Blood pressure is influenced by several vasoactive factors that also regulate nephron transport. An imbalance in regulation of salt reabsorption by the nephron contributes to hypertension. In the spontaneously hypertensive rat (SHR), the responses to dopamine and angiotensin II in the proximal nephron are diminished and enhanced, respectively. This partially explains why the proximal tubule of ...

The slow-reacting substances (SRS) consist of leukotrienes C, D, and E (LTC, -D, -E) 1 and are derived from the lipoxygenase pathway of arachidonic acid (20:4) metabolism. In examining possible mechanisms for the vasoactive effects of SRS (1-4), we found that cultures o f human endothelial cells release the vasodilatory agent, prostacyclin, on exposure to 10 -9 to 10 -6 M LTC (5). Previous repo...

Congenital extra hepatic port systemic shunt, is a rare clinical entity which can lead to hepatopulmonary syndrome wherein blood from portal vein directly drains into circulation, causing an alteration in metabolism of pulmonary vasoactive substances, vasodilatation, diffusion-perfusion defects, and eventually, arterial hypoxemia due either increase vascular resistance or the creation arteriove...

Pial arterioles supplying the hindlimb somatosensory cortex dilate in response to contralateral sciatic nerve stimulation. The mechanism of this pial vasodilation is not well understood. One possibility is that vasoactive metabolites released during brain activation may diffuse to subarachnoid cerebrospinal fluid (CSF) to dilate pial vessels. To test this hypothesis, we implanted closed cranial...

Although concerned primarily with gas exchange, the lungs have other functions which are unrelated to ventilation. The cells and enzyme systems of the pulmonary vascular bed change the biological activity of a variety of substances presented to them via the pulmonary circulation. The lungs have the ability to clear certain vasoactive hormones from the pulmonary blood and to synthesize or activa...