Showing papers by "Karolinska Institutet published in 1968"

In vitro studies on central and peripheral monoamine neurons at the ultrastructural level.

Abstract: Using ice-cold 3% potassium permanganate as a fixative (Richardson, 1966), isolated tissues from the central and peripheral nervous system were investigated in the electron microscope, with the object of identifying monoamine-containing neurons at the ultrastructural level. Thin brain slices and peripheral tissues from untreated rats and from rats treated with drugs interfering with monoamine metabolism (e.g. reserpine, H 44/68 or tetrabenazine) were incubated in physiological buffer solutions without and with monoamines in different concentrations. In certain cases, drugs interfering with monoamine metabolism (e.g. amphetamine, desipramine, cocaine or phenoxybenzamine) in different concentrations were added to the incubation medium.

Structure of Porcine Cholecystokinin‐Pancreozymin

Abstract: Cholecystokinin-pancreozymin has been found to have the partial structure Lys (Ala1, Gly1, Pro1, Ser1) · Arg · Val (Ile1, Met1, Ser1) Lys · Asn (Asx1, Glx1, His1, Leu2, Pro1, Ser2) Arg. Ile (Asp1, Ser1) Arg · Asp [Gly1, Met2, Trp1, Tyr (SO3H)] Asp · Phe · NH2. Of the four peptide bonds in this polypeptide, three arginyl and one lysyl, that are cleaved by trypsin only the arginyl-valine bond is cleaved by thrombin, with retention of the cholecystokinin and pancreozymin activities of the original molecule in the C-terminal heptacosapeptide. The C-terminal tryptic octapeptide too has strong cholecystokinin and pancreozymin activity. Except for the replacement of a threonine with methionine the eight amino acid units of this peptide are the same as those that comprise the corresponding part of the molecule of caerulein. Also like that in caerulein, the phenolic group of the only tyrosine of cholecystokinin-pancreozymin is esterified with sulphuric acid.

Evidence for a central 5-hydroxytryptamine receptor stimulation by lysergic acid diethylamide.

Abstract: 1. Lysergic acid diethylamide (LSD) and the 5-hydroxytryptamine (5-HT) precursor, 5-hydroxytryptophan produced similar functional effects in rat spinal cord and brain to the 5-hydroxytryptamine precursor 5-hydroxytryptophan, which indicates that LSD stimulates central 5-HT receptors.2. By means of combined histochemical and biochemical techniques it was found that LSD reduced the turnover rate of brain and spinal cord 5-HT, studied after inhibition of the tryptophan hydroxylase by alpha-propyldopacetamide. The turnover of brain noradrenaline but not dopamine was somewhat accelerated.3. The functional and chemical effects by LSD were related to dose and to time. They were not observed after the LSD analogues 2-bromo-LSD and methylsergide.4. The retardation of the 5-HT turnover by LSD may be due to negative feed-back mechanisms evoked by direct stimulation of the central 5-HT receptors.

Thioredoxin. 6. The amino acid sequence of the protein from escherichia coli B.

Abstract: Peptide A, the C-terminal cyanogen bromide fragment of thioredoxin, was degraded with chymotrypsin and pepsin. Partial sequences of 12 chymotryptic and 6 peptic peptides and the N-terminal tryptic peptide of trifluoro-acetylated peptide A were determined. The results were used to establish the order of the previously described tryptic peptides of peptide A and lead to the complete amino acid sequence of peptide A. Previous experiments had established the amino acid sequence of peptide B, the N-terminal cyanogen bromide fragment of thioredoxin and the present results thus give the complete amino acid sequence of thioredoxin from Escherichia coli B. The molecule contains 108 residues in a single polypeptide chain with a molecular weight of 11,657 as calculated from the sequence. The functional group of the protein occurs in position 32 to 35 and consists of a disulfide bridge formed by two half-cystine residues separated by a glycine and a proline residue. No metals were found as part of the functional group.

The effect of local anaesthetics on the central circulation and respiration in man and dog.

Abstract: SUMMARY The effect on the central circulation and respiration of intravenously infused equipotent doses of mepivacaine and bupivacaine was studied in 11 healthy men and in four conscious dogs. The subconvulsive dose in man and dogs was 5 mg/kg b.w., for mepivacaine infused at a constant rate for 20 minutes, and 1.25 mg/kg b.w. for bupivacaine during the same infusion period. This infusion rate was increased fivefold in the dogs to produce seizures. Lidocaine 5 mg/kg b.w. was also infused in four volunteers for 20 minutes. The subconvulsive dose in man gave a mean plasma level of 5-6 μg/ml for mepivacaine and 2.1 μg/ml for bupivacaine. After infusion of mepivacaine at the same rate, the plasma level in the dogs was only half that found in man. The convulsive level in the dogs was about 10 μg/ml for mepivacaine and at least 4 μg/ml for bupivacaine. Mepivacaine elicited in most cases a slight increase in cardiac output. This increase was obviously due to a slight rise in both heart rate and stroke volume. The systemic arterial blood pressure increased moderately in spite of a slight decrease in the systemic vascular resistance. The systolic pressure in the right ventricle and the pulmonary arterial pressures increased moderately during the infusion, while the filling pressure of both the right and the left ventricle was unaffected. No ECG changes were observed during the infusion of anaesthetic agents apart from those normally found in connection with an increase in heart rate. No significant changes were observed in PaCO2, pH, oxygen saturation or PaO2 in man. During convulsions in the dogs there were distinct rises in cardiac output, heart rate and systemic arterial blood pressure. At the same time PaCO2 and standard bicarbonate fell, while pH showed a tendency to fall. Thus, the present study did not reveal any depressive effect of mepivacaine, bupivacaine or lidocaine on the central circulation and respiration either during the infusion of a subconvulsive dose in man and the dog or during the infusion of a convulsive dose in the dog. Seizures occurred in one volunteer when lidocaine was infused. ZUSAMMENFASSUNG UND SCHLUSSFOLGERUNGEN An 11 gesunden Versuchspersonen und 4 wachen Hunden wurde die Wirkung intravenos infundierter, gleich-wirksamer Dosen von Mepivacain und Bupivacain auf Kreislauf und Atmung untersucht. Beim Menschen und beim Hund war die subkonvulsive Dosis 5 mg pro kg. Korpergewicht Mepivacain mit konstanter Geschwindigkeit uber 20 Minuten infundiert, bzw. 1,25 mg pro kg Korpergewicht Bupivacain uber den gleichen Zeitraum infundiert. Diese Infusionsgeschwindigkeit wurde beim Hund auf das Funffache erhoht, um Krampfe hervorzurufen. Ferner wurden 5 mg pro kg Korpergewicht Lidocain bei 4 freiwilligen Versuchspersonen uber einen Zeitraum von 20 Minuten infundiert. Die subkonvulsiven Dosen ergaben beim Menschen einen mittleren Plasmaspiegel von 5-6 μg/ml fur Mepivacain und 2,1 μg/ml fur Bupivacain. Nach Infusion mit der gleichen Einflussgeschwindigkeit war der Plasmaspiegel von Mepivacain beim Hund nur halb so hoch wie der beim Menschen gefundene. Der krampfauslosende Plasmaspiegel war beim Hund etwa 10 μg/ml fur Mepivacain und uber 4 μg/ml fur Bupivacain. Mepivacain fuhrte in den meisten Fallen zu einem leichten Anstieg des Herz-Minuten-Volumens. Dies war offensichtlich bedingt durch eine leichte Erhohung sowohl der Herzfrequenz als auch des Schlagvolumens. Der arterielle Blutdruck stieg trotz einer leichten Abnahme des systemischen Gefasswiderstandes massig an. Wahrend der Infusion wurde auch ein massiger Anstieg des systolischen Druckes im rechten Ventrikel und in der Arteria pulmonalis beobachtet, wahrend der Fullungsdruck der rechten und der linken Herz-kammer unbeeinflusst blieb. Wahrend der Infusion der Lokalanaesthetika wurden keine EKG-Ver-anderungen, abgesehen von denen, die bereits normalerweise in Verbindung mit erhohter Herzfrequenz gefunden werden, beobachtet. Auch bezuglich des PaCO2, des pH, der Sauerstoffsattigung und des PaO2 zeigten sich beim Menschen keine signifikanten Veranderungen. Beim Hund kam es wahrend der Krampfe zu deutlicher Erhohung des Herz-Minuten-Volumens, der Herzfrequenz und des systemischen Standard-Bicarbonat, wahrend auch das pH fallende Tendenz zeigte. Die vorliegenden Untersuchungen haben also keine depressive Wirkung von Mepivacain, Bupivacain oder Lidocain auf die zentrale Zirkulation und Atmung aufgedeckt, und zwar sowohl wahrend der Infusion subkonvulsiver Dosen beim Menschen und beim Hund, als auch wahrend der Infusion von Krampfdosen beim Hund. Bei einem Freiwilligen kam es zu Krampfen wahrend der Infusion von Lidocain.

Long-term prognosis in idiopathic scoliosis.

Abstract: (1968) Long-Term Prognosis in Idiopathic Scoliosis Acta Orthopaedica Scandinavica: Vol 39, No 4, pp 456-465

Studies on reaction and binding of monoamines after fixation and processing for electron microscopy with special reference to fixation with potassium permanganate

Abstract: In the present paper certain properties of potassium permanganate (KMnO4), a fixative used for electron microscopical investigations, have been studied in model test tube experiments and on tissues. Evidence was obtained that KMnO4 reacts with different types of biogenic monoamines resulting in a formation of a precipitate. In addition, also various monoamine analogues, precursors and metabolites reacts with KMnO4. The reaction taking place may be an oxidation-reduction-reaction in which KMnO4 is reduced, probably mainly to manganese dioxide by hydroxyl groups of the amines and related compounds. This is corroborated by the fact that no reaction takes place between KMnO4 and β-phenylethylamine or amphetamine, two substances, which lack hydroxyl groups.

Human forearm muscle metabolism during exercise. II. Uptake, release and oxidation of individual FFA and glycerol.

Abstract: The uptake, release, and oxidation of individual free fatty acids (FFA) in the human forearm were studied during a 60-min exercise period. Muscular uptake of FFA rose with the arterial concentration. The muscle showed a slight preference for linoleic and oleic acid compared to palmitic acid. The forearm RQ indicated a constant fat oxidation during the period of exercise. The uptake of FFA covered about 50 per cent of the fat oxidation. On the average 60 per cent of the muscular FFA-14C uptake was oxidized to 14CO2. The remaining radioactivity left the muscle as water-soluble metabolite(s). β-Hydroxybutyrate leaving the muscle was shown to be labeled. No release of glycerol accompanied the release of FFA during exercise. Glycerol-1-14C was oxidized by the exercising muscle. Glycerol dehydrogenase activity was demonstrated in human skeletal muscle.

Histochemical studies on the distribution of catecholamines and 5-hydroxytryptamine after intraventricular injections.

Abstract: Using the histochemical method for the demonstration of DA, NA and 5-HT it has been possible to demonstrate, in reserpine treated rats, that intraventricularly administered DA, NA, α-methyl-DA and α-methyl-NA in doses of 1–2 μg are specifically taken up by the parts of the DA and NA neurons lying close to the ventricles and the subarachnoidal space. The distribution of this uptake is described in detail. No uptake and accumulation of DA and NA was observed unless the monoamineoxidase had been inhibited whereas the α-methylated compounds which are resistant to monoamineoxidase accumulated without monoamineoxidase inhibition. Intraventricularly administered 5-HT was specifically taken up and accumulated in the 5-HT neurons within the same zone provided that monoamineoxidase had been inhibited. The distribution of this uptake is described in detail. After high doses of CA (5–10 μg) these amines accumulated to some extent also in the 5-HT neurons while no such accumulation was observed in the CA neurons after high doses of 5-HT. Thus, the present results indicate that there exists a specific reserpine-resistant, amine-concentrating mechanism at the nerve cell membrane of CA and 5-HT neurons. In areas where the exogenous amine concentrations probably were high there also occurred an accumulation of DA and NA in the CA neurons although the monoamineoxidase was not inhibited. Finally, in a certain area of the hypothalamus, CA was found to accumulate even after low doses (1–2 μg), in nerve cell bodies which probably normally do not contain CA.

Localization of indolealkylamines in CNS.

Abstract: Publisher Summary This chapter provides an account of recent studies on central 5-HT neurons using histochemical and biochemical techniques. Little was known about the cellular localization of 5-HT in the central nervous system until the development of the histochemical fluorescence method for the demonstration of catecholamines (CA) and 5-HT. Tryptamine and melatonin are the indolealkylamines normally present in brain. Tryptamine is found only in low amounts with an unknown regional distribution, and melatonin is highly concentrated in the pineal gland. The 5-HT nerve cell bodies are mainly localized to the raphe nuclei of the lower brainstem (nuc.raphe pallidus, obscurus, pontis, dorsalis, and medianus). Some are also found surrounding the pyramidal tract and in the medioventral part of the caudal tegmentum. No 5-HT cell bodies are found in the spinal cord, the diencephalon, or the telencephalon. The highest amount of 5-HT nerve terminals are so far found in the lumbar enlargement and especially in the sacral part of the spinal cord, where the terminals are fine and have strongly yellow fluorescent varicosities, the average varicosity being about 1 p thick as seen in the fluorescence microscope. There are two different ways of mapping out the 5-HT neurons, which complement one another excellently. One is by way of monoamine oxidase (MAO) inhibition, the other by way of lesions, after which the anterograde and retrograde degenerative changes are observed.

Movement of Dentinal and Pulpal Fluid Caused by Clinical Procedures

Abstract: The effects of some clinical procedures on the fluid contents of the dentin and pulp were studied in vitro. The method involved measurement of the movement of the meniscus in a tube and glass capillary filled with physiologic saline solution and attached to the root pulp of the extracted tooth. Drilling was found to produce expansion and an outward movement of fluid from the apex to the tooth.

Position and Velocity Sensitivity of Muscle Spindles in the Cat. I. Primary and Secondary Endings Deprived of Fusimotor Activation

Abstract: Responses of primary and secondary muscle spindle endings of the ankle extensor and flexor muscles in the cat were studied in the absence of fusimotor activation by applying length changes of triangular form over a large range of velocities. Both position and velocity responses were determined. No differences were obtained in these responses between endings in extensor and flexor muscles or between endings in fast and slow muscles. It was found necessary to subdivide the velocity responses into two different components based on the great difference in time course of their transients. Mathematical expressions for the two components are given in an Appendix. They were denoted the ‘quick’ and the ‘slow’ velocity responses respectively. Primary and secondary endings differed both with respect to the ‘quick’ and the ‘slow’ components of the velocity response. Endings with response characteristics typical of both primary and secondary endings were distinguished as a special group. They have been referred to as endings of intermediate type. Some possible spindle mechanisms responsible for the observed properties of the spindle endings are discussed.

Histochemistry of developing cat muscles.

Abstract: The histochemical differentiation of developing muscle has been dcscribed in some fairly recent papers (Becke t t & Bourne 1958, Dubowi tz 1963, 1965, 1966, FenicheI 1963, 1966, WirsCn & Larsson 1964, Germino , D’Albora & W a h r m a n n 1965, Nystro in 1966, Beat ty , Basinger & Bocek 1967, Karpat i & Engel 1967a). Wirse‘n & Larsson (1964) suggested that the three fibre types of adult vertebrate muscle develop as three distinct populations, whereas other authors have expressed the opinion that, at an early stage, all fibres are similar, and that differentiation into various types takes place from this common pool of fibres (e.g. Dubowi tz 1963, Gerniino et al. 1965). The postnatal differentiation of “slow-red” and “fast-white” mammalian muscles has not, however, been compared earlier. In adult animals, the histochemical appearance of these two types of muscle is known to differ (Nachmias & Padyku la 1958, Ste in & Padyku la 1962, Ogata & Mori 1964, Roinanul 1964, Henneinan & Olson 1965, Bocek & Beat ty 1966), the “fast-white” muscle showing a more heterogeneous population of fibre types than the “slow-red” one. The “slow-red” and “fast-white” mammalian muscles are also known to differ morphologically in various respects (see review by A d a m s , Denny-Brown & Pearson 1962), as well as physiologically (Ranuier 1874, Denny-Brown 1929, Buller, Eccles & Eccles 1960 a ) . In the cat, n difference is also found between the two types of muscle with respect to the phenomenon of post-tetanic twitch potentiation ( B r o w n & uon Euler 1938, B o w m a n , Goldberg & Raper 1962, S fandaer t 1964, Buller & Lewis 1965, N y s t r o m 1968a). Sandow, Taylor & Preiser (1965) discussed the possibility that the myoplasmic concentration of Ca++ might be the factor governing the intensity of mechanical activation. Furthermore, the contractile activity (= tension) has been shown to increase in parallel with the myofibrillar ATPase activity, when induced by graded concentrations of Ca++ ( W e b e r , Herz & Reiss 1964, Schudler 1967). In young kittens and adult cats, “slow-red” and “fast-white” muscles have been found to differ completely in their capacity to increase twitch tension following

Pulp reaction to heat.

Abstract: The effect of a regulated amount of heat applied to the human dental pulp has been examined. Under the cavities of those teeth extracted immediately and not exposed to heat there were no appreciable changes. Under the cavities exposed to heat and extracted immediately, there was marked aspiration and loss of odontoblasts. The teeth which had been subjected to heat and which were then retained for one month gave no discomfort. Under the cavities of one half of the teeth not exposed to heat, there was no evidence of damage; the other half showed very slight changes in the odontoblast and predentin areas. Pathoses occurred in the pulps of all teeth subjected to heat. The following features were found in the test teeth but not in the control teeth: In 16 teeth, a homogenized collagenous tissue contiguous with the dentin wall was found; this was devoid of dentinal tubules but had cells and capillaries enclosed. In 19 teeth, the “cell-rich” zone in the pulp horn was absent, and there was cellular degeneration and a reduced number of cells; in 4 of them this was interpreted as localized necrosis. These pulps presented no signs of demarcation of the necrotic areas or exudative cells.

Sympathetic Innervation of the Juxtaglomerular Cells of the Kidney

Abstract: Combination of a histochemical fluorescence method for biogenic monoamines and staining of juxtaglomerular cell granules demonstrated sympathetic nerve terminals in the rat kidney in the walls of the parts of the juxtaglomerular arterioles that contain granulated cells. This forms a morphological basis for a direct influence of sympathetic nervous activity on the liberation of renin. The juxtaglomerular granules were nonfluorescent, an indication that, in the rat, the granulated juxtaglomerular cells are not equivalent to mast cells.