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Ovarian follicular fluid eicosanoid concentrations during the pre-ovulatory period in humans
PROSTAGLANDINS
OVARIAN
FOLLICULAR FLUID EICOSANOID CONCENTRATIONS DURING E PRE-OWLATOR PERIOD IN TT , S.R. Killick A.R. Priddy 5, f. ~?.nl.t$~!.$j3rri~2, M. Sullivan3, L. Pate1
Departments of Obstetrics and Gynaecology' and Statisticsa, University Hospital of South Manchester, West Didsbury, Manchester M20 ELR, England and Department of Obstetrics and Gynaecology3 Hammersmith Hospital, Du Cane Road, London W12 OHJ, England
ABSTRACT Prostaglandins are involved in ovulation and in every mammal studied so far, ovulation has been inhibited by prostaglandin inhibition. Information regarding the role of leukotrienes and thromboxanes in ovulation is more limited. In order to study the production of eicosanoids in human pre-ovulatory follicular fluid, follicular aspiration was timed by means of serial ultrasound scans and human chorionic gonadotrophin (hCG) to be immediately pre11 women were studied and the eicosanoids measured by ovulatory. radioimmunoassay (RIA). The follicular fluid was found to contain leukotriene (LT) B4, LTC4 (D4, E ), prostaglandin (PC) E PGF (TX j' Bf. 6 keto PGF and thromboxane This is the first'publi%ed report of 1" eukotrienes in human fol icular fluid in spontaneous cycles, and is one of the few reports showing prostaglandins and The significance of demonstrating leukotrienes in thromboxanes. human follicular fluid is discussed as is the correlation between individual eicosanoids in the human ovary. INTRODUCTION Arachidonic acid can be metabolised by the enzyme, cyclooxygenase, to form prostaglandins and thromboxanes or by the enzyme, 5-lipoto form the leukotrienes. oxygenase, Products of arachidonic acid metabolism via the cyclooxygenase pathway in the ovary have been studied extensively since the early 1970's and are involved in mammalian ovulation. In humans, follicular fluid from women in spontaneous cycles has been found to contain PGE 2, PGF2,x, 6 keto PGFIK and TXB2 (1,2). Follicular fluid PGF increases in the pre-ovulatory period (3) and prostaglandin such as indomethacin are capable of synt"n:etase inhibitors inhibiting ovulation in humans when given at high doses over the peri-ovulatory period (4).
AUGUST
1989 VOL. 39 NO. 2
197
PROSTAGLANDINS
Lipoxygenase products of arachidonic acid metabolism may also be involved in ovulation. In rats, lipoxygenase inhibitors can inhibit ovulation in a dose dependent manner (5). Lipoxygenase enzymes were first reported in human granulosa cells in 1986 by Feldman et al (6) and LTB has been detected in human follicular fluid from hyperstimula 2ed follicles (7). It is not clear, however, whether superovulation modifies leukotriene biosynthesis. This study was designed to determine whether leukotrienes could be measured in preovulatory follicular fluid from women in spontaneous cycles, and to determine the relative levels of cyclooxygenase and lipoxygenase products. PATIENTS
AND METHODS
Eleven patients who had given informed consent, and who were being sterilised by tubal ligation were studied. They had no gynaecological symptoms and were not taking oral contraception. The women were scanned by ultrasound every one or two days from day 8 of their cycle to assess the size and rate of growth of the dominant follicle and to predict the approximate day of ovulation as far in advance as possible. A Diasonics DSI-RF sector scanner with a 3.5 or 5 MHZ trans-abdominal transducer (Diasonics, Paris, Frnace) was used for all scans and mean follicular diameter calculated from measurements in three planes. The date of sterilisation was timed for when a large pre-ovulatory follicle was present. When the dominant follicle reached a minimum diameter of 18 mm, 5000 units of hCG was given intramuscularly. hCG was administered to regulate the onset of the ovulatory process and to enable follicular fluid to be obtained at a reproducible temporal point within this process. Sterilisation was performed between 17 and 19.5 hours after hCG administration. General anaesthesia and muscle relaxation were used in all cases. At the time of sterilisation follicular fluid was aspirated from the dominant follicle with a needle and syringe. Aliquots of fluid were immediately transferred to ice cold containers each containing indomethacin to prevent contamination with platelet cyclooxygenase. The final concentration of indomethacin in solution was 50 UB. The fluid was centrifuged at 900 g for ten minutes. Clean samples were stored at -2O'C until assayed in one batch to avoid inter-assay variation. Radioimmunoassay Arachidonic acid metabolites were extracted from the follicular In brief, the samples fluid as has been described previously (8).
198
AUGUST
1989 VOL. 38 NO. 2
PROSTAGLANDINS
were acidified to pH3 with 15 p/ml 8.6 M formic acid and loaded onto pre-conditioned sep-pak Cl8 columns. These were washed with distilled water and then petroleum spirit (10 ml of each) prior to elution of arachidonic acid metabolites with 5 ml methyl formate into siliconized glass tubes. The sep-paks were finally washed with 80% ethanol-water (10 mls). The methyl formate was evaporated under a stream of nitrogen and the samples resgspended in 500 ul of ethanol and then stored under The extraction efficiencies for prostaglandins nitrogen at -70 C. were 70-90s and 50-60s for the leukotrienes. In-house assays were used to measure PGE PGF,; ",o",;;zdPGFti TXB2. All the antibodies were raised agi;nst eicosanoids as previously reported (9), and the standards were Sigma. In all cases the intra-assay variation was 8% at the concentrations encountered, LTB4 and the peptide-leukotrienes were measured using commercial kits (Amersham International). was not possible to determine individual peptide-leukotrienes, adequate RIA's to measure each of the peptide leukotrienes separately are not currently available, so these are expressed single group.
and from
It as as a
RESULTS Follicular fluid LTB4, LTC (D , Ed), PGE PGF 2ar, 6 keto 2' TXB2 concentrations are shiwn ?n Table 1.
PGF
lcx
and
In the eleven patients, an association between individual eicosanoid concentrations was assessed using Pearson Correlation Coefficients, as the data was normally distributed. There was a significant association between follicular fluid LTB and LTC4 (D4, E4) concentration (p=O.O36), There was a highly significant association between follicular fluid PGE2 and PGF concentration (p=O.OOl) and a significant association between fol f ocular fluid PGF and TXB 2 concentration (p=O.O26). There was no correlation betzen the concentrations of the leukotrienes (LTB and in the $o%c~T~$'f%~dE4) prostaglandins (PGE2 and PGF,& DJSCUSSION Our data indicate that leukotrienes are present in pre-ovulatory follicular fluid from women in spontaneous cycles. Leukotriene and prostaglandin levels are similar, under hCG stimulation, and may therefore be of similar importance in ovulation. The role of prostaglandins in ovulation is well documented (10) but leukotrienes may also be involved. Ovulation has been likened to an inflammatory response because of histological changes which occur at the apex of the follicle prior to rupture (ll), LTB4 is chemotactic for
AUGUST
1999 VOL. 39 NO. 2
199
PROSTAGLANDINS
Table
1
Follicular
T Patient Number
eicosanoid
Follicular
LTB4
LTC4
w/ml
(D ,E4) ng 4ml
1
3.38
2
concentrations
fluid
6 keto
concentration
PGFIQ
TXB2
PGE2
PGF
w/ml
w/ml
w/ml
Wm 2Y
16.77
1.9
0.18
15.69
15.88
3.71
16.28
1.0
0.07
9.43
3
5.53
19.41
1.6
0.13
17.46
16.51
4
1.07
14.13
1.1
0.17
9.27
8.28
5
2.40
17.70
1.6
0.10
11.53
6.41
6
2.11
11.89
1.3
0.12
10.88
3.28
7
5.62
21.19
0.6
0.10
10.31
a
4.16
19.74
1.8
0.06
8.11
2.30
9
2.44
14.28
1.1
0.09
10.91
3.67
10
4.95
16.68
1.3
0.08
11.72
11
4.01
11.66
0.6
0.09
7.82
5.61
3.58 + 1,47
16.34 -+ 3.12
11.20 + 2.98 ti
7.24 I 4.88 _
Mean -+ S.D. -_
200
fluid
1.3 -+ 0.4
0.11 + 0.04 II-
AUGUST
1999 VOL. 39 NO. 2
PROSTAGLANDINS
releases lysosomal enzymes and increases vascular leucocytes, all factors which may be important in the ovulatory permeability, Little is known about the effect of the peptide leukotrienes process. cc,, D4' E ) on ovulation but they were present in high concentrations in the fol 4.ocular fluid and are known to cause vasoconstriction, which could potentiate the ischaemia at the apex of the follicle which precedes ovulation. The variation in individual eicosanoid concentrations in Table did not reflect any variation in the time after hCG that the follicle was aspirated.
1
There was a positive correlation between follicular fluid PGE and This has been shown in agimal PGF concentrations in this study. stu ? ies (10) and is probably due to the LH surge initiating protein synthesis and cyclooxygenase production via cyclic AMP. This could also explain the correlation between follicular fluid and TXB . It is not clear why 6 keto PGF PGF did not also sho?a positi?e correlation but this may reflec ? a lack of function of this eicosanoid in the ovulatory process. The concentration of follicular fluid 6 keto PGF was in fact low in comparison to the other eicosanoids, and simi I”ar to previous reported values (2). There was a positive correlation between follicular fluid LTB4 and E4) concentrations suggesting a similar mechanism as , with induction of 5-lipoxygenase. There was no correlation between the concentration of follicular fluid leukotrienes (LTB4 and LTC4, D4, E ) and prostaglandins This may indicate tha f ovulation (PGE2 and PGF2$. involves preferential s emulation of cyclooxygenase. Alternatively there may be separate pools of substrate arachidonic acid for leukotriene and prostaglandin production respectively, as has been previously reported (12), although the evidence for this is not convincing. In summary, leukotrienes as well as other eicosanoids are present in human pre-ovulatory follicular fluid in spontaneous cycles. Leukotriene and prostaglandin levels are similar, under hCG stimulation. However, whether leukotrienes will assume similar importance in ovulation as prostaglandins, will depend on further research in the absence of hCG and on the kinetics of leukotriene production within the follicle. ACKNOWLEDGEMENTS We wish
AUGUST
to thank
Miss
Julie
1989 VOL. 38 NO. 2
Chesters
for typing
the manuscript.
201
PROSTAGLANDINS
REFERENCES 1.
Seibel, M.M., S.L. Swartz, D, Smith, L. Levesque, and M.L, Taymor. In vivo prostaglandin concentrations in human preovulatory follicles. Fertil.Steril. -42: 482, 1984.
2.
Ylikorkala, O., and A. Tenhunen. Follicular fluid prostaglandins in endometriosis and ovarian hyperstimulation. Fertil.Steril. -41: 66, 1984.
3.
Darling, M.R.N., M. Jogee, and M.G. Elder. Prostaglandin FZor levels in the human ovarian follicle. Prostaglandins -23: 551, 1982.
4.
Killick, S.R., and M. Elstein. Pharmacological luteinized unruptured follicles by prostaglandin inhibitors. Fertil.Steril. -47: 773, 1987.
5.
Reich, R., F. Kohen, Z. Naor, and A. Tsafriri. Possible involvement of lipoxygenase products of arachidonic acid Prostaglandins pathway in ovulation. -26: 1011, 1983.
6.
Feldman, E., S. Haberman, A.O. Abisogun, R. Reich, D. Levran, S. Maschiach, H. Zuckermann, E. Rudack, J, Dor, and A. Tsafriri. Arachidonic acid metabolism in human granulosa cells: evidence for cyclooxygenase and lipoxygenase activityin vitro. Human Reprod. -1: 353, 1986.
7.
Heinonen, P.K., R. Punnonen, R. Ashorn, Prostaglandins, Morsky, and E. Seppala. leukotriene in human follicular fluid. 253, 1986.
8.
Rose, M-P., M.G. Elder, metabolism in the human 1987.
9.
Prostaglandin Glance, D.G., M.G. Elder, and L. Myatt. production and stimulation by angiotension II in the isolated Am.J.Obstet.Gynecol. perfused human cotyledon. -151: 387, 1985.
E. Kujansuu, P. thromboxane and J.Reprod.Fertil. 2:
and L. Myatt. Arachidonic acid Trophoblast Res. -2: 71, placenta.
10.
Armstrong, D.T. Prostaglandins perspectives -2: 6, 1986.
11,
Espey, L.L. hypothesis.
12.
Kuehl, F-A. Jnr, H.?'. Dougherty, and E.A. between prostaglandins and leukotrienes. -33: 1, 1984. Editor:
202
and ovulation.
Ovulation as an inflammatory Biol.Reprod. -22: 73, 1980.
H. Behrman
production of synthetase
Received:
Prostaglandin
response
- a
Ham, Interactions Biochem.Pharmacol. Accepted:
10-13-88
AUGUST
6 12-89
1989 VOL. 38 NO. 2
OVARIAN
FOLLICULAR FLUID EICOSANOID CONCENTRATIONS DURING E PRE-OWLATOR PERIOD IN TT , S.R. Killick A.R. Priddy 5, f. ~?.nl.t$~!.$j3rri~2, M. Sullivan3, L. Pate1
Departments of Obstetrics and Gynaecology' and Statisticsa, University Hospital of South Manchester, West Didsbury, Manchester M20 ELR, England and Department of Obstetrics and Gynaecology3 Hammersmith Hospital, Du Cane Road, London W12 OHJ, England
ABSTRACT Prostaglandins are involved in ovulation and in every mammal studied so far, ovulation has been inhibited by prostaglandin inhibition. Information regarding the role of leukotrienes and thromboxanes in ovulation is more limited. In order to study the production of eicosanoids in human pre-ovulatory follicular fluid, follicular aspiration was timed by means of serial ultrasound scans and human chorionic gonadotrophin (hCG) to be immediately pre11 women were studied and the eicosanoids measured by ovulatory. radioimmunoassay (RIA). The follicular fluid was found to contain leukotriene (LT) B4, LTC4 (D4, E ), prostaglandin (PC) E PGF (TX j' Bf. 6 keto PGF and thromboxane This is the first'publi%ed report of 1" eukotrienes in human fol icular fluid in spontaneous cycles, and is one of the few reports showing prostaglandins and The significance of demonstrating leukotrienes in thromboxanes. human follicular fluid is discussed as is the correlation between individual eicosanoids in the human ovary. INTRODUCTION Arachidonic acid can be metabolised by the enzyme, cyclooxygenase, to form prostaglandins and thromboxanes or by the enzyme, 5-lipoto form the leukotrienes. oxygenase, Products of arachidonic acid metabolism via the cyclooxygenase pathway in the ovary have been studied extensively since the early 1970's and are involved in mammalian ovulation. In humans, follicular fluid from women in spontaneous cycles has been found to contain PGE 2, PGF2,x, 6 keto PGFIK and TXB2 (1,2). Follicular fluid PGF increases in the pre-ovulatory period (3) and prostaglandin such as indomethacin are capable of synt"n:etase inhibitors inhibiting ovulation in humans when given at high doses over the peri-ovulatory period (4).
AUGUST
1989 VOL. 39 NO. 2
197
PROSTAGLANDINS
Lipoxygenase products of arachidonic acid metabolism may also be involved in ovulation. In rats, lipoxygenase inhibitors can inhibit ovulation in a dose dependent manner (5). Lipoxygenase enzymes were first reported in human granulosa cells in 1986 by Feldman et al (6) and LTB has been detected in human follicular fluid from hyperstimula 2ed follicles (7). It is not clear, however, whether superovulation modifies leukotriene biosynthesis. This study was designed to determine whether leukotrienes could be measured in preovulatory follicular fluid from women in spontaneous cycles, and to determine the relative levels of cyclooxygenase and lipoxygenase products. PATIENTS
AND METHODS
Eleven patients who had given informed consent, and who were being sterilised by tubal ligation were studied. They had no gynaecological symptoms and were not taking oral contraception. The women were scanned by ultrasound every one or two days from day 8 of their cycle to assess the size and rate of growth of the dominant follicle and to predict the approximate day of ovulation as far in advance as possible. A Diasonics DSI-RF sector scanner with a 3.5 or 5 MHZ trans-abdominal transducer (Diasonics, Paris, Frnace) was used for all scans and mean follicular diameter calculated from measurements in three planes. The date of sterilisation was timed for when a large pre-ovulatory follicle was present. When the dominant follicle reached a minimum diameter of 18 mm, 5000 units of hCG was given intramuscularly. hCG was administered to regulate the onset of the ovulatory process and to enable follicular fluid to be obtained at a reproducible temporal point within this process. Sterilisation was performed between 17 and 19.5 hours after hCG administration. General anaesthesia and muscle relaxation were used in all cases. At the time of sterilisation follicular fluid was aspirated from the dominant follicle with a needle and syringe. Aliquots of fluid were immediately transferred to ice cold containers each containing indomethacin to prevent contamination with platelet cyclooxygenase. The final concentration of indomethacin in solution was 50 UB. The fluid was centrifuged at 900 g for ten minutes. Clean samples were stored at -2O'C until assayed in one batch to avoid inter-assay variation. Radioimmunoassay Arachidonic acid metabolites were extracted from the follicular In brief, the samples fluid as has been described previously (8).
198
AUGUST
1989 VOL. 38 NO. 2
PROSTAGLANDINS
were acidified to pH3 with 15 p/ml 8.6 M formic acid and loaded onto pre-conditioned sep-pak Cl8 columns. These were washed with distilled water and then petroleum spirit (10 ml of each) prior to elution of arachidonic acid metabolites with 5 ml methyl formate into siliconized glass tubes. The sep-paks were finally washed with 80% ethanol-water (10 mls). The methyl formate was evaporated under a stream of nitrogen and the samples resgspended in 500 ul of ethanol and then stored under The extraction efficiencies for prostaglandins nitrogen at -70 C. were 70-90s and 50-60s for the leukotrienes. In-house assays were used to measure PGE PGF,; ",o",;;zdPGFti TXB2. All the antibodies were raised agi;nst eicosanoids as previously reported (9), and the standards were Sigma. In all cases the intra-assay variation was 8% at the concentrations encountered, LTB4 and the peptide-leukotrienes were measured using commercial kits (Amersham International). was not possible to determine individual peptide-leukotrienes, adequate RIA's to measure each of the peptide leukotrienes separately are not currently available, so these are expressed single group.
and from
It as as a
RESULTS Follicular fluid LTB4, LTC (D , Ed), PGE PGF 2ar, 6 keto 2' TXB2 concentrations are shiwn ?n Table 1.
PGF
lcx
and
In the eleven patients, an association between individual eicosanoid concentrations was assessed using Pearson Correlation Coefficients, as the data was normally distributed. There was a significant association between follicular fluid LTB and LTC4 (D4, E4) concentration (p=O.O36), There was a highly significant association between follicular fluid PGE2 and PGF concentration (p=O.OOl) and a significant association between fol f ocular fluid PGF and TXB 2 concentration (p=O.O26). There was no correlation betzen the concentrations of the leukotrienes (LTB and in the $o%c~T~$'f%~dE4) prostaglandins (PGE2 and PGF,& DJSCUSSION Our data indicate that leukotrienes are present in pre-ovulatory follicular fluid from women in spontaneous cycles. Leukotriene and prostaglandin levels are similar, under hCG stimulation, and may therefore be of similar importance in ovulation. The role of prostaglandins in ovulation is well documented (10) but leukotrienes may also be involved. Ovulation has been likened to an inflammatory response because of histological changes which occur at the apex of the follicle prior to rupture (ll), LTB4 is chemotactic for
AUGUST
1999 VOL. 39 NO. 2
199
PROSTAGLANDINS
Table
1
Follicular
T Patient Number
eicosanoid
Follicular
LTB4
LTC4
w/ml
(D ,E4) ng 4ml
1
3.38
2
concentrations
fluid
6 keto
concentration
PGFIQ
TXB2
PGE2
PGF
w/ml
w/ml
w/ml
Wm 2Y
16.77
1.9
0.18
15.69
15.88
3.71
16.28
1.0
0.07
9.43
3
5.53
19.41
1.6
0.13
17.46
16.51
4
1.07
14.13
1.1
0.17
9.27
8.28
5
2.40
17.70
1.6
0.10
11.53
6.41
6
2.11
11.89
1.3
0.12
10.88
3.28
7
5.62
21.19
0.6
0.10
10.31
a
4.16
19.74
1.8
0.06
8.11
2.30
9
2.44
14.28
1.1
0.09
10.91
3.67
10
4.95
16.68
1.3
0.08
11.72
11
4.01
11.66
0.6
0.09
7.82
5.61
3.58 + 1,47
16.34 -+ 3.12
11.20 + 2.98 ti
7.24 I 4.88 _
Mean -+ S.D. -_
200
fluid
1.3 -+ 0.4
0.11 + 0.04 II-
AUGUST
1999 VOL. 39 NO. 2
PROSTAGLANDINS
releases lysosomal enzymes and increases vascular leucocytes, all factors which may be important in the ovulatory permeability, Little is known about the effect of the peptide leukotrienes process. cc,, D4' E ) on ovulation but they were present in high concentrations in the fol 4.ocular fluid and are known to cause vasoconstriction, which could potentiate the ischaemia at the apex of the follicle which precedes ovulation. The variation in individual eicosanoid concentrations in Table did not reflect any variation in the time after hCG that the follicle was aspirated.
1
There was a positive correlation between follicular fluid PGE and This has been shown in agimal PGF concentrations in this study. stu ? ies (10) and is probably due to the LH surge initiating protein synthesis and cyclooxygenase production via cyclic AMP. This could also explain the correlation between follicular fluid and TXB . It is not clear why 6 keto PGF PGF did not also sho?a positi?e correlation but this may reflec ? a lack of function of this eicosanoid in the ovulatory process. The concentration of follicular fluid 6 keto PGF was in fact low in comparison to the other eicosanoids, and simi I”ar to previous reported values (2). There was a positive correlation between follicular fluid LTB4 and E4) concentrations suggesting a similar mechanism as , with induction of 5-lipoxygenase. There was no correlation between the concentration of follicular fluid leukotrienes (LTB4 and LTC4, D4, E ) and prostaglandins This may indicate tha f ovulation (PGE2 and PGF2$. involves preferential s emulation of cyclooxygenase. Alternatively there may be separate pools of substrate arachidonic acid for leukotriene and prostaglandin production respectively, as has been previously reported (12), although the evidence for this is not convincing. In summary, leukotrienes as well as other eicosanoids are present in human pre-ovulatory follicular fluid in spontaneous cycles. Leukotriene and prostaglandin levels are similar, under hCG stimulation. However, whether leukotrienes will assume similar importance in ovulation as prostaglandins, will depend on further research in the absence of hCG and on the kinetics of leukotriene production within the follicle. ACKNOWLEDGEMENTS We wish
AUGUST
to thank
Miss
Julie
1989 VOL. 38 NO. 2
Chesters
for typing
the manuscript.
201
PROSTAGLANDINS
REFERENCES 1.
Seibel, M.M., S.L. Swartz, D, Smith, L. Levesque, and M.L, Taymor. In vivo prostaglandin concentrations in human preovulatory follicles. Fertil.Steril. -42: 482, 1984.
2.
Ylikorkala, O., and A. Tenhunen. Follicular fluid prostaglandins in endometriosis and ovarian hyperstimulation. Fertil.Steril. -41: 66, 1984.
3.
Darling, M.R.N., M. Jogee, and M.G. Elder. Prostaglandin FZor levels in the human ovarian follicle. Prostaglandins -23: 551, 1982.
4.
Killick, S.R., and M. Elstein. Pharmacological luteinized unruptured follicles by prostaglandin inhibitors. Fertil.Steril. -47: 773, 1987.
5.
Reich, R., F. Kohen, Z. Naor, and A. Tsafriri. Possible involvement of lipoxygenase products of arachidonic acid Prostaglandins pathway in ovulation. -26: 1011, 1983.
6.
Feldman, E., S. Haberman, A.O. Abisogun, R. Reich, D. Levran, S. Maschiach, H. Zuckermann, E. Rudack, J, Dor, and A. Tsafriri. Arachidonic acid metabolism in human granulosa cells: evidence for cyclooxygenase and lipoxygenase activityin vitro. Human Reprod. -1: 353, 1986.
7.
Heinonen, P.K., R. Punnonen, R. Ashorn, Prostaglandins, Morsky, and E. Seppala. leukotriene in human follicular fluid. 253, 1986.
8.
Rose, M-P., M.G. Elder, metabolism in the human 1987.
9.
Prostaglandin Glance, D.G., M.G. Elder, and L. Myatt. production and stimulation by angiotension II in the isolated Am.J.Obstet.Gynecol. perfused human cotyledon. -151: 387, 1985.
E. Kujansuu, P. thromboxane and J.Reprod.Fertil. 2:
and L. Myatt. Arachidonic acid Trophoblast Res. -2: 71, placenta.
10.
Armstrong, D.T. Prostaglandins perspectives -2: 6, 1986.
11,
Espey, L.L. hypothesis.
12.
Kuehl, F-A. Jnr, H.?'. Dougherty, and E.A. between prostaglandins and leukotrienes. -33: 1, 1984. Editor:
202
and ovulation.
Ovulation as an inflammatory Biol.Reprod. -22: 73, 1980.
H. Behrman
production of synthetase
Received:
Prostaglandin
response
- a
Ham, Interactions Biochem.Pharmacol. Accepted:
10-13-88
AUGUST
6 12-89
1989 VOL. 38 NO. 2