• The Korean Journal of Physiology
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• v.24 no.2
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• pp.319-329
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• 1990

Effects of atrial natriuretic peptide (ANP) on blood pressure, plasma lenin activity, aldosterone and renal excretion were compared in conscious spontaneously hypertensive rats (SHR) and normotensive Wistar rats fed low, medium or high sodium diet (2, 10, 25 mmol NaCl/100g diet) for 6 weeks. ANP infusion (380 ng/kg/min for 20 min) produced reductions in blood pressure, plasma renin activity, and aldosterone level, but marked increases in hematocrit, urine flow, and excretions of sodium and potassium. The low sodium group showed a significantly enhanced aldosterone lowering effect of ANP than the high sodium group. However, three salt groups showed no difference in effects of ANP on blood pressure, plasma renin activity, hematocrit and diuresis. Natriuretic response to ANP was significantly greater in the high salt-than in the low sait-SHR, but was not different between the Wistar salt groups. There were strain differences in effects of ANP: SHR showed greater responses of blood pressure and natriuresis than Wistar rats. Above results indicate that aldosterone-lowering and natriuretic effects of ANP were modifed by different dietary sodium intakes. However, blood pressure- and renin-lowering, or diuretic effects of ANP were not affected by dietary sodium intakes. The mechanisms whereby dietary sodium intakes alter the effects of ANP in the pathogenesis of hypertension are not clear.

• Journal of Food Hygiene and Safety
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• v.5 no.1
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• pp.7-12
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• 1990

The disposition of Brazilin including plasma concentration-time profiles, excretions via urine and bile, and plasma protein binding was investigated after intravenous or oral administration of radio labeled Brazilin ($^3H-Brazilin$) to male Wistar rats. The main pharmac:okinetic parameters were as follows; $t\;_{ 1/2}$, 13.71 hr; AUC, $53.38\;\mu\textrm{g}{\cdot}hr/ml$; AUMC, $1013.4I\;\mu\textrm{g}{\cdot}hr^2/ml$, MRT, 18.95 hr; Vss, 17778 mllkg and CL, 936.77 ml/hr.kg. The 2nd peak was found in the plasma concentration-time profiles indicating potential enterohepatic circulation. The enterohepatic circulation was supported by the bile excretion. After oral administration, about 64.4 % of administered radioactivity was excreted into the bile within 10 hours and its excretion rate reached maximum at 3 hours after administration. The Vss was extremely high, 17.8 l/kg indicating distribution of brazilin in most organs (tissues) with high concentration of brazilin in some organs. Brazilin was distributed into most of organs (spleen, adrenal, pancreas, kidney, thymus, lung, heart, liver, prostate, epididymus, testis, fat, muscle and done) except brain. High concentration of Brazilin was detected especially in liver, kidney, epididymus and testis. Approximately, 62.9% and 44.1% of the dose was excreted for intravenous and oral administration, respectively. About 80% of the dose eventually excreted into urine was excreted within 24 hr after dosing. Plasma protein binding of brazilin resulted in $40\;{\pm}\;4%$ by ultrafiltration method.

• Journal of Life Science
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• v.9 no.2
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• pp.136-145
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• 1999

The purpose of this study was to evaluate the effect of organic slovents and noise on hearing loss. We selected organic solvents exposed group of 32 cases, noise exposed group of 31 cases, both noise and solvent exposed group of 31 cases, and control group of 53 cases and studied the relation between exposure level of noise and organic solvents and degree of hearing loss. The results were as follows. The subjects under investigation were exposed to noise and organic solvents under threshold limit values and the amount of urinary hippuric acid excretion were also under biological exposure indices. In case of noise, both noise and organic solvents exposed group and noise exposed group were more exposed than organic solvents exposed group(p<0.05). When urinary hippuric acid excretion were concerned, both noise iud organic solvents exposed group and organic solvents exposed group showed higher values than noise exposed group(p<0.05). In comparison of mean auditory threshold values by frequency, on the air conduction test, both noise and organic solvents exposed group showed significantly higher hearing loss than noise exposed group in 500Hz of right ear, 500 and 2000Hz of left ear(p<0.05). Forty-three cases among 147 subjects were regarded as hearing loss group and average age(42.6years) of hearing loss group was higher than normal groups average age of 38.0 years. Urinary hippuric acid excretions of hearing loss group were significantly higher than normal group(p<0.05). Thirty-eight percent(12cases) of noise exposed group, 40.6 $\%$(13cases) of organic solvents exposed group, 51.6 $\%$(16cases) of both noise and organic solvents exposed group, and 3.8 $\%$(2cases) of unexposed group were regarded as hearing losers. Exposed groups showed higher incidence of hearing loss than unexposed group but there were no significant differences among the exposed groups. The variables showing significant correlation with hearing loss were age and the amount of hippuric acid in urinary excretion. When age were adjusted for the purpose of seeing the effects of hearing losses due to organic solvent, urinary excretion of hippuric acids was the only variable with significant correlation with hearing loss (p<0.05). When odds ratio to hearing loss between control and exposed groups was considered, noise exposed group showed 6.1 times (95 $\%$ CI: 3.3-8.7), organic solvents exposed group showed 7.4 times (95 $\%$ CI: 3.5-14.6) and both noise and organic solvents exposed group showed 17.2 times(95% CI: 5.6-31.8) higher values than unexposed group(p<0.01). Above results suggest that health screening test of hearing loss is also needed in organic solvents exposed workers.