5-HT1-like receptor-mediated contraction in the human internal mammary artery.

We wished to characterize the 5-hydroxytryptamine (5-HT) receptors mediating vasoconstriction in the human internal mammary artery (IMA). Segments of the IMA obtained from patients undergoing coronary by-pass surgery were suspended in an organ bath and exposed to 5-HT and sumatriptan (SUM), a 5-HT1-like receptor agonist, in the presence and absence of potassium chloride (KCl) and angiotensin II. 5-HT induced concentration-dependent contractions in all quiescent and pre-contracted preparations.

A giant bladder stone: managed with osteotome.

An unusual case of bladder stone is presented. The size of stone and the operation technique were exceptional in the urologic literature. The stone could be palpated on physical examination.

Effects of dexfenfluramine on glucose drinking and glucose-conditioned flavour preferences in rats: taste versus post-ingestive conditioning.

A comparison was made of the effects of dexfenfluramine (DF, 3-10 mg kg-1) on intake of and conditioning with glucose solutions varying in orostimulant properties (taste) and post-ingestive actions (calories), in rats. First, sham-feeding, using gastric-fistulated rats, was performed to assess the orostimulant properties of the solutions. Then, two experiments were done.

5-HT1-like and 5-HT2A receptors mediate 5-hydroxytryptamine-induced contraction of rabbit isolated mesenteric artery.

The contractions induced by 5-hydroxytryptamine (5-HT) and the 5-HT1-like receptor agonist, sumatriptan, were investigated in the open ring preparations of rabbit mesenteric artery in order to characterize the 5-HT receptors. 5-HT induced concentration-dependent contractions. Sumatriptan did not induce any contraction of unstimulated rings, whereas it elicited concentration-dependent contractions in preparations given a moderate tone by a threshold concentration of prostaglandin F2 alpha (PGF2 alpha).

Amplification of responses to sumatriptan by various agonists in rabbit isolated iliac artery.

Rabbit iliac arteries (IA) were almost unresponsive to the serotonin (5-HT1-like) receptor agonist sumatriptan under control conditions, whereas this agent elicited concentration-dependent contractions in IA rings given a moderate tone by threshold concentrations (EC10-EC20) of prostaglandin F2 alpha (PGF2 alpha), angiotensin II (AII), histamine, norepinephrine (NE), phenylephrine (PE), or potassium chloride. These results suggest that 5-HT1-like receptors are uncovered not only by histamine or thromboxane/prostaglandin receptor agonists, as shown in rabbit renal and femoral arteries, but also by various agonists in rabbit IA as shown in this study.

Comparison of the effect of endothelium on the responses to sumatriptan in rabbit isolated iliac, mesenteric and carotid arteries.

The contractions induced by the 5-hydroxytryptamine (5-HT) and 5-HT1-like receptor agonist sumatriptan in open ring segments of rabbit iliac, mesenteric and common carotid arteries were studied isometrically in vitro. The alteration of the responses by removal of the endothelium and by inhibitors of nitric oxide synthase and cyclooxygenase was investigated. 5-HT induced concentration-dependent contractions of all these three arterial segments.

Characterization of 5-hydroxytryptamine receptors in rabbit isolated iliac artery.

To characterize the 5-hydroxytryptamine (5-HT) receptors, the contractile effects of both 5-HT and the 5-HT1-like receptor agonist sumatriptan were investigated in isolated open ring preparations of the rabbit common iliac artery. 5-HT induced concentration-dependent contractions. Sumatriptan did not induce any contraction of unstimulated preparations, whereas it elicited concentration-dependent contractions in preparations given a moderate tone with a threshold concentration of prostaglandin F2 alpha.