The distribution and excretion of radioactivity from [14C]citrinin (3 mg/kg, i.v) was determined in male rats. At 0.5 h after administration maximum values of 14.7% and 5.6% of total radioactivity were observed in the liver and kidneys, respectively, and by 6 h decreased to 7.5% in the liver and 4.7% in the kidney. Plasma concentration of 14C decreased from 9.2% at 0.5 h to 4.7% at 6.0 h. 2 plasma elimination rates were observed, with half-lives of 2.6 and 14.9 h, respectively. Approximately 80% of the administered 14C activity was excreted in feces and urine by 24 h after administration. A second group of rats was pretreated with 50 mg/kg of citrinin, i.p., 4 days prior to administration of 3 mg/kg [14C]citrinin, i.v. 30% of the pretreated animals died and the remaining animals were divided into 2 groups on day 4 after pretreatment; rats which were "nephrotoxic" and rats which had "recovered" from the initial insult of citrinin. Proteinuria and glucosuria as well as enhanced urine output were observed in "nephrotoxic" rats 4 days after pretreatment. 24 h after [14C]citrinin, only 13% of 14C activity was detected in the urine of "nephrotoxic" rats. The plasma disappearance curve had 2 elimination rates, with half-lives of 0.6 and 14.1 h. "Nephrotoxic" rats retained 7.5% of the administered radioactivity in the liver compared to 1.3% in the "recovered" rats 24 h after the tracer dose and 47% of the radioactivity was either excreted in feces or in the colon contents after 72 h compared to 17.5% in "recovered" rats. Extraction of urine samples from "nephrotoxic" and "recovered" rats with chloroform suggested increased water soluble metabolites of citrinin in the urine from "nephrotoxic" rats. These data also suggested that in normal rats the kidneys are the major route of elimination of citrinin and its metabolite(s) while in rats rendered nephrotoxic by citrinin pretreatment, elimination is more dependent on hepatic excretion.

Animals↗

PubMedDate not supplied

A 90-day toxicity study of the effects of petroleum middle distillates on the skin of C3H mice.

Petroleum middle distillates (PMDs) elicit skin tumors in mouse epidermal carcinogenesis studies. The response is characterized by a long latency with only a small percentage of animals developing tumors. Although the carcinogenic activity of certain other petroleum hydrocarbons largely depends upon the presence of polycyclic aromatic hydrocarbons (PAHs), many PMDs contain relatively low concentrations of PAHs. PMDs are also irritating to mouse skin, and chronic irritation may be involved in the development of skin tumors. This study was conducted to investigate the patterns of cutaneous irritation elicited by topical application of PMDs having compositional differences. The three PMDs selected for study were a steam cracked gas oil (SCGO), a lightly refined paraffinic oil (LRPO), and a jet fuel (JF). Male C3H/HeNCr1BR mice (25/group) were treated topically (37.5 microliters 2x/week for 13 weeks) with 10%, 50% or 100% (undiluted) concentrations of each PMD. Catalytically cracked clarified oil (CCCO, 10%), a potent carcinogen to mouse skin, was also tested. The vehicle was a noncarcinogenic mineral oil with a viscosity of 90 SUS. Cutaneous changes were evaluated by gross observations and light microscopy. Cutaneous irritation was the only significant toxic response in this study. Neither the vehicle nor any of the 10% PMD concentrations produced significant cutaneous irritation. The 10% CCCO and 50% PMD treatments all elicited slight to moderate proliferative and inflammatory changes in mouse skin. Ulcers were also observed microscopically in mice treated with 10% CCCO and 50% SCGO. The 100% SCGO treatment produced evidence of necrosis on Days 1-7 but not later in the study despite continued treatment. In contrast, the irritating effects of 100% LRPO were not evident until 2-3 weeks of study, and at study completion were characterized by moderately severe inflammatory and proliferative changes. The effects of 100% JF were qualitatively similar to 100% LRPO but less marked. Thus, the SCGO caused a different pattern of cutaneous responses than either LRPO or JF. The possible relationships of these cutaneous changes to epidermal carcinogenesis are being studied further.

Animals↗

PubMedDate not supplied

The normal foot.

The term "normal foot" has many different interpretations. This article reviews some of the ways in which the word "normal" has been used historically to describe the foot. Also discussed are the problems of attempting to determine what should constitute a normal foot and proposed criteria for distinguishing between the normal and the pathological.

Foot↗

PubMedDate not supplied

Automated rodent respiratory monitor and histogram computer- a preliminary report.

Explore the source record for details and available documents.

Animals↗

PubMedDate not supplied

Dysfunction of the peroneus longus after fracture of the cuboid.

The author presents two case histories to demonstrate the disabling effects of fracture of the cuboid. He believes that a fracture of the cuboid is as disabling as an intra-articular fracture and should be treated in the same manner because an injury to any sinus or sulcus that contains a synovial lining for the free gliding action of a tendon should receive the same treatment as a joint injury.

Adult↗