ABSTRACT
Historical data are presented for neoplasms and related proliferative lesions from 1,170 Sprague-Dawley rats that served as controls in 9 carcinogenicity (2 year) studies conducted in the Safety Evaluation Facility of Ciba-Geigy Corporation, Summit, New Jersey. The most common neoplasm was pituitary adenoma, which occurred in 62.2% of the male and 84.7% of the female rats. Incidences of other neoplasms that occurred in more than 6.0% of the rats were, for males, benign pheochromocytoma (19.0%), cutaneous keratoacanthoma (7.9%), pancreatic islet cell adenoma (7.5%), benign testicular interstitial cell tumor (6.5%), and thyroid C-cell adenoma (6.5%). For females these incidences were mammary fibroadenoma (31.3%), mammary adenocarcinoma (16.8%), and mammary adenoma (6.5%). Focal cortical hypertrophy/cystic degeneration of the adrenal, a focal nonneoplastic lesion of zona fasciculata cells that often degenerate into large cysts, was present in 23.4% of all male and 82.7% of all female rats. Criteria for the differential diagnoses of selected neoplasms and related lesions are presented.
Subject(s)
Carcinogens/toxicity , Neoplasms, Experimental/pathology , Rats, Sprague-Dawley/anatomy & histology , Animals , Female , Male , Neoplasms, Experimental/epidemiology , Rats , Reference ValuesABSTRACT
This study was conducted to determine the morphologic effects of a single, high dose of adriamycin on rat dorsal root ganglion (DRG) neurons in the presence of sciatic nerve crush. The left sciatic nerve of each rat was crushed either before or after adriamycin treatment. At termination of the study, thin-sections of plastic-embedded DRG specimens were examined by light microscopy. Numbers of necrotic neurons in rats subjected to nerve crush on day 1 followed by drug treatment on day 3 were compared to numbers of necrotic neurons in animals receiving nerve crush on day 3 preceded by drug on day 1. The percentage of necrotic neurons seen on the crushed side was similar to that on the uncrushed side. Also the percent of necrotic neurons was reduced when nerve crush was done before treatment (3.7%) rather than after (7.7%) which suggests a protective effect. The difference between the mean percent of necrotic neurons in rats subjected to nerve crush before adriamycin treatment as compared to after drug treatment approached statistical significance (p = 0.056).
Subject(s)
Doxorubicin/toxicity , Ganglia, Spinal/pathology , Neurons/drug effects , Sciatic Nerve/physiology , Animals , Body Weight/drug effects , Ganglia, Spinal/drug effects , Ganglia, Spinal/physiology , Male , Necrosis/chemically induced , Necrosis/physiopathology , Neurons/physiology , Rats , Rats, Inbred StrainsABSTRACT
Sprague-Dawley CD rats received daily oral doses (45 mg/kg) of the cationic amphiphilic tricyclic antidepressant imipramine HCl (Tofranil) for up to two years. Representative specimens of liver, lung, spleen, mesenteric lymph node, retina and dorsal root ganglion were examined for myeloid bodies (MB). The extent that MB affected a given cell or group of cells was qualitatively determined. Myeloid bodies were observed in a variety of cell types after one year of administration to treated rats. They were less common after a subsequent three month recovery period. Fewer MB were observed in rats treated for one year than were previously reported in short term studies. Fewer MB were seen after two years of treatment than after one year although the same organs were affected. Thus, MB appear to decrease in number with increasing time of compound administration. This may result from a more efficient metabolism of the drug or because of decreased levels of phospholipid in aged rats.
