Systemic pressure-flow reactivity to norepinephrine in rabbits: impact of endotoxin and fluid loading.

Objective: This study aimed to evaluate the impact of fluid loading on hemodynamics and vascular hypocontractility to norepinephrine (NE) in an endotoxic shock model.

Design: Mean arterial pressure (MAP), aortic blood flow velocity (AoV, 20 MHz Doppler) and aortic conductance (AoC = AoV/MAP) were studied during 180 min (T0-T180) in 41 anesthetized and ventilated rabbits.

Interventions: Shock was induced by a 600 micrograms/kg bolus injection of endotoxin.

Specific response of mouse tumor-feeding arterioles to stimulation by 5-HT1 agonists.

Using intravital microscopy, we compared the responses to 5-HT1 receptor stimulation by the host-modified arterioles feeding a Meth-A tumor implanted in the flank of female Balb/c mice with the responses of tumor-independent arterioles (TIA) and those of control arterioles from mice without tumor. Topical administration of 5 x 10(-5) M serotonin in the presence of 10(-4) M ketanserin (5-HT2 receptors inhibitor) induced arteriolar vasodilation in TIA (+13%) and in the control arterioles (+19%), but induced constriction (-14%) in the tumor-feeding arterioles (TFA). Topical administration of the general 5-HT1 agonist 5-carboxamidotryptamine maleate (10(-6) to 10(-4) M) or the 5-HT1A agonist buspirone (2 x 10(-6) to 2 x 10(-4) M) induced vasoconstriction that was dramatically higher in TFA than in TIA or control arterioles (p < 0.

[Ketanserin and random skin flaps. An experimental study in the rat].

This prospective randomised study in a rodent model was designed to analyse the value of a serotonin antagonist, ketanserin, on the survival of random skin flaps in Wistar rats. Our study demonstrates the statistical value of this molecule. The surface of skin necrosis was statistically lower in the group of rats treated with pre and post operative subcutaneous injection of ketanserin.

Effects of L-arginine and L-nitro-arginine treatment on blood pressure and cardiac output in a rabbit endotoxin shock model.

Objective: To verify the effect of nitric oxide system modification during sepsis, not only in terms of pressure but also in terms of perfusion flow.

Design: Experimental, comparative study.

Setting: Laboratory of a university hospital.

[Specific reactivity to serotonin of afferent vessels in human pharyngolaryngeal carcinoma. Methodology and initial results].

This work describes an experimental protocol studying action of Serotonin (5-HT) on vessels feeding human pharyngolaryngeal carcinoma. Right and left superior laryngeal arteries were obtained during total (pharyngo)laryngectomy. As tumor growth is asymmetrical, tumor and opposite side arteries were considered as tumor (T) and control (C) vessels, respectively.