Newborn rats exhibit a torporous response to cold stress at 2°C
from which they revive after several hours exposure even though
respiratory, cardiovascular, and muscular movements have ceased.
At less severe temperatures (20 to 25°C) the rats respond with a non-torporous
decrease in metabolic and physiologic activity and a lowering...
Rat luteal cells from functional and non-functional
corpora lutea (corpora lutea rendered non-functional by
hypophysectomy) were preserved for light and electron
microscopy in Bouin's and glutaraldehyde-osmium fixation
respectively. Material for electron microscopy was dehydrated
with ethanol, embedded in Araldite and stained
with lead hydroxide or uranyl acetate-lead citrate. Examination
of...
The effects of coumestrol on the uterine weight, uterine fluid
imbibition, uterine nucleic acid content, adrenal weight and body
weight of female rats were studied. Daily doses of 20 micrograms
of coumestrol per 0.1cc propylene glycol were administered subcutaneously
to spayed rats following a seven day recovery period,
for durations...
Normal adult rats absorbed and metabolized C¹⁴-labeled acetate
rapidly. The greatest percentage of the administered radioactivity
was recovered in the expired CO₂, however small amounts of radioactivity
were also found in the urine and feces. There were two rates
of C¹⁴O₂ elimination in normal adult rats. The small amount of...
A single oral dose of DDT, ranging from 40 to 200 mg/kg, had
a drastic effect on the in vivo acetate metabolism in rats. The normal
elimination pattern of the expired ¹⁴CO₂ from ¹⁴C-labelled
acetate was distorted, and the rate of output of the ¹⁴CO₂ was decreased.
The ratio of...
Virtually nothing is known regarding the quantitative significance
of the several catabolic sequences involved in the breakdown of
glucose in the intact rat. Studies in this and other laboratories have
shown that the Embden-Meyerhof-Parnas pathway, the pentose
phosphate pathway and the glucuronic acid pathway are operative in
several tissues of...
Preliminary toxicity studies of BCNU in rats revealed that significant
prolongations of pentobarbital hypnosis were associated with
all doses employed. Investigations were undertaken to determine the
underlying mechanism responsible for this observed effect. Studies
on the in vitro metabolism of pentobarbital by hepatic microsomes
of BCNU-treated animals demonstrated that significant...
There has been no toxicologic proof that the long-term, low-level
exposure of man to chlorophenothane (DDT) is linked with an
increased susceptibility to toxicity or disease. Acute pretreatment
of rats with 75-100 mg/kg DDT has been demonstrated to potentiate
CCI₄-induced hepatotoxicity in that species (McLean and McLean,
1966). Since the...
Electrical stimulation of the vagus nerves produces an excitatory
contraction response in the isolated rat stomach. This contraction
response was abolished by atropine to unmask the vagal inhibitory
response (VIR) elicited during low frequency vagal stimulation.
Babring and Gershon (1967), after working on guinea-pigs and mice,
hypothesized that both serotonin...