bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of metabolic inhibitors on phenylalanine influx in cerebral cortex slices from mature and immature rats
Authors: Laakso Maija‐Liisa 
Published: December 2008

AbstractEarlier investigations have shown that the transport of aromatic amino acids into cerebral cortex slices of rats changes during ontogenetic development. In order to illuminate the possible influence of the developmental alterations of energy metabolism in the brain on the changes of the amino acid transport the influx of phenylalanine into cerebral cortex slices of adult and 7‐day‐old rats was measured in the presence of metabolic inhibitors. Also the levels of lactate, ATP, ADP, AMP and creatine phosphate in the slices were measured. The used inhibitors cyanide, dinitrophenol and iodoacetate, which disturb certain steps of energy metabolism, had very similar effects in both age groups on phenylalanine influx and on the levels of energy‐rich phosphates. The correlation between the level of ATP and the influx of phenylalanine was positive in both age groups, but the slopes of the regression lines were different. If ATP supplies energy for amino acid transport, its utilization, rather than its availability is a limiting factor in the slices from 7‐day‐old rats. Developmental changes in energy metabolism seem to have a minimal role in the changes of amino acid transport during the maturation of the brain. Changes in the properties of cell membrdne carriers and in the transmembrane ionic gradients may be more important.
Further evidence for the involvement of microtubules in the proximo‐distal intra‐axonal transport of acetylcholine and related enzymes in rat sciatic nerve
Authors: Heiwall P.‐O. , Larsson P.‐A. , Dahlström A. 
Published: December 2008

AbstractThe two mitotic inhibitors colchicine (COL) and podofyllotoxin (POD) and their respective isomers, IumiCOL and picropodofyllin (picPOD) were tested for their effect on the intraaxonal transport (AXT) of acetylcholine (ACh) and the cholinergic enzymes in rat sciatic nerve. The mitotic inhibitors and their isomers were dissolved in saline + 10%, ethanol (COL and lumiCOL) or dimethylformamid (DMFA) (POD and picPOD) and injected (3–5 γl) subepineurally into the sciatic nerve. As controls the vehicle (saline+ 10% ethanol or DMFA) alone were injected into some rats. 2 h later a crush operation was performed 15 mm distal to the site of injection. The accumulation of ACh or the two enzymes, ACh‐esterase (AChE) and cholineacetyltransferase (CAT), in the nerve segment proximal to the crush (12 h before death) was used as a measure of the AXT. COL and POD were very effective in inhibiting AXT of all 3 substances, while their isomers, lumiCOL and picPOD, were essentially without effect on AXT in equimolar concentrations (0.1 M). The effects on AXT of the 4 test substances thus appear related to their affinity to bind to tubulin, which is several orders of magnitude higher for COL and POD than for their isomers. The results further support the view that intact microtubules are essential for AXT of both membrane‐bound (AChE) and soluble (CAT) enzymes, as well as of ACh in rat motor nerves.
Thyrotropin‐releasing factor: Distribution in neural and gastrointestinal tissues
Authors: Leppäluoto J. , Koivusalo F. , Kraama R. 
Published: December 2008

AbstractSpecimens of several rat tissues were purified with methanol extraction, gel filtration and cation exchange chromatography and measured for thyrotropin‐releasing factor (TRF) concentration by radioimmuno‐assay. TRF immunoreactivity of neural tissues (hypothalamus, spinal cord, medulla, cerebrum and cerebellum) and gastrointestinal tissues (pancreas, stomach, duodenum and colon) behaved as synthetic TRF during the purification. This dual distribution suggests that TRF‐secreting cells have their origin in the embryonal neuroectoderm.
Plasma vasopressin in ethanol intoxication and hangover
Authors: Linkola Jaakko , Ylikahri Reino , Fyhrquist Frej , Wallenius Marja 
Published: December 2008

AbstractThe effect of ethanol intoxication and hangover on immunoreactive plasma arginine vasopressin (AVP) concentration was studied in 7 healthy supine men in controlled clinical conditions. In 6 subjects plasma AVP increased above control values at the time of maximal blood ethanol Concentration. The highest AVP values were observed in the subjects having nausea and vomiting and the worst hangover symptoms. During hangover plasma AVP values were higher than the controls and the response of plasma AVP to upright posture was exaggerated. The dissociation of plasma AVP concentration and ethanol diuresis suggested that the suppression of AVP release is not the sole determinant of ethanol diuresis. The study may indicate that the toxic effects of ethanol and the severity of hangover symptoms are associated with the state of hydration and individual sensitivity of AVP triggering mechanisms.
Reflex adrenergic control of endocrine pancreas evoked by unloading of carotid baroreceptors in cats
Authors: Järhult Johannes , Holst Jens Juul 
Published: December 2008

AbstractThe effects of unloading of the carotid baroreceptors on arterial plasma glucose concentration as well as on portal plasma immunoreactive glucagon (IRG) and insulin (IRI) concentrations were studied in an‐estethized, vagotomized cats either by sectioning the sinus nerves or by lowering the pressure in the isolated carotid sinuses. Complete elimination of the carotid baroreceptor discharge by cutting the sinus nerves caused an increase in the arterial plasma glucose concentration by 100% and an increase in the portal IRG level by about 200%, whereas the portal IRI concentration decreased to 50% of its basal value. These baroreceptor‐induced changes of the plasma IRG and IRI levels seemed to be graded in relation to the drop in carotid blood pressure and they were clearly detectable when the pressure was lowered from 120 to 90 mmHg in the isolated carotid sinus preparation. The described reflex hyperglycemia, hyperglucago‐nemia and hypoinsulinemia were mediated to the pancreas and liver mainly by the sympatho‐adrenal system, since cutting the splanchnic nerves above the adrenal glands abolished the hyperglycemic and hypoinsulinemic responses and markedly depressed the magnitude of the hyperglucagonemic response. In adrenalectomized cats, complete unloading of the baroreceptors evoked both hyperglucagonemia and hypoinsulinemia although the magnitude of the hormonal responses was diminished. In animals where the pancreas and liver were sympathectomized but the adrenal glands left intact, cutting the sinus nerves evoked a doubling of the IRG level and a slight increase in plasma glucose, but no significant change of the IRI level. I.v. infusion of adrenaline (1 γg/kg × min) or noradrenaline (5 γg/kg × min) caused pronounced increases in IRG and plasma glucose and a clear‐cut reduction of IRI. We conclude that the function of the endocrine pancreas in the cat can be influenced by variations in the blood pressure by means of a reflex control which originates from arterial baroreceptors. This reflex adjustment of the endocrine pancreas is mediated chiefly by two links of the sympatho‐adrenal system, namely by catecholamine‐release from the adrenal medulla and, more importantly. by a direct adrenergic nerve fibre influence on the α‐ and β‐cells.
Differential effect on the sympathetic transmitter level in uterus and other organs of guinea‐pig by drugs interfering with adrenergic nerve functions
Authors: Thorbert G. , Alm P. , Owman Ch. , Rosencren E. , Sjöberg N.‐O. 
Published: December 2008

Abstract5 types of adrenergic blocking agents with different modes of action were administered and the rate of transmitter depletion was studied in different uterine regions of guinea‐pig, and compared with that in the heart and submandibular gland by a combination of fluorescence histochemical and spectrofluorimetric methods. The tyrosine‐hydroxylase inhibitor, H 44/68, as well as reserpine and guanethidine, produced a more efficient reduction in neuronal noradrenaline in the heart and submandibular gland than in the uterus. A differential action on the sympathetic transmitter, though less clearcut, was seen with 6‐hydroxydopamine. The noradrenaline‐depleting effect of metaraminol did not distinguish between those adrenergic nerves supplying the uterus from those of the control tissues. It is suggested that the differential effects may be related to a lower activity in the uterine adrenergic nerve system, probably because this system is to a large extent composed of short adrenergic neurons, which appear to have a particularly slow transmitter turnover.
Effect of intraantral pH on basal gastrin release into the circulation and antral lumen in anesthetized cats
Authors: Uvnås‐Wallensten Kerstin 
Published: December 2008

AbstractUvnås‐Wallensten, K. Effect of intraantral pH on basal gastrin release into the circulation and antral lumen in anesthetized cats. Acta physiol. scand. 1978. 104. 386–393.In acute experiments on cats antral pouches were perfused with solutions of different pH (1–13). After antrum passage the gastrin levels in the perfusates were measured with radioimmunoassay and the amounts of gastrin released into the antral lumen per minute calculated. The venous gastrin levels were determined concomitantly. Small amounts of gastrin (1 000–1 500 pg/min) were released into the antrum during perfusion with 0.1 M HCI. Subsequent perfusion with 0.15 M NaCl (pH 6.8) did not significantly increase the release of gastrin. On the other hand, 0.1 M phosphate buffer (pH 7.4) caused a dramatic augmentation of the gastrin output into the antral lumen (˜17 fold). A concomitant increase of peripheral gastrin levels was observed. Also other alkaline solutions such as 0.15 M NaHCO, (pH 8), 0.15 M Tris buffer (pH 8) or 0.01 and 0.1 M NaOH (pH 12 and 13) promoted the release of gastrin. It is discussed whether the gastrin release at alkaline pH is induced by the alkaline pH itself or by anions such as HPO‐4 HCO‐3 and OH‐. The apparent effect of pH could then be due to the formation of these ions at higher pH.
Effects of acetylcholine, noradrenaline, and prostaglandins on the isolated, perfused human fetal urethra
Authors: Anderson K.‐E. , Person C. G. A. , Alm P. , Kullander S. , Ulmsten U. 
Published: December 2008

AbstractAnderson, K.‐E., C. G. A. Person, P. Alm, S. Kullanderand U. Ulmsten,Effects of acetylcholine, noradrenaline, and prostaglandins on the isolated, perfused human fetal urethra. Acta physiol scand. 1978.104. 394–401.Preparations of the isolated bladder‐urethral junction obtained from human fetuses at midgestation were suspended in Krebs solution (37°C), and the urethral lumen was perfused at a low rate (2 ml/h). Resistance to flow and changes in longitudinal tension were recorded. In additional experiments, isometric tension changes were recorded in isolated detrusor strips. The occurrence of adrenergic nerve terminals was investigated by the fluorescence technique of Falck and Hillarp. Acetylcholine (0.1‐1.0 μg/ml) produced a concentration‐related increase in longitudinal tension and in resistance to flow; the effects were unaffected by phenoxybenzamine (0.1μg/ml), but completely inhibited by atropine (0.1μg/ml). The effect on tension was more marked than that on resistance to flow. Noradrenaline (0.005‐1.0μg/ml) also produced a concentration related increase in longitudinal tension and in resistance to flow; the effects were abolished by phenoxybenzamine (0.1μg/ml). The amine had a more pronounced effect on resistance to flow than on longitudinal tension. ProstaglandinF2α(0.1‐0.5μg/ml) increased longitudinal tension and resistance to flow; the effects were not antagonized by atropine (0.1 pg/ml) or by phenoxybenzamine (0.1μg/ml). In preparations contracted by noradrenaline or acetylcholine, prostaglandinsEland E, (0.02‐0.2μg/ml) decreased resistance to flow and longitudinal tension. Acetylcholine (0.02‐0.2μg/ml) and prostaglandin F2α(0.0‐0.5μg/ml) contracted, noradrenaline (0.05‐0.5μg/ml) relaxed, and prostaglandin Eland E2(0.1–5.0μg/ml) had no consistent effects on the detrusor strips. Histochemically, no adrenergic nerve terminals could be demonstrated in the detrusor. bladder neck or urethra.
Inhibition of compound 48/80‐induced intradental sensory nerve activity by disodium cromoglycate and serotonin antagonists
Authors: Olgart Leif , Gazelius Bertil 
Published: December 2008

AbstractOlgart, L. and B. Gazelius, Inhibition of compound 48/80‐induced intradental sensory nerve activity by disodium cromoglycate and serotonin antagonists. Acta physiol. scand. 1978. 104. 415–421.Local application of compound 48/80 induced long lasting nerve activity in intradental sensory nerves in the teeth of cats and dogs. This effect was inhibited by pretreatment with disodium cromoglycate (DSCG) given locally (2 × 10‐2 M) or i.a. (20 mg/min). DSCG did not have any effect on the nerve excitability per se, as judged from the responses to hypertonic NaCl and air blasts applied to exposed dentin before and after administration of DSCG. Local treatment with lysergic acid diethylamide (0.1‐1 mg/ml) and methysergide (0.05‐0.5 mg/ml) selectively reduced or inhibited the compound 48/80 induced nerve activity. Systemic administration of methysergide (12.5 μglkg) prevented the excitatory effects of compound 48/80 but was without effect when administrated during a state of established activity. The present findings support the hypothesis that compound 48/80 has an indirect effect on intradental sensory nerves and indicate that vascular reactions take part in intradental sensory nerve excitation.
Effects of hyperinsulinemia on lactose secretion and glucose uptake by the goat mammary gland
Authors: Hove Knut 
Published: December 2008

AbstractHove, K. Effects of hyperinsulinemia on lactose secretion and glucose uptake by the goat mammary gland. Acta physiol. scand. 1978. 104. 422–430.Lactose secretion by goat mammary glands was studied after intra‐arterial infusions of insulin and/or glucose causing rises in plasma insulin concentrations in mammary venous blood of about 3–5 mg/ml. Such levels are sufficient to strongly stimulate insulin sensitive processes when present in the systemic circulation. Two goats with mammary glands in situ and two with one of the glands autotransplanted to the neck were used for the experiments. Increasing the insulin concentration in blood to the mammary gland induced a decrease in lactose yields during a 3 h infusion (p < 0.02). Simultaneously arterial plasma glucose decreased by 15–20 mg/100 ml to about 50 mg/100 ml. When the systemic hypoglycemic effect of the insulin infusion was offset by a simultaneous intra‐venous infusion of glucose, no significant change in lactose secretion was observed during 8 hours of hyperinsulinemia. No change in mammary glucose uptake as measured by mammary blood flow x mammary arterio‐venous glucose differences could be detected. (Average glucose uptake for 2 h before infusion: 30.9 mg/min; during 8 h of infusion: 31.2 mg/min.) It may be concluded that increased levels of insulin in the blood perfusing the mammary gland did not affect mammary glucose uptake or lactose synthesis as long as blood glucose was maintained at normal levels. The results therefore indicate that the glucose turnover in mammary glands, which in high yielding dairy ruminants represents the main organ of glucose utilization in the body, is in fact independant of changes in plasma insulin concentrations.
The distribution and secretion of kallikrein in some exocrine organs of the rat
Authors: ØRstavik Torill Berg 
Published: December 2008

Abstract ørstavik, T. B. The distribution and secretion of kallikrein in some exocrine organs of the rat. Acta physiol. scand. 1978. 104. 431–442.Extractable kallikrein was quantitated in the submandibular, sublingual, and parotid glands and in the pancreas. No kallikrein was detected in the exorbital lacrimal glands and tears. The highest kallikrein concentrations (EU/ml) were in all major salivary gland secretions seen after α‐adrenergic stimulation, less after β‐adrenergic and least after parasympathetic stimulation. When taking into account the large variations in salivary flow rate, α‐adrenergic stimulation was in the parotid and particularly in the submandibular gland found to result in the highest kallikrein secretory activity measured by the kallikrein secretory rate (EU/ min). This shows that the kallikrein‐rich granular tubular cells are selectively activated through α‐adrenergic sympathetic receptors. The differences observed in the parotid saliva were small and not always statistically significant. However, when cervical nerve stimulation was superimposed upon parasympathetic stimulation, kallikrein secretory rate as well as kallikrein concentration increased. The large individual variations in salivary gland kallikrein content and secretion and the rather small differences observed in kallikrein secretory rate after nervous stimulation of the parotid and sublingual glands, may indicate that the kalli‐krein‐containing striated ducts are also influenced by factors other than the secretory nerves. The kallikrein concentration and secretory rate in urine was studied. A strong positive correlation between kallikrein secretory rate and fluid volume was found in urine but not in saliva.
Adenosine and cyclic AMP in cerebral cortex of rats in hypoxia, status epilepticus and hypercapnia
Authors: Rehncrona Stig , Siesjö Bo K. , Westerberg Eva 
Published: December 2008

AbstractRehncrona, S., B. K. Siesjöand E. Westerberg,Adenosine and cyclic AMP in cerebral cortex of rats in hypoxia, status epilepticus and hypercapnia. Acta physiol. scand. 1978.104. 453–463.The influence of hypercapnia, hypoxia and status epilepticus on cerebral cortex concentrations of adenosine, adenine nucleotides and cyclic AMP was studied on lightly anaesthetized (70% N2O) and artificially ventilated rats. Neither hypercapnia (arterial Pco2about 80 and about 300 mmHg) nor hypoxia (minimal values of 19 mmHg) altered tissue concentrations of AMP, cyclic AMP or adenosine. Bicuculline‐induced status epilepticus was accompanied by increased concentrations of cyclic AMP but adenosine concentration did not change. Experiments with ischemia, and those in which tissue hypoxia was exaggerated by unilateral carotid artery ligation, showed that tissue adenosine concentrations were elevated only when AMP concentrations rose. It is concluded that the marked increase in cerebral blood flow which occurs in hypoxia and status epilepticus is unrelated to changes in tissue adenosine concentration and that the increase in cyclic AMP during neuronal hyperactivity is triggered by other mechanisms than adenosine accumulation.
Release of substance P‐like immunoreactivity into the antral lumen of cats
Authors: Uvnäs‐Wallensten K. 
Published: December 2008

AbstractUvnas‐Wallensten, K. Release of substance P‐like immunoreactivity into the antral lumen of cats. Acta physiol. scand. 1978.104. 464468.SPLI can be detected in antral perfusates of cats. Experiments were performed in anesthetized cats provided with antral pouches. The pouches were perfused with 0.1 M HCI and 0.15 M NaCl. The concentration of SPLI in the perfusates was determined by radioimmunoassay. Basal output varied between 0–60 pp/min. Electrical vagal stimulation (2–10 Hz) caused release responses varying between 100–800 pg. Ach given i.v. or intraantrally also released SPLI into the antral lumen as well as adrenaline given i.v.
Inhibition of acetylcholine release in guinea pig ileum by adenosine
Authors: Gustafsson Lars , Hedqvist Per , Fredholm Bertil B. , Lundgren Cösta 
Published: December 2008

AbstractGustafsson, L., P. Hedqvist, B. B. Fredholmand G. Lundgren,Inhibition of acetylcholine release in guinea pig ileum by adenosine. Acta physiol. scand. 1978.104. 469–478.The effect of adenosine on cholinergic neuroeffector transmission was studied in the isolated guinea pig ileum. Adenosine caused a dose‐dependent and inverse frequency‐dependent inhibition of contraction responses to transmural nerve stimulation. Blockade of adrenergic neurotransmission did not alter the inhibitory effect of adenosine. Adenosine also inhibited contraction responses to serotonin, angiotensin and high potassium, but not the responses to acetylcholine, histamine or direct electrical stimulation of the smooth muscle cells. Adenosine had little effect on basal outflow of acetylcholine but inhibited markedly and reversibly the release of acetylcholine induced by nerve stimulation. Acetylcholine was determined with gas chromatography‐mass spectrometry. The results provide direct evidence that adenosine inhibits cholinergic neuroeffector transmission in the gut by a prejunctional action on acetylcholine release. This may be of functional importance since adenine compounds are released during stimulation of intestinal nerves.
Studies on the melanin‐affinity of metal ions
Authors: Larsson Bengt , Tjälve Hans 
Published: December 2008

AbstractLarsson, B. and H. Tjälve, Studies on the melanin‐affinity of metal ions. Acta physiol. scand. 1978. 104. 479–484.Melanin has a capacity to accumulate metal ions in vivo and in rim. In the present study, the relative melanin‐affinity of various metal ions has been determined in vim by use of the bisquaternary ammonium compound paraquat as a reference ion. Paraquat has previously been shown to bind to melanin with ionic binding as the dominant mechanism of interaction. The relative melanin‐affinity of the metal ions was determined by studying the ability of the metal ions to compete with paraquat for combining with the melanin. Pigment from beef eyes and synthetic melanin prepared from L‐DOPA with tyrosinase were used. The affinity for melanin of the metal ions increased with increasing valencies. The order of affinity of the alkali metals was Cs+:> Rb+ ‐> K+ > Na+ > Li+ and of the alkaline earth metals Ba2+ > Sr2+ > Ca2+ > Mg2+. T1+ had a slightly higher affinity than the alkali metals. Pb2+ had the strongest affinity of the divalent cations and Cu2+ was next in order. Ni2+, Co2+ and Mn2+ showed affinities in the mentioned order. La3+ and Gd3+, which are chemically similar although the former is diamagnetic and the latter paramagnetic, showed a similar affinity for the melanin, suggesting that it is the chemical and not the magnetic properties which determine the affinity. The studied metal ions showed the same order of affinity for the synthetic melanin as for the eye‐melanin, suggesting that the protein moiety of the pigment granules plays a minor role in the binding of the metal ions. Melanin has been shown to contain numerous free carboxyl groups. The results are consistent with the hypothesis that the metal‐ion binding of the melanin can be ascribed to a cation‐exchange activity with the free carboxyl groups in the melanin polymer as the main binding‐sites.
Sympathetic innervation of the urinary bladder and urethral muscle in the pig
Authors: Larsen Jens‐Jørgen , Nordling Jørgen , Christensen Bjørn 
Published: December 2008

AbstractLarsen, J.‐J., J. Nordling and B. Christensen, Sympathetic innervation of the urinary bladder and urethral muscle in the pig. Acta physiol. scand. 1978. 104. 485–490.The sympathetic innervation of the lower urinary tract was studied in the female and male pig using a specific histochemical technique for visualization of noradrenaline containing nerves. In smooth muscle from the detrusor few evenly distributed adrenergic nerve terminals were found. A greater number of terminals were observed in the trigone, bladder neck and urethra. There was no sex difference. In smooth muscle specimens from pig detrusor and trigone sympathetic nerve terminals were more abundant than in corresponding tissue from humans.