AMMONIUM SULFATE CAS N°: 7783-20-2

OECD SIDS
AMMONIUM SULFATE
5. TOXICITY ID: 7783-20-2
DATE: 18.04.2006
difference between air- and ammonium sulfate exposed animals
was both in spontaneously breathing and paralyzed animals. The
residual volume / twice total lung capacity (RV/TLC), measured
in paralyzed animals, was also significantly higher in
ammonium sulfate exposed rats than in air-exposed rats. Carbon
monoxide diffusion capacity and quasistatic compliance were
not affected by aerosol exposure. Compared with air-exposed
animals, ammonium sulfate exposed rats showed a decreased
slope of single-breath N2 washout curves.
Test condition:
There were no consistent differences observed between 5- and
20-day exposed animals.
The test animals (from Charles River Breeding Labs, Portage,
Mich.) were isolated for 3 weeks after delivery. Following
isolation, animals were assigned to exposure groups such that
preexposure body weight distributions were the same for all
experimental groups exposed at the same time.
Anesthetized animals were instilled intratracheally with
either sterile saline or porcine pancreatic elastase (EO127,
Sigma Chemical Co.; 75 units/100 g bw). Elastase activity was
determined immediately before daily instillations by the
method of Sachar et al. (1955, Proc. Soc. Exp. Biol. Med. 90,
323-326), using elastin-orcein as substrate.
The doses of elastase were selected as the
maximum doses tolerated that produced less than 10% acute
mortality, based on results of previous studies (Busch et
al., 1984, Environ. Res. 33, 473-496).
Following instillation rats were given prophylactic
tetracycline (60 mg/L) in their drinking water
for 2 weeks to prevent pulmonary infections, occasionally
observed in preliminary studies, following the instillations.
Three weeks following intratracheal instillations, the then
approximately 14 week old rats were exposed in Hazleton
Systems Model 1000 stainless steel chambers for 5 or 20 days
to filtered room air or 1 mg/m3 ammonium aerosol.
Chamber aerosol concentration was monitored continuously and
the variations throughout the chamber were less than 5% of the
mean concentration. Aerosol concentrations were
determined from four daily, 90-min, filter-pad samples;
ammonium sulfate concentrations were determined by an
automated methyl-thymol blue method. Particle-size
distribution was measured from combined Mercer cascade
impactor samples, collected over 15 hours of exposure during a
5-day week. Daily impactor samples were collected at a
constant flowrate of 2 liters/min on glass coverslips.Mass
median aerodynamic diameter (MMAD) and geometric standard
deviation (GSD) of the aerosol were calculated using a program
which compared the impactor data with a log-normal
distribution (Hill et al., 1979; PNL-2405. Pacific Northwest
Laboratory. Richland. WA. Available from NTIS,
Springfield.Va.).
For the evaluation of pulmonary function, animals were
anesthetized by intraperitoneal injection with ethyl
carbamate and then intubated with an esophageal catheter and
placed prone in a flow-type plethysmograph. Transpulmonary
pressure (airway pressure minus esophageal pressure) was
determined by electronic subtraction of the two signals.
Before making any measurements, the lungs were inflated
twice to total lung capacity to establish a constant volume
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