Systemic availability of acetylsalicylic acid in normal men and women and its effect on in vitro platelet aggregability

1983 ◽  
Vol 24 (5) ◽  
pp. 679-682 ◽  
Author(s):  
S. E. Husted ◽  
A. K. Pedersen ◽  
T. Petersen ◽  
E. Geday
Keyword(s):  
Acetylsalicylic Acid ◽  
Systemic Availability ◽  
Men And Women ◽  
Platelet Aggregability ◽  
Normal Men

FORMATION OF EPITESTOSTERONE BY HUMAN BLOOD AND ADRENAL TISSUE

1967 ◽  
Vol 54 (2) ◽  
pp. 208-214 ◽  
Author(s):  
Jorge Blaquier ◽  
Ralph I. Dorfman ◽  
Enrico Forchielli
Keyword(s):  
Venous Blood ◽  
Endocrine Gland ◽  
Men And Women ◽  
Peripheral Venous Blood ◽  
Adrenal Tissue ◽  
Idiopathic Hirsutism ◽  
Normal Human ◽  
Normal Men ◽  
Peripheral Production

ABSTRACT Whole peripheral venous blood from normal men and women, and from females with idiopathic hirsutism was incubated in vitro with labelled testosterone, androstenedione and dehydroepiandrosterone. Epitestosterone was formed consistently from added testosterone, in some cases from androstenedione but not from dehydroepiandrosterone. The rate of formation of epitestosterone from testosterone by blood of normal men and women is similar, whereas the rate of formation in blood from female idiopathic hirsutes was several fold greater. In a similar manner, normal human adrenal tissue also formed epitestosterone from added testosterone but not from androstenedione nor dehydroepiandrosterone. These results suggest that the origin of urinary epitestosterone can be the resultant of both peripheral production and endocrine gland secretion.

INTERCONVERSION OF PROGESTERONE AND 20α-DIHYDROPROGESTERONE AND OF ANDROSTENEDIONE AND TESTOSTERONE IN VITRO BY BLOOD AND ERYTHROCYTES

1968 ◽  
Vol 58 (3) ◽  
pp. 419-444 ◽  
Author(s):  
H. J. van der Molen ◽  
D. Groen
Keyword(s):  
Dehydrogenase Activity ◽  
Venous Blood ◽  
Hydroxysteroid Dehydrogenase ◽  
Linear Increase ◽  
Equivalent Amount ◽  
Men And Women ◽  
Peripheral Venous Blood ◽  
Normal Men

ABSTRACT Peripheral venous blood and erythrocytes from normal men and women, as well as from dogs, rabbits and sheep were incubated with 14C-labeled progesterone*, 20α-dihydroprogesterone, androstenedione and testosterone. The presence in blood and erythrocytes of a 20α-hydroxysteroid dehydrogenase activity, catalyzing the interconversion progesterone ⇄ 20α-dihydroprogesterone, and of a 17β-hydroxysteroid dehydrogenase activity, catalyzing the interconversion androstenedione ⇆ testosterone was observed. Incubation with washed erythrocytes in the presence of glucose and several co-factors favoured the formation of the reduced compounds: 20α-dihydroprogesterone or testosterone. Incubations with washed erythrocytes, without addition of glucose and co-factors, favoured the formation of the oxidized compounds: progesterone and androstenedione. Incubation of steroids with whole blood, resulted in metabolism of progesterone to 20α-dihydroprogesterone and of androstenedione to testosterone. The formation of the product during incubation in vitro increased linearly with time of incubation (15—180 min). Incubations of 20 ml blood or the equivalent amount of erythrocytes with substrate amounts of steroids varying from 0.5 to 3000 μg, gave a linear increase in the amount of product formed. The possible significance of these observations in vitro for steroid metabolism in vivo is discussed.

A Heparin-coated Circuit Maintains Platelet Aggregability in Response to Shear Stress in an In Vitro Model of Cardiopulmonary Bypass

1998 ◽  
Vol 80 (09) ◽  
pp. 437-442 ◽  
Author(s):  
I. Hioki ◽  
K. Onoda ◽  
T. Shimono ◽  
H. Shimpo ◽  
K. Tanaka ◽  
...  
Keyword(s):  
Shear Stress ◽  
Cardiopulmonary Bypass ◽  
Membrane Skeleton ◽  
Platelet Glycoprotein ◽  
Platelet Surface ◽  
Platelet Aggregability ◽  
Vitro Model ◽  
Platelet Defects ◽  
Set Up

SummaryAlterations in platelet aggregability may play a role in the pathogenesis of qualitative platelet defects associated with cardiopulmonary bypass (CPB). We circulated fresh heparinized whole blood through tubing sets coated with heparin (C group, n = 10) and through non-coated sets (N group, n = 10) as a simulated CPB circuit. Shear stress (108 dyne/cm2)-induced platelet aggregation (hSIPA), plasma von Willebrand factor (vWF) activity and platelet glycoprotein (GP) Ib expression were measured, before, during, and after this in vitro set up of circulation. In the two groups, the extent of hSIPA significantly decreased during circulation and was partially restored after circulation. Decreases in the extent of hSIPA were significantly less with use of heparin-coated circuits. There was an equivalent reduction in plasma vWF activity, in the two groups. Expression of platelet surface GP Ib decreased significantly during circulation and recovered after circulation. Reduction of surface GP Ib expression during circulation was significantly less in the C group than that in the N group. Decrease in surface GP Ib expression correlated (r = 0.88 in either group) with the magnitude of hSIPA, in the two groups. The progressive removal of surface GP Ib was mainly attributed to redistribution of GP Ib from the membrane skeleton into the cytoskeleton. Our observations suggest that use of heparin-coated circuits partly blocks the reduction of hSIPA, as a result of a lesser degree of redistribution of GP Ib.

Significance of Platelet β-Adrenoceptors for Platelet Responses In Vivo and In Vitro

1992 ◽  
Vol 68 (06) ◽  
pp. 687-693 ◽  
Author(s):  
P T Larsson ◽  
N H Wallén ◽  
A Martinsson ◽  
N Egberg ◽  
P Hjemdahl
Keyword(s):  
Ex Vivo ◽  
High Dose ◽  
Platelet Aggregability ◽  
Adrenoceptor Agonist ◽  
Dose Infusion ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Factor Antigen

SummaryThe significance of platelet β-adrenoceptors for platelet responses to adrenergic stimuli in vivo and in vitro was studied in healthy volunteers. Low dose infusion of the β-adrenoceptor agonist isoprenaline decreased platelet aggregability in vivo as measured by ex vivo filtragometry. Infusion of adrenaline, a mixed α- and β-adrenoceptor agonist, increased platelet aggregability in vivo markedly, as measured by ex vivo filtragometry and plasma β-thromboglobulin levels. Adrenaline levels were 3–4 nM in venous plasma during infusion. Both adrenaline and high dose isoprenaline elevated plasma von Willebrand factor antigen levels β-Blockade by propranolol did not alter our measures of platelet aggregability at rest or during adrenaline infusions, but inhibited adrenaline-induced increases in vWf:ag. In a model using filtragometry to assess platelet aggregability in whole blood in vitro, propranolol enhanced the proaggregatory actions of 5 nM, but not of 10 nM adrenaline. The present data suggest that β-adrenoceptor stimulation can inhibit platelet function in vivo but that effects of adrenaline at high physiological concentrations are dominated by an α-adrenoceptor mediated proaggregatory action.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

Inhibition of Spontaneous Platelet Aggregation by Sulfinpyrazone

1979 ◽  
Vol 42 (02) ◽  
pp. 621-625 ◽  
Author(s):  
G G Nenci ◽  
G Agnelli ◽  
M Berrettini ◽  
P Parise ◽  
E Ballatori
Keyword(s):  
Platelet Aggregation ◽  
Crossover Study ◽  
Double Blind ◽  
Platelet Aggregability ◽  
Initiation Of Therapy ◽  
Spontaneous Platelet Aggregation ◽  
Blind Crossover Study ◽  
Double Blind Crossover Study

SummaryIn a randomized double-blind crossover study in 16 patients with enhanced in vitro spontaneous platelet aggregation, sulfinpyrazone proved to be effective in normalizing platelet aggregability within 4 days after initiation of therapy.

Hysterical traits and variability of mood in normal men

1979 ◽  
Vol 9 (2) ◽  
pp. 301-304 ◽  
Author(s):  
Peter V. Rabins ◽  
Phillip R. Slavney
Keyword(s):  
Men And Women ◽  
Normal Women ◽  
Normal Men

SynopsisIn a study of 40 normal men it was found that self-ratings on variability of mood were positively correlated with self-ratings on hysterical traits. These results are similar to those found in normal women and lend support both to the validity of the concept of hysterical personality and to the idea that men and women experience fluctuations of mood in a similar way.

Sulfation in vitro of mucus glycoprotein by submandibular salivary gland: effects of prostaglandin and acetylsalicylic acid

1988 ◽  
Vol 966 (3) ◽  
pp. 287-296 ◽  
Author(s):  
Varahabhotla L.N. Murty ◽  
Jan Bilski ◽  
Yun H. Liau ◽  
Amalia Slomiany ◽  
Bronislaw L. Slomiany
Keyword(s):  
Salivary Gland ◽  
Acetylsalicylic Acid ◽  
Submandibular Salivary Gland ◽  
Mucus Glycoprotein

scholarly journals Prolactin and Male Fertility: The Long and Short Feedback Regulation

2009 ◽  
Vol 2009 ◽  
pp. 1-13 ◽  
Author(s):  
M. K. Gill-Sharma
Keyword(s):  
Chromatin Condensation ◽  
Feedback Regulation ◽  
Pituitary Hormones ◽  
Feedback Mechanism ◽  
Reproductive Hormones ◽  
Male Rats ◽  
Normal Men

In the last 20 years, a pituitary-hypothalamus tissue culture system with intact neural and portal connections has been developed in our lab and used to understand the feedback mechanisms that regulate the secretions of adenohypophyseal hormones and fertility of male rats. In the last decade, several in vivo rat models have also been developed in our lab with a view to substantiate the in vitro findings, in order to delineate the role of pituitary hormones in the regulation of fertility of male rats. These studies have relied on both surgical and pharmacological interventions to modulate the secretions of gonadotropins and testosterone. The interrelationship between the circadian release of reproductive hormones has also been ascertained in normal men. Our studies suggest that testosterone regulates the secretion of prolactin through a long feedback mechanism, which appears to have been conserved from rats to humans. These studies have filled in a major lacuna pertaining to the role of prolactin in male reproductive physiology by demonstrating the interdependence between testosterone and prolactin. Systemic levels of prolactin play a deterministic role in the mechanism of chromatin condensation during spermiogenesis.

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