摘要:

AbstractIn anesthetized cats electric afferent stimulation of nerve branches emanating from the gastric corpus region promptly elicited reflex gastric relaxation. The response was not blocked by atropine, guanethidine or cervical spinal cord transection but was abolished by cervical vagotomy, showing that the vagal “relaxatory” fibres to the stomach mediate this reflex effect. Transient distension of the stomach produced a long‐lasting gastric relaxation with similar characteristics as that obtained by the mentioned afferent electric stimulation. By vagal blockade in atropinized cats it was shown that the vagal nerves exerted no or only slight relaxatory effects if the stomach was only slightly filled, hut then had a profound relaxatory effect when the stomach was moderately or greatly filled. It is concluded that a vago‐vagal gastro‐gastric relaxatory reflex exists where the vagal non‐adrenergic relaxatory fibres serve as the efferent link. The reflex can be activated from gastric mechanoreceptors responding to distension and is suggested to be involved in the regulation of receptive relaxation in gast

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05457.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractIn anesthetized or decerebrate unanesthetized cats administration of the emetic drug apomorphine produced pronounced and long‐lasting relaxation of the stomach. When apomorphine induced somatomotor retching or vomiting movements they were always preceded by gastric relaxation. The gastric relaxatory response to apomorphine could not be blocked by atropine or guanethidine but was completely abolished after vagotomy. Vagotomy, if performed during the relaxed state of the stomach after apomorphine administration, resulted in a prompt decrease of gastric volume. Injection of apomorphine had no essential effect on gastric contractions induced by efferent electrical vagal stimulation, indicating that the splanchnic nerves were of minor or no importance for the apomorphine induced gastric relaxation.—It is concluded that the emetic drug apomorphine produces gastric relaxation by activation of the vagal non‐adrenergic relaxatory nerve fibres to the stomach. The results indicate that the relaxation of the proximal part of the stomach known to appear early in the vomiting act, is mediated by these relaxatory nerve f

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05458.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractIsotope dilution technique has been used to examine the effect of histamine loading on the metabolism of orally and parenterally administered14C‐histamine. 3% and 45% of the radio‐activity was recovered in the urine of goats and pigs, respectively, when only14C‐histamine was given orally. In goats the radioactivity was mostly present as unidentified metabolites. In goats, oral loading with 0.9–1.2 g histamine increased the fraction excreted as ImAA on an average from about 5% to 34% whereas the amount of unidentified metabolites was reduced. Independent of the dose given about 30% of orally administered radioactivity was excreted as14CO2. In pigs a moderate increase in14‐imidazoleacetic acid was observed after oral histamine loading. In contrast to i.v. administered histamine, orally administered histamine was partly excreted as14C‐conjugated histamine in the pig. In pigs and goats neither oral nor i.v. histamine loading seemed to have any effect on the fraction excreted in urine as14C‐histamine. The only significant effect on histamine catabolism of i.v. loading of histamine was a reduction of the fraction excreted as14C‐1.4‐MeHi. However, such loading of histamine in pigs seems to liberate histamine and/or histamine metabolites, since the increments in urinary histamine and histamine metaboiites exceeded the

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05459.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractPreviously, thein vivometabolism of histamine in domestic animals has been examined. Ruminating and non‐ruminating species seemed to metabolize both parenterally and orally administered Hi in different ways. The present report is concerned with the ability of various tissues from the two types of animal to metabolize histamine. In all species kidney was the most active, and lung one of the least active histamine degrading tissues. In ruminating species, liver seemed to be the most active tissue next to kidney, while intestinal mucosa was of relatively minor importance. In the non‐ruminating species mucosa of the small intestine was the most active tissue after kidney, while liver was less active. Imidazoleacetic acid and an unidentified “metabolite XI” were the 2 main metabolites of histamine in most tissues examined, both at low and high substrate concentrations. The formation of “metabolite XI” was prevented by 10‐4M aminoguanidine. Addition of S‐adenosylmethionine to the incubation mixtures in‐creased the inactivation rate of histamine in the lung of all species examined, in the intestinal mucosa of the ruminants and in the liver of the non‐ruminants. 1,4‐McH, did not seem to be oxidized to any extent in t

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05460.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe effects of chlorpromazine, imipramine, and quinidine on resting membrane potential, action potential, twitch and tetanic tensions, and on the active state were investigated in single frog skeletal muscle fibres. Chlorpromazine in concentrations 10‐6–10‐5M, and imipramine and quinidine in concentrations 10‐5–5 × 10‐5M, did not affect the resting membrane potential but produced a dose‐dependent decrease in the rate of rise, rate of fall, and overshoot of the action potential. The duration, measured at –50 mV, was prolonged. The drugs potentiated the isometric twitch by increasing the duration of the active state. Tetanic tension was not affected. In high concentrations (chlorpromazine 3 × 10‐5M, imipramine and quinidine>5 × 10‐5M) the drugs caused a successive widening and decrease of amplitude of the action potential and finally blocked the electrical activity. After a marked initial increase, the peak twitch tension was reduced in parallel with the changes of the action potential. The reduction in twitch amplitude was probably due to incomplete activation of the fibres. The mechanisms of the effects on the excitation‐contraction coupling induced by chlorpromazine, imipramine, and

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05461.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractLymph or blood plasma, rich in diamine oxidase (DAO; EC 1.4.3.6.) activity was obtained from donor rabbits, after i.v. injection of heparin. The lymph or, after heparin neutralization, the blood serum was injected into recipient rabbits, and the elimination of the transfused DAO activity was studied. Analogously to earlier findings in man, the elimination rate of transfused DAO activity was several times more rapid than is indicated by the apparent rate of return to normal levels in rabbits, after heparin‐induced increase in blood plasma DAO activity. Furthermore, our findings indicate the possibility of 2 different components of the elimination of transfused postheparin rabbit DAO activity, somewhat contrasting to the findings in ma

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05462.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe postheparin DAO increase in blood plasma has been shown to depend on intact intestines in rat and rabbit. Our findings indicate, however, that sources of mobilizable DAO may be found also outside the small intestine in these species. In the rat, after partial portal stricture for a week. hepatectomy was followed by an intense and rather sustained post‐heparin DAO increase, as compared to normal, or shamoperated, rat

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05463.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractA new method has been developed for studying interstitial fluid protein concentration: A 3 cm long and 0.5 mm thick nylon thread was sewn into subcutaneous tissue of ether anesthetized rats and left for equilibration with interstitial fluid for 35 to 240 min. The wick was then pulled out, both ends cut off, and the middle part quickly transferred to a tared vial containing 2 ml saline and weighed. Blood‐stained wicks, about 1 out of 5, were discarded. After 24 h elution the wick was removed, dried and weighed, allowing calculation of wick fluid volume. Total protein, albumin and hemoglobin concentrations were measured in the eluate. Hemoglobin concentration was less than 0.2 g/100 ml in all but one wick. Implantation of 73 wicks in 24 rats for 35 to 120 min gave an average albumin concentration of 2.10 (S.D. 0.24) g/100 ml, or 63% of plasma albumin concentration. Total protein concentration in 80 wicks averaged 3.44 (S.D. 0.30) g/100 ml, 56% of plasma. The concentrations did not change during this time interval and were reduced by less than 10% by antihistamine/antiserotonin treatment. An irregular rise in concentrations after more than 2 h implantation was delayed by antihistamine/antiserotoni

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05464.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe morphological changes appearing in sensitized rat mast cells incubated with antigen at 25° C for times ranging from 30 s to 10 min were studied using light and electron microscopy. Histamine release was assayed in parallel. After a latent period of 30 s, during which no histamine release or morphological changes occurred, degranulation and histamine release commenced and increased progressively with time. The first changes were seen in the most peripherally‐located granules, and consisted of a fusion of the cell membrane with the perigranular membrane and a swelling and a reduction of the electron‐density of the granules. With increasing time these changes were seen to spread deeper into the cells, resulting in the formation of labyrinthic cavities contatining changed granules; such granules were also seen outside the cells. Using the extracellular tracer lanthanum these apparently intracellular cavities were demonstrated to be in unbroken communication with the extracellular milieu. Thus when sensitized rat mast cells are incubated with antigen sequential exocytosis of histamine‐storing granules take place. The results agree with the hypothesis that histamine release takes place by ion exchange between histamine and extracellular cations both in granules expelled from the cells and in those retained in cavities open to the ex

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05465.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

AbstractThe action of ethyl alcohol on retinal function was analyzed by comparing its effects on the conventional and low‐intensity ERG in the dark‐adapted intact sheep eye. The results showed an increase of theb‐wave and a decrease of thea‐wave amplitude after small doses of alcohol (b.a.c. 20–40 mg%). The low‐intensity ERG,i.e.the electroretinographic responses belowb‐wave threshold has recently been shown to consist of a slow, corneanegative receptor response and two fast d.c. responses of opposite polarities from the inner nuclear layer. The negative d.c. response is considered inhibitory in nature and the positive d.c. response excitatory. Administration of alcohol had no effect on the isolated receptor response but elicited an amplitude increase of the positive d.c. response. The results from the low‐intensity ERG experiments suggest the mechanism behind the effects of alcohol on retinal functions to be a selective suppression of the negative d.c. response. Hereby the “controlling” function on the cells generating the positive d.c. response is suppressed, thus “releasing” the positive d.c. response and theb‐wave, which has been shown to be built up by the positive d.c. response. The decrease of thea‐wave appears to be secondary to the increase of theb‐wave, all the more as it was shown that alcohol had no effect on the receptor response. At high blood alcohol con‐centrations, the a‐wave as well as theb‐wave amplitude were found to diminish as an expression for a presum

ISSN:0001-6772    

DOI:10.1111/j.1748-1716.1973.tb05466.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY