STUDIES ON THE CONVERSION OF OESTRADIOL LINKED TO A CYTOSTATIC AGENT (ESTRACYT®) IN VARIOUS RAT TISSUES

1976 ◽  
Vol 82 (3) ◽  
pp. 661-672 ◽  
Author(s):  
Per Aage Høisaeter
Keyword(s):  
Prostatic Cancer ◽  
Nitrogen Mustard ◽  
Phosphate Group ◽  
Ventral Prostate ◽  
Rat Tissues ◽  
Cytostatic Agent ◽  
Metabolic Conversion ◽  
Different Tissues

ABSTRACT Estracyt®, a compound of nitrogen-mustard linked to oestradiol phosphate, is used in the treatment of human prostatic cancer. The metabolism of this compound has been studied in different tissues of the rat both in vivo and in vitro. The phosphate group in position 17 of the oestradiol moiety is rapidly split off from the compound. An oestrone-cytostatic compound was extractable from the liver half an hour after the injection of Estracyt®. In addition the in vitro results showed that only the liver was able to convert the oestradiol-cytostatic compound to an oestrone-cytostatic one. When animals were killed 24 h after a 3-day period of Estracyt® treatment, the dominating metabolite in the ventral prostate was an oestrone-cytostatic compound, but traces of free oestrone could also be demonstrated. No such compound, however, was found in liver, diaphragm or blood at this time. It is concluded that in vivo an oestrone-cytostatic compound seems to be preferentially retained in the ventral prostate after Estracyt® injection whilst the metabolic conversion of the oestradiol-cytostatic compound into an oestrone-cytostatic one possibly occurs in the liver.

THE BINDING OF [1,2-3H]TESTOSTERONE WITHIN NUCLEI OF THE RAT PROSTATE

1969 ◽  
Vol 44 (3) ◽  
pp. 323-333 ◽  
Author(s):  
W. I. P. MAINWARING
Keyword(s):  
Molecular Weight ◽  
Equilibrium Dialysis ◽  
Prostate Gland ◽  
Ventral Prostate ◽  
Rat Tissues ◽  
Receptor Complex ◽  
Rat Prostate ◽  
Binding Component

SUMMARY The specificity of the binding of [1,2-3H]testosterone to nuclei of various rat tissues in vivo has been studied. A significant amount of radioactivity was retained in the nuclei of androgen-dependent tissues only, particularly the ventral prostate gland. The bound radioactivity was only partially recovered as [1,2-3H]testosterone; the remainder was identified as [3H]5α-dihydrotestosterone. Efforts were made to characterize the binding component, or 'receptor', in prostatic nuclei. On digestion of nuclei labelled in vivo with [1,2-3H]testosterone, with enzymes of narrow substrate specificity, only trypsin released tritium, suggesting that the receptor is a protein. On the basis of subfractionation studies of labelled nuclei, the receptor is an acidic protein. The androgen—receptor complex could be effectively extracted from the prostatic nuclei in 1 m-NaCl and from the results of fractionations on a calibrated agarose column, the complex has a molecular weight 100,000–120,000. The specificity of the binding of steroids to such 1 m-NaCl extracts in vitro was investigated by the equilibrium dialysis procedure. Under these conditions, the specificity of the binding of [1,2-3H]testosterone demonstrated in vivo could not be simulated. The receptor is probably part of the chromatin complex but its precise intranuclear localization cannot be determined by biochemical procedures alone.

A Physiologic Regulator of Collagen-Induced Platelet Aggregation: Inhibition by Clq

1981 ◽  
Vol 45 (02) ◽  
pp. 110-115 ◽  
Author(s):  
György Csákó ◽  
Eva A Suba
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Platelet Reactivity ◽  
High Specificity ◽  
Turbidimetric Method ◽  
Specific Manner ◽  
Aggregation Inhibition ◽  
Different Tissues

SummaryPlatelet aggregations were studied by a turbidimetric method in citrated human platelet-rich plasmas (PRP) in vitro. Human Clq inhibited the aggregations caused by collagens derived from different tissues and species. Clq was needed by weight in comparable quantities to collagen for neutralizing the aggregating effect. The dependence of the inhibitory reaction on the preincubation of platelets with Clq and the differences in the occurrence of aggregating substances in supernatants of PRP triggered with collagen in the presence or absence of Clq, confirmed that Clq exerts its effect by preventing fixation of collagen to platelets. In addition, the high specificity of the inhibitory action of Clq for collagen-induced platelet aggregation was demonstrated by results obtained for testing a variety of aggregating agents in combination with Clq and/or collagen.Since normal concentrations of Clq in the blood are in the range of inhibitory doses of Clq for collagen-induced platelet aggregations in vitro and upon activation of complement Clq is known to dissociate from Cl, it is proposed that Clq may participate in a highly specific manner in regulating platelet reactivity to collagen in vivo.

In Vivo and in Vitro Pharmacologic Purification of Bone Marrow Contaminated with Tumor Cells Using VP16-213 and Nitrogen Mustard

1984 ◽  
pp. 183-196 ◽  
Author(s):  
Patrick J. Stiff ◽  
Thomas P. U. Wustrow ◽  
Alan R. Koester ◽  
Michael F. Derisi ◽  
Bayard D. Clarkson
Keyword(s):  
Bone Marrow ◽  
Tumor Cells ◽  
Nitrogen Mustard

Atrial natriuretic factor binding sites in the jejunum

1989 ◽  
Vol 256 (2) ◽  
pp. G436-G441 ◽  
Author(s):  
C. Bianchi ◽  
G. Thibault ◽  
A. De Lean ◽  
J. Genest ◽  
M. Cantin
Keyword(s):  
Binding Sites ◽  
Atrial Natriuretic Factor ◽  
Specific Binding ◽  
Rat Tissues ◽  
Rat Jejunum ◽  
Specific Binding Sites ◽  
Natriuretic Factor ◽  
Atrial Natriuretic

We have studied the localization and the characterization of atrial natriuretic factor (ANF) binding sites by radioautographic techniques. Quantitative in vitro radioautography with a computerized microdensitometer demonstrated the presence of high-affinity, low-capacity 125I-ANF-(99-126) binding sites (Kd, 48 pM; Bmax, 63 fmol/mg protein) mainly in the villi of 20-microns slide-mounted transverse sections of the rat jejunum. Competition curves showed 50% inhibitory concentrations of 55 and 1,560 pM for ANF-(99-126) and ANF-(103-123), respectively. In vivo electron microscope radioautography showed that 80% of the silver grains were localized on the lamina propria fibroblast-like cells, 18% on mature enterocytes, and 2% on capillaries. Bradykinin and adrenocorticotropin did not compete with ANF binding. These results demonstrate that ANF binding sites in the rat jejunum possess the pharmacological characteristics of functional ANF receptors encountered in other rat tissues, and ultrastructural radioautographs show their cellular distribution. Taken together, these results demonstrate the presence and the localization of specific binding sites for ANF in the jejunal villi of the rat small intestine.

scholarly journals Studies on the form and synthesis of messenger ribonucleic acid in the rat ventral prostate gland, including its tissue-specific stimulation by androgens

1974 ◽  
Vol 137 (3) ◽  
pp. 513-524 ◽  
Author(s):  
W. Ian P. Mainwaring ◽  
Peter A. Wilce ◽  
Allan E. Smith
Keyword(s):  
Prostate Gland ◽  
Sodium Dodecyl ◽  
Ventral Prostate ◽  
Experimental Conditions ◽  
Free System ◽  
Cell Free System ◽  
Messenger Ribonucleic Acid ◽  
Selective Incorporation

1. When prostate polyribosomes are labelled with radioactive precursors in vivo and subsequently dissociated with sodium dodecyl sulphate, a heterogeneous 6–15S RNA species may be identified that possesses all of the distinctive properties of mRNA. 2. Apart from the selective incorporation of 5′-fluoro-orotic acid into this 6–15S RNA component, it is bound by nitrocellulose filters under experimental conditions where only poly(A)-rich species of RNA are specifically retained. Most importantly, however, only the 6–15S RNA fraction is capable of promoting the incorporation of amino acids into peptide linkage in an mRNA-depleted cell-free system derived from ascites-tumour cells. 3. With the development of a simpler method for labelling the total RNA fraction of the prostate gland in vitro, the poly(A)-enriched RNA fraction may be readily isolated by adsorption and elution from oligo(dT)-cellulose. The synthesis of the poly(A)-enriched 6–15S RNA fraction is stringently controlled by androgens in a highly tissue- and steroid-specific manner. 4. From an analysis of the proteins synthesized in the ascites cell-free system in the presence of the poly(A)-rich RNA fraction, it appears that protein synthesis in the prostate gland is stimulated in a rather general way, even during the earliest phases of the androgenic response. This conclusion may require modification when more specific means of analysis are available than those used in the present investigation. 5. The implications of these findings to the mechanism of action of androgens are discussed.

scholarly journals Evaluation of the Granulopoiesis during Antiblastic Treatment

1967 ◽  
Vol 17 (1) ◽  
pp. 18-29
Author(s):  
A. Fieschi ◽  
C. Sacchetti
Keyword(s):  
Bone Marrow ◽  
Nitrogen Mustard ◽  
Steroid Treatment ◽  
Granulocyte Count ◽  
Favourable Change ◽  
Blood Granulocyte

SummarySelected subjects have been treated with cyclophosphamide and nitrogen mustard. The granulocytopenia has been followed by repeated in vivo labeling with DFP32 and the endotoxin test for evaluating the availability of the granulocyte reserve. The effect of steroid treatment on the recovery of the granulopoiesis has been studied with autotransfusions of in vitro DFP32 labeled granulocytes in the same subject and performed before, during and after the treatment was discontinued.The following conclusions have been reached:1. The efficiency of the granulopoiesis is based upon the availability of the bone marrow granulocyte reserve.2. The bone marrow granulocyte mobilization with endotoxin and the in vivo granulocyte labeling with DFP32 give an evaluable information about the bone marrow granulocyte reserve.3. The granulocytopenia due to antiblastic therapy corresponds to a depletion of the bone marrow granulocyte reserve.4. The recovery of a “normal granulocyte count” preceeds the rebuilt of a “normal availability” of the bone marrow granulocyte reserve.5. The recovery of the blood granulocyte count after prednison is not associated with any favourable change of the granulopoiesis.

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