摘要:

AbstractIn the dog, différent cardiorespiratory reactions were identified in two types of anaphylactic shock and in C5a‐AT (anaphylatoxin)‐induced shock. AU three types had in common a portai blood pooling with conséquent decrease in the venous return, cardiac output, and arterial pressure. In anaphylaxis (a) of the first type, at a low titer of hemagglutinating antibodies, the latent period was 68 s and heart and lung function was unchanged. In the second type, at high titer, the latency was 19 s and pulmonary hypertension and decreased heart contractility occurred. After AT injection pulmonary hypertension appeared with tachypnea and unchanged heart function. Tachyphylaxis, but not cross‐over tachyphylaxis against the anaphylactic agent and AT was observed in dogs and isolated guinea pig lungs. AT induced a tran‐sient release and a. a prolonged release of histamine, prostaglandins (PGs), and thromboxane A2and endoperoxides from guinea pig lungs. SRS‐A was released only in a. Indomethacin inhibited AT‐induced release of PGs in guinea‐pig lungs and AT‐induced hypotension in the dog though it did not prevent the drop in cardiac output. Thèse model studies suggest that différent patterns of clinical a. can occur, depending on the type of antibodies and/or

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00103.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractA phosphorylation of endogenous acceptor protein(s) has been demonstrated to occur in membraneous vesicles prepared from Ehrlich ascites tumour cells. The reaction was catalyzed by endogenous protein kinase in the présence of exogenous (γ32P)ATP. A considérable increase of the spécifie protein kinase activity took place when the plasma membrane préparation was subjected to a further gradient centrifuga‐tion in Dextran T 150. This was done in the présence of a slightly alkaline phosphate buffer containing Mg‐ions which resulted in the formation of a well defined vesicular préparation at density 1.035 in the gradient. The apparent Kmand Vmaxfor the reaction with vesicles and exogenous (γ32P)ATP were deter‐mined and found to be 0.022 mM and 0.23 nmol × mg‐1× 10 min‐1, respectively. Neither cyclic AMP nor cyclic GMP did stimulate the protein kinase‐catalyzed reaction. Instead, a clear inhibition of the reaction by the cyclic nucleotides was unexpectedly registered. Adenosine at 0.5 mM also inhibited the reaction. Calcium ions were inhibitory at ail concentrations tested in the présence of a fixed (γ32P)ATP/Mg2+ratio. When Mg‐ions were stoichiometrically replaced by Ca‐ions practical

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00104.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractIn order to study the influence of progesterone on the myometrial activity ovarian secretion of progesterone was stimulated by intravenous injection of human chorion gonadotrophin (HCG, 75 IU) in 9 nonpregnant rabbits. 4 rabbits, used as controls, were given only saline. Plasma progesterone concentration in blood samples taken at frequent intervals (2–4 h) during the recording was measured by radioimmunoassay. In the controls, the myometrial activity and the plasma levels of progesterone did not change. After 1 h of HCG administration the amplitude of contraction began to decrease and the frequency began to increase after 3 h. After about 5 h the changes in amplitude and frequency were generally fully developed. This pattern of myometrial activity persisted throughout the recording period (12 h) and was also present in recordings made after 24 and 48 h of HCG injection. A maximal increase in plasma progesterone concentration (5.0 ng/ml) had already occurred by 2 h after the HCG injection and gradually decreased thereafter. It is concluded that an elevation in the level of progesterone in non‐pregnant rabbits resulting from increased ovarian output (through HCG) has a pronounced and immediate depressing effect on the character of myometrial activity which is indicative of a shift from nonpregnant to pregnant t

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00105.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe relationship between the rate of pancreatic HCO‐3secretion and plasma H+‐ion concentration was investigated in 15 pentothal anesthetized, secretin infused pigs (1.8 C.U./kg b.w. h‐1intravenously) during acute metabolic and respiratory acid‐base disturbances. Pancreatic HCO‐3secretion increased to 196 ± 10% of control during alkalosis and fell to 41 ± 4% of control during acidosis. Partial metabolic compensation of respiratory acidosis restored HCO‐3secretion to 87 ± 6% of control. A proportional relationship was found between HCO‐3secretion and plasma pH. Different, proportional relationships were found between HCO‐3secretion and plasma HCO‐3concentration during metabolic and respiratory acid‐base changes. HCO‐3secretion was independent of H+‐ion concentration in pancreatic juice. Plasma H+‐ion concentration, therefore, seems to determine the rate of pancreatic HCO‐3secretion. This finding supports the hypothesis that a proton pump is responsible

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00106.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe rate of noradrenaline (NA) turnover in the non‐pregnant and pregnant guinea‐pig uterus was determined after the administration of the labelled precursor, tyrosine. Endogenous NA was determined fluori‐metrically. In non‐pregnant animals the turnover of3H‐NA was slower in the uterine horns (t½= 10 h) and cervix (t½= 9 h) than in the reference organ, heart (t½= 6 h). During pregnancy (60–65 dayspost coitum)endogenous NA in the heart increased in pace with tissue weight gain; yet, in the uterus there was a drastic reduction, down to zero levels.3H‐NA turnover increased significantly in the cervix, no3H‐NA formation remained in the uterine horn (a situation resembling that following 6‐hydroxydopamine induced sympathectomy of non‐pregnant animals), and the turnover was unaltered in the heart. The observations confirm the general idea, illustrated by the results in the heart, of a functional adaptation with a constant neuron‐target relationship during increased physiological demands. They also confirm that a very peculiar and complex neuron‐target relationship develops in the uterus during pregnancy‐involving functional and structural denervation of the adrenergic nerve plexus in the uterine horn, whereas an increased activation might explain the changes in neuronal NA an

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00107.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractIn an attempt to reveal the importance of prostaglandins in the control of regional blood flow 20 mg/kg b.wt. indomethacin was giveni.v.in conscious resting rabbits. Regional blood flow determinations were made before and 20 min after the injection using the labelled microsphere technique. The blood flow in the stomach wall was reduced by 0.75 ± 0.17 g·min‐1·g‐1from a level of 1.64 ± 0.24 g·min‐1·g‐1. In jejunum the corresponding figures were 0.44 ± 0.12 and 1.26 ± 0.17 and in the brain 0.29 ± 0.10 and 1.24 ± 0.10. The blood flow in the liver via the hepatic artery increased by 0.20 ± 0.02 g·min‐1·g‐1from a level of 0.13 ± 0.02 g·min‐1·g‐1. In the retina there was a reduction in blood flow by 2.75 ± 1.03 mg·min‐1from a starting level of 15.1 ± 2.3 mg·min‐1. In a number of other tissues investigated there were no significant effects of the drug. The results suggest that under resting conditions prostaglandins play a role in the control of blood flow in the gastrointestinal tract, the brain and the retina—tissues which are likely

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00108.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe effects of 4‐aminopyridine (4‐AP) were studied on isolated single muscle fibres of the frog and toe muscles of the rat. In both muscle preparations, 4‐AP potentiated the twitch amplitude without significantly affecting the tetanus response. There was an increase of the time to peak tension and, in frog muscle, an increased time to half relaxation. 4‐AP produced no change of the resting membrane potential. The rate of decay and, hence, the total duration of the action potential were markedly prolonged. 4‐AP did not induce contractures by itself nor did it affect the contracture induced by caffeine. The mechanical threshold was determined by measuring the contracture response to various degrees of depolarization by potassium. This threshold was not affected by 4‐AP. Twitch potentiation by 4‐AP was independent of the extracellular calcium concentration. It is concluded that 4‐AP potentiates the twitch response by increasing the release of activator calcium into the myofibrillar space by prolongation of the action potential. In addition, there may be a more direct inhibitory action of 4‐AP on the calcium re‐uptake by the sarcoplasmic retic

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00109.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe presence of DOPA decarboxylase in cerebral microvessels (capillaries and venules) impedes the passage of circulating amine precursors into the brain. The relative amount of DOPA decarboxylase in this trapping mechanism as compared to the parenchymaper sewas estimated in various CNS regions, measuring the formation of dopamine from L‐DOPAin vitroorin vivoin two experimental models on rats and rabbits: (1) On the basis of the treatment with a peripheral decarboxylase inhibitor (carbidopa, which inhibits also microvascular DOPA decarboxylase in the CNS) it could be calculated that the enzyme in the microvessels of the caudate nucleus (rich in catecholamine nerve terminals), cerebellum (poor in catecholamine nerves), and spinal cord comprised 25, 91 and 79 per cent, respectively, of the total enzyme activity. (2) Measurement of dopamine formation in the spinal cord following transection at the midthoracic level (which causes degeneration of the catecholamine neurons caudal to the lesion since they are all descending) indicated that a similar fraction as found in the carbidopa model, 71 per cent, of the total tissue decarboxylase activity resided in the microvessel walls. The results show that a considerable portion of tissue decarboxylase in the CNS is present in the microvessel walls, where it represents part of an enzymatic blood‐brain barrier mechan

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00110.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe effect of close intraarterial infusions of vasoactive intestinal polypeptide (VIP) on gastric motility, intestinal fluid transport and colonic motility were studied in the cat. Regional blood flow was also followed in all experiments. In the stomach VIP produced a gastric relaxation and a blood flow increase. The motility response was similar to that observed when eliciting the vago‐vagal reflex relaxation by distending the esophagus. In the small intestine a hyperemia and a decrease of net water uptake was observed. When infusing small amounts of VIP a decrease of net water uptake was seen without any change of intestinal blood flow. Large amounts of VIP produced a transient secretory state in the small intestine. In the colon a hyperemia was seen immediately upon starting the infusion of the drug. After 2–3 min of infusion a contraction of the colon was apparent. The administration of atropine to the animal did not significantly affect any of the responses produced by VIP. The results are discussed in relation to VIP as a possible neurotransmitter in the gastrointestinal tr

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00111.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

AbstractThe vascular anatomy of the filiform and fungiform papillae of the feline tongue was studied by i.a. injection of India ink. Vascular loops of various appearances were found in the types of papillae studied,i.e.the large and the small filiform papillae and the fungiform ones. Such hairpin loops may function as counter‐current exchangers and to test this hypothesis tissue osmolality was determined in the papillae, while exposing them to various isotonic electrolyte solutions. The large filiform papillae with a vascular arrangement similar to that of intestinal villi exhibited a marked osmolar gradient from tip to base when exposed to a solution containing both glucose and sodium. If sodium and/or glucose was excluded from the solution, tissue osmolality was significantly decreased. This was also the case when the chloride ions of the solution was substituted with sulphate. The small filiform papillae are only provided with one or a few capillary loops. They exhibited a less marked osmolar gradient than the large ones and none of the different electrolyte solutions decreased the gradient. In the fungiform papillae a tissue hyperosmolality at the tip was also demonstrated. It is proposed that the papillary epithelium is provided with active transport mechanism(s) and that the papillary vessels function as countercurrent multipliers. The functional importance of these mechanisms are tentatively discusse

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1979.tb00112.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY