The effects of betamethasone (BM) on endothelial nitric oxide synthase (eNOS) expression in adult baboon femoral arterial endothelial cells.

Glucocorticoids have significant effects on endothelium mediated vascular function throughout life. The baboon model has been used extensively to study cellular responses to glucocorticoids at several stages of the lifespan. Endothelial nitric oxide synthase (eNOS) is a major regulator of endothelium dependent arterial vasodilation. We have previously demonstrated that synthetic glucocorticoids down regulate eNOS in the baboon placenta. We have now conducted studies to determine whether glucocorticoids would alter eNOS expression in adult systemic vascular endothelial cells in this important animal model. We explored this potential mechanism in endothelial cells from femoral arteries of adult baboons at necropsy and cultured to the fourth passage. Endothelial cells were treated with 10-100nM betamethasone for 24h at 37 degrees C. Vascular endothelial growth factor (VEGF) was used as a positive control and medium as negative controls. The role of glucocorticoid receptor mediation in betamethasone-induced eNOS changes was investigated with the glucocorticoid receptor antagonist mifepristone. RNA (real-time quantitative RT-PCR) and protein (ELISA) were extracted and measured for eNOS. Expression and subcellular distribution of glucocorticoid receptor were detected with fluorescence labeled antibody microscopy. eNOS mRNA and protein in baboon endothelial cells were downregulated 25% by betamethasone treatment. This effect was attenuated by pre-incubation with mifepristone (P < 0.01). VEGF upregulated eNOS transcription and translation (P < 0.001), medium did not alter eNOS expression. We observed that mifepristone and VEGF increased glucocorticoid receptor cytoplasmic accumulation by fluorescence microscopy. We conclude that betamethasone can downregulate eNOS in cultured baboon endothelial cells via the glucocorticoid receptor pathway.

Passage-dependent changes in baboon endothelial cells--relevance to in vitro aging.

In vitro cell culture system is a useful model for aging-related changes in a wide spectrum of biomedical research. In this study, we explored the passage and donor age-dependent changes in baboon macrovascular endothelial cells that are relevant to both in vitro cell culture aging models and experiments using cell culture techniques. We collected baboon femoral arterial samples from nine baboons ranging in age from 6 months to 30 years (equivalent to humans approximately 18 months to 90 years of age). We then cultured baboon femoral artery endothelial cells (BFAECs) in standard DMEM medium with 20% fetal calf serum with 1:3 split for subculture. Endothelial functions were documented by morphology, Dil-LDL uptake and expression of eNOS, MCP-1, vWF, VCAM-1, ICAM-1, and E-Selectin with or without cytokine stimulation. Most of the cells became nonmitotic after 30 population doublings, or 10 passages, when they became flattened, enlarged, and senescent. While it took approximately 3 days to reach confluence from three-dilution seeding at early passages (<6), confluence was not achieved even after 7 days of culture for cells after the 9th or 10th passage. There was a linear decline in eNOS expression with passage. However, this decline was significantly less in endothelial cells from a young baboon (6 months) than those from an old baboon (30 years). While basal expression of adhesion molecules was not changed with passaging, responses to cytokine stimulation appeared to be increased in later passaged cells. Our study has provided evidence for passage-related changes in key endothelial functions. The donor age-related differences in this in vitro aging process suggests that in vitro endothelial culture can serve as a biomarker for in vivo aging. Nonhuman primates can provide a model for investigating such aging-related biological characteristics.

[Anaphylaxia induced by etoposide--a case report].

A 32-year-old woman, gravida 4, para 2, visited Teikyo University Hospital with complaints of abnormal uterine bleeding and lower abdominal pain. Urine hCG level was 1,024 x 10(3) IU/l. MRI examination showed a vascular, rich solid mass 10 cm in diameter at the posterior region of the uterus. Under the clinical diagnosis of choriocarcinoma, she underwent total hysterectomy with right salpingooophorectomy. The ovarian choriocarcinoma was confirmed by pathologic examination. Additional chemotherapy was planned using the combined regimen of etoposide, methotrexate, actinomycin D, cyclophosphamide and oncovin. After 2 min of etoposide administration (100 mg/m2), the patient complained of acute dyspnea, which was caused by bronchospasms and cutaneous flushing. Etoposide infusion was immediately stopped, and anti-anaphylaxic treatment was done by administering hydroxyzine hydrochloride. Five min after the episode had occurred, the patient recovered. This episode was thought to have been induced by etoposide, but etoposide was a key agent for choriocarcinoma. Thus, we devised a modified chemotherapy using etoposide as follows. The regimen was hydrocortisone 100 mg i.v. q6 h and promethazine hydrochloride 50 mg i.m. q6 h for 24 h before infusion of etoposide. The etoposide concentration was diluted to 50%, and the drug administration rate reduced by half. With the modified regimen, the patient showed no anaphylaxic symptoms. The few reports on anaphylaxic reactions to chemotherapeutic agents induced by side effects must be taken into account when we use these drugs.