Actions of 1,4-dihydropyridines in isolated mesenteric vascular beds.

Recent studies indicate that the vasorelaxation induced by nitrendipine may be mediated partially by increased release of nitric oxide (NO). To study this effect in more detail and to examine the vasodilating effect of other 1,4-dihydropyridines (1,4-DHP) with regard to a possible involvement of NO, we investigated the effects of nitrendipine, nifedipine, nisoldipine, and nimodipine on isolated mesenteric vascular bed an the influence of L-NG-nitroarginine (L-NNA) on 1,4-DHP-induced vasorelaxation. Perfusion with these 1,4-DHP resulted in a concentration-dependent increase in global flow and vascular diameter in all vessel branches.

Comparative nephrotoxic effects of cis-platinum (II), cis-palladium (II), and cis-rhodium (III) metal coordination compounds in rat kidneys.

A Sprague-Dawley rat kidney perfusion technique was used in situ to study the effects of cis-dichloro-diamine platinum, PdCl2 (2,6-diaminopyridine), and RhCl3 (2,6-diaminopyridine) on sodium and calcium retention in the whole kidney. The technique involves perfusion of both kidneys via the abdominal aorta and then through the right and left renal arteries and dorsal aorta. Compared to controls, kidneys perfused independently with the three coordination compounds showed approximately equal to 45% decrease and approximately equal to 117% increase in Na+ and Ca2+ retention, respectively.

Oxyphil cell carcinoma of the parathyroid: a rare cause of hyperparathyroidism.

Oxyphil carcinoma of the parathyroid is an extremely rare tumour, only two previous patients having been reported. We report a 55-year-old woman with this condition, who presented with a picture of hyperparathyroidism, including hypercalcaemia, hypercalciuria, hypophosphataemia, increased alkaline phosphatase, and bony lesions. Biopsy of a bone lesion was consistent with brown tumour.

Propranolol unmasks class III like electrophysiological properties of norepinephrine.

Isolated perfused spontaneously beating rabbit hearts were treated with increasing concentrations of norepinephrine (0.01, 0.1, 0.

Oncogenicity of AKR mink cell focus-inducing murine leukemia virus correlates with induction of chronic phosphatidylinositol signal transduction.

Naturally occurring recombinant murine leukemia viruses (MuLVs), termed mink cell focus-inducing (MCF) viruses, are the proximal leukemogens in spontaneous thymic lymphomas of AKR mice. The mechanism by which these viruses transform lymphocytes is not clear. Previous studies have implicated either integrational activation of proto-oncogenes, chronic autocrine immune stimulation, and/or autocrine stimulation of growth factor receptors (e.

A new endothelium-dependent vasoconstricting factor (EDCF) in pig coronary artery.

In order to investigate the influence of the endothelium on hypoxia-induced vasospasms we examined vascular tone after reduction of the oxygen supply, dependent on endothelial function. Therefore, after ligation of all side branches, vessel segments of porcine or human right coronary arteries or of rabbit abdominal aorta, prepared either with or without endothelium, were cannulated, perfused with Tyrode's solution and arranged in a serial manner (system I: endothelium-denuded vessel followed by a normal segment; system II: normal vessel followed by an endothelium-denuded segment). The pressure gradient over each segment was continuously measured as a function of vessel radius.

Vasoconstrictions mediated by an endothelium-derived vasoconstricting factor (EDCF).

To enlighten the role of endothelium in the generation of vasospasms we examined vascular tone after reduction of oxygen supply in dependence on endothelial function in isolated vessels (rabbit aorta abdominalis, pig coronary, and pulmonary artery). Therefore, after ligation of all side branches, vessel segments, prepared either with or without endothelium, were cannulated and arranged in two systems (with two segments each) in a serial manner (system I: endothelium-denuded vessel followed by an endothelium-denuded segment) and perfused with Tyrode's solution (constant flow 20 ml/min). Pressure gradient over each segment was continuously measured.