Effects of caffeine and its reactive metabolites theophylline and theobromine on the differentiating testis

A previous study in the rat (Pollard et al. 1990) established that caffeine, when administered during pregnancy, significantly inhibited the differentiation of the seminiferous cords and subsequent Leydig cell development in the interstitium. However, that study could not distinguish between the direct effects of caffeine and/or the intermediary secondary toxic effects of metabolites such as theophylline and theobromine. Because the fetus lacks the appropriate enzyme systems, clearance of toxic substances takes place via the placenta and maternal liver. Thus, a suitable in vitro system can effectively differentiate between primary and secondary drug effects. In the present study, 13-day-old fetal testis, at the stage of incipient differentiation, were cultured for 4 days in vitro in the presence of graded doses of caffeine, theophylline or theobromine. It was found that explants exposed to caffeine or theobromine differentiated normally, developing seminiferous cords made up of Sertoli and germ cells, soon followed by the differentiation of functionally active Leydig cells appearing in the newly formed interstitium. However, explants exposed to theophylline failed to develop seminiferous cords and, as a consequence, Leydig cells. In conclusion, insights obtained from different experimental methods, such as organ culture or whole organism studies, are not always identical. It may be prudent, therefore, to take into account that certain experimental techniques, despite providing valuable information, may require confirmation by other test methods in order to obtain an in-depth understanding of mechanisms of action involved.

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Management practices for control of runoff losses from cotton furrows under storm rainfall. I. Runoff and sediment on a black Vertosol

Soil Research ◽

10.1071/sr00082 ◽

2002 ◽

Vol 40 (1) ◽

pp. 1 ◽

Cited By ~ 35

Author(s):

D. M. Silburn ◽

S. F. Glanville

Keyword(s):

Leydig Cells ◽

Management Practices ◽

Drug Effects ◽

Companion Paper ◽

Toxic Substances ◽

Pesticide Transport ◽

Simulated Rain ◽

Runoff Losses ◽

Storm Rainfall

Improved practices are needed to minimise soil erosion and related agrochemical transport from cotton fields during rain. We evaluated two options available to cotton growers, namely retention of surface cover and controlling wheel traffic, using simulated rain on a hill–furrow system on a well-aggregated black Vertosol. A companion paper explores effects on pesticide transport. Increasing cover resulted in an increase in the rain ultivar by use the fetus lacks the appropriate enzyme systems, clearance of toxic substances takes place via the placenta and maternal liver. Thus, a suitable in vitro system can effectively differentiate between primary and secondary drug effects. In the present study, 13-day-old fetal testis, at the stage of incipient differentiation, were cultured for 4 days in vitro in the presence of graded doses of caffeine, theophylline or theobromine. It was found that explants exposed to caffeine or theobromine differentiated normally, developing seminiferous cords made up of Sertoli and germ cells, soon followed by the differentiation of functionally active Leydig cells appearing in the newly formed interstitium. However, explants exposed to theophylline failed to develop seminiferous cords and, as a consequence, Leydig cells. In conclusion, insights obtained from different experimental methods, such as organ culture or whole organism studies, are not always identical. It may be prudent, therefore, to take into account that certain experimental techniques, despite providing valuable information, may require confirmation by other

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Direct effects of the pineal hormone melatonin on testosterone synthesis of Leydig cells in Djungarian hamsters (Phodopus sungorus) in vitro

Neuroscience Letters ◽

10.1016/0304-3940(95)12183-8 ◽

1995 ◽

Vol 201 (3) ◽

pp. 247-250 ◽

Cited By ~ 11

Author(s):

Marek Niedziela ◽

Alexander Lerchl ◽

Eberhard Nieschlag

Keyword(s):

Leydig Cells ◽

Phodopus Sungorus ◽

Direct Effects ◽

Testosterone Synthesis

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Effects of clodronate-containing liposomes on testicular macrophages and Leydig cells in vitro

Journal of Endocrinology ◽

10.1677/joe.0.1550087 ◽

1997 ◽

Vol 155 (1) ◽

pp. 87-92 ◽

Cited By ~ 7

Author(s):

DE Brigham ◽

G Little ◽

YO Lukyanenko ◽

JC Hutson

Keyword(s):

Direct Effect ◽

Dose Response ◽

Leydig Cell ◽

Leydig Cells ◽

Direct Effects ◽

Testosterone Production ◽

Identical Response ◽

Testicular Macrophages

We undertook the present studies to determine if clodronate-containing liposomes have direct effects on Leydig cells. Macrophages and Leydig cells were isolated and maintained separately in culture. Following treatment with clodronate-containing liposomes, macrophages were killed in a dose-response fashion over a range of 5-200 microliters liposomes. By comparison, a 500 microliters dose was required to kill Leydig cells, but this was not dependent upon clodronate since liposomes containing buffer elicited an identical response. The concentration of testosterone in medium from Leydig cells treated with clodronate-containing liposomes was significantly reduced compared with untreated cells. However, we subsequently found that liposomes can adsorb testosterone. Therefore, testosterone production was determined at various times following removal of liposomes from Leydig cells, thereby circumventing this complication. It was found that testosterone production was not altered by liposomes under these conditions. Finally, free clodronate had no effect on testosterone production, even at doses representing the amount present within the 500 microliters dose of liposomes. In summary, clodronate-containing liposomes killed testicular macrophages at a far smaller dose than required to kill Leydig cells. Most importantly, neither liposomes no free clodronate had a direct effect on testosterone production. Thus, clodronate-containing liposomes represent a valuable tool to study Leydig cell-macrophage interactions.

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Application of an in vitro system in the study of chemotherapeutic drug effects on DNA replication

Journal of Cellular Biochemistry ◽

10.1002/(sici)1097-4644(19960601)61:3<444::aid-jcb11>3.0.co;2-j ◽

1996 ◽

Vol 61 (3) ◽

pp. 444-451 ◽

Cited By ~ 7

Author(s):

Maria J. Diaz-Perez ◽

Irving W. Wainer ◽

Maria Zannis-Hadjopoulos ◽

Gerald B. Price

Keyword(s):

Dna Replication ◽

Drug Effects ◽

Chemotherapeutic Drug ◽

In Vitro System

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The Effect of Dipyridamole and RA 233 on Human Platelet Function in Vitro

Thrombosis and Haemostasis ◽

10.1055/s-0038-1648112 ◽

1973 ◽

Vol 29 (03) ◽

pp. 694-700 ◽

Cited By ~ 4

Author(s):

Paul L. Rifkin ◽

Marjorie B. Zucker

Keyword(s):

Mechanism Of Action ◽

Human Blood ◽

Glass Bead ◽

Heart Valves ◽

Human Platelet ◽

Drug Effects ◽

Simple Relation ◽

Prosthetic Heart Valves ◽

Induced Aggregation

SummaryDipyridamole (Persantin) is reported to prolong platelet survival and inhibit embolism in patients with prosthetic heart valves, but its mechanism of action is unknown. Fifty jxM dipyridamole failed to reduce the high percentage of platelets retained when heparinized human blood was passed through a glass bead column, but prolonged the inhibition of retention caused by disturbing blood in vitro. Possibly the prostheses act like disturbance. Although RA 233 was as effective as dipyridamole in inhibiting the return of retention, it was less effective in preventing the uptake of adenosine into erythrocytes, and more active in inhibiting ADP-induced aggregation and release. Thus there is no simple relation between these drug effects.

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In Vitro Assay of Platelet Adhesiveness with Washed and Tanned Human Red Cells

Thrombosis and Haemostasis ◽

10.1055/s-0038-1651281 ◽

1968 ◽

Vol 20 (03/04) ◽

pp. 384-396 ◽

Cited By ~ 1

Author(s):

G Zbinden ◽

S Tomlin

Keyword(s):

Platelet Adhesion ◽

Sodium Citrate ◽

Blood Platelets ◽

In Vitro Assay ◽

Red Cells ◽

Platelet Adhesiveness ◽

Vitro Assay ◽

In Vitro System ◽

Human Red Cells

SummaryAn in vitro system is described in which adhesion of blood platelets to washed and tannic acid-treated red cells was assayed quantitatively by microscopic observation. ADP, epinephrine and TAME produced a reversible increase in platelet adhesiveness which was antagonized by AMP. With Evans blue, polyanetholsulfonate, phthalanilide NSC 38280, thrombin and heparin at concentrations above 1-4 u/ml the increase was irreversible. The ADP-induced increase in adhesiveness was inhibited by sodium citrate, EDTA, AMP, ATP and N-ethylmaleimide. EDTA, AMP and the SH-blocker N-ethylmaleimide also reduced spontaneous platelet adhesion to red cells. No significant effects were observed with adenosine, phenprocoumon, 5-HT, phthalanilide NSC 57155, various estrogens, progestogens and fatty acids, acetylsalicylic acid and similarly acting agents, hydroxylamine, glucose and KCN. The method may be useful for the screening of thrombogenic and antithrombotic properties of drugs.

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Inhibition of the Activities of α2-Plasmin inhibitor (PI) and CI inhibitor (CI-Inh) by the Synthetic Fibrinolytic Agent, 3-Hydroxypropyl Flufenamide (Flu-HPA)

10.1055/s-0038-1665785 ◽

1979 ◽

Author(s):

L Miles ◽

J Burnier ◽

M Verlander ◽

M Goodman ◽

A Kleiss ◽

...

Keyword(s):

Plasminogen Activators ◽

Inhibitory Effect ◽

Mechanisms Of Action ◽

Flufenamic Acid ◽

Clot Lysis ◽

Factor Xiia ◽

Dependent Inhibition ◽

Normal Human ◽

Plasmin Inhibitor

Flu-HPA is one of a series of flufenamic acid derivations that enhances plasminogen-dependent clot lysis in vitro. Studies of possible mechanisms of action of Flu-HPA were undertaken. The influence of Flu-HPA on the inhibition of purified plasmin by purified PI was studied. PI activity was assessed by its inhibition of the clevage of the tripeptide S-2251 (H-D-Val-Leu-Lys-pNA) by plasmin. Flu-HPA was dissolved in DMF or in methonol and preincubated with PI before addition of plasmin. At Flu-HPA concentrations greater than 1mM and up to 60mM, the inhibitory activity of PI was totally lost. The inhibitory effect of normal human plasma on plasmin was also completely abolished at concentrations of Flu-HPA between 2.5 and 40mM. The effect of Flu-HPA on the inhibition of purified plasma kallikrein by purified CI-Inh was also studied. CI-Inh activity was measured by its inhibition of cleavage of the tripeptide Bz-Pro-Phe-Arg-pNA by kallikrein. When Flu-HPA, dissolved in DMF or in methonol, was preincubated with CI-Inh, a concentration dependent inhibition of CI-Inh activity was observed. CI-Inh activity was abolished by concentrations of Flu-HPA greater than 1mM. Flu-HPA also inhibited the activity of CI-Inh on purified Factor XIIa. These observations suggest that this flufenamic acid derivative may enhance fibrinolysis not only by inhibiting PI activity but also by decreasing the inactivation of plasminogen activators by CI-Inh.

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The Mesothelial Cell as a Non-Thrombogenic Surface

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661149 ◽

1984 ◽

Vol 52 (02) ◽

pp. 102-104 ◽

Cited By ~ 25

Author(s):

L J Nicholson ◽

J M F Clarke ◽

R M Pittilo ◽

S J Machin ◽

N Woolf

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Blood Flow ◽

Cell Surface ◽

Mesothelial Cell ◽

Mesothelial Cells ◽

Plastic Film ◽

In Vitro System ◽

Scanning Electron

SummaryA technique for harvesting mesothelial cells is described. This entails collagenase digestion of omentum after which the cells can be cultured. The technique has been developed using the rat, but has also been successfully applied to human tissue. Cultured rat mesothelial cells obtained in this way have been examined by scanning electron microscopy. Rat mesothelial cells grown on plastic film have been exposed to blood in an in vitro system using a Baumgartner chamber and have been demonstrated to support blood flow. No adhering platelets were observed on the mesothelial cell surface. Fibroblasts similarily exposed to blood as a control were washed off the plastic.

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