Reirradiation tolerance of the rat heart.

Purpose: To investigate the influence of reirradiation on the tolerance of the heart after a previous irradiation treatment.

Methods And Materials: Female Wistar rats were locally irradiated to the thorax. Development of cardiac function loss was studied with the ex vivo working rat heart preparation (20).

Changes in cardiac performance and sympathetic stimulation during and after fractionated radiotherapy in a rat model.

The consequences of fractionated irradiation on the number of cardiac alpha- and beta-adrenergic receptors, myocardial norepinephrine concentration and in vitro assessed heart function were studied in Sprague-Dawley rats. Animals were locally irradiated on the thorax with a total dose of 50 Gy, in 5 weeks, using two different fractionation schemes (5 x 2.0 Gy/week and 3 x 3.

Virus-induced airway hyperresponsiveness in the guinea-pig: possible involvement of histamine and inflammatory cells.

1. Guinea-pig tracheal contractions by histamine and by the cholinoceptor agonist, arecoline, are significantly enhanced (30% and 20%, respectively), 96 h after intra-tracheal inoculation with Parainfluenza-3 (PI-3) virus. 2.