White, Margueritte Mabry, Robert E. McCullough, Rebecca Dyckes, Alastair D. Robertson, and Lorna G. Moore. Effects of pregnancy and chronic hypoxia on contractile responsiveness to a1-adrenergic stimulation. J. Appl. Physiol. 85(6): 2322–2329, 1998.—Decreased contractile response to vasoconstrictors in uterine and nonuterine vessels contributes to increased blood flow to the uterine circulation...

The purpose of this study was to investigate the changes in vasocontractile responses in atherosclerosis, using abdominal aortic strips isolated from Watanabe heritable hyperlipidemic (WHHL) rabbits and Japanese White (control) rabbits. The aortic strips from WHHL rabbits showed a significantly lower contractile response to angiotensin II than that in strips from control rabbits. The contractil...

Decreased contractile response to vasoconstrictors in uterine and nonuterine vessels contributes to increased blood flow to the uterine circulation during normal pregnancy. Pregnancies complicated by preeclampsia and/or chronic hypoxia show a reversal or diminution of these pregnancy-associated changes. We sought to determine whether chronic hypoxia opposes the reduction in contractile response...

BACKGROUND Muscarinic-receptor antagonists and β-adrenoceptor agonists are used, alone or in combination, as first-line treatment for chronic obstructive pulmonary disease. Both drugs decrease airway smooth muscle tone by post-junctional mechanisms but they may have opposing effects on pre-junctional acetylcholine (ACh)-release. METHODS We studied the effects of the muscarinic-receptor antago...

atp-sensitive potassium (katp) channel openers have a relaxation effect due to the lower cellular membrane potential and inhibit calcium influx. there has been considerable interest in exploring katp channel openers in the treatment of various diseases such as cardiovascular, cerebrovascular, and urinary system disease and premature labor. the purpose of this study was to synthesize 3,3,6,6-tet...

Elevated protein kinase C βII (PKCβII) expression develops during heart failure and yet the role of this isoform in modulating contractile function remains controversial. The present study examines the impact of agonist-induced PKCβII activation on contractile function in adult cardiac myocytes. Diminished contractile function develops in response to low dose phenylephrine (PHE, 100 nM) in cont...

Pendrin is a Cl-/HCO3- exchanger expressed in the apical regions of renal intercalated cells. Following pendrin gene ablation, blood pressure falls, in part, from reduced renal NaCl absorption. We asked if pendrin is expressed in vascular tissue and if the lower blood pressure observed in pendrin null mice is accompanied by reduced vascular reactivity. Thus, the contractile responses to KCl and...

BACKGROUND AND AIMS the neural mechanisms of distension-induced esophagoupper esophageal sphincter (UES) reflexes have not been explored in humans. We investigated the modulation of these reflexes by mucosal anesthesia, acid exposure, and GABA(B) receptor activation. In 55 healthy human subjects, UES responses to rapid esophageal air insufflation and slow balloon distension were examined before...

Electrical field stimulation (EFS) produced a biphasic contractile response; viz. initial rapid phasic contraction and second slow tonic contraction, in isolated guinea pig vas deferens. Pretreatment with the substrate of nitric oxide (NO) synthase (NOS), 1 mM L-arginine (L-ARG), augmented both the initial rapid and the second slow contractile responses to EFS (5 Hz, 0.5 msec, 30 V, for 30 sec)...