 2008

Summary— The pineal gland of the rat has been studied using a highly specific and sensitive fluorescence microscopical method for the cellular localization of certain biogenic monoamines, in combination with fluorimetric determinations of 5‐hydroxytryptamine (5‐HT) levels under normal and experimental conditions. Exceptionally large amounts of 5‐HT have been found in the gland. This amine is located partly in the parenchymal cells and partly in the pineal sympathetic nerves. There is strong evidence to support the view that the sympathetic nerves are noradrenergic, but take up 5‐HT from the parenchymal cells into their terminal portions, which run within the gland. A unique feature thus exists in the sympathetic nerves of the rat's pineal in that they contain two different monoamines.

The experiments have shown that half of the pineal 5‐HT is located in the sympathetic nerves, and that the rest is stored in the parenchyma. A small portion of this parenchymal pool is dependent on an intact innervation and is lost on denervation. After the injection of noradrenaline, the fluorescence of the pineal nerves changes to show the characteristics of a catecholamine. Half of the pineal 5‐HT is then depleted, showing that the neuronal 5‐HT is replaced by the administered noradrenaline. No change can be registered in pineal 5‐HT levels 22 hours after the administration of α‐methyl‐m‐tyrosine. However, metaraminol causes a pronounced depletion of pineal 5‐HT. A reaccumulation of the 5‐HT fluorescence in the pineal nerves can be brought about by the injection of nialamide to reserpinized animals, as it occurs in the cerebral nerves containing 5‐HT.
Range of Sympathetic Discharge and Reflex Vascular Adjustments in Skeletal Muscle during Hemorrhagic Hypotension
Authors: Lundoren Ove , Lundwall Jan , Mellander Stefan
Published: December 2008

Lundgren, O., J Hemorrhage is associated with an increase in the sympathetic vasoconstrictor fiber discharge to skeletal muscle, ranging from values below 1 imp/sec up to about 7 implsec, the rate of discharge being related to the extent of bleeding. The reflex increase in sympathetic activity is, as a rule, fairly well maintained during prolonged hemorrhage. Normally, this elicits a reflex constriction of resistance and capacitance vessels and an increase in the pre‐/post‐capillary resistance ratio leading to decreased capillary pressure and absorption of extravascular fluid. The constriction of the capacitance vessels and the fluid absorption both tend to compensate for the reduction of intravascular fluid volume in the early phase of hemorrhage. However, there is a gradual decline in the reflex vascular response, despite maintained vasoconstrictor fiber discharge, evidently due to competitive action of locally produced dilator factors. This decline is more pronounced the more severe the reduction in muscle blood Row accompanying hemorrhage. The decline is more pronounced in the precapillary vessels than in postcapillary vessels. Therefore, in the later stages of hemorrhage the pre‐/postcapillary resistance ratio may decrease to such an extent that fluid escapes from the circulation by filtration, leading to further derangement of cardiovascular function.
The Effect of Parathyroid Hormone and Vitamin D on Serum Calcium in Rats
Authors: Toverud Svein Utheim
Published: December 2008

Conflicting evidence exists regarding the hypothesis that vitamin D is essential for the calcium‐mobilizing action of parathyroid hormone. A re‐investigation was undertaken by feeding weanling vitamin D‐deficient rats a vitamin D‐free diet containing 0.7 % calcium and 0.6 % phosphorus (diet D,) for 3 weeks. At day I, when the mean serum calcium level was 7.1 mg/100 ml, the diet was replaced by 10 % glucose in saline. Different groups received either A) 100 I.U. vitamin D on day 2; B) injections of 200 and 100 units parathyroid extract (PTE) on days 4 and 5, respectively; C) a combination of treatments A and B; or D) saline injections. The serum calcium levels, determined 6 hours after the last PTE injection, permitted calculation of mean individual increase expressed in mg/100 ml: A) + 1.04, B) + 0.86, C) + 2.58, D) – 0.57.

Continuous feeding with diet D, or one containing less protein resulted also in a significant response to PTE. Parathyroidectomy, but not sham operation, resulted in a substantial fall in serum calcium in rats fed diet D.,

The conclusions are: 1) The calcium‐mobilizing action of parathyroid hormone in the rat is either independent of, or requires only minute amounts of, vitamin D. 2) At the one dose level investigated, no evidence for interaction between the effects of vitamin D and parathyroid extract was found when intestinal calcium absorption was minimal.