The Impact of the Food Quality Protection Act on the Future of Plant Disease Management.

The Food Quality Protection Act mandates new considerations in pesticide regulatory decisions. Endocrine disruption, determination of the need for an additional safety factor for infants and children, aggregate exposure to each pesticide, and cumulative exposure to pesticides with a common mechanism of toxicity will all become part of the risk assessment process. A reduction in availability of fungicides for many current uses appears to be a likely result of this act.

Reductive assays for S-nitrosothiols: implications for measurements in biological systems.

Bioactive SNOs are found in many tissues. We speculated SNOs might be misidentified in conventional assays which reduce NO-3 to NO. S-Nitrosothiols were exposed to saturated VCl3 in HCl, 1% KI in acetic acid, photolysis, or CuCl and CSH in He; NO was measured by chemiluminescence.

Differential human renal tubular responses to dopamine type 1 receptor stimulation are determined by blood pressure status.

We performed the present studies to determine whether a proximal renal tubular dopamine D1-like receptor defect exists in human essential hypertension. Twenty-four subjects were studied (13 normotensive and 11 hypertensive) in a randomized, double-blind, vehicle-controlled study using fenoldopam, a selective D1-like receptor agonist. Subjects were studied in sodium metabolic balance at 300 mEq/d, after which the salt sensitivity of their blood pressure was determined.

Renal interstitial fluid angiotensin. Modulation by anesthesia, epinephrine, sodium depletion, and renin inhibition.

Using a microdialysis technique, we monitored changes in right and left renal interstitial fluid angiotensins in anesthetized and conscious dogs (both n = 5) in response to right renal interstitial epinephrine (0.2 mg/kg per minute) administration. Renal interstitial and plasma angiotensin levels also were monitored in conscious dogs (n = 4) in response to dietary sodium deprivation (10 mmol/d) for 5 consecutive days.

Localization of angiotensin peptide-forming enzymes of 3T3-F442A adipocytes.

We have demonstrated that angiotensinogen is synthesized by 3T3-F442A cells and is hydrolyzed to angiotensins I and II (ANG I and II) by this model adipocyte system. This study was designed to determine whether ANG I is generated by renin or some other enzyme and where the formation of ANG I and/or II occurs in 3T3-F442A cells. Renin mRNA was not detected by Northern blot analysis of poly(A)(+)-selected RNA from cultures of fully differentiated adipocytes nor by the more sensitive polymerase chain reaction, implying that renin is not synthesized in this model adipocyte system.

Combined acute hypoxemia and hypercapnic acidosis increases atrial natriuretic polypeptide in conscious dogs.

To evaluate the changes in atrial natriuretic polypeptide during acute hypoxemia and acute hypercapnic acidosis, conscious mongrel dogs with controlled sodium intake were evaluated in four protocols: (1) 80 min of acute hypoxemia (PaO2 = 34 +/- 1 mm Hg) followed by 40 min of combined hypoxemia and hypercapnic acidosis (PaO2 = 38 +/- 1 mm Hg, PaCO2 = 60 +/- 3 mm Hg, pH = 7.15 +/- 0.03) (n = 7); (2) 40 min of combined acute hypoxemia and hypercapnic acidosis (PaO2 = 36 +/- 1 mm Hg, PaCO2 = 56 +/- 2 mm Hg, pH = 7.

Role of vasopressin in renal vascular changes with hypoxemia and hypercapnic acidosis in conscious dogs.

To evaluate the role of vasopressin in the renal changes during combined acute hypoxemia and acute hypercapnic acidosis, eight conscious female mongrel dogs prepared with controlled sodium intake at 80 meq/24 h for 4 days were studied in one of the following six protocols: acute hypoxemia (80 min, arterial PO2 34 +/- 1 mmHg) followed by combined acute hypoxemia and hypercapnic acidosis (40 min, arterial PO2 35 +/- 1 mmHg, arterial PCO2 58 +/- 1 mmHg, pH = 7.20 +/- 0.01) during 1) intrarenal vehicle at 0.

Dopamine-1 and dopamine-2 mechanisms in the control of renal function.

Dopamine (DA), a catecholamine produced in the kidney, is a renal vasodilator and natriuretic substance, but its action at dopamine-1 (DA-1), dopamine-2 (DA-2) and alpha- and beta-adrenergic receptors limits its effectiveness as a heuristic tool and pharmacologic agent. We have studied the effects of highly selective DA-1 and DA-2 receptor agonists and antagonists in normal human subjects and experimental animals to determine the precise physiological role of renal dopamine at DA-1 and DA-2 receptors within the kidney. We studied fenoldopam, a selective DA-1 agonist, in normal human subjects in metabolic balances at high (300 mEq/day) and low (10 mEq/day) sodium (Na) intake.

Selective peripheral dopamine-1 receptor stimulation. Differential responses to sodium loading and depletion in humans.

Dopamine-1 (DA1) receptors in the renal tubules may be involved in the regulation of sodium homeostasis. To test this hypothesis, fenoldopam, a selective DA1 agonist, was infused at 0.05 microgram/kg/min i.

Role of atrial natriuretic peptide in the response to blood volume expansion in the weanling rat.

After acute blood volume expansion (BVE) in the rat, diuresis and natriuresis are reported to be minimal in rats 20 to 30 d of age, but increase to mature levels by 40 d of age. To evaluate the role of atrial natriuretic peptide (ANP) and its renal action in BVE, anesthetized Sprague-Dawley rats were studied at 25 to 30 (group I) and 45 to 50 d of age (group II). Hematocrit, mean arterial pressure, glomerular filtration rate, urine flow rate, urine sodium excretion, urine cyclic GMP excretion, and plasma ANP concentration [( ANP]) were measured before and after infusion of donor littermate whole blood, 2.

Atrial natriuretic factor in essential hypertension.

We measured circulating levels of immunoreactive atrial natriuretic factor (ANF) in 10 patients with untreated, uncomplicated mild to moderate essential hypertension and in 15 normotensive controls. ANF concentrations were significantly higher in the hypertensive group than in the control group (38.4 +/- 6.

Diuresis and natriuresis during continuous dopamine-1 receptor stimulation.

Stimulation of renal dopamine-1 (DA1) receptors for 3 hours produces an increase in renal plasma flow and sustained natriuresis. The present study was designed to assess the response of renal hemodynamic and tubular function to long-term DA1 receptor stimulation. Fenoldopam, a selective DA1 receptor agonist, was infused intravenously for 24 hours in 10 normal male subjects in metabolic balance at 150 mEq sodium and 60 mEq potassium intake in a single-blind, vehicle-controlled protocol.

Renal sensitivity to angiotensin II in the conscious dog.

Local formation of angiotensin II (AII) within the kidney has been demonstrated. Changes in renal function induced by inhibitors of the renin-angiotensin system have been the basis for the postulate that AII may act as a paracrine substance in the kidney. We studied the renal action of chronic intrarenal infusions of AII at doses between 2 and 2000 fmol/kg X min in uninephrectomized conscious dogs monitored on 80 meq daily sodium intake.

Dopaminergic suppression of angiotensin II-induced aldosterone secretion in man: differential responses during sodium loading and depletion.

Previous studies have shown that aldosterone secretion may be inhibited by dopaminergic mechanisms in man. Dopamine does not inhibit aldosterone responses to angiotensin II in sodium-replete normal subjects. Since sodium deficiency is associated with a reduction in renal dopamine formation, we investigated the effect of dopamine on angiotensin II-induced aldosterone secretion in the sodium-depleted state.

Specific effects of triarimol on sterol biosynthesis in Ustilago maydis.

1. Triarimol (2 mug/ml) severely inhibited ergosterol synthesis in sporidia of Ustilago maydis. In control cells ergosterol accounted for 70-85% of the total sterols, In sporidia treated 9.