Age-associated changes in large blood vessels were characterized by increased arterial wall thickness, luminal dilation and impaired endothelial function. But little is known about the effect of age on structural and functional changes in small resistance arteries. The mechanisms underlying age-associated endothelial dysfunction in rat mesenteric resistance arteries were investigated in the pre...

To test whether structural alterations observed in the mesenteric vasculature of Wistar-Kyoto spontaneously hypertensive rats (SHR) were dependent on the presence of hypertension, male SHR and Wistar-Kyoto normotensive (WKY) rats were treated in utero and postnatally with hydralazine up to 28 weeks of age. Treated SHR, WKY, and untreated WKY rats had comparable blood pressures that were less th...

Although insulin-mediated vasodilation is impaired in insulin resistance, the mechanisms of this are unknown. We investigated factors mediating vasoactive responses to insulin in control and insulin-resistant rats. Responses to insulin in small mesenteric arteries from control and insulin-resistant rats were investigated after blocking endothelin-A receptors, cyclooxygenase, nitric oxide syntha...

An increased Ca2+ influx attributed to dihydropyridine-sensitive L-type Ca2+ channels has been demonstrated in mesenteric vascular smooth muscle cells of spontaneously hypertensive rats (SHR). This study examined whether an upregulation of the pore-forming alpha1C subunit of the L-type Ca2+ channel underlies this ionic defect. With the use of mesenteric arcade arteries from 12- to 16-week-old S...

A 50-year-old woman who was a heavy smoker presented with intermittent claudication of both lower extremities. An abdominal aortogram with bilateral lower extremity runoff demonstrated marked arteriosclerotic occlusive disease of the superficial femoral arteries. It also demonstrated a huge meandering mesenteric artery as an important collateral system (A). Note that the inferior mesenteric art...

In isolated perfused rabbit mesenteric arteries, prostaglandin (PG) E, and E,, 1-5 ng/ml, did not alter the basal perfasion pressure, but reduced tbe vasoconstrictor responses to sympathetic nerve stimulation; the responses to injected Borepinephrine were reduced by PGE, and TariaMy affected by PGE,. In contrast, in rat mesenteric arteries PGE, and PGE,, 1-5 ng/ml, potentiated the vasoconstrict...

Mesenteric arteries were isolated from the spontaneous diabetic BB rats, non-diabetic BB rats and regular Wistar control rats. Gross morphology indicated that the mesenteric vascular bed of the control Wistar rats hacl a normal development of mesenteric fat pad around the vessels, while that of the diabetic BB rats showed drastically reduced perivascular fat pad, suggesting greater mobiTization...

Salt-sensitive hypertension is associated with impaired NO/cGMP signaling. We hypothesized that increased superoxide production by NADPH oxidase and altered endothelial NO synthase (NOS3) phosphorylation determine endothelial dysfunction in hypertension. Experiments tested if NO/cGMP signaling and NOS3 serine phosphorylation are decreased and NADPH oxidase activity is increased in mesenteric ar...

15-Lipoxygenase (15-LO-1) metabolizes arachidonic acid (AA) to 11,12,15-trihydroxyeicosatrienoic acids (THETAs) and 15-hydroxy-11,12-epoxyeicosatrienoic acids (HEETA) that dilate rabbit arteries. Increased endothelial 15-LO-1 expression enhances arterial relaxations to agonists. We tested the effect of hypoxia on 15-LO-1 expression, THETA and HEETA synthesis, and relaxations in rabbit arteries....

BACKGROUND Increased sympathetic activity has been implicated in hypertension. Adenosine has been shown to play a role in blood flow regulation. In the present study, the endogenous adenosine neuromodulatory role, in mesenteric arteries from normotensive and spontaneously hypertensive rats, was investigated. METHODS AND RESULTS The role of endogenous adenosine in sympathetic neurotransmission...