Modulation of nitric oxide improves cyclosporin A-induced hypertension in rats and primates.

Cyclosporin-induced hypertension is a major complication of immunosuppression in transplant recipients but its pathophysiology is only partly understood. Cyclosporin reduces endothelium-dependent vasodilation and increases endothelin synthesis and release, which may contribute to this hypertension. We examined the effects of: (1) nitric oxide enhancement with L-arginine administration and antagonism with N-nitro-L-arginine; and (2) chronic endothelin receptor blockade with the non-peptide endothelin receptor antagonist, bosentan, in two animal models of cyclosporin-induced hypertension.

Bosentan ameliorates cyclosporin A-induced hypertension in rats and primates.

Cyclosporine-induced hypertension is a major problem in transplant therapy. The pathophysiology of this disease is unclear. Cyclosporine increases endothelin synthesis and release, which may contribute to this hypertension.

Differential effects of a novel non-peptide endothelin receptor antagonist (bosentan) in rat liver and vasculature.

1. We studied the effects of the non-selective, non-peptide, orally active endothelin (ET) receptor antagonist bosentan (Ro 47-0203) on rat hepatic and mesenteric vascular membrane 125I-ET-1 binding characteristics in vitro and ex vivo (after bosentan by gavage in vivo). 2.

Effect of acute and chronic treatment with the angiotensin II subtype 1 receptor antagonist EXP 3174 on baroreflex function in conscious spontaneously hypertensive rats.

Objective: To determine whether the angiotensin II subtype 1 (AT1) receptor antagonist EXP 3174 can modify the baroreceptor-heart rate reflex in conscious rats.

Design: EXP 3174 was given acutely, both peripherally and centrally, as well as chronically to spontaneously hypertensive rats (SHR), and baroreflex function was then examined.

Methods: Baroreceptor reflex activity was assessed by constructing sigmoidal mean arterial pressure (MAP)-heart rate curves after injection of pressor (phenylephrine) and depressor (sodium nitroprusside) agents.

Laser marking of thin organic films.

The threshold marking response of a laser-irradiated dye-polymer thin film is described by a simple, thermally thresholding model. The apparent loss of thermal reciprocity is related to active reflectance changes during mark formation. It is shown that incorporation of measured differences between physical and optically detected mark lengths are required for the model to accurately replicate the subsequent marking response.

Thermal modeling studies of organic compact disk-writable media.

The marking response of optical data storage structures is controlled by the interplay of optical and thermal effects. Relatively simple analytical expressions were derived that provided a qualitative and semiquantitative description of the optical and thermal characteristics of an organic dye-based optical recording medium. These were used to explain various phenomena that were observed during recording experiments that were performed on compact disk-writable media and to evolve a new understanding of the mark formation process.

Influence of laser read and bias power levels on the performance of thermomagnetooptic recording media.

Read and bias power levels are capable of noticeably altering the response of thermomagnetooptic recording materials. The heating caused by the read power can decrease signal levels due to the temperature dependence of the polar Kerr rotation. Preheating caused by bias power levels also influences media sensitivity and responses during the writing process.