bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flow and Protein Content of Lymph in Resting and Exercising Skeletal Muscle
Authors: Jacobsson S. , Kjellmer I. 
Published: December 2008

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractIntracellular 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

AbstractThe 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

AbstractChanges 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

AbstractGymnotus 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

AbstractPerfusion 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

AbstractIn 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

AbstractIn 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

AbstractAngiocardiography 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

AbstractTissue 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

AbstractRats 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

AbstractIn 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

AbstractA 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

AbstractThe 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

AbstractPosture, 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

AbstractIn 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

AbstractIn 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

AbstractAreskog, 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.