Effect of glucagon administration on serum calcium and inorganic phosphorus in the freshwater mud eel,Amphipnous cuchia

Summary Glucagon injection inAmphipnous cuchia evokes a decreased level of serum calcium on day 1 which progresses till day 3. This response declines after day 5. The serum inorganic phosphorus level does not show any significant change.     

Increase of free 5-hydroxytryptamine in blood plasma by reserpine and a benzoquinolizine derivative

Zusammenfassung Nach Vorbehandlung von Kaninchen mit einem Monoaminoxydase-Hemmer des Hydrazin-Typs wurde plättchenreiches Plasma mit Reserpin und einem Benzochinolizin-Derivat inkubiert. Im Plasma kam es dadurch zu einem Anstieg des nicht an Thrombozyten gebundenen 5HT, der dem Abfall des Amins in den Thrombozyten entsprach. Bei Kontrolltieren (ohne Monoaminoxydase-Hemmer) führte die Inkubation von plättchenreichem Plasma mit Reserpin zu keinem Anstieg des freien 5HT im Plasma, obgleich es in den Thrombozyten zu einer starken Senkung des Amins kam.

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Supported by a grant from the Finnish Medical SocietyDuodecim.     

Effect of age,sex, hypophysectomy and gonadectomy on plasma corticosterone levels and adrenal weights following the administration of ACTH and stress

Zusammenfassung Injektion von 2 IE ACTH in hypophysektomierte unreife Ratten beiderlei Geschlechts: kein Geschlechtsunterschied des Corticosteron-Plasma-Spiegels (CPS). Gleiche Behandlung von weiblichen hypophysektomierten, geschlechtsreifen Ratten: 1/2 h nach der Injektion bereits höherer CPS. Kastrierte, weibliche unbelastete Ratten zeigten keinen Unterschied in der Höhe des CPS gegenüber kastrierten, unbelasteten männlichen Ratten. Nebennieren-Belastung solcher weiblicher Ratten durch bilaterale Fraktur der Tibiae und Fibulae: höherer CPS 1, 3 und 6 h nach Fraktur. Die Befunde deuten darauf hin, dass die weibliche Nebenniere eine grössere Empfindlichkeit für ACTH-Wirkung hat.

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This investigation was supported by Grant No. HE 06975.     

Effect ofBordetella pertussis vaccine on plasma corticosterone level and on ACTH-induced corticosterone secretion in rats

Zusammenfassung Der Corticosteron-Gehalt des Rattenplasmas wurde durch BPV-Behandlung vorübergehend reduziert, obwohl die ACTH-Wirkung auf den Corticosteron-Spiegel im Plasma unverändert blieb.     

Effects of blood sampling,anesthesia and surgery on plasma vasopressin concentration in rats

The influence of blood sampling, anesthesia and surgery on plasma vasopressin concentration was assessed in rats. Mean plasma concentration in conscious, chronically catheterized rats was 1.4±0.1 pg/ml (n=6). This value remained constant over repeated plasma samplings in the same animals. On the other hand, decapitation increased the plasma vasopressin concentration to 6.0±2.4 (in pg/ml) (n=6), inactin anesthesia to 2.9±0.6 (n=6), anesthesia and femoral cannulation to 13.3±5.8 (n=6) and surgery for renal micropuncture to 81.3±35.0 (n=6). It is concluded that the level of circulating plasma vasopressin is highly dependent on the sampling technique and is closely related to the extent of surgery.     

New aspects on the storage of 5-hydroxytryptamine in blood platelets

Zusammenfassung Blutplättchen verschiedener Spezies speichern 5-Hydroxytryptamin zusammen mit Nukleotiden (hauptsächlich Adenosin- und Guanosin-5-Triphosphat) und bivalenten Kationen (Ca und Mg) in spezifischen, subzellulären Organellen, welche elektronenoptisch eine starke Osmiophilie aufweisen. Speicherstellen für 5HT scheinen bereits in den Megakaryozyten vorhanden zu sein, da in diesen Zellen nach Zufuhr von exogenem 5HT osmiophile Organellen erscheinen, die denjenigen der Plättchen entsprechen. Die Aufnahme von biogenen Monoaminen durch isolierte Speicherorganellen hängt von der chemischen Struktur der Amine und der Temperarur ab; es bestehen keine Anhaltspunkte für einen aktiven 5HT-Transport.Analystische Ultrazentrifugation des Inhalts von isolierten Speicherorganellen von Kaninchen-Blutplättchen sowie von artifiziellen Lösungen ergibt, dass 5HT wahrscheinlich in Form hochmolekularer, gemischter Aggregate mit Nukleotiden und bivalenten Kationen akkumuliert. Die Bildung solcher Aggregate erklärt die osmotische Stabilität sowie möglicherweise andere biologische Eigenschaften der Speicherorganellen vor allem bezüglich Aufnahme von 5HT und dessen Freisetzung durch gewisse Substanzen, z. B. Tyramin.     

Effects of blood sampling, anesthesia and surgery on plasma vasopressin concentration in rats.

The influence of blood sampling, anesthesia and surgery on plasma vasopressin concentration was assessed in rats. Mean plasma concentration in conscious, chronically catheterized rats was 1.4 +/- 0.1 pg/ml (n = 6). This value remained constant over repeated plasma samplings in the same animals. On the other hand, decapitation increased the plasma vasopressin concentration to 6.0 +/- 2.4 (in pg/ml) (n = 6), inactin anesthesia to 2.9 +/- 0.6 (n = 6), anesthesia and femoral cannulation to 13.3 +/- 5.8 (n = 6) and surgery for renal micropuncture to 81.3 +/- 35.0 (n = 6). It is concluded that the level of circulating plasma vasopressin is highly dependent on the sampling technique and is closely related to the extent of surgery.     

Effects of handling normal and bulbectomized rats at adrenal and plasma corticosterone levels

Summary Normal and bulbectomized adult rats, male and female, handled daily for 4 weeks, show plasma and adrenal corticosterone values significantly lower than the non-handled ones.     

The effect of hunger on free fatty acid and corticosterone plasma levels in rats.

The time function of free fatty acids and of corticosterone in plasma in fed and fasted rats was investigated. Also a study of the influence of hypoxia on the concentration of plasma free fatty acids was carried out. Whereas fasting does not seem to stimulate lipolysis markedly before 12 h, 2 h of hypoxia elevate the free fatty acid level to its maximum. In the fasted condition, all values are significantly higher than corticosterone in the fed animal.     

Increased plasma creatine kinase activity in rabbits: Effect of systematically repeated blood sampling

Summary Various physical, chemical and biological factors are involved in an increased plasma creatine kinase activity. Repeated blood sampling induced in all rabbits studied a reaction of similar pattern but of different intensity, expressed by a maximum of plasma CPK activity. The physiological origins of this variation of CPK activity seems to be, as seen in control animals, the consequence of emotional stress due to handling and possibly an additional stress due to the venepunctures.Supported by Grant No. 73.7.1654 of the Délégation générale à la Recherche scientifique et technique.     

Action of reserpine and imipramine on intracellular storage of 5-hydroxytryptamine in blood platelets

Zusammenfassung In isolierten Blutplättchen von Katzen vermindert Imipramin im Gegensatz zu Reserpin das endogene 5-Hydroxytryptamin (5HT) und die 5HT-Speicherorganellen nicht wesentlich, obwohl es wie Reserpin die Aufnahme von exogenem 5HT herabsetzt. Hemmung des Membrantransportes von 5HT durch Imipramin scheint also das intrazellulär gespeicherte 5HT nur relativ wenig zu beeinflussen.     

The action of calcium and thrombin on isolated 5-hydroxytryptamine organelles of blood platelets

Zusammenfassung In isolierten 5-Hydroxytryptamin-(5HT)-Organellen aus Blutplättchen von Kaninchen, im Gegensatz zu intakten Plättchen, bewirkt Thrombin keine wesentliche Freisetzung von 5HT und Adenosin-Triphosphat (ATP). Anderseits erzeugen geringe Konzentrationen von Kalzium starke Verminderung von 5HT und ATP in den Organellen, hingegen nicht in intakten Plättchen. Nach elektronenmikroskopischen Befunden verursacht Kalzium hochgradige morphologische Veränderungen der isolierten 5HT-Organellen.     

Effects of thyroxine and exercise on the glandular and plasma levels of corticosterone in the male rat

Summary The results presented here demonstrates that the thyroid gland is essential for normal corticosterone production. They further show that exercise stimulates this production whether the thyroid gland is present or not. The release or metabolism of corticosterone seems dependent upon an intact thyroid gland since plasma levels of corticosterone are decreased during exercise if the thyroid is absent. The administration of thyroxine is not sufficient to renew these levels.     

Effect of haemolysis on plasma and serum immunoglobulin estimations

Summary Plasma IgG, IgM and IgA estimations were carried out in blood samples with varying degrees of haemolysis, produced by controlled ultrasonication. Extent of haemolysis was determined by plasma haemoglobin, plasma potassium and packed cell volume; and plasma IgG, IgM and IgA estimations showed a steady and significant fall with increasing haemolysis. A calculated correction is proposed which compensates for the dilutional effect of haemolysis, during estimations of plasma and serum immunoglobulins.     

Effect of an oral contraceptive on plasma dehydroepiandrosterone concentrations

Summary Plasma concentrations of dehydroepiandrosterone were measured in women by radioimmunoassay. It was found that a single dose of a combination type oral contraceptive Minovlar^® reduced dehydroepiandrosterone concentrations significantly.We would like to thank Dr M.L'E. Orme for helpful discussions.