[ 125 i ] angiotensin ii ( 2200 ci / mmol ) was purchased from amersham international plc ( amersham , berks u . k .). angiotensin ii , saralasin and other reagents unless otherwise specified were purchased from sigma chemical co . ( poole , dorset , u . k .). basic fibroblast growth factor ( bfgf ) was purchased from rd systems ( minneapolis , u . s . a ). losartan ( dup753 ; ( 2 - n - butyl - 4 - chloro - 5 - hydroxymethyl - 1 -[ 2 -( 1h - tetrazol - 5 - yl ) biphenyl - 4 - yl ) methyl ] imidazole ) and pd123177 ( 1 -( 4 - amino - 3 - methylphenyl )- methyl - 5 - diphenyl - acetyl - 4 , 5 , 6 , 7 - tetrahydro - 1h - imidazo [ 4 , 5 - c ] pyridine - 6 - carboxylic acid ) were from dupont merck pharmaceuticals and kindly provided by dr . n . m . barnes , university of birmingham . components for the culture medium were obtained from flow laboratories ( high wycombe , berks ., u . k .). myometrium was collected from women undergoing total abdominal hysterectomy . patients selected had no apparent endocrinological problems and no local organic pathologies . all tissues were obtained from 20 - 48 year old women with a history of regular menstrual cycles . none of the patients had taken any hormonal medication for at least 3 months before the surgery . the tissue was rinsed in sterile saline and rapidly frozen over dry - ice , wrapped in parafilm to prevent dehydration and stored at - 70 ° c . until they were sectioned for receptor autoradiographic studies . frozen myometrium and fibroid tissues were surrounded in embedding medium ( oct compound , miles scientific ) before 20 μm sections were cut using a cryostat (- 15 to - 1 9 ° c .) and thaw mounted onto gelatin - coated glass slides for receptor autoradiographic studies . sections were stored ( less than 2 week ) desiccated at - 80 ° c . until used . tissue samples were placed into sterile calcium and magnesium - free hbss containing penicillin ( 100 u / ml ) and streptomycin ( 100 μg / ml ) for transfer to the laboratory . myometrial cells were isolated by collagenase digestion . briefly , myometrium was finely chopped and incubated in hbss containing 1 mg / ml collagenase ia , 20 mm hepes , 100 u / l penicillin , 100 μg / ml streptomycin and 5 μg / ml fungizone at 37 ° c . until the cells were dispersed . myometrial cells were obtained by centrifugation for 15 minutes at 400 g over 60 % percoll and the cells washed with hbss . myometrial cells were characterised by their ability to respond to oxytocin and staining for actin . slide mounted human myometrial / fibroid sections were removed from storage and allowed approximately 30 min to equilibrate to room temperature . to reduce endogenous levels of angiotensin ii in the tissue , the sections were preincubated for 60 min in incubation buffer ( mm ; sodium chloride , 150 ; sodium dihydrogen phosphate , 50 ; magnesium chloride , 10 ; ethyleneglycol - bis -( β - amino - ethyl ether )- n , n &# 39 ;- tetra - acetic acid , 5 and 0 . 4 % w / v bovine serum albumin , ph 7 . 4 ) at 25 ° c . the slides were then incubated in incubation buffer which contained 0 . 1 nm [ 125 i ] angiotensin ii in the absence ( total binding ) or presence of competing compound ( either 1 . 0 μm unlabelled angiotensin ii , 1 . 0 μm dup753 , 1 . 0 μm pd123177 or 1 . 0 μm dup753 plus 1 . 0 μm pd123177 ) for 60 min at 25 ° c . immediately following incubation , the tissue sections were washed in ice - cold incubation buffer for 2 min and dipped ( 1 s ) in ice - cold distilled water to remove buffer salts . the sections were rapidly dried in a stream of cold dry air and exposed to hyperfilm -[ 3 h ] ( amersham international ) in x - ray cassettes together with [ 125 i ] standards ( amersham international ) for 10 days . autoradiographic films were developed in kodak lx 24 developer ( 5 min ) and kodak unifix ( 5 min ) and were quantitated by reference to [ 125 i ] standards ( fmol / mg tissue ; amersham ) using image analysis . cells were maintained in 175 cm 2 flasks in dulbecco &# 39 ; s modified eagle &# 39 ; s medium ( dmem ) containing 10 % ( v / v ) fetal calf serum ( fcs ), 1 % l - glutamine , 20 mm hepes and 1 % antibiotic - antimycotic mixture ( 10 , 000 u penicillin , 10 μg streptomycin , and 25 μg ml - 1 fungizone ) at 37 ° c . in a humidified atmosphere of air / co 2 ( 19 : 1 ) until 95 % confluent . thereafter , the cells were trypsinised , washed and re - plated at a density of 10 × 10 3 cells per well in 24 - well plates in 1 ml of dmem with 10 % fcs for the proliferation studies . after 24 hrs , the medium was removed and replaced with serum - free dmem . after a further 24 hrs , the experiments were initiated on quiescent monolayers of myometrial cells . to the serum - starved myometrial cells was added either angiotensin ii ( 0 . 1 μm or 1 . 0 μm ) in the presence or absence of 1 % fcs or bfgf ( 20 ng / ml ) or fcs ( 1 %) alone or dup753 with or without angiotensin ii ( 0 . 1 μm ) and cell growth measured at day 4 and day 6 by counting cell numbers in a coulter counter as described below . the corresponding medium was replaced every 24 hrs with fresh medium . calibration of the coulter counter was achieved by counting the myometrium cell suspension at reduced aperture size ranging from 0 to 32 . a calibration curve was constructed from the cell counts on the function of the aperture size , and the aperture size corresponding to the middle point of the plateau part of the calibration curve was used for the cell counting . the aperture size used for myometrium cell counting was 16 . at defined time - points , the growth media was removed and the cells were washed with 1 ml of isotonic saline ( 0 . 9 % sodium chloride ), followed by the addition of 1 ml of 10 mm hepes buffer containing 1 . 5 mm magnesium chloride , and 2 drops of zap - oglobin ( coulter electronics ltd ., luton , beds ., uk ) containing 2 . 5 % acetic acid to each well . the 24 - well plate was allowed to incubate at 37 ° c . for 10 min . after which , the suspended cells were pipetted up and down to disperse the cell clusters . the cell suspension was then added to 9 ml of counting solution containing 0 . 9 % sodium chloride and 0 . 5 % formalin in a coulter counter container . each well was washed three times with the counting solution from the same container and effluent collected in the same container . the number of cells in each well was counted at the aperture size of 16 on the coulter counter ( coulter electronics ltd ., luton , beds u . k .). three readings were taken for each well and a mean value of the three readings obtained . the mean (± sd ) value of cell counts from the triplicate wells was calculated . with the development of non - peptide angiotensin ii receptor ( at ) antagonists , attention has focused on the at receptor as a target to pharmacologically manipulate the renin - angiotensin system . using quantitative receptor autoradiography , we have pharmacologically characterised the presence of at 2 receptors on non - pregnant myometrium and fibroids ( fig1 ). dark regions indicate high density of labelled receptors . it is clear from the fig1 that the fibroid region contains a higher density of angiotensin ii receptors than normal myometrium . fig1 ( a ) to 1 ( e ) are autoradiograms of the distribution of [ 125 i ] angiotensin ii binding to adjacent sections ( 20 μm ) of the human non - pregnant myometrium containing a fibroid . in fig1 ( a ), total binding of such labelled angiotensin ii is illustrated . fig1 ( b ) shows binding in the presence of the at 1 receptor selective ligand dup753 ( 1 . 0 μm ). fig1 ( c ) shows binding in the presence of the at 2 receptor selective ligand pd123177 ( 1 . 0 μm ). fig1 ( d ) shows binding in the presence of dup753 ( 1 . 0 μm ) plus pd123177 ( 1 . 0 μm ). fig1 ( e ) shows binding in the presence of unlabelled angiotensin ii ( 0 . 1 nm ). dark regions indicate high densities of labelled receptors . the difference in density between fig1 ( a ) and 1 ( b ) represents at 1 receptor specific binding . this receptor subtype is weakly expressed in myometrium . the difference in density between fig1 ( a ) and 1 ( c ) represents at 2 receptor specific binding . the fibroid region in fig1 ( c ) shows a lower at receptor expression than the same region in fig1 ( b ), thus indicating that the fibroid has predominantly at 2 type receptors . the fibroid had a higher density of angiotensin ii receptors than normal myometrium . the difference between fig1 ( a ) and 1 ( d ) represents specific at 1 plus at 2 receptor - density , and the difference between fig1 ( d ) and 1 ( e ) represents a newly discovered , non - at 1 / non - at 2 angiotensin ii recognition site . the intensity of expression of such non - at 1 / non - at 2 angiotensin ii recognition site in the fibroid tissue only disappears in the presence of cold angiotensin ii ( 1 μm ), thus indicating that this is an additional high affinity angiotensin ii recognition site . this newly discovered site is pharmacologically distinct from known at receptor subtypes , and sar - thr - angiotensin ii and sar - ala - angiotensin ii can selectively displace [ 125 i ] angiotensin ii from this site ( fig2 ). the results of growth experiments are given in attached fig3 ( a ) and 3 ( b ) which are graphs plotting mean cell count against time in days . it will be seen from fig3 ( a ) that the presence of angiotensin ii ( 0 . 1 μm ) in culture medium has a significant effect on myometrial cell growth and that after six days in culture there is approximately a 100 % increase in myometrial cell proliferation compared to cells in culture medium devoid of angiotensin ii . it is also interesting to note that the angiotensin ii - induced response is comparable to that induced by a classic growth factor such as bfgf ( table 1 ). table 1______________________________________ days 0 day (+/- sd ) 4 days (+/- sd ) 6 days (+/- sd ) ______________________________________control ( 1 % fcs ) 65 . 83 +/- 1 . 52 127 . 00 +/- 12 . 53 146 . 33 +/- 16 . 22 ag ii ( 0 . 1 μm 64 . 33 +/- 2 . 73 167 . 33 +/- 21 . 55 333 . 67 +/- 7 . 51 in 1 % fcs ) bfgf ( 20 ng / ml 63 . 90 +/- 1 . 88 167 . 33 +/- 25 . 11 307 . 33 +/- 49 . 69 in 1 % fcs ) ______________________________________ in addition , angiotensin ii receptor antagonists blocked the effect of angiotensin ii on cell proliferation . it can be seen in fig3 ( b ) as an example that dup753 inhibits the effects of angiotensin ii on cell proliferation . preliminary data also shows that pd177123 also inhibits angiotensin ii - mediated cell growth . consequently , it is reasonable to infer that reduction of the level of angiotensin ii or blocking of the high affinity angiotensin ii binding sites in the fibroid will lead to a reduction in , or inhibition of , fibroid growth . the invention proposes to treat patients in one of the following ways : ( 1 ) by oral administration of the drug and this may be the preferred method of treatment . ( 4 ) directly at the site of the tumour using an ultrasound directed local injection into the fibroid ( as some of these compounds are water soluble , they could be placed in an oil - based solution and then injected so as to give slow release of the active drug ). ( 5 ) as a pellet inserted directly at the site of the tumour using the long - acting near - zero order releasing system with the aid of laproscopy . as discussed above , fig1 a - 1e are different autoradiograms of the distribution of [ 125 i ]- angiotensin ii binding to adjacent sections ( 20 μm ) of the human non - pregnant myometrium containing a fibroid . the difference in density between ( a ) and ( b ) represents at 1 receptor specific binding ( this receptor subtype is not detected in myometrium ); difference in density between ( a ) and ( c ) represents at 2 receptor specific binding ; difference between ( a ) and ( d ) represents specific at 1 plus at 2 receptor density and the difference between ( d ) and ( e ) represents the newly discovered , non - at 1 / non at 2 angiotensin ii recognition site . note the intensity of expression of such non - at 1 / non - at 2 angiotensin ii recognition site in the fibroid tissue which only disappears in the presence of cold angiotensin ii suggesting that the fibroid expresses high levels of the binding site . as discussed above , fig2 a - 2j are different autoradiograms of the distribution of [ 125 i ] angiotensin ii binding to adjacent sections ( 20 μm ) of the human non - pregnant myometrium ( myo ) and fibroid ( fib ). as discussed above , fig3 ( a ) illutrates the effect of angiotensin ii on myometrial cell proliferation . myometrium cells were maintained in dulbecco &# 39 ; s modified eagle &# 39 ; s medium ( md ) with 10 % ( v / v ) fcs , containing 1 % l - glutamine , 20 mm hepes and 1 % antibiotic - antimycotic mixture ( 10 , 000 u penicillin , 10 mg streptomycin ) at 37 ° c . in a humidified atmosphere of air / co 2 ( 19 : 1 ) until 95 % confluent . for the proliferation studies , the cells were plated at a density of 10 × 10 3 cells per well in 24 well plates in 1 ml of dmem with 10 % fcs . after 24 hrs the medium was removed and replaced with serum - free dmem . after a further 24 hrs , the experiment was initiated on quiescent monolayers of myometrial cells . to each of the wells in triplicate was added 1 ml of angiotensin ii ( 0 . 1 μm ) or dmem alone , in the presence or absence of 1 % fcs . the cell growth was measured at day 4 and day 6 by counting cell numbers in a coulter counter . each point represents the mean ± sem of triplicate determinations from a single experiment , typical of three others . as discussed above , fig3 ( b ) illustrates the effect of at 1 receptor ligand ( dup753 ) on angiotensin ii - induced myometrial cell proliferation . myometrium cells were maintained in dulbecco &# 39 ; s modified eagle &# 39 ; s medium ( md ) with 10 % ( v / v ) fcs , containing 1 % l - glutamine , 20 mm hepes and 1 % antibiotic - antimycotic mixture ( 10 , 000 u penicillin , 10 mg streptomycin ) at 37 ° c . in a humidified atmosphere of air / co 2 ( 19 : 1 ) until 95 % confluent . for the proliferation studies , the cells were plated at a density of 10 × 10 3 cells per well in 24 well plates in 1 ml of dmem with 10 % fcs . after 24 hrs the medium was removed and replaced with serum - free dmem . after a further 24 hrs , the experiment was initiated on quiescent monolayers of myometrial cells . to each of the wells , in triplicate , was added 1 ml of 1 % fcs as control or angiotensin ii ( 0 . 1 μm ), or dup753 ( 1 μm ) or dup753 plus angiotensin ii ( 0 . 1 μm ) in the presence of 1 % fcs . the cell growth was measured at day 4 and day 6 by counting cell numbers in a coulter counter . each point represents the mean ± sem of triplicate determinations from a single experiment , typical of three others . serial 3 μm sections of formalin - fixed , paraffin - embedded tissue were used for immunohistochemistry . sections were de - paraffinized by incubation for 5 min with histoclear and hydrated through methanol to water . endogenous peroxidase activity was quenched by 0 . 3 % ( v / v ) hydrogen peroxide in methanol for 10 minutes . the primary antibodies were rabbit polyclonal antibodies raised against the human renin , angiotensin converting enzyme , ang1 , ang ii and at 1 receptor . non - immune goat serum ( 10 % in 0 . 01 mol / l pbs , ph 7 . 2 ) was used as a dilution of the primary antibody to reduce non - specific binding . amplification of the primary antibody reaction was achieved using a goat anti - rabbit secondary antibody ( diluted 1 : 200 in 0 . 01 mol / l pbs , ph 7 . 2 ) for 30 min followed by a complex of streptavidin ( dako ltd , bucks , uk ) and biotinylated peroxidase ( dako ltd , bucks , uk ). finally , the binding was visualised by the addition of 0 . 5 mg / ml diaminobenzidine ( sigma chemical co . ltd , poole , dorset , uk ) and 0 . 01 % hydrogen peroxide in 0 . 01 mmol / l pbs to the antigen - antibody complex . between each step the sections were washed in 3 × 200 ml of 0 . 1 % ( v / v ) polyoxylene - 10 - oleoyl - ether in 0 . 01 mmol / l pbs , ph 7 . 2 , over a period of 15 min . all incubations of antisera were carried out at room temperature in a wet chamber mounted on a rocking tray which ensures a movement of antiserum over the whole section . the sections were counterstained with mayers haematoxylin , dehydrated and mounted . using the immunocytochemistry described above , the primary antibodies raised against renin , angiotensin converting enzyme , angiotensin i and angiotensin ii were used to show that the components of the renin - angiotensin system ( ras ) are expressed in myometrium and fibroids . this suggests that there is local ras within the tissue itself , further supporting the functional studies . in addition , immunoreactive at 1 receptor protein was localised in myometrial smooth muscle cells and around the blood vessels , indicating that myometrium and fibroid tissues contain at 1 receptors in addition to at 2 receptors which were clearly identified using autoradiography results . evidence also indicates that there is intense vascularization around the uterine fibroid and also within the fibroids as qbn10 ( a marker of endothelial cells ) intense endothelial cell staining in immunohistochemical sections . myometrial cells prepared as described previously were resuspended in culture medium containing dmem supplemented with 10 % ( v / v ) fcs , 10 mm l - glutamine , 20 mm hepes , 100 u / mi penicillin and 100 / μg / ml streptomycin in 24 well plates at a density of approximately 250 × 10 3 cells per well and maintained at 37 ° c . in a humidified atmosphere of air / co 2 ( 19 : 1 ). dna synthesis was assayed by measuring [ 3 h ]- thymidine incorporation into dna . subconfluent myometrial cells were made quiescent by incubation with serum - free medium for 48 h , the medium being replaced with serum - free medium containing 0 . 2 % ( w / v ) bovine serum albumin ( bsa ) and [ 3 h ]- thymidine ( 0 . 2 μci / well ). the cells were further incubated for 48 h in the presence of angiotensin - converting enzyme ( ace ) inhibitor ( 0 . 1 and 1 . 0 mm captopril , hatched and solid columns respectively ) or angiotensin ii ( 100 nm agii , crossed column ). the medium was then removed and the cells incubated with 10 % cold trichloroacetic acid tca ) at 4 ° c . for 15 min . tca - precipitated material was redissolved in 0 . 2 m naoh and the radioactivity determined by liquid scintillation counting in a β - scintillation analyser . positive and negative controls for proliferation were established by incubating cells with 10 % fetal calf serum ( square column ) and by growth in the absence of the agonist in serum - free medium ( open column ). as shown in fig4 dna synthesis was reduced by almost 50 % of control ( open column -- 0 % fcs ) in the presence of ace inhibitor . this suggests that myometrial cells have the capacity to generate endogenous angiotensin ii which promotes myometrial cell growth . use of ace inhibitors will reduce the ability of these cells to proliferate . in another series of experiments , using the procedures described above in relation to fig3 a and 3b , the results as shown in fig4 b were obtained . as fig5 shows , angiotensin ii - mediated cell proliferation is significantly inhibited when the cells are incubated with 1 . 00 μm of dup753 or pd123177 or / and dup753 plus pd123177 . this suggests that in myometrial cells , angiotensin ii stimulates cells proliferation via at 1 or at 2 receptor subtype . start patient on 2 . 5 mg once daily for one week . increase dose to 5 mg once daily for 12 weeks then increase dose to 10 mg for a further 12 weeks . monitor size of fibroid and continue at this dose until fibroids fibroid / uterus reduces in size by 50 %. reduce dose to 5 mg once daily for as long as required . drug may be orally administered .
the use of a ) an angiotensin - converting enzyme inhibitor such as captopril or enalapril , b ) an angiotensin ii - receptor antagonist such as saralasin or losartan , or c ) a renin inhibitor , such as remikiren or - phenylalanyl - histidyl - achpa - isoleucylamino ]- 2 - methyl - 2 - dihydroxy - 1 , 3 - propane , for the manufacture of a medicament for the treatment of uterine fibroids is disclosed . the ace inhibitor may be used concomitantly or sequentially with a gonadotropin - releasing hormone agonist such as buserelin or goserelin .