Erythropoietin and growth factors exhibit differential angiogenic potential in mouse heart.

BACKGROUND: The possible angiogenic effect of recombinant human erythropoietin (rHuEpo) and several possibly angiogenic cytokines such as basic fibroblast growth factor (bFGF), acidic fibroblast growth factor (aFGIF) and vascular endothelial growth factor (VEGF) was investigated in mouse heart. MATERIALS AND METHODS: Mice were divided into five groups (n = 7/group): A, control; B, rHuEpo-treated; C, (aFGF-treated); D, (VEGF-treated); E, (bFGF-treated). The antibody mouse anti-human CD31 was used to evaluate the vessels present in histological preparations. RESULTS: The results show a significant increase of the vessel number per optical field in the rHuEpo-treated, the bFGF-treated and the VEGF-treated animals compared to controls whereas aFGF did not show any significant angiogenic activity. CONCLUSION: Erythropoietin has a significant angiogenic effect in the mouse heart, similar to the effect of other angiogenic factors such as bFGF and VEGF whereas aFGF does not exhibit any effect.

Human leptin induces angiogenesis in vivo.

Leptin is an adipocyte-produced peptide, which plays a crucial role in the regulation of body weight. There is also evidence that leptin stimulates endothelial cell proliferation and the formation of capillary-like tubes in vitro. The disc angiogenesis system was used to measure the angiogenic effect of leptin in vivo. Discs containing 25, 50, 100 and 250ng/ml of leptin were implanted subcutaneously in Wistar rats, removed after a growth period of 7 and 14 days, and compared with spontaneous growth controls and with positive controls containing equivalent doses of vascular endothelial growth factor (VEGF). Discs were examined morphologically for stroma and vessel development and by immunohistochemistry for quantitative evaluation of angiogenesis. The specificity of the angiogenic effect of leptin was tested by blocking leptin with a polyclonal anti-leptin antibody. Leptin induced a significant level of angiogenesis in a dose-dependent manner both at 7 and 14 days, with a peak at the dose of 100ng/ml. The angiogenic activity of leptin was completely abolished by the anti-leptin neutralizing antibody. VEGF also induced significant dose-dependent angiogenesis at the same time points with a peak observed at a concentration of 100ng/ml. The angiogenic response to leptin was significantly higher at 7 days compared with VEGF but not at the 14-day time point. In conclusion, leptin has a specific angiogenic effect in vivo, which is dose- and time-dependent in a concentration range of 25-250ng/ml. This effect is equivalent to the angiogenic effect of VEGF but is evident earlier compared with VEGF.

Erythropoietin enhances angiogenesis in an experimental cyclosporine A-induced nephrotoxicity model in the rat.

1. Erythropoietin (EPO) is a hormone regulating the proliferation and differentiation of erythroid precursor cells. The hypothesis that haematopoietic and endothelial cells share a common haemanglioblast progenitor among others is based on the finding that both cell lineages express cell surface antigens, such as CD31 and CD34. 2. In the present study, we investigated the angiogenic potential of recombinant human erythropoietin on cyclosporine A (CsA)-induced nephrotoxicity in the rat kidney and compared it with the effect of basic fibroblast growth factor (bFGF), a well-known angiogenic factor. 3. Rats were divided into five groups: A (control), B (EPO treated), C (CsA treated), D (CsA + EPO treated) and E (CsA + bFGF treated). Mouse anti-human CD31 and CD34 antibodies were used to evaluate the kidney vessels present in histological preparations. 4. Glomerular and peritubular capillaries in Group B (EPO) were increased compared with the control (Group A; P < 0.05). Reduction of the same kidney vessels (glomerular and peritubular capillaries) in Group C (CsA; P < 0.05) compared with controls was observed, whereas in Groups D (CsA + EPO treated) and E (CsA + bFGF treated), capillaries were increased compared with Group C (CsA; P < 0.05). 5. Erythropoietin has a significant angiogenic effect in rat kidney with CsA-induced nephrotoxicity, similar to the effect of the other angiogenic factor bFGF.

The angiogenetic effect of intramuscular administration of b-FGF and a-FGF on cardiac muscle: the influence of exercise on muscle angiogenesis.

Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischaemic diseases, there are still many unanswered questions, including the method of administration, the correct dose of these factors, and the duration of the therapeutic approach. Exercise has also been suggested to induce neovascularizaiton in muscles. We evaluated the angiogenetic effects of the intramuscular administration of basic-fibroblast growth factor (b-FGF) and acidic-fibroblast growth factor (a-FGF) in rat heart, compared with rats who exercised daily. In conclusion, both the intramuscular administration of b-FGF and exercise increased significantly angiogenesis in the heart in contrast to the intramuscular administration of a-FGF, which was ineffective.

Serum leptin levels and their response during laparoscopic and open cholecystectomy.

We compared serum leptin responses during and after laparoscopic and open cholecystectomy, and assessed their correlation with the responses of inflammatory cytokines. Serum levels of leptin, interleukin-1alpha (IL-1alpha), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) were measured by an enzyme-linked immunoassay in 31 patients who underwent laparoscopic cholecystectomy and in 24 patients who underwent open cholecystectomy. Serum samples were obtained preoperatively, at 10 and 30 min after the commencement of surgery, and at 6 and 24 h after the operation. The cumulative responses of leptin, IL-1alpha, IL-6 and TNF-alpha to surgery were calculated and the associations between them were evaluated. Serum leptin levels were significantly increased at 24 h after both procedures. The serum leptin concentration at this time point and the cumulative leptin response were significantly lower after laparoscopic cholecystectomy than after open cholecystectomy. Changes in serum IL-1alpha, TNF-alpha and IL-6 concentrations showed similar kinetics in both groups, with postoperative IL-6 levels being consistently lower in the laparoscopic cholecystectomy group. Cumulative IL-6 and TNF-alpha responses were significantly lower after laparoscopic cholecystectomy than after open cholecystectomy. The cumulative responses of leptin, IL-1alpha and IL-6 correlated significantly with each other. Leptin may be involved in the systemic inflammatory response to surgical injury, and the postoperative leptin elevation and cumulative leptin response are significantly lower after laparoscopic cholecystectomy than after open cholecystectomy.

Evaluation of leptin, interleukin-1beta, tumor necrosis factor-alpha and vascular endothelial growth factor in serum and follicular fluids of women undergoing controlled ovarian hyperstimulation as prognostic markers of ICSI outcome.

BACKGROUND: Cytokines play an important but controversial role during ovarian folliculogenesis for the development of mature and fertilizable oocytes. In this study, leptin, interleukin-1beta (IL1beta), tumor necrosis factor-alpha (TNFalpha) and vascular endothelial growth factor (VEGF) in serum and follicular fluids (FF) of women undergoing ovarian hyperstimulation were evaluated as prognostic markers of the outcome of intracytoplasmic sperm injection (ICSI) cycles. MATERIALS AND METHODS: Ninety-five ICSI cycles were included in the study. The cytokines were measured in serum and FF samples with enzyme immunoassay methods. RESULTS: The cytokine concentrations in serum were not significantly correlated with the cytokine concentrations in FFs. Serum IL1beta was inversely-correlated with the number of retrieved oocytes. Serum TNFalpha was negatively-correlated with fertilization rate. In FFs, TNFalpha was positively-correlated with leptin. Leptin and VEGF in FFs were negatively-associated with pregnancy outcome. CONCLUSION: Leptin and VEGF concentrations in FFs may serve as prognostic markers of success after ovarian hyperstimulation and ICSI.

The angiogenetic effect of intramuscular administration of VEGF on muscle. The influence of exercise on angiogenesis.

UNLABELLED: Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischemic diseases, there are still unanswered questions including the method, doses or duration of therapeutic approach. We evaluated the angiogenetic effects of vascular endothelial growth factor (VEGF) on rat heart and gastrocnemius muscles when this was administered intramuscularly and compared them to those obtained from rats, which exercised daily. CONCLUSION: Both daily swimming exercise and intramuscular administration of VEGF increased angiogenesis in rat heart, even though exercise alone was the only one that increased angiogenesis quite significantly. The combined protocol (administration of growth factor and exercise) led to an increase of angiogenesis in cardiac muscles. In contrast, there was no effect on the lateral gastrocnemius muscle either by VEGF or exercise, whereas these together induced angiogenesis locally at the site of injection.