m-Cresol - ipcs inchem

OECD SIDS
p-CRESOL
5. TOXICITY ID: 106-44-5
DATE: 24.05.2004
Signs of neurobehavioral toxicity were documented during pretreatment, 1
and 6 hours after dosing on study day 1 and prior dosing on study days 2,
7, 14, 30, 60 and 90 including salivation, urination, tremors, piloerection,
diarrhea, pupil size, pupil response, lacrimation, hypothermia, vocalization,
exophthalmus, palpebral closure, convulsions (type and severity),
respiration (rate and type), impaired gait, positional passivity, locomotor
activity, stereotypy, startle response, righting reflex, performance on a wire
maneuver, forelimb grip strength, positive geotropism, extensor thrust, limb
rotation, tail pinch reflex, toe pinch reflex, hind limb splay.
gross and histopathologic examination
Result : Mortality: control: 1 female(2.5 %), 600 mg-gr: 4 males and 4 females (40
%), gross and histopathologic examination: aspiration or inhalation of the
TS, pulmonary edema
body weight gain: 600 mg-gr., males less than control during week 1
mean food consumption, 600 mg-gr., males and females: significantly less
than control
clinical signs: dose related in incidence: salivation, myotonus, tremors,
urine wet abdomen, hypoactivity, rapid respiration
neurobehavioral toxicity:
600 mg-group, males and females: initial part of the study: incidence of
palpebral closure, rales, laboured respiration; locomotor activity less than
concurrent controls; at study termination: a trend towards increased
urination.
Other differences from controls with regard to behavioral tests were
evaluated as sporadic in nature by the authors (no further details given).
necropsy:
brain weights of treated animals comparable to controls; gross and
microscopic examination of tissues revealed no lesions which were
attributable to treatment
Reliability : (2) valid with restrictions
limited documentation (only study summary available)
Flag : Critical study for SIDS endpoint
04.02.2004 (145) (129) (171)
5.10 EXPOSURE EXPERIENCE
Remark : In vitro production of p-cresol from tyrosine by bacteria
isolated from normal human gut was examined. Strictly
anaerobic and facultatively anaerobic bacteria were grown
at 37oC in the presence of 0.01% tyrosine for 72 and 48 hr
respectively. The growth atmospheres for the bacteria were
nitrogen, hydrogen and carbon dioxide and air respectively.
p-Cresol production from tyrosine was seen with the
strictly anaerobic gut bacteria but not the facultatively
anaerobic bacteria. p-Cresol is, therefore, produced
endogenously from tyrosine, an amino acid present in most
proteins, by strictly anaerobic bacteria in the intestine.
According to the results of studies in cancer patients, endogenous p-Cresol
does not contribute significantly to the development of large bowl caner
(18 patients versus 10 normal healthy persons.
Reliability : (2) valid with restrictions
Flag : Critical study for SIDS endpoint
15.01.2003 (133)
Remark : The probable oral lethal dose for humans is 50-500 mg/kg bw.
Reliability : (2) valid with restrictions
Flag : Critical study for SIDS endpoint
10.01.2003 (172)
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