Anti-A and anti-B titers, age, gender, biochemical parameters, and body mass index in Japanese blood donors.

It has been reported that anti-A and anti-B (ABO antibody) titers decrease with age, but little is known about the association between ABO antibody titers and physiologic/biochemical parameters such as body mass index (BMI), gamma-glutamyl transpeptidase (GGT), and total cholesterol (T-Cho). We investigated the present situation of ABO antibody titers among healthy blood donors in Japan and the physiologic/biochemical factors that may be associated with changes in ABO antibody titers. Plasma from 7450 Japanese blood donors was tested for ABO antibody titers using ABO reverse typing reagents by an automated microplate system; donor samples were classified into low, middle, and high titers according to the agglutination results obtained with diluted plasma samples. Multivariate regression analysis was performed to analyze the association between ABO antibody titers and age, gender, biochemical parameters (alanine transaminase [ALT], GGT, globulin, T-Cho, and glycosylated albumin [GA]), and BMI according to the ABO blood groups. A significant correlation between ABO antibody titers and age/gender, except for gender in anti-A of blood group B donors, was observed. BMI showed significant but negative correlations with anti-A and anti-B (ß = -0.085 and -0.062, respectively; p < 0.01) in blood group O donors. In addition, significant but negative correlations between GGT and T-Cho with anti-B of blood group A donors (ß = -0.055 and -0.047, respectively; p < 0.05) were observed. Although differences existed among the ABO blood groups, ABO antibody titers seem to be associated with physiologic and biochemical parameters of healthy individuals.

Regulation of the lysophosphatidylserine and sphingosine 1-phosphate levels in autologous whole blood by the pre-storage leukocyte reduction.

BACKGROUND AND OBJECTIVES: The effect of leukoreduction and storage periods on the accumulation of bioactive lysophospholipids and substances in human autologous blood (AB units) has not been fully investigated. MATERIALS AND METHODS: The accumulation of bioactive lysophospholipids such as sphingosine 1-phosphate (S1P) and lysophosphatidylserine (LysoPS) in AB units during the storage was investigated. The time-dependent changes and the effect of the filtration in pre-storage leuckoreduction (LR) and unmodified samples derived from 46 AB units were analysed. Additionally, the changes of lysophospholipids and platelet releasate, namely ß-thromboglobulin (ß-TG), induced by exposure of whole blood (WB) or platelet-rich plasma (PRP) to the filter material were analysed. RESULTS: LysoPS, but not S1P levels, time-dependently and significantly increased in both unmodified and LR samples. LysoPS significantly decreased in LR compared with unmodified samples, whereas S1P increased in LR compared with unmodified samples. In addition, exposure of WB and/or PRP to the filter material in vitro resulted in increased levels of S1P, LysoPS and ß-TG. CONCLUSIONS: LR effectively reduced the accumulation of LysoPS in AB units. On the other hand, it increased concentrations of S1P due to platelet activation by exposure to the filter material. These suggest that increases of S1P levels in LR and LysoPS in the unmodified samples were mainly caused by the leukocytes and/or platelets and that LR was effective in inhibiting the accumulation of LysoPS.

Impact of immunoreactive substances contained in apheresis platelet concentrate on postoperative respiratory function in surgical patients receiving platelet transfusion: a prospective cohort study.

OBJECTIVES: To construct an alternative policy for the donor selection of platelet concentrate (PC), a clinical study exploring the features of lung injury following PC administration is needed. BACKGROUND: Although a male-donor-only policy for plasma products appears to have efficiently reduced transfusion-related acute lung injury (TRALI), this policy may not be applied to PC because of supply shortages. METHODS AND MATERIALS: We prospectively examined pulmonary function after the transfusion of PC in informed surgical patients treated at a tertiary university hospital in Japan. The contributions of immunoreactive substances contained in the PC to respiratory function after PC transfusion was then statistically examined. RESULTS: Eighty-six patients (56 men, 30 women) were enrolled in the analysis. Fifty-four cases experienced respiratory failure (PaO2 /FiO2 <300 mmHg) after transfusion. Five cases were diagnosed as possible TRALI based on permeability pulmonary oedema, while 23 cases were diagnosed as transfusion-associated circulatory overload (TACO) based on chest radiograph findings. A multivariate logistic regression analysis identified the presence of anti-granulocyte antibody as a significant predictor of possible TRALI [P = 0.023; odds ratio (OR), 13.0; 95% confidence interval (CI), 1.4-118.3]. Meanwhile, anti-leukocyte antibody class II was identified as a significant independent predictor of TACO (P = 0.010; OR, 18.4; 95% CI, 2.0-170.1). CONCLUSIONS: Our data suggest that antibodies contained in PC may contribute to the deterioration of respiratory function after PC transfusion, although the diagnoses of TACO and TRALI may have overlapped among the patients with pulmonary distress in this cohort.

Adenosine differentially amplifies luteinizing hormone- over follicle-stimulating hormone-mediated effects in acute cultures of rat granulosa cells.

Adenosine has been shown to acutely amplify LH-dependent events in luteal cells and FSH-dependent events in granulosa cells. In this study, the specificity of purines on mature rat granulosa cell ATP levels in short term culture was assessed, and a comparison of the relative effect of adenosine on amplification of FSH- and LH-stimulated cAMP accumulation was made. Adenosine rapidly and significantly increased ATP levels in granulosa cells. This effect was maximal (approximately 2-fold) within 60 min of culture and occurred in the absence or presence of FSH or LH. The increase in granulosa cell ATP levels by adenosine was dose dependent, with half-maximal and maximum responses of 10 and 30 microM adenosine, respectively. Dipyridamole (10 microM), a purine transport inhibitor, blocked the adenosine-dependent increase in granulosa cell ATP levels. Adenosine and 5'-AMP were equipotent in increasing cell ATP levels; adenine also increased ATP levels, but was significantly less active (approximately 50% of adenosine), whereas hypoxanthine, inosine, and xanthine were inactive. FSH was consistently found to decrease granulosa cell ATP levels by about 30% in the absence or presence of adenosine, whereas LH had no effect on cell levels of ATP. Both FSH and LH significantly stimulated cAMP accumulation in granulosa cells, but the maximal response to FSH was substantially greater than that to LH. Adenosine significantly amplified cAMP accumulation in response to both FSH and LH, but the effect of adenosine on this response to FSH was modest. Amplification by adenosine of cAMP accumulation in response to LH was substantial and about 2- to 3-fold greater than that seen with FSH. These studies show that purines acutely and specifically increase ATP levels in rat granulosa cells. Since adenosine augments LH-dependent cAMP accumulation to a greater extent than FSH-stimulated cAMP production, we suggest that adenosine may favor premature follicular luteinization and, perhaps, function as a mediator of atresia in the developing follicle.

Transport and selective utilization of adenosine as a prosubstrate for luteinizing hormone-sensitive adenylate cyclase in the luteal cell.

The objective of the present studies was to examine adenosine uptake in the rat luteal cell, to characterize the cellular products after uptake, and to assess the role of adenosine transport and conversion to cAMP in amplification of LH-stimulated cAMP accumulation. Adenosine uptake showed an apparent Km of 7.3 +/- 0.6 microM, and a maximum velocity of 2.2 +/- 1.4 pmol/min X 10(5) cells at 24 C; uptake was temperature dependent (Q10 = approximately 3) and inhibited by dipyridamole (IC50 = 7 microM). Radiolabeled adenosine uptake was inhibited by AMP (IC50 = 14 microM), ATP (IC50 = 16 microM), guanosine (IC50 = 20 microM), inosine (IC50 = 22 microM), ADP (IC50 = 26 microM), and theophylline (IC50 = 5 mM); no inhibition by adenine, hypoxanthine, xanthine, prostaglandin F2 alpha (PGF2 alpha), PGE2, or LH was seen. Cellular products of radiolabeled adenosine uptake were found primarily in the trichloroacetic acid-soluble fraction (88%), and 90% of the radioactivity in this fraction comigrated with adenine nucleotides on electrophoresis; time-dependent incorporation of radioactivity into RNA, DNA, and protein was also seen. Adenosine transport did not appear to be related to the functional state of the luteal cell; for example, no change in the characteristics of uptake was seen in cells obtained from hypophysectomized animals or in cells incubated directly with PGF2 alpha or LH. Adenosine increased cell ATP levels in a dose-dependent manner in parallel with amplification of LH-stimulated cAMP accumulation. A substantial proportion of the total cAMP produced by the cells was derived from extracellular adenosine (40-90%). This response was directly related to the concentration of adenosine, and LH increased the magnitude of cAMP derived from adenosine by about 2-fold. Based on the present studies, adenosine uptake in the luteal cell appears to occur by a dipyridamole-sensitive, phosphorylation-dependent transport system which is independent of pituitary hormones or PG regulation. Moreover, amplification of LH-dependent cAMP accumulation by adenosine appears to be primarily a mass effect due chiefly to utilization of extracellular adenosine by the cell as a prosubstrate for conversion into cAMP by adenylate cyclase.

The association between granulosa cell aromatase activity and oocyte-corona-cumulus-complex maturity from individual human follicles.

The steroidogenic capability of granulosa cells isolated from 12 preovulatory human follicles was correlated with the stage of maturation of the corresponding oocyte-corona-cumulus-complex ( OCCC ). Individual follicles from human menopausal gonadotropin (hMG) stimulated cycles were aspirated 36 h after administration of hCG. Granulosa cells were cultured for 150 min and corresponding OCCC were evaluated for maturity before fertilization with human sperm. Granulosa cell aromatase activity was measured using 1 beta-3H-testosterone as substrate by quantitating the amount of 3H2O produced. Progesterone production by the granulosa cells was measured as was follicular fluid levels of combined hCG and LH activity and FSH and PRL. Follicular fluid concentrations of combined hCG plus LH activity decreased somewhat while FSH levels increased as OCCC matured. PRL levels did not vary. Granulosa cell progesterone production did not change with maturity of OCCC . However, aromatase activity decreased as OCCC matured with levels from granulosa cells with immature OCCC vs. intermediate and mature OCCC of 260 +/- 148 vs. 129 +/- 53 (SE) pg E2/10(5) cells, respectively (P less than 0.07). Although granulosa cells responded variably to hMG stimulation from individual to individual, and the response was not predictable from peripheral serum estradiol levels, follicles isolated from the same patient had a definite diminution in aromatase activity with OCCC maturation. From these preliminary results, aromatase activity in immediately preovulatory granulosa cells declined as OCCC matured in hMG/hCG stimulated cycles.

Observations on the development of certain ascending inputs to the thalamus in rats. I. Postnatal development.

We have studied the postnatal development of the major ascending afferents to the thalamus in postnatal rats using tetramethylbenzidine histochemistry following wheat germ agglutinin-conjugated horseradish peroxidase injections into either the dorsal column nuclei, the deep cerebellar nuclei, or the inferior colliculus. By the day of birth, the efferents from each of these regions have already entered, and arborized extensively within, their appropriate thalamic relay nuclei. However, the overall distribution of each of these ascending afferent systems differs dramatically from that seen in mature rats. In neonatal rats, a substantial proportion of the ascending axons extend beyond the thalamus and often enter the internal capsule, some bypassing the thalamus altogether. In addition, some of the axons which enter and arborize within the thalamus extend beyond their appropriate terminal field into adjoining thalamic nuclei. Retrograde tracing experiments utilizing Fast blue indicate that the cells of origin of these overshooting axons are distributed similarly to the cells of origin of the definitive thalamic afferents. These early erroneous projections are all subsequently eliminated and the characteristically restricted adult distribution of each afferent system is evident by P30. These results indicate that developmental overgrowths and targeting errors of thalamic afferent fibers are not unique to the visual system (where they have been documented previously), but may be a general feature in the development of these pathways.

Complement system in abnormal pregnancy and chorionic neoplasia: immunotherapy and chemotherapy of chorionic neoplasia.

In normal pregnancy, the activity of the alternate pathway elevates latently and compensatorily for the suppression of cellular immunity. Aging of the placenta becomes a trigger for the onset of labor and production of C3-a. In cases of hydatidiform mole, abruptio placentae, threatened abortion, and chorionic malignancy, the activity of the complement system is depressed, especially that of C3-activator and alternate pathway. This may in turn result from activation of complement by the pathologic lesion of the chorionic villi. In pathologic lesions of the placenta, activation of alternate pathway can lead to a number of diseases. Immunotherapy is effective in the prevention of malignant transformation of hydatidiform mole. Immunotherapy and combination chemotherapy are markedly effective for treatment of metastatic chorionic malignancy.

More confined indications for use of combined passive and active immunization for preventing perinatal development of hepatitis B virus carrier-state--based on the natural history of hepatitis B virus-vertical transmission.

To find more confined criteria for use of passive and/or active immunization for preventing perinatal development of hepatitis B virus (HBV) carrier-state than maternal HBe antigenemia, maternal HBsAg-titers (R-PHA) around delivery and infantile HBeAg-titers-(EIA) are discussed. No children whose maternal HBsAg-titers around delivery were lower than 3(6) developed carrier-state in spite of maternal HBe antigenemia. In addition, at age 2 months serum HBeAg-titers of 6 children who had acquired persistent HBsAb were lower than 25, while those of 5 children who had developed carrier-state were higher than 70. These findings may contribute to the establishment of more confined indications for the administration of HBIG and/or HB vaccine to the children born to HBeAg-positive carrier women, saving not only HBIG and HB vaccine but all accompanied efforts of both patients and medical staff as well.

[A study on the uterine contractile effect of 16, 16-dimethyl-trans-delta 2-PGE1 methyl ester (ONO-802) (author's transl)].

Abortifacient effects of 16,16-dimethyl-trans delta 2-PGE1 methyl ester (ONO-802) were studied clinically. The uterine contractile effect of the agent was compared with those of PGF2 alpha and oxytocin (OXY) in the unanesthetized rabbit. 1. Intermittent intravaginal administration of ONO-802 was applied to 32 cases of legal abortion, 15 of missed abortion and 17 of hydatid mole. Eighty eight, 100 and 81 per cent of these patients resulted in abortion, respectively, with fewer side effects than those of natural PGs. 2. In the five groups of non- or pseudo-pregnant rabbits and those in their 7-9, 14-16 and 19-28 days in pregnancy, uterine contractile effects of these agents were assessed by both the contractile patterns and area of contractile curves of initial 5 minutes. The results are as follows: 1) In the non-pregnant rabbits, all of these agents revealed marked uterine contractile effect. 2) ONO-802 induced uterine contraction characterized by its wedge-shaped curves continued considerably longer than that induced by others. 3) ONO-802 revealed much stronger effect on uterine contraction in 7-9 day-of-pregnant rabbits. 4) Fourteen-16-day-of-pregnant rabbits were least influenced by the three agents as regards their uterine contraction in accordance with the highest progesterone levels in their sera among the three groups of pregnant rabbits.

[The effect of vasoactive intestinal peptide on the rat ovary].

In recent years, the localization and physiological significance of vasoactive intestinal peptide (VIP) in various organs have been studied. Investigations of the significance of VIP in the ovary have been done, but the detailed mechanism of action is still unknown. We made in vitro studies of VIP using rat ovaries. Ovarian granulosa cells were collected after treatment with estrogen in immature hypophysectomized rats. Luteal cells were collected from immature rats treated with pregnant mare serum (PMS) and human chorionic gonadotropin (hCG). These cells were cultured in a serum free medium for 48 hr in the absence or presence of various amounts of VIP. We determined the amount of steroids produced in the culture medium by specific RIA. Activities of 3 beta-HSD in the granulosa cells were determined by the amount of progesterone formed from labelled pregnenolone. Induction of LH-receptor in the granulosa cells by VIP and VIP-receptor in these cells was investigated. VIP stimulated estrogen and progesterone production dose and time dependently with an approximate ED50 value of 3 x 10(-8) M. The amount of cyclic adenosine monophosphate (c-AMP) was similarly increased. VIP enhanced 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity when incubated with the granulosa cells for 24 hours. VIP stimulated the granulosa cells in a way similar to follicle stimulating hormone (FSH), but the stimulating effect was slightly less than that of FSH. Unlike FSH, VIP did not induce LH-receptor. The binding of 125I-VIP with the granulosa cells was blocked, dose dependently, by unlabelled VIP, suggesting the presence of VIP-receptor in the granulosa cells. Another peptide, PHM-27, stimulated the granulosa cells although its potency was less than that of VIP. In contrast, gastrin, CCK and secretion did not stimulate the granulosa cells at all. According to the present study. VIP did not exert any effect on the luteal cells, and progesterone production in vitro was not stimulated by this peptide. The VIP effects seem to be at least partly c-AMP dependent and may be mediated through the VIP-receptor in the granulosa cells. The observed direct effects of VIP suggest that it may act as a local hormone to regulate the ovarian function.

[Combined passive and active immunization for preventing the development of the infantile carrier state in hepatitis B virus vertical transmission].

By applying hepatitis B (HB) immunoglobulin (HBIG) and HB vaccine (vaccine) to 43 infants born to HB e antigen (HBeAg)-positive HB surface antigen (HBsAg) carrier women intramuscularly, and sub-and/or intra-cutaneously, respectively, the clinical usefulness of combined passive and active immunization in preventing infantile development of the carrier state was evaluated. The results obtained in this study are summarised as follows: Of the 43 infants, 5 (11.6%) developed the carrier state and 38(88.4%) were persistent HBsAb-positive. This carrier-rate was found to be significantly lower than that of 78 non-treated infants (73.1%) born to HBeAg-positive carrier women (control). Four of 15 infants (26.7%), who received HBIG every 4 months, developed carrier state, while only one case (3.6%) fell into carrier state in 28 infants who received HBIG every 3 months. In 30 infants whose vaccination was started at 2 or 4 months of age, 93.3% of the cases became persistent HBsAb-positive within 12 months, while 76.9% of 13 infants who underwent the first vaccination at 12 months of age became persistent HBsAb-positive. No adverse effects of HBIG and HB vaccine were observed in this study. In addition, the mean values for serum glutamic pyruvic transaminase (SGPT) were 35 and 69mu/ml in the treated and control groups, respectively. Thus, the present study demonstrates that the infantile development of HBsAg carrier state by HB virus-vertical transmission could be safely, economically and easily prevented by early initiation of vaccination and re-administration of HBIG within 3 months.

Inhibition of rat ovarian 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), 17 alpha-hydroxylase and 17,20 lyase by progestins and danazol.

The site of action of synthetic progestins or danazol in the treatment of endometriosis is considered to be mainly the hypothalamo-pituitary level, but the direct action to the uterine endometrium and the ovary is also suggested. We investigated the effect of these synthetic steroids to rat ovarian steroidogenic enzymes. The effect of norethisterone, levonorgestrel, danazol, gestrinone, desogestrel and 3-keto-desogestrel was studied in vitro. The sources of the enzymes were prepared from ovaries of immature rats treated either with pregnant mare serum gonadotropin (PMS) and human chorionic gonadotropin (hCG) for 3 beta-hydroxy steroid dehydrogenase (3 beta-HSD), or with PMS for 17 alpha-hydroxylase and 17,20 lyase. The substrates used were pregnenolone (P5) for 3 beta-HSD, progesterone (P4) for 17 alpha-hydroxylase, and 17 alpha-hydroxy-progesterone (17 alpha-OH-P4) for 17,20 lyase. The substrates were incubated with the enzyme sources and coenzymes, and the products formed were measured. All the steroids inhibited 3 beta-HSD, and the inhibition by gestrinone (Ki = 3.0 microM) and 3-keto-desogestrel (17.5 microM) was particularly marked. Only desogestrel (Ki = 30.3 microM) and danazol (168 microM) inhibited 17 alpha-hydroxylase. All the steroids inhibited 17,20 lyase, and the inhibition by desogestrel (Ki = 0.70 microM), danazol (0.80 microM), and gestrinone (30 microM) was particularly marked.

Molecular genetics of transformer, a genetic switch controlling sexual differentiation in Drosophila.

The transformer gene is one of a set of regulatory genes that form the hierarchy controlling all aspects of somatic sexual differentiation in Drosophila melanogaster. The gene transformer occupies an intermediate position in this hierarchy. Analysis of this gene has allowed us to determine the mechanism by which it is regulated in a sex-specific manner and to examine the way in which the regulatory hierarchy is organized. The female-specific expression of the tra gene, previously inferred from genetic observations, is based on sex-specific alternative splicing of tra pre-mRNA and is not the result of sex-specific transcriptional activation. The female-specific RNA produced by this alternative splicing is the functional mediator of tra activity. Multiple genetic, molecular, and transformation experiments show that female-specific activation of genes or gene products occurs in the order Sex lethal greater than transformer greater than transformer-2 greater than doublesex greater than or equal to intersex greater than female differentiation. The results do not distinguish the level at which transformer might regulate the downstream gene transformer-2. Neither transformer nor any of the down-stream genes feedback on, or participate in, alternative splicing of transformer RNA. The mechanism by which Sex lethal regulates transformer splicing appears to be a repression of the use of one of a pair of splice acceptor sites.

[A prospective study of psychosomatic reaction to hysterectomy].

Psychosomatic reaction to hysterectomy was prospectively studied by means of psychological tests and a questionnaire. One hundred and twenty patients who had simple hysterectomy were examined before and as long as one year after operation. The mean score for A-state, a state anxiety scale, was high before operation and rapidly declined postoperatively. SRQ-D and CMI, which represent depressive and neurotic states, respectively, showed rather high scores before and 2 weeks after operation. Mean scores in these psychological tests declined to a plateau within 6 months after operation, and there were less psychological and physiological symptoms and there was improved physical activity, showing that most patients can over come psychosomatic problems caused by hysterectomy. A close correlation was observed between the results of psychological tests and the number of psychological symptoms. Forty patients with a high SRQ-D score showed abnormality in other scales. Psychosomatic disorders associated with hysterectomy are characterized by various symptoms but mainly by a depressive state. High SRQ-D patients were divided into three subgroups: A) the SRQ-D score is constantly high, B) the SRQ-D is high for the first several weeks, and C) the score increased after discharge. Patients in each subgroup showed signs of a characteristic personality. These results show the presence of a different psychosomatic approach to the patients personally.

Sexual transmission of hepatitis B surface antigen. Infection of husbands by HBsAg carrier-state wives.

The husbands of 68 hepatitis B surface antigen (HBsAg) carrier-state wives were tested for the presence of hepatitis B surface antibody (HBsAb) and antigen (HBsAg) to assess possible transmission of HBsAg. Eight (11.8%) of the 68 husbands gave negative results for HBsAg and 22 (32.4%) positive results for HBsAb. Furthermore, eight (26.7%) of 30 husbands with presumed HBsAg transmission from their wives developed acute viral hepatitis after marriage, and e antigen (eAg) was detected in the serum from all eight wives. Although HbsAg was not detected in specimens of sputum and cervical mucus of carrier-state women by reverse passive haemagglutination, it was detected in the vaginal discharge of women during days 1--6 of the menstrual cycle at a rate ranging from 20--60%. Thus, sexual transmission of HBsAg seems to occur, particularly if sexual contact takes place during or immediately after menstruation.

[Dopamine increases the ovarian progesterone synthesis of PMSG-treated rats by regulating 3 beta-HSD activity].

Little is known about the dopamine system in the ovary. The present study has been undertaken to investigate the effect of dopamine (DA) on the ovarian steroidogenic enzymes of pregnant mare serum gonadotropin (PMSG)-treated immature rats. Ovarian cells from PMSG-treated rats were cultured for 1-5 hours with or without DA, D1 agonists or bulbocapnine (Bul)(D1 antagonist). Progesterone (P) and estradiol (E2) in the media were assayed by specific RIAs. The enzyme activities were assayed by adding radioactive substrates in the media before incubation. DA and D1 agonists increased P in the media which was caused by the increment of 3 beta -hydroxysteroid dehydrogenase (3 beta -HSD) activity because cholesterol side chain cleavage enzyme (CSCC) activity showed no significant change. The stimulating effects of DA and DA agonists on P and 3 beta -HSD activity were inhibited by Bul. DA showed no effect on 17 alpha-hydroxylase activity. DA decreased 17.20 lyase activity, but this decrement was probably a non specific effect. DA alone did not affect the E2 level in the media and aromatase activity. The present results suggest that DA mainly stimulated 3 beta -HSD activity of the PMSG-treated rat ovary which regulated P synthesis.

The involvement of dopamine in the regulation of steroidogenesis in rat ovarian cells.

To investigate a role for dopamine (DA) in steroidogenesis in the rat ovary, ovarian cells of pregnant-mare-serum gonadotropin (PMSG)-treated rats were incubated with DA agonists, antagonists, adrenergic drugs and beta-blocker for 1 h. DA, norepinephrine (NE) and isoproterenol (Iso) increased the level of progesterone (P4) and cAMP in the conditioned medium. D1 agonists (SKF38393, SKF82526J, CY208-243) increased P4 secretion, while the D2 agonist, bromocriptine, showed no significant effect on P4 secretion. The effect of NE or Iso was inhibited by the beta-blocker propranolol (Pro), but was not suppressed by the D2 antagonist, domperidone. The effects of D1 agonists were suppressed by bulbocapnine (Bul), while neither Pro nor the D2 antagonist, domperidone, affected the levels of P4. The D1 receptor was demonstrated in the PMSG-treated rat ovary, and its Bmax was 1.33 fmol/mg tissue and the Kd was 0.357 nM. These results suggest that DA has a direct stimulatory effect on P4 secretion in PMSG-treated rat ovarian cells through they D1 receptor. The observed action may indicate a physiological role for DA in the regulation of ovarian functions in rats.