The offspring of diabetic mothers (ODM) have an increased risk of developing metabolic and cardiovascular dysfunction. However, few studies have focused on susceptibility to disease in offspring of mothers developing diabetes during pregnancy. We developed an animal model of late-gestation diabetic pregnancy and characterized metabolic and vascular function in the offspring. Diabetes was induced by streptozotocin (50 mg/kg, i.p.) in pregnant rats on gestational day 13 and partially controlled by twice-daily injections of insulin. At 2 months of age, ODM had slightly better glucose tolerance than controls (p < 0.05), however, by 6 months of age this trend reversed. Hyperinsulinemic-euglycemic clamp revealed insulin resistance in male ODM (p < 0.05). In 6-8 mo old female ODM, aortas showed significantly enhanced contractility to potassium chloride (KCl), endothelin-1 (ET-1) and noradrenaline (NA). No differences in responses to endothelin-1 and noradrenaline were apparent with co-administration of NG-nitro-L-arginine (L-NNA). Relaxation to acetylcholine but not nitroprusside was significantly impaired in female ODM. In contrast, males displayed no between group differences in response to vasoconstrictors while relaxation to nitroprusside and acetylcholine was greater in ODM compared to control animals. Thus, development of diabetes during pregnancy programs gender specific insulin resistance and vascular dysfunction in adult offspring.

. Newborn lamb coronary artery reactivity is programmed by early gestation dexamethasone before the onset of systemic hypertension. Am J Physiol Regul Integr Comp Physiol 289: R1169 -R1176, 2006. First published June 16, 2005 doi:10.1152/ajpregu.00369.2005.-Exposure of the early gestation ovine fetus to exogenous glucocorticoids induces organ-specific alterations in postnatal cardiovascular physiology. To determine whether early gestation corticosteroid exposure alters coronary reactivity before the development of systemic hypertension, dexamethasone (0.28 mg ⅐ kg Ϫ1 ⅐ day Ϫ1 ) was administered to pregnant ewes by intravenous infusion over 48 h beginning at 27 days gestation (term, 145 days). Vascular responsiveness was assessed in endotheliumintact coronary arteries isolated from 1-wk-old steroid-exposed and age-matched control lambs (N ϭ 6). Calcium imaging was performed in fura 2-loaded primary cultures of vascular smooth muscle cells (VSMC) from the harvested coronary arteries. Early gestation steroid exposure did not significantly alter mean arterial blood pressure or coronary reactivity to KCl, thromboxane A 2 mimetic U-46619, or ANG II. Steroid exposure significantly increased coronary artery vasoconstriction to acetylcholine and endothelin-1. Vasodilatation to adenosine, but not nitroprusside or forskolin, was significantly attenuated following early gestation steroid exposure. Endothelin-1 or U-46619 stimulation resulted in a comparable increase in intracellular calcium concentration ([Ca 2ϩ ]i) in coronary VSMC isolated from either dexamethasone-treated or control animals. However, the ANG II-or KCl-mediated increase in [Ca 2ϩ ]i in control VSMC was significantly attenuated in VSMC harvested from dexamethasone-treated lambs. Coronary expression of muscle voltage-gated L-type calcium channel ␣-1 subunit protein was not significantly altered by steroid exposure, whereas endothelial nitric oxide synthase expression was attenuated. These findings demonstrate that early gestation glucocorticoid exposure elicits primary alterations in coronary responsiveness before the development of systemic hypertension. Glucocorticoidinduced alterations in coronary physiology may provide a mechanistic link between an adverse intrauterine environment and later cardiovascular disease. calcium imaging; endothelium; endothelial nitric oxide synthase; fetal programming EXPOSURE OF THE EARLY GESTATION ovine fetus to exogenous glucocorticoids induces organ-specific changes in postnatal cardiovascular physiology. The hypertensive aspect of this model of fetal programming was first described by Dodic et al. in 1998 (3). In their studies, the offspring of ewes given dexamethasone for 48 h beginning at 27 days gestation (term, 145-150 days) were hypertensive at 4 mo of age and remained hypertensive at 10 and 18 mo of age, despite normal intrauterine and postnatal growth. Using an identical model, we recently reproduced the hypertensive phenotype and demonstrated unique alterations in coronary artery reactivity (17). More speci...

Exposure of the early gestation ovine fetus to exogenous glucocorticoids induces alterations in postnatal cardiovascular physiology, including hypertension. To determine whether autonomic function and systemic vascular reactivity are altered by in utero programming before the development of systemic hypertension, we examined arterial baroreflex function and in vivo hemodynamic and in vitro vascular responses to vasoactive agents in 10- to 14-day-old newborn lambs exposed to early gestation glucocorticoids. Dexamethasone (Dex, 0.28 mg.kg-1.day-1) or saline was administered to pregnant ewes by intravenous infusion over 48 h beginning at 27 days gestation (term 145 days), and lambs were allowed to deliver (n=6 in each group). Resting mean arterial blood pressure (MABP; 77+/-1 vs. 74+/-3 mmHg) and heart rate (HR; 249+/-9 vs. 226+/-21 beats/min) were similar in Dex-exposed and control animals, respectively. The arterial baroreflex curve, relating changes in HR to MABP, was significantly shifted toward higher pressure in the Dex-exposed lambs although no change in the sensitivity (gain) of the response was seen. In vivo changes in blood pressure in response to bolus doses of ANG II (20, 50, and 100 ng/kg) and phenylephrine (2, 5, and 10 microg/kg) were similar in the two groups. However, Dex lambs displayed greater decreases in MABP in response to ganglionic blockade with tetraethylammonium bromide (10 mg/kg; -30+/-3 vs. -20+/-3 mmHg, P<0.05) and greater increases in MABP after nitric oxide synthase blockade with NG-nitro-L-arginine (25 mg/kg; 23+/-3 vs. 13+/-2 mmHg, P<0.05) compared with control lambs. By in vitro wire myography, mesenteric and femoral artery microvessel contractile responses to KCl were similar, whereas responses to endothelin (in mesenteric) and norepinephrine (in femoral) were significantly attenuated in Dex lambs compared with controls. Femoral vasodilatory responses to forskolin and sodium nitroprusside were similar in the two groups (n=4). These findings suggest that resetting of the baroreflex, accompanied by increased sympathetic activity and altered nitric oxide-mediated compensatory vasodilatory function, may be important contributors to programming of hypertension.

Acetylcholine; blood pressure; developmental biology; fetal programming

Background: Primary Epstein-Barr virus (EBV) infection frequently occurs early after transplantation (Tx) in seronegative pediatric heart Tx recipients who receive organs from seropositive donors and is the key risk factor for the development of post-transplant lymphoproliferative disorder (PTLD). The routine use of post-Tx EBV-PCR monitoring offers the opportunity to study the time course of primary EBV infection and the influence of differing immunosuppressive regimens. Methods: We studied 15 consecutive seronegative recipients who received a primary heart Tx from a seropositive donor. All were managed with tacrolimus-based immunosuppression with 9/15 also receiving 5 days of induction with rabbit antithymocyte globulin (Thymoglobulin). Surveillance was by whole blood real-time EBV-PCR approximately monthly for the first 6 months, then every 2 months for 6 months, then approximately quarterly thereafter. Results: Mean age at transplant was 5.4 years, and mean donor age was 8 years. Positive donor EBV serostatus prior to any donor transfusion was confirmed in 6 cases. One patient developed PTLD. A total of 270 PCR measurements were made (average 18/pt). 12/15 experienced primary EBV infection with first positive PCR 24-307 days post-Tx; median 38 days (Thymoglobulin pts 33d vs. non-Thymoglobulin pts 93d). Of 12 patients who developed detectable viral loads, 7 (58%) did so within 6 weeks of Tx. Peak EBV viral load ranged from 2,600 to 380,000 copies/ml; median 28,500 copies/ml (Thymoglobulin pts 26,000 vs. non-Thymoglobulin pts 47,000). Time to peak viral load was 32-1023 days, median 177 (Thymoglobulin pts 121d vs. non-Thymoglobulin pts 239d). Of the 3 patients who never developed a measurable viral load, none had pre-transfusion confirmation of donor seropositive status. Seronegative recipients with seronegative donors have not demonstrated early (first six weeks) viral loads, and screening of filtered blood products are also EBV-PCR negative suggesting that the loads observed in this study were not due to blood product use during cardiopulmonary bypass. Conclusions: EBV seronegative pediatric Tx recipients receiving hearts from seropositive donors experience very early EBV infection with evidence of viremia often within 4-6 weeks of Tx. Induction therapy may be associated with earlier viremia. EBV-PCR screening more frequently than monthly maybe indicated early after Tx in this population if any form of experimental / therapeutic intervention is planned at the time of primary EBV infection. Tumor necrosis factor (TNF) plays a crucial role in the pathogenesis of graft-vs-host disease (GVHD), the major cause of treatment-related mortality (TRM) after allogeneic bone marrow transplantation (BMT). We tested the hypothesis that early rises in TNF (on day 7 following BMT) predict the development of significant GVHD and TRM. Ratios of soluble TNF receptor 1 (TNFR1) levels (day 7 level/pre-BMT level) was used as a surrogate marker for TNF in 440 myeloablative allogeneic BMT pts with a median age of 42y (range 0-65y)....