Function of beta 1 integrins on human decidual cells during implantation

In the present study, the effects of antibodies against specific beta 1 integrin heterodimers on mouse embryo attachment and spreading were tested to identify the role of the beta 1 integrins in early implantation. We developed assays for the attachment of mouse embryos and for trophoblastic spreading on cultured human decidual cells. Blastocysts became attached to the cultured decidual cells in the presence of a purified mouse monoclonal IgG1 antibody (negative control) after the embryos hatched from the zona pellucida. The majority of hatched blastocysts attached within 24 h of culture. Blastocysts that were attached to decidual cells exhibited extensive outgrowth after 48 h. The addition of antibodies directed against the beta 1 and alpha integrin subunits to the cultured decidual cells did not affect the rates of hatching or attachment of the blastocysts. However, the outgrowth of embryos on the decidual cells was inhibited by the addition of a monoclonal antibody against the beta 1 subunit in a dose-dependent manner, implying that blastocyst attachment and outgrowth are mediated by different mechanisms. Although the area of trophoblast outgrowth in the presence of a mouse monoclonal lgG1 antibody was increased during 96 h of culture, anti-beta 1 antibody blocked the outgrowth of trophoblasts in a dose-dependent manner. Both the incidence and extent of trophoblastic outgrowth were also significantly reduced in the presence of antibodies against the alpha 1, alpha 2, alpha 5, and alpha 6 subunits. These observations suggest that beta 1 integrins on decidual cells may be involved in blastocyst development and differentiation following attachment.

Regulation and function of an activation-dependent epitope of the beta 1 integrins in vascular cells after balloon injury in baboon arteries and in vitro

Migration and proliferation of endothelial cells (ECs) and smooth muscle cells (SMCs) contribute to the response to injury in damaged and atherosclerotic vessels. These events might be regulated by cellular interactions with extracellular matrix through the expression and activation of integrins. To study the functions of beta 1 integrins in the vessel wall, we used monoclonal antibody (MAb) 15/7, which recognizes an activation epitope of beta 1 integrin subunits, and MAb 8A2, which induces a high affinity form of beta 1 integrins recognized by MAb 15/7. Immunohistochemical analyses were done on samples of normal baboon saphenous arteries and from arteries subjected to balloon injury. EC and SMC expressed the activation epitope of beta 1 integrin in uninjured arteries. By contrast, in balloon-injured arteries 6 weeks after injury, regenerating EC did not express the activation epitope, and there was no decrease in the expression of total beta 1 integrin, whereas SMC migrating into the intima exhibited decreased expression of the total and activated beta 1 integrin. Flow cytometer analysis of cultured cells indicated that baboon EC and SMC weakly express the activation epitope of beta 1 integrin. Next, we determined by utilizing MAb 8A2 the effects of increased expression of activation epitope of beta 1 integrin on the functions of SMC and EC. The activation of beta 1 integrins on SMC induced by MAb 8A2 enhanced SMC adhesion and suppressed SMC migration in a Boyden chamber assay. SMC proliferation was inhibited by MAb 8A2 dose-dependently. Similarly, MAb 8A2-induced activation of beta 1 integrins on EC suppressed EC migration into a wound. However, MAb 8A2 did not affect the basic fibroblast growth factor-induced proliferation of EC, although it blocked the decrease in EC number caused by the removal of basic fibroblast growth factor. These results suggest that activation of beta 1 integrins in vascular cells is regulated in a cell-type dependent manner and plays an important role in modulating vascular cell functions.

Regulation of vascular smooth muscle cell migration and proliferation in vitro and in injured rat arteries by a synthetic matrix metalloproteinase inhibitor

Smooth muscle cell (SMC) migration and proliferation and extracellular matrix remodeling are essential aspects of the arterial response to injury, vessel development, and atherogenesis. Matrix metalloproteinase (MMP) expression is associated with SMC proliferation and migration after arterial injury. To assess the role of MMPs in SMC proliferation and migration and intimal thickening, we measured the effect of the synthetic MMP inhibitor BB94 (Batimastat) on DNA synthesis and migration of SMCs in vitro as well as the formation of a neointima after balloon injury to the rat carotid artery. BB94 dose-dependently inhibited SMC migration induced by platelet-derived growth factor (PDGF)-BB through a filter coated with a thick basement membrane matrix (Matrigel) layer but did not show any inhibitory effect on SMC migration through a lightly coated filter. At concentrations up to 1 mumol/L, BB94 did not alter DNA synthesis induced by PDGF-AA or PDGF-BB. Treatment with 30 mg BB94.kg-1.d-1 IP for 7 or 14 days after balloon injury to the rat carotid artery decreased the total number of intimal SMC nuclei and suppressed intimal thickening. SMC proliferation (5-bromo-2'-deoxyuridine labeling) was decreased in the media at 2 days, whereas it was increased in the intima at 7 but not 14 days. These results suggest that BB94 inhibits intimal thickening after arterial injury by decreasing SMC migration and proliferation and support the conclusion that MMPs play a significant role in regulating intimal thickening in injured arteries.

Morphology and biodegradability of a binary blend of poly((R)-3-hydroxybutyric acid) and poly((R,S)-lactic acid)

The miscibility, morphology, and biodegradability of a binary blend of bacterial poly((R)-3-hydroxybutyric acid)(P((R)-3HB);Mn = 300,000) with atactic poly((R,S)-lactic acid)(P((R,S)-LA);Mn = 9,000) were studied by means of differential scanning calorimetry, optical microscopy, scanning electron microscopy, and hydrolysis with an without enzyme. Differential scanning calorimetry revealed that a P((R)-3HB)-P((R,S)-LA) blend had a single glass-transition temperature for all proportions of the components. The spherulites of P((R)-3HB) were volume filled in the blend films, indicating the inclusion of amorphous P((R,S)-LA) within the spherulites. The spherulitic growth rate decreased with an increase in the content of P((R,S)-LA). These results indicate that the P((R)-3HB)-P((R,S)-LA) blend is miscible in the melt and in the amorphous state. The enzymatic hydrolysis of P((R)-3HB)-P((R,S)-LA) blend films was carried out at 37 degrees C for 19 h in 0.1 M potassium phosphate buffer (pH 7.4) with an extracellular poly(hydroxybutyrate) depolymerase from Alcaligenes faecalis T1. The rate of enzymatic surface erosion decreased with increasing P((R,S)-LA) content in the blend films. The simple hydrolysis of P((R)-3HB)-P((R,S)-LA) blend films without enzyme was also conducted at 37 degrees C in a 0.01 M potassium phosphate buffer (pH 7.4) for 150 days. The hydrolytic scission of P((R)-3HB) polymer chains was accelerated by blending with P((R,S)-LA). However, the rate of enzymatic hydrolysis was much faster than the rate of nonenzymatic hydrolysis.

[A successful surgical replacement for mitral regurgitation after cardiac arrest due to widely ruptured chordae tendineae]

A 47-year-old woman, who has mitral regurgitation previously diagnosed in another hospital, was transferred to our intensive care unit for acute congestive heart failure. Just after admission, her respiratory state became worse and she suddenly fell into cardiac arrest. Five minutes later she recovered through cardiopulmonary resuscitation. The pulmonary artery pressure, however, which reached 85/43 mmHg with a Swan-Ganz catheter, had been exceeding systemic pressure. On echocardiography ruptured chordae tendineae of the mitral anterior leaflet was most suspected. Five days after the intensive treatment with a use of IABP, we operated upon her. On the operative findings most rough zone chordae of both leaflets including two strut chordae were ruptured with severe prolapsing. Thus we chose prosthetic valve replacement rather than mitral valve repair. We replaced the mitral valve with a Carbomedix 25 mm. Postoperatively the mean pulmonary artery pressure remained still high as 40 mmHg. With a continuous intravenous administration of prostaglandin E1, the pulmonary artery pressure became lower gradually. The patient was able to wean from respirator on the 18th postoperative day. The patient was discharged on the 49th postoperative day. The mitral valve removed at operation showed myxomatous degeneration and idiopathic ruptured chordae tendineae on the pathological examination. In summary a 47-year-old woman underwent mitral valve replacement 5 days after cardiac arrest from acute severe mitral regurgitation due to widely ruptured chordae tendineae of both leaflets. She survived the operation and got well. The mitral valve showed myxomatous degeneration on pathological examination.

Stable and general-purpose chemiluminescent detection system for horseradish peroxidase employing a thiazole compound enhancer and some additives

A stable and highly sensitive chemiluminescent detection system for horseradish peroxidase (HRP)/luminol/hydrogen peroxide using a newly designed thiazole compound enhancer has been established. Some additives for the chemiluminescent reaction were explored to overcome some defects of the reaction such as rapid decay and high background of light emission. Recrystallization of luminol and the addition of several detergents into the reacting solution were effective to increase specific light emissions. The addition of skim milk into the reacting solution reduced the background. Consequently, skim milk combined with a detergent increased the signal to noise ratio about 20 times compared with the reactions in the absence of both additives. The optimal concentration of enhancer and the addition of egg albumin stabilized the emission. In the new method, 6x 10(-18) mol of HRP was detectable. This would be the most sensitive enhanced chemiluminescent detection system for HRP. Furthermore, we could detect picogram per milliliter (10(-17) mol) concentrations of a trace component in biological materials such as endothelin-1 by employing this reaction.

In vitro fertilization and development of immature and mature bovine oocytes cryopreserved by ethylene glycol with sucrose

Immature and mature bovine oocytes were frozen slowly in 1.8 M ethylene glycol (EG) with different concentrations of sucrose (0, 0.1, and 0.2 M). After thawing and dilution of the cryoprotectant by a one-step procedure, the survival of the oocytes was assessed morphologically and also by in vitro fertilization and culture. Sucrose had no effect on the survival and fertilization rates of frozen-thawed oocytes. However, higher cleavage rates of frozen-thawed immature oocytes were obtained with 0.2 M sucrose used in combination with EG. Moreover, none of the immature oocytes frozen in EG without sucrose developed into blastocysts, but about 1% of immature oocytes frozen with sucrose developed into blastocysts. The cleavage rates of mature oocytes frozen in EG were significantly lower with sucrose than without sucrose. However, no significant difference was observed in the development to blastocysts. Transfer of four blastocysts derived from frozen-thawed immature oocytes into two recipient heifers resulted in one pregnancy.

The effects of clonidine and tizanidine on responses of nociceptive neurons in nucleus ventralis posterolateralis of the cat thalamus

The effects of intravenous clonidine and tizanidine on nociceptive neurons in the nucleus ventralis posterolateralis (VPL) of the thalamus, a key station in the lateral system of ascending pain pathways, were evaluated in urethane-chloralose anesthetized cats. Intravenous clonidine and tizanidine produced a dose-dependent (5 and 10 micrograms/kg, and 25 and 50 micrograms/kg, respectively) suppression of responses of nociceptive specific (NS) and wide dynamic range (WDR) neurons in the VPL to high threshold splanchnic input. In contrast, the responses of both NS and WDR units to electrical stimulation of spinothalamic tract fibers in the ventrolateral funiculus (VLF) were little affected. We conclude that a site of suppressive action of the alpha 2-adrenoceptor agonists, as observed in nociceptive VPL neurons, is at the level of the spinal dorsal horn rather than in the VPL itself.

Mechanism of angiogenic effects of saponin from ginseng Radix rubra in human umbilical vein endothelial cells

1. The effects of saponin from Ginseng Radix rubra on angiogenesis (tube formation) and its key steps (protease secretion, proliferation and migration) in human umbilical vein endothelial cells (HUVEC) were examined to elucidate the mechanism of the tissue repairing effects of Ginseng Radix rubra. The effect on a wound healing model was also studied. 2. Tube formation was measured by an in vitro system. The activity and immunoreactivity of tissue-type plasminogen activator (tPA) as a protease for angiogenesis and the immunoreactivity of its inhibitor, plasminogen activator inhibitor-1 (PAI-1), were measured in conditioned medium of HUVEC stimulated for 24 h with saponin. Cell proliferation was measured by counting the cell numbers at 2-7 days after seeding. Migration was measured by Boyden's chamber method. The effect on wound healing was studied in the skin of diabetic rats. 3. Saponin at 10-100 micrograms ml-1 significantly stimulated tube formation by HUVEC in a dose-dependent manner. Saponin in a similar concentration-range increased the secretion of tPA from HUVEC as estimated by immunoreactivity and enzyme activity. On the other hand, PAI-1 immunoreactivity was slightly increased at 10 micrograms ml-1 of saponin, but then was significantly decreased at 50 and 100 micrograms ml-1. Cell proliferation was only slightly enhanced by 1-100 micrograms ml-1 of saponin, but migration was significantly enhanced by 10-100 micrograms ml-1 in a dose-dependent manner. Moreover, saponin stimulated wound healing with enhanced angiogenesis in vivo. 4. These results indicate that saponin stimulates tube formation mainly by modifying the balance of protease/protease inhibitor secretion from HUVEC and enhancing the migration of HUVEC, and that it is effective in vivo.

Failure of heparin to inhibit intimal hyperplasia in injured baboon arteries. The role of heparin-sensitive and -insensitive pathways in the stimulation of smooth muscle cell migration and proliferation

BACKGROUND

Heparin is a potent inhibitor of smooth muscle cell (SMC) growth and intimal hyperplasia in animal models but has been ineffective in inhibiting restenosis in humans. This difference may relate to flaws in clinical study design or, alternatively, to interspecies differences in SMC response to heparin. To determine whether heparin could inhibit intimal hyperplasia in a species more closely related to humans, we studied the effect of a low-molecular-weight heparin (LMWH) on baboon SMC proliferation and migration in culture and in arteries subjected to experimental angioplasty.

METHODS AND RESULTS

LMWH or saline was infused continuously after experimental angioplasty of baboon peripheral arteries (six animals per group). After 28 days, bromodeoxyuridine (BrdU) was given to label proliferating cells, and balloon-injured arteries were perfusion-fixed in situ and removed for analysis. All arteries had reendothelialized (Evans blue dye exclusion). LMWH increased partial thromboplastin time (LMWH, 81.7 +/- 8.4 seconds versus saline, 34.7 +/- 0.8 seconds [mean +/- SEM]; P = .004) but failed to inhibit intimal thickening or SMC proliferation (intimal area: LMWH, 0.19 +/- 0.03 mm2 versus saline, 0.21 +/- 0.03 mm2; BrdU labeling: LMWH, 2.9 +/- 0.6% versus saline, 2.4 +/- 0.4%; P = NS). In culture, LMWH and standard heparin (100 micrograms/mL) significantly inhibited serum-induced but not platelet-derived growth factor (PDGF-BB)-induced SMC proliferation (% control, serum: LMWH, 60.5 +/- 4.0%, P = .0002; standard heparin, 29.4 +/- 8.2%, P = .0001; % control, PDGF-BB: LMWH, 117.7 +/- 11.3%, P = NS; standard heparin, 90.9 +/- 14.4%, P = NS) and SMC migration (% control, serum: LMWH, 15.3 +/- 1.9%, P = .0198; standard heparin, 26.4 +/- 13.8%, P = .0032; % control, PDGF-BB: LMWH, 98.5 +/- 14.3%, P = NS; standard heparin, 100.0 +/- 13.5%, P = NS).

CONCLUSIONS

LMWH failed to inhibit intimal hyperplasia in a baboon angioplasty model. Furthermore, LMWH blocked serum-induced but not PDGF-BB-induced SMC proliferation and migration in culture. Thus, heparin-sensitive and -insensitive pathways exist for SMC activation. The relative importance of each pathway induced by injury may vary between species and thus account for different responses to heparin.

Relationship between functional levels and movement in tetraplegic patients. A retrospective study

The aim of the present study was to set targets for each spinal lesion level after determining the relationship between the spinal lesion level and movement abilities in patients with tetraplegia following injury to the cervical cord. A total of 109 patients, 96 men and 13 women were included in the study. We mainly examined locomotion and transfer capabilities according to Zancolli's classification. The results of this study showed that 50% of the patients classified as C6A, 75% of C6B1 and 96% of the patients classified C6B2 accomplished bed transfer. The number of patients who could manage toilet transfer was 53% in the group classified as C6B1 and 85% in group C6B2. These results suggest that achievement of those classified as C6B2 is a clue to the assumption that the patient will achieve toilet transfer capability and can perform ADL independently.

Differential inhibitory mechanisms in VPL versus intralaminar nociceptive neurons of the cat: I. Effects of periaqueductal gray stimulation

Nociceptive thalamic units receiving afferent input from the greater splanchnic nerve (SPL) were recorded from the nucleus ventralis posterolatealis (VPL) and intralaminar nuclei in urethane-chloralose anesthetized cats. The effects of stimulating the periaqueductal gray (PAG), or the nucleus raphe dorsalis (NRD) on responses of nociceptive thalamic units were investigated. Forty-eight nociceptive specific (NS) and 20 wide dynamic range (WDR) units with SPL input were found in the shell region of the caudal VPL. Following electrical stimulation of either the ventral PAG or the NRD, responses to SPL input were inhibited in all NS and WDR units tested. Responses of these units to electrical stimulation of spinothalamic tract fibers in the ventrolateral funiculus (VLF) were also inhibited following the PAG/NRD stimulation. These results suggest that PAG/NRD stimulation-produced inhibition of both NS and WDR units may be partially mediated by an ascending antinociceptive mechanism. Intralaminar nociceptive units with SPL input were found in the nuclei centralis lateralis (CL), paracentralis (Pc), and parafascicularis (Pf). The effects of conditioning electrical stimulation of either the ventral PAG or the NRD on responses of intralaminar nociceptive units were studied. Of 113 intralaminar nociceptive units studied, 68 units were unaffected, 23 units were excited and 22 units were inhibited following the conditioning stimulation. In the units in which responses to SPL stimulation were inhibited, responses elicited by electrical stimulation of the mesencephalic reticular formation (MRF) were also inhibited. These data suggest that although there is an ascending inhibitory pathway from PAG/NRD to intralaminar nuclei, this system is far less potent compared with the ascending inhibitory system acting upon the VPL.

Differential inhibitory mechanisms in VPL versus intralaminar nociceptive neurons of the cat: II. Effects of systemic morphine and CCK

In urethane-chloralose anesthetized cats, the effects of intravenous morphine on responses of thalamic nociceptive units were studied. In both nociceptive specific (NS) and wide dynamic range (WDR) units recorded from the nucleus ventralis posterolateralis (VPL), intravenous morphine suppressed unit responses to the greater splanchnic nerve (SPL) stimulation, but had little effect on responses to stimulation of spinothalamic tract fibers in the ventrolateral funiculus. In nociceptive units recorded from nuclei centralis lateralis (CL) and parafascicularis (Pf) of the intralaminar nuclei, intravenous morphine suppressed responses to stimulation of the mesencephalic reticular formation as well as to SPL stimulation. Intravenous cholecystokinin (CCK) antagonized the suppressive action of morphine on responses of VPL units, but did not antagonize the suppressive action of morphine on responses of intralaminar units. The results suggest that intravenous morphine inhibits synaptic transmission of nociceptive impulses in the intralaminar nuclei as well as in the spinal cord, but not in the VPL, and that CCK antagonizes the antinociceptive action of morphine in the spinal cord, but not in the intralaminar nuclei.

Effects of beta-1 integrins in the process of implantation

The expression and function of beta 1 integrins on human decidual cells were investigated. Flow cytometric analysis revealed that the cultured decidual cells expressed a high level of the beta 1 subunit on the cell surface. Mouse blastocysts attached to and spread onto cultured human decidual cells. Attachment of the blastocysts was a necessary prerequisite for the further outgrowth of trophoblasts. The addition of a monoclonal antibody recognizing the beta 1 subunit to the cultured decidual cells did not affect the rates of hatching and attachment of blastocysts. The outgrowth of embryos on decidual cells was inhibited by the addition of the anti-beta 1-subunit antibody in a dose-dependent manner. Furthermore, exposure of decidual cells to the anti-beta 1-subunit antibody significantly inhibited the extent of outgrowth of trophoblasts, implying that blastocyst attachment and outgrowth is mediated by different mechanisms. These observations suggest that beta 1 integrins on decidual cells may be involved in the process of blastocyst development and differentiation after attachment.

Different functions of the platelet-derived growth factor-alpha and -beta receptors for the migration and proliferation of cultured baboon smooth muscle cells

Migration of medial smooth muscle cells (SMCs) and their proliferation in the intima contribute to thickening of injured and atherosclerotic vessels. These events have been proposed to be regulated in part by platelet-derived growth factor (PDGF). Two separate PDGF receptors have been identified, PDGF-R alpha and PDGF-R beta. To study the functions of PDGF-R alpha and PDGF-R beta in vascular SMCs, neutralizing monoclonal antibodies (mAbs) specific for each of the two receptors were used. These antibodies allowed us to evaluate the role of each receptor for PDGF-induced proliferation and migration of cultured baboon SMCs. Both PDGF-AA and PDGF-BB stimulated SMC growth, with PDGF-BB being more potent than PDGF-AA. Studies with anti-PDGF-R alpha and anti-PDGF-R beta mAbs revealed that both PDGF receptors promoted the stimulatory signals for proliferation. In contrast, PDGF-BB stimulated SMC migration, whereas PDGF-AA had no stimulatory activity on its own. Additionally, PDGF-AA was able to suppress migration induced by PDGF-BB or fibronectin in modified Boyden's chamber assay. When PDGF-BB-induced migration was separated into chemotactic and chemokinetic activities, only the chemotactic component was inhibited by PDGF-AA. The suppression of SMC migration by PDGF-AA was eliminated by anti-PDGF-R alpha mAb. In addition, PDGF-BB, in the presence of anti-PDGF-R beta, bound only to PDGF-R alpha and caused suppression of SMC migration induced by fibronectin. These results suggest that when activated by ligand binding, both PDGF-R alpha and PDGF-R beta stimulate proliferation. In contrast, only activation of PDGF-R beta stimulates migration, whereas ligand binding to PDGF-R alpha leads to inhibition of cell migration. These observations provide support for the conclusion that PDGF-R alpha and PDGF-R beta may play different roles in SMC function and may be involved in different regulatory mechanisms during vascular remodeling.

Effects of quality and developmental stage on the survival of IVF-derived bovine blastocysts cultured in vitro after freezing and thawing

Factors affecting viability of IVF-derived bovine blastocysts after freezing and thawing were investigated. A total of 1,101 ova matured and fertilized in vitro were cultured under 2 different conditions, 1) in TCM-199 on granulosa cell monolayers at 5% CO(2) in air and 2) in synthetic oviduct fluid (SOF) medium without somatic cell support at 5% CO(2), 5% O(2), 90% N(2). All blastocysts that developed from the 2 different culture systems were individually classified into 4 grades of embryo quality and were then frozen by conventional slow freezing. Developmental rates of the IVF-derived ova to blastocysts and the survival rates of the frozen-thawed blastocysts were not different between the SOF medium (16 and 49%) and the co-culture system (13 and 61%, respectively). Survival of frozen-thawed blastocysts was affected by embryo quality in both the SOF and co-culture systems (P<0.001). Blastocysts produced in vitro were also individually classified into 3 developmental stages and were then cultured for 3 d in the co-culture system with granulosa cells after freezing and thawing. There was a difference in the survival rate of frozen-thawed embryos between blastocyst developmental stages (early vs mid, P<0.05; mid vs expanded, P<0.01; early vs expanded, P<0.001). The post-thawing survival rate of blastocysts frozen at Day 7 (62%) of culture was higher compared with that of Day 8 (45%), but there was no difference in survival rate between Day 7 and 8 of culture. The results indicate that the quality and developmental stage of blastocysts are important factors influencing their survival after freezing and thawing.

Effect of surfactant lavage in a rabbit model of meconium aspiration syndrome

Meconium aspiration syndrome (MAS) is a frequent cause of respiratory distress in neonates. Recent reports have suggested that surfactant dysfunction contributes to the pathophysiology of MAS and surfactant therapy improves oxygenation of infants with MAS. We evaluated the effect of bronchial lavage with surfactant solution in a rabbit model of meconium aspiration. All animals were given 5 mL/kg of a 20% slurry of human meconium into the endotracheal tube and mechanically ventilated. The animals were then divided into saline lavage (n = 5) or surfactant lavage (n = 5). Lavage was performed an hour after meconium instillation. After the lavage the total amount of meconium recovered was measured. Blood gas was monitored during the experiment. The amount of meconium recovered by saline lavage was 14%, and by surfactant lavage was 57%. The surfactant group had a significant improvement in gas exchange, whereas the saline group had no improvement. It was concluded that the lavage with surfactant solution effectively washed out meconium and improved gas exchange in rabbit model of MAS.

Neuropathology of infant with Pena-Shokeir I syndrome

In an infant with clinical features of Pena-Shokeir I syndrome, who survived for 182 days, neuropathologic examination revealed little myelination in peripheral nerves with group atrophy of muscle fibers, dysplasia of inferior olivary and dentate nuclei, and leptomeningeal heterotopia. Congenital peripheral neuropathy associated with minor brain anomalies is characteristic in this patient, and may cause absence of fetal movements leading to ankylosis of multiple joints, absence of breathing in association with pulmonary hypoplasia, absence of swallowing causing polyhydramnios, and absence of movements of facial muscles causing craniofacial anomalies.

Evaluation of the efficacy of nicorandil in patients with ischemic heart disease by exercise Tl-201 myocardial SPECT

The effect of nicorandil on myocardial perfusion in ischemic heart disease was studied using exercise-load Tl-201 myocardial SPECT (Ex-SPECT). ExSPECT was carried out in 12 patients with previous myocardial infarction (OMI) and 9 with angina pectoris (AP) before and after administration of nicorandil 15 mg/day, for three or more weeks; %Tl uptake and the washout rate in infarcted or ischemic areas were calculated from short axial images using the Bull's eye method. In the OMI group, %Tl uptake and washout rates in the infarction areas improved significantly from 52.4% and 0.25 before nicorandil to 60.4% and 0.38 after nicorandil. In the AP group, too, %Tl uptake and washout rates showed a significant improvement from 56.9% and 0.10 before to 69.1% and 0.33 after administration of nicorandil. Six subjects who had not received the drug, and who showed negative washout rates, had high improvement rates when nicorandil was administered, suggesting that the drug could increase myocardial perfusion during exercise loading as well as suppressing coronary spasm. Ex-SPECT was carried out in 4 subjects before and after the administration of nicarandil and after subsequent surgical treatment (PTCA or CABG) and the effects of the two therapies were compared. The washout rate was improved from 0.01 to 0.34 by the administration of nicorandil, and a notable increase in coronary artery blood flow was achieved compared to the level after surgical treatment, i.e. 0.50. It is concluded that normal dosages of nicorandil have a powerful direct effect of dilating the coronary arteries without any influence on preload or afterload.

[A case of "familial" type cardiac myxoma]

We report a case of "Familial" type cardiac myxoma observed in mother and daughter. The mother had myxomas in the bilateral atrium, which were completely resected together with the peripheral tissue. Her first child (daughter) had myxoma in the outflow tract of the right ventricle. The wide range resection of tumor and tumor pedicle with the free wall of right ventricle and ventricular septum was tried, however, the resection range was limited for anatomical restriction. Cardiac echo, MRI and superhigh-speed CT are useful for detection of the site of tumor in presence, its mobility and the site to which the pedicle adhered and did not make us recognize necessity of cardiac catheter test. When "Familial" or "Complex" type lesion is suspected, it is necessary to investigate carefully other sites except a tissue with the tumor and the patient's family and recurrence after tumor resection.

A novel procedure for the preparation of biologically active recombinant peptides using a cyanylation reaction

A cysteine specific cleavage reaction was used for the preparation of biologically active peptides from recombinant fusion proteins. The fusion protein through cysteine was prepared by a recombinant DNA technology and then treated with cyanylating reagents such as 2-nitro-5-thiocyanatobenzoic acid (NTCB) and 1-cyano-4-(dimethylamino) pyridinium tetrafluoroborate (DMAP-CN) to release the desired product. As an example, we have selected a glucagon-like peptide 1 (7-37) (termed insulinotropin). We constructed an expression vector for a fusion protein in which insulinotropin and human basic fibroblast growth factor (hbFGF) mutein (abbreviated as CS 23) are connected by cysteine and then expressed it in Escherichia coli cells. The fusion protein, after refolding, was purified by heparin affinity chromatography, since CS23 has a strong affinity for heparin. The affinity-purified fusion protein was treated with NTCB or DMAP-CN to give crude insulinotropin, which was then purified by reversed phase (rp) high-performance liquid chromatography (HPLC). From various criteria such as amino acid analysis, amino acid sequence and the biological activity, the purified material obtained was found to be methionylated insulinotropin (Met-insulinotropin) with full activity. The specificity and simplicity of the present method make it versatile and convenient for the preparation of biologically active peptides.

Migratory and proliferative effect of platelet-derived growth factor in rabbit retinal endothelial cells: evidence of an autocrine pathway of platelet-derived growth factor

Angiogenesis is a crucial event in the progression of diabetic retinopathy. Migration and proliferation of endothelial cells (EC) are important steps in angiogenesis and are caused by angiogenic factors such as basic fibroblast growth factor (bFGF). In this work, capillary EC were isolated from rabbit retinal tissues and rabbit retinal EC (RREC) were found to secrete a migration factor for RREC in conditioned medium (CM). The activity was inhibited by an anti-platelet-derived growth factor (PDGF) antibody, but not by an anti-bFGF antibody. We also found that RREC showed a migratory response to PDGF. The response was induced by PDGF-BB and PDGF-AB dose dependently, but not by PDGF-AA, indicating that it was mediated by PDGF-beta receptor-dependent pathways, and that the PDGF-like factor was PDGF-BB or -AB. In addition, PDGF-BB induced the proliferation of RREC as well as bFGF. These data indicate that RREC have an autocrine pathway of PDGF by the secretion of and the response to PDGF. PDGF may play significant parts in angiogenesis in the progression of diabetic retinopathy.

Gonadotropin stimulates ovarian renin-angiotensin system in the rabbit

The present study was undertaken to assess the role of ovarian renin-angiotensin system (RAS) in the preovulatory cascade induced by gonadotropin exposure. In the in vitro perfused rabbit ovaries, exposure to human chorionic gonadotropin (hCG) enhanced the secretion rate of angiotensin II (Ang II) within 1 h. The secretion rate reached maximal levels at 6 h and then declined thereafter. The intrafollicular Ang II content and renin-like activity were also significantly increased at 2 and 4 h after exposure to hCG, compared with control ovaries perfused with medium alone. The level of intrafollicular Ang II after hCG exposure significantly exceeded the concentration of Ang II in an equivalent volume of plasma. The addition of 1 microM captopril to the perfusate significantly inhibited the secretion rate of Ang II stimulated by hCG; however, captopril affected neither the ovulatory efficiency nor prostaglandin production in ovaries treated with hCG. Captopril significantly inhibited the resumption of meiosis in the ovulated ova and follicular oocytes stimulated by hCG. The administration of 100 micrograms Ang II at 2-h intervals to the perfusate reversed the inhibitory effects of captopril on hCG-induced oocyte maturation. In conclusion, these data indicate that gonadotropin stimulates renin-like activity and Ang II production in the rabbit ovary. Ovarian renin-angiotensin system may play an important role in the process of oocyte maturation after exposure to gonadotropin.

Stimulatory effect of NH4+ on the transport of leucine and glucose in an anaerobic alkaliphile

An anaerobic alkaliphile, EP01, specifically requires NH4+ for the acceleration of amino acid and glucose transport [Koyama, N. (1988) FEBS Lett. 253, 187-189]. In this paper, we attempted to clarify how NH4+ is involved in the transport system. The bacterium acidifies the cytoplasm, which was suggested to result in NH4+ accumulation when NH4Cl was added to the medium. Increase of the NH4Cl concentration administered to the medium caused the acceleration of leucine and glucose transport, which was accompanied by an increase in the internal pH and the absolute internal concentration of NH4+, whereas a decrease in the concentration ratio of internal NH4+/external NH4+ was observed. The addition of 3 mM NH4Cl, which resulted in significant stimulation of leucine and glucose transport, raised the internal NH4+ concentration by 42 mM, but the internal pH only by 0.1 units. It seems more likely that leucine and glucose transport are accelerated depending on the increase in the internal NH4+ concentration rather than the increase in the internal pH. By the imposition of an inwardly directed Na+ gradient, the K(+)-loaded membrane vesicles accumulated leucine and glucose, indicating that a sodium chemical potential is available for active transport. The membrane of the bacterium exhibited a Na(+)-stimulated ATPase activity which was remarkably enhanced by the addition of NH4Cl, depending on its concentration, and was inhibited by vanadate. Leucine and glucose transport were inhibited by vanadate. Based on these results, we propose a mechanism in which NH4+ contributes internally to leucine and glucose transport, depending on its concentration, by the activation of a Na(+)-translocating ATPase responsible for the generation of a sodium chemical potential.

Locally produced angiotensin II induces ovulation by stimulating prostaglandin production in in vitro perfused rabbit ovaries

The present study was undertaken to investigate the role of exogenous and endogenous angiotensin II (Ang II) in ovarian steroidogenesis and production of prostaglandin (PG) in in vitro perfused rabbit ovaries. The addition of 100 or 10 micrograms Ang II at 2-h intervals to the perfusate did not stimulate progesterone production, but significantly stimulated estradiol (E2) production by perfused rabbit ovaries. When the specific antagonist of Ang II, saralasin at 2 x 10(-6) M, was added to the perfusate 30 min before the onset of Ang II administration, Ang II-stimulated production of E2 was significantly blocked. Ang II also significantly stimulated both PGE2 and PGF2 alpha production, while the addition of saralasin to the perfusate significantly inhibited the Ang II-stimulated production of PG. The levels of PGs in ovaries perfused with saralasin plus 100 micrograms Ang II did not differ significantly from those in control ovaries perfused with medium alone. Exposure to human CG (hCG) significantly stimulated production of progesterone and E2 by perfused rabbit ovaries, while the concomitant administration of 2 x 10(-6) M saralasin significantly reduced only E2 production. Addition of saralasin to the perfusate inhibited hCG-stimulated PG production in a dose-dependent manner. The ovulatory efficiency in ovaries treated with hCG alone or hCG plus saralasin was significantly correlated with PG production by perfused rabbit ovaries at 12 h after exposure to hCG. The production of PG stimulated by Ang II was completely reduced by indomethacin treatment during the entire perfusion period. Indomethacin completely blocked Ang II-induced ovulation, but not Ang II-stimulated oocyte maturation. Concurrent administration of staurosporine, a protein kinase C inhibitor, at 10(-6) M significantly inhibited Ang II-stimulated meiotic maturation of ovulated ova and follicular oocytes. In conclusion, these results indicate that Ang II has a direct role in ovarian production of E2 and PG. An intrinsic renin-angiotensin system in the rabbit ovary may act as an intermediary of gonadotropin-stimulated PG production. Locally produced Ang II may induce ovulation in the rabbit ovary, at least in part, by stimulating PG production.

Cytokines in the peritoneal fluid of patients with endometriosis

OBJECTIVE

To determine which of the various cytokines interleukin-5 (IL-5), interleukin-6 (IL-6) and interleukin-1 (IL-1) are important in endometriosis.

METHODS

Peritoneal fluid (PF) samples were taken from 55 women at the time of either laparotomy or laparoscopy, and were examined for the levels of IL-5, IL-6 and IL-1 using each cytokine specific sandwich enzyme-linked immunosorbent assay. Thirty-two patients had pelvic endometriosis, eight post-pelvic inflammatory disease, four advanced cancer, three adenomyosis, three benign ovarian tumor, and other diseases. Statistical analysis was performed with the Mann Whitney test, chi-square test or Fisher's test.

RESULTS

Both IL-5 and IL-6 levels in PF specimens with endometriosis tended to be higher than normal, while the same specimens were mostly interleukin-1 beta (IL-1 beta) negative. Of great interest was the negative correlation between log (IL-5) and IL-6 (Fisher's test, P < 0.04).

CONCLUSION

These findings support the concept that IL-5 and IL-6 but not IL-1 are associated with endometriosis.

Purification and characterization of an autocrine migration factor for vascular smooth muscle cells (SMC), SMC-derived migration factor

Migration of medial smooth muscle cells (SMC) into the intima is a key step in intimal thickening of atherosclerotic tissues. We previously reported that cultured SMC secrete a potent migration factor for SMC, named SMC-derived migration factor (SDMF). We purified this factor to homogeneity from 20 liters of serum-free conditioned medium of cultured rat aortic SMC by sequential heparin-Sepharose column, red-Sepharose column, TSK-heparin high performance liquid chromatography (HPLC) column, and Superose 6 HPLC column chromatographies. SDMF was found to be a 58-kDa polypeptide by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Reduction by mercaptoethanol caused only a slight decrease in its molecular mass to 53 kDa. Preparative isoelectric focusing revealed that SDMF is a basic protein with a pI of approximately 10. Purified SDMF enhanced the migration of rat SMC dose dependently, its maximal activity being 4 times that of platelet-derived growth factor-BB. In contrast, SDMF did not enhance the migration of endothelial cells from either human umbilical cord vein or rabbit retinal tissue. SDMF had no effect on the proliferation of SMC. These findings suggest that SDMF enhances SMC migration in vascular walls and that the autocrine system of SMC migration contributes to the formation of intimal thickening in atheroma formation.

Angiogenic effects of advanced glycation end products of the Maillard reaction on cultured human umbilical cord vein endothelial cells

The effects of advanced glycation end products (AGE) of the Maillard reaction on proliferation, migration and angiogenesis of cultured human umbilical vein endothelial cells (HUVEC) were studied. In an in vitro angiogenesis system, tube formation of HUVEC was dose-dependently stimulated by AGE at 0.5-50 micrograms/ml. Migration of HUVEC was also stimulated by AGE in a similar concentration range, and checkerboard analysis revealed that AGE were chemotactic but not chemokinetic. Proliferation of HUVEC was not affected by AGE. These data provide evidence that AGE are angiogenic.

Ascending inhibition of nociceptive neurons in the nucleus ventralis posterolateralis following conditioning stimulation of the nucleus raphe magnus

Recordings were made from neurons in the nucleus ventralis posterolateralis (VPL) of urethane-chloralose-anesthetized cats, following both noxious mechanical stimulation of the integument and electrical stimulation of the greater splanchnic nerve (SPL). The effects of stimulating the nucleus raphe magnus (NRM) on responses obtained from these units were investigated. Units responding to noxious mechanical stimulation of the integument with SPL input were found in the posterior shell region of the VPL. Responses elicited from these units by electrical stimulation of the SPL were inhibited following conditioning stimulation in or near the NRM. Inhibition could still be demonstrated after bilateral section of the dorsolateral funiculi at the level of C3-C4. Responses of these units to electrical stimulation of the ventrolateral funiculus (VLF) of the cervical cord were also inhibited following conditioning stimulation in or near the NRM. These results suggest that inhibition of these units produced by conditioning NRM stimulation may be partially mediated by an ascending pathway, in addition to the well-known descending spinal pathways. Glutamate stimulation of the NRM inhibited responses of nociceptive VPL units to SPL stimulation, but responses of the same units to VLF stimulation were little affected by the glutamate stimulation of the NRM. Inhibition of responses of nociceptive VPL units to SPL stimulation may be due to anti-dromic excitation of brainstem neurons having efferent connection with the NRM.

Increased platelet activating factor in the tracheal aspirates from neonates with patent ductus arteriosus

We investigated platelet-activating factor (PAF) in the tracheal aspirate from 3 intubated low birth weight infants with symptomatic patent ductus arteriosus (PDA). PAF increased with the onset of symptomatic PDA and decreased to the control range soon after the ductal closure. The concentration of PAF in 26 samples taken during symptomatic PDA (median 16 pg/micrograms lipid phosphorus, range 1.4-1,200 pg/micrograms lipid phosphorus) was significantly higher than that of 31 samples from the same three patients during the periods without symptomatic PDA (median 1.9 pg/micrograms lipid phosphorus, range 0-12 pg/micrograms lipid phosphorus; P < 0.001). All 3 infants later developed chronic lung disease. These results suggest that large shunting PDA provokes PAF release to the air way of the neonate and that PAF might play a role in chronic lung disease developing after symptomatic PDA.

Granulocyte elastase alpha 1-proteinase inhibitor complex measurement in very low birthweight infants with severe intraventricular hemorrhage

We investigated the relationship between the levels of granulocyte elastase alpha 1-proteinase inhibitor complex (E-alpha 1-PI) in plasma and severe intraventricular hemorrhage (IVH) in very low birthweight infants. The concentrations of E-alpha 1-PI and the ratio of the concentrations of E-alpha 1-PI to polymorphonuclear leucocyte counts within 24 h of birth in infants with severe IVH were significantly higher compared with those in infants without severe IVH. E-alpha 1-PI seems to be a useful indicator of IVH.

Effects of growth hormone on follicle growth, oocyte maturation, and ovarian steroidogenesis

OBJECTIVES

To assess the effects of GH on follicle growth, oocyte maturation, ovulation, and ovarian steroidogenesis.

DESIGN

In vitro perfused rabbit ovary.

INTERVENTIONS

The rabbit ovaries were perfused with medium alone, with GH at 1, 10, 100, or 200 ng/mL, or with 50 IU hCG for 12 hours.

MAIN OUTCOME MEASURES

The follicle diameter, the percent change in follicle diameter, the percentage of oocytes achieving germinal vesicle breakdown, and the production of P and E2 by the perfused rabbit ovaries.

RESULTS

The addition of GH to the perfusate increased the follicle diameter at 12 hours after perfusion in a dose-dependent manner. The percent change in follicle diameter in GH-treated ovaries did not differ significantly from that in hCG-treated ovaries at each time point of perfusion. However, ovulation did not occur in either the control ovaries or the experimental ovaries treated with GH. Exposure to GH at a concentration of > 10 ng/mL significantly stimulated the resumption of meiosis, as compared with the contralateral control ovaries. Although the concentration of P in the perfusate did not differ significantly between GH-treated and control ovaries, GH stimulated E2 production by the perfused rabbit ovaries in a dose-dependent manner.

CONCLUSIONS

Growth hormone acts on the rabbit ovary to stimulate follicle growth, oocyte maturation, and ovarian E2 production.

Nucleus ventralis posteromedialis neurons relaying somatosensory lingual input to the cerebral cortex in the cat

The cortical projection of somatosensory lingual units in the nucleus ventralis posteromedialis (VPM) of the thalamus was studied in urethane-chloralose anesthetized cats. Ipsilateral lingual units were recorded from the lateral subdivision of nucleus ventralis posteromedialis parvocellularis (VPMpcl). They were antidromically excited following electrical stimulation of the ventral aspect of the coronal gyrus or its caudally adjacent orbital gyrus. From these same cortical areas, positive surface potentials were recorded following electrical stimulation of the ipsilateral lingual nerve. Electrical stimulation of the same cortical areas elicited jaw opening movement. Contralateral somatosensory lingual units were recorded from the VPM proper. They were antidromically excited following electrical stimulation of the SI somatosensory cortex.

Electrophysiological study of dorsal column function in streptozocin-induced diabetic rats: comparison with 2,5-hexanedione intoxication

Dorsal column function and peripheral motor and sensory conduction velocities (MCV, SCV) were evaluated in experimental diabetic rats and compared with those in 2,5-hexanedione (2,5-HD) intoxicated rats. Hyperglycemia was induced by a single injection of streptozocin, and electrophysiological studies were performed 4 and 12 weeks after the injection. For 8 weeks 2,5-HD was administered daily by drinking water to make the 2,5-HD neuropathy rats. Age-matched rats were used as control. In diabetic rats, gracile surface potentials evoked by electrical stimulation of the lumbosacral trunk remained normal during the experimental period, whereas the N and P waves of the evoked potentials were suppressed and the duration of the N wave was prolonged in the 2,5-HD rats. In 4-week diabetic rats, the antidromic compound action potentials of the gracile tract recorded at the most proximal site of lumbosacral trunk were normal. In 12-week diabetic rats, the gracile tract conduction velocity (GTCV) was decreased, although the duration of these potentials was normal. By contrast, the GTCV was decreased and the duration was markedly prolonged in 2,5-HD rats. These findings might indicate that temporal dispersion of incoming volleys in the gracile tract is increased in 2,5-HD rats, but not in diabetic rats. These results suggest that diabetic myelopathy exists that but the magnitude and progression of this condition are quite different from those of 2,5-HD intoxication, typical dying-back-type neuropathy and that the dorsal column is less vulnerable than the peripheral nerve in diabetes mellitus.

Study of the efficacy of nicorandil in patients with ischaemic heart disease using Exercise-T1-201 myocardial tomography

The effect of nicorandil on myocardial perfusion in ischaemic heart disease has been studied using exercise-load T1-201 myocardial SPECT (Ex-SPECT). Ex-SPECT was carried out in 12 patients with previous myocardial infarction (OMI) and 9 with angina pectoris (AP) before and after administration of nicorandil 15 mg/day, for three or more weeks; % T1 uptake and the washout rate in infarcted or ischaemic areas were calculated from short axial images using the Bull's eye method. In the OMI group, % T1 uptake and washout rates in the infarction areas improved significantly from 52.4% and 0.25 before nicorandil to 60.4% and 0.38 after it. In the AP group, too, % T1 uptake and washout rates showed a significant improvement from 56.9% and 0.10 before to 69.1% and 0.33 after administration. Six subjects who had not received the drug, and who showed negative washout rates, had high improvement rates when nicorandil was administered, suggesting that the drug could increase myocardial perfusion during exercise loading as well as suppressing coronary spasm. Ex-SPECT was done in 4 subjects before and after nicorandil and after subsequent surgical treatment (PTCA or CABG) and the effects of the two therapies were compared. The washout rate was improved from 0.01 to 0.34 by administration of nicorandil, and a notable increase in coronary artery blood flow was achieved compared to the level after surgical treatment, i.e. 0.50. It was concluded that, normal dosages of nicorandil have a powerful direct effect of dilating the coronary arteries without any influence on preload or afterload.

Pulmonary surfactant apoprotein-A in neonates with different respiratory disorders

A serial determination of pulmonary surfactant apoprotein-A (SP-A) was made on tracheal aspirates from seven intubated infants with different types of respiratory failure in the first week of life. A two-site immunoassay with monoclonal antibodies was adopted to determine the SP-A concentration. The concentrations of albumin in the same samples were also assayed, and these data were expressed as the ratio of SP-A to albumin (SP-A/albumin ratio), and evaluated against clinical data such as the arterial-alveolar oxygen tension ratio (a/APO2) or ventilatory index. In infants with respiratory distress syndrome, the SP-A/albumin ratio was initially low, and increased gradually in the first few days of life with the improvement of a/APO2 and ventilatory index. The complication of pulmonary hemorrhage due to patent ductus arteriosus (PDA) resulted in a temporary decrease in the ratio. The infant with transient tachypnea of the newborn showed higher concentration from the first day of life and, in the course of PDA without pulmonary hemorrhage, the ratio did not decrease. The cases of congenital pneumonia showed the SP-A/albumin ratio remaining low while the infection was evident. These data suggest that the SP-A/albumin ratio of the tracheal aspirate can be used for the quantitative and qualitative evaluation of endogenous pulmonary surfactant in newborn infants with different respiratory disorders.

Regulatory effects of platelet-derived growth factor-AA homodimer on migration of vascular smooth muscle cells

Migration of medial smooth muscle cells (SMC) into the intima is important in intimal thickening of atherosclerotic tissues. To study the functions of three isoforms of platelet-derived growth factor (PDGF) in atherosclerosis, we investigated their effects on SMC migration by Boyden's chamber method. Although PDGF-AB and PDGF-BB enhanced SMC migration dose-dependently, PDGF-AA did not enhance SMC migration, but instead inhibited SMC migration induced by PDGF-AB or PDGF-BB. PDGF-AA also inhibited SMC migration induced by two other migration factors, fibronectin and SMC-derived migration factor. PDGF-AA is considered to be coexpressed with transforming growth factor (TGF)-beta 1 in atherosclerotic tissues. Treatment of SMC with TGF-beta 1 reduced an autocrine migration activity from SMC. Studies using anti-PDGF antibody revealed that an increased secretion of PDGF-AA by TGF-beta 1 caused the reduced migration activity. cAMP increase by forskolin and dibutyryl cAMP suppressed SMC migration, whereas cAMP decrease by pertussis toxin had no effects on PDGF-AA-suppressed migration. In contrast, staurosporine, an inhibitor of protein kinase C, enhanced SMC migration and neutralized the inhibitory effect of PDGF-AA. These findings suggest that PDGF-AA regulates SMC migration in intimal thickening in atheroma formation and that protein kinase C may play an important role in the inhibitory mechanism of PDGF-AA.

Possible involvement of leukotrienes in human luteal function

The present study was undertaken to assess the ability of human corpora lutea to produce leukotriene B4 (LTB4). The maximum capacity of luteal cells to secrete progesterone was attained on day 4, and both the basal production and the responsiveness to hCG decreased thereafter. In contrast, the production of LTB4 by cultured luteal cells was significantly reduced on day 4, but increased thereafter. The basal concentration of LTB4 produced by luteal cells varied from 75 to 590 pg/10(5) cells/2 days. LTB4 production appeared to decrease concomitantly with increased-progesterone production in cultured luteal cells. Exposure to hCG decreased significantly LTB4 production by cultured luteal cells on day 4. An inhibitor of the lipoxygenase pathway, nordihydroguaiaretic acid (NDGA), inhibited LTB4 production in a dose-dependent manner. However, NDGA did not affect basal progesterone production by the cultured luteal cells. A significant inverse relationship existed between the accumulation rates of progesterone and LTB4 in the luteal cells. Furthermore, the addition of LTB4 inhibited progesterone production in a dose-dependent manner in both the presence and absence of hCG. In conclusion, LTB4 could be synthesized by human corpora lutea in vitro, and correlated inversely with the secretion rates of progesterone. These data suggest that LTB4 produced locally in the corpus luteum may be an important regulator in human luteal regression.

Angiotensin II directly induces follicle rupture and oocyte maturation in the rabbit

To investigate the possible direct involvement of angiotensin II (Ang II) in ovulation and oocyte maturation, Ang II at 100 or 10 micrograms was administered at 2-h intervals in the in-vitro perfused rabbit ovaries. The addition of Ang II in the perfusate induced ovulation in vitro in the absence of gonadotropin, while ovulation did not occur in any contralateral control ovaries. However, the ovulatory efficiency in the Ang II-treated ovaries was significantly lower than in hCG-treated ovaries. Ang II significantly stimulated the meiotic maturation of ovulated ova and follicular oocytes. Concomitant addition of the specific receptor antagonist of Ang II, saralasin, 30 min before the onset of Ang II administration blocked Ang II-induced ovulation in a complete manner. Although saralasin did not inhibit completely hCG-induced ovulation and oocyte maturation, these results suggest that Ang II produced in the ovary may act locally in the process of ovulation.