Subchronic rat inhalation study with Skydrol 500B-4 fire resistant hydraulic fluid.

Skydrol 500B-4 fire resistant hydraulic fluid, a proprietary phosphate ester mixture composed principally of dibutyl phenyl phosphate (DBPP) and tributyl phosphate (TBP) and used as a commercial airline hydraulic fluid, was evaluated in an inhalation toxicity study of Sprague-Dawley rats. Target exposure levels used in the study were 0, 5, 100, and 300 mg/m3, and exposures were maintained for 6 hr/day, 5 days/week. Mass median aerodynamic diameters determined for particles in the mid- and high-exposure inhalation chambers were 2.85 microns and 3.31 microns, with geometric standard deviations of 1.99 microns and 1.92 microns, respectively. The percentage of particles less than 10 microns in diameter were 96.4% in the mid-exposure chamber and 95.5% in the high-exposure chamber. After 6 weeks of Skydrol exposure, 10 rats/sex/group were euthanized and then assessed for indications of possible chemical toxicity. Another 15 rats/sex/group were studied for a total of 13 weeks of exposure. The only clinical sign of chemical toxicity was the observation of a reddish nasal discharge with accompanying oral salivation in mid- and high-exposure animals of both sexes, indicative of an irritant response. Statistically significant reduced body weights; increased absolute and relative liver weights; and decreased erythrocyte counts, hemoglobin levels, and hematocrit values were observed in high-exposure female rats euthanized after 13 weeks of Skydrol exposure. High-exposure male rats also had increased absolute and relative liver weights and decreased hematocrit values after 13 weeks. Plasma cholinesterase levels were decreased in high-exposure female rats both 6 and 13 weeks after the study was initiated.(ABSTRACT TRUNCATED AT 250 WORDS)

Response of dairy cows to high doses of a sustained-release bovine somatotropin administered during two lactations. 2. Health and reproduction.

Eighty-two lactating Holstein cows in their first, second, or third lactation received either one, three, or five concurrent i.m. injections of a unit dose (.6 g) of zinc methionyl bST (sometribove) or five doses of the vehicle. Injections were given at 14-d intervals from 60 +/- 3 d postpartum until the end of lactation or necropsy. Thirty-eight animals were continued on treatment for a 2nd yr. Sometribove did not affect the incidence of ketosis, milk fever, tetany, or pneumonia. Digestive disorders, primarily cows going off feed, were increased by bST during yr 1 only. The incidence of lameness was increased by bST in some time frames because of an increase in the 3.0-g bST group. Lameness was not associated with treatment-specific histopathologic changes or with abnormalities in cartilage or bone. Reproductive health generally was unaffected by treatment, but delayed conception and increased incidence of abortion were noted. Incidence of cystic ovaries was unaffected by bST. Pregnancy rates were decreased during the 100-d breeding interval of yr 1 but not during the 215-d interval of yr 2. The incidence of clinical mastitis was increased by bST, primarily at the 3.0-g dose. During the 2-yr study, 0, 3, 3, and 2 cows died or became moribund on 0, .6, 1.8, and 3.0 g of bST, respectively. Health issues identified for further evaluation included lameness and clinical mastitis for the 3.0-g group and early removal from the herd and decreased reproductive performance for all bST groups. Bovine somatotropin caused no treatment-specific toxic effects in dairy cows even at 3.0 g every 14 d.

13-week inhalation toxicity study and fertility assessment in rats exposed to atmospheres containing adiponitrile.

Adiponitrile is an aliphatic dinitrile that is used as an intermediate in the synthesis of hexamethylenediamine. In order to asses potential health effects associated with industrial exposure, rats were exposed 6 h/d, 5 d/wk for 4 or 13 wk to atmospheres containing a range of adiponitrile concentrations and observed for signs of toxicity. A fertility assessment was also included as a component of the 13-wk study. Mortality and reduced weight gain were observed within 1 wk only in rats exposed to 493 mg/m3. Evidence of slight anemia was present in rats exposed to 99 mg/m3 and above. There was no histopathological evidence of organ toxicity in about 30 tissues from both sexes exposed up to 99 mg/m3, the highest concentration tested, for 13 wk. In addition, fertility, as monitored by reproductive performance and litter parameters, was normal in both males and females similarly exposed.

Minimally functional rat adrenal medullary pheochromocytomas.

In this study of 29-month-old male Fischer and Sprague-Dawley rats, the tumor pheochromocytoma occurred in seven of 20 Fischer rats (35%) and ten of 22 Sprague-Dawley rats (45%). Mean blood pressures and mean urinary vanillylmandelic acid levels of rats with pheochromocytomas did not vary significantly from rats with no tumors. Pheochromocytoma in our rats generally was non-functional or of minimal clinical significance. The content of chromaffin granules in tumor cells varied from abundant to not detectable, thus it was apparent that the absence of detectable chromaffin granules does not eliminate the diagnosis of pheochromocytoma.

The effects of drugs and chemicals upon the structure of the adrenal gland.

The susceptibility of the endocrine tissues to compound-induced lesions may be ranked in the following decreasing order of frequency: adrenal, testis, thyroid, ovary, pancreas, pituitary, and parathyroid. The first two are by far the most frequently affected. Pathologists unaccustomed to the evaluation of endocrine effects are often unaware of the number of compounds producing specific lesions in the adrenal. Compounds may produce changes in one of the following zones: fasciculata/reticularis, glomerulosa, or medulla. They are listed in this paper by affected zones. In the fasciculata/reticularis lesions are generally either degenerative or proliferative; in the glomerulosa they are necrotic or atrophic; in the medulla lesions are generally hypertrophic or proliferative.

The toxicity of ochratoxin to ruminants.

Among the mold toxins the most toxic ochratoxin, ochratoxin A, commonly occurs in many grains, other feedstuffs, and in soil but in low concentrations. The amount required to produce acute toxicity in ruminants makes such occurrences unlikely. Toxic effects are more likely to occur in chronic low-level intoxication. The lethal single oral dose in cattle is high, probably being a few milligrams more than 13 mg/kg. The lethal level produced by repeated feeding to goats was 3 mg/kg. Ochratoxin A occurred in cows milk and urine but only when massive doses were ingested. Abortion or fetal death, though occurring in rodents, are unlikely to be induced in cattle.

Butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) effects on serum and liver lipid levels in Gallus domesticus.

The food antioxidants, butylated hydroxyanisole (BHA) and butylated hydroxy-toluene (BHT) were fed to chickens to determine their effect on lipid metabolism. BHA and BHT did not affect chicken growth, blood lipid levels or liver lipid levels when the birds were fed a normal ration. When a high fat, high cholesterol ration was fed, chickens developed increased levels of blood and liver lipids and experienced decreased growth rates. The addition of either antioxidant in the presence of a high fat high cholesterol diet maintained higher serum lipid levels and caused decreases in liver lipid levels.

Identification of T-2 toxin in moldy corn associated with a lethal toxicosis in dairy cattle.

Over a 5-month period during the winter of 1970-71, 20% of the lactating Holstein cows in a Wisconsin dairy herd died after prolonged ingestion of a diet containing 60% moldy corn infested with Fusarium tricinctum (2 x 10(5) propagules per g of moldy corn). Ethyl acetate extracts of the ground dried corn induced severe dermal reactions when applied to the skin of shaved 60-g albino rats and killed four of five 100-g rats that were force fed 1 ml in 2 ml of pure corn oil. T-2 toxin (3-hydroxy-4, 15-diacetoxy-8-[3-methylbutyryloxy]-12, 13-epoxy-Delta(9)-trichothecene) at concentrations of 2 mg per kg of dry corn was identified in purified extracts of the moldy corn by means of gas-liquid chromatography and mass spectrometry. This concentration of T-2 toxin in the moldy feed and the nature of the toxic effects observed strongly suggest a major causal relationship.