Tamar Rosenbaum

Learn More
We studied the effects of nerve growth factor (NGF), fibroblast growth factor (FGF), and dibutyryl-cAMP (dbcAMP) on rat pancreatic β-cell morphology and of NGF and dbcAMP on insulin secretion. After 2 wk in culture, nearly 3% of β-cells extended neurite-like processes spontaneously; when cells were treated with NGF, almost 30% of them extended processes. In(More)
Previous studies have reported that the numbers of beta- and alpha-adrenergic receptors increase in ischemic myocardium. In vivo studies have raised questions regarding the mechanisms involved in the adrenergic receptor alterations and the consequences of these alterations. The purpose of this study was to evaluate potential relationships among(More)
Differentiation and function of pancreatic beta cells are regulated by a variety of hormones and growth factors, including nerve growth factor (NGF). Whether this is an endocrine or autocrine/paracrine role for NGF is not known. We demonstrate that NGF is produced and secreted by adult rat pancreatic beta cells. NGF secretion is increased in response to(More)
Nerve growth factor (NGF) induces neuritelike process outgrowth in cultured adult pancreatic beta cells. DbcAMP partially mimics this effect on cell morphology, and both compounds act synergistically to promote neuritelike process outgrowth. To determine if NGF- and dbcAMP-induced differentiation was accompanied by changes in beta cell electrical activity,(More)
We analyzed the effect of a brief exposure to nerve growth factor (NGF) on insulin secretion and macroscopic barium currents of single adult rat pancreatic beta-cells. After a 1-h exposure to NGF (50 ng/ml), single beta-cells show a 2.5-fold increase in the insulin secretion index in 5.6 mmol/l glucose and a nearly twofold increase in 15.6 mmol/l glucose(More)
This study investigated the influence of hypoxia on alterations in the beta-adrenergic receptor-adenylate cyclase system. Cultured neonatal rat ventricular myocytes were subjected to normoxia (incubator PO2 135-145 mmHg) or hypoxia (incubator PO2 0-14 mmHg) and, in crude membrane preparations, beta-receptor binding properties were measured with(More)
We analyzed the effect of culturing adult rat beta cells with NGF2.5 S for 5 to 7 days on macroscopic barium current (I(Ba)), and determined the role of Na and Ca channels on neurite-like process extension induced by NGF and dbcAMP, and by KCI depolarization. After five days in culture with 2.5S NGF, beta cells exhibit a 102% increase in I(Ba) density. This(More)
SUMMARY. Previous studies have reported that the numbers of p"-and a-adrenergic receptors increase in ischemic myocardium. In vivo studies have raised questions regarding the mechanisms involved in the adrenergjc receptor alterations and the consequences of these alterations. The purpose of this study was to evaluate potential relationships among(More)
  • 1