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.

Rapid concentration and purification of retrovirus by flocculation with Polybrene

We have previously shown that the combined addition of Polybrene (PB) and chondroitin sulfate C (CSC) to retrovirus stocks leads to the formation of retrovirus-polymer complexes (i.e., flocs) that rapidly sediment onto cells, increases the efficiency of gene transfer, and can be used to rapidly concentrate and purify retrovirus stocks. The viruses remain associated with the polyelectrolyte complexes, however, which may complicate their use in downstream applications. In this study we determined if retrovirus could be flocculated using only one polymer (PB). We found that when retrovirus stocks were incubated with 320 microg/ml of PB, more than 70% of the viruses, and fewer than 0.3% of all other proteins, were pelleted by low-speed centrifugation. In contrast to retrovirus complexes formed with two polymers, retrovirus flocculated with PB disaggregated when they were resuspended in fresh medium. We conclude that flocculation of retroviruses with a single cationic polymer (PB) is a useful method for rapidly concentrating and purifying retroviruses, and may prove particularly useful when it is desirable to generate purified virus that is not part of a polymer complex.

Reversible hexadimethrine-induced alterations in glomerular structure and permeability

Female Munich-Wistar rats received hexadimethrine (HDM) i.v. until the onset of proteinuria (PEAK)--a period of not more than 30 min. There were four experimental groups: C (control), H (HDM only), HH (HDM and heparin), and HHD (identical to HH but with dextran clearances measured). Rats in groups HH and HHD received a heparin bolus after the PEAK period, whereas rats in group H did not. HDM led to dramatic increases in both albumin and IgG excretion. Glomerular filtration rate and renal plasma flow rate were reduced by 30 to 50% after HDM infusion. Neutral dextran clearances for radii greater than 30 A were elevated during the PEAK period, and, concurrently, there was extensive intraglomerular microthrombosis, obliteration of foot processes, and disruption of filtration slit diaphragms. One hour later, glomerular filtration rate, renal plasma flow rate, dextran clearances, and proteinuria returned to baseline in groups HH and HHD but not in group H. Recovery in heparin-treated rats was associated with reversal of HDM-associated morphological alterations. Membrane pore-size parameters calculated from the dextran clearances indicate that HDM leads to a detect in glomerular size-selectivity. The facts that maximal albuminuria tended to precede maximal excretion of IgG and that increases in albumin excretion were proportionately greater than those of dextran or IgG suggest that HDM also leads to a time-dependent defect in glomerular charge-selectivity.

Urinalysis for detection of chemically induced renal damage (2)--Changes in urinary excretions of enzymes and various components caused by p-aminophenol, puromycin aminonucleoside and hexadimethrine

In order to establish sensitive methods of detecting minor renal damage, changes of enzymes, protein, tubular cell counts, and creatinine in the urine were investigated in rats to which nephrotoxic chemicals had been administered. Daily administration of p-aminophenol (PAP) dose-dependently increased urinary excretions of lactate dehydrogenase (LDH) and its isoenzymes (LDH5 = LDH4 greater than LDH3 greater than LDH2 = LDH1), aspartate aminotransferase (GOT), alkaline phosphatase (ALP), gamma-glutamyl transpeptidase (gamma-GTP), leucine aminopeptidase (LAP), lysozyme (LZM), N-acetyl-beta-D-glucosaminidase (NAG) and acid protease together with increased counts of tubular cells in the urine. Tubular cell counts, LDH and GOT were more sensitive indicators in the PAP tubulonephritis. Single i.v. injection of puromycin aminonucleoside (PM) dose-dependently increased urinary excretions of LDH and its isoenzymes (LDH1 = LDH5 greater than LDH2 = LDH4 greater than LDH3), GOT, NAG, acid protease and protein but degree of the increases in these enzymes was lower than those in the rats treated with PAP. PM increased excretions of high molecular weight proteins but did not increase ALP, gamma-GTP, LAP, LZM and tubular cells excretions. Single i.v. injection of hexadimethrine increased urinary excretion of LDH and its isoenzymes (LDH1 = LDH5 greater than LDH2 greater than LDH3 = LDH4), GOT, LZM, NAG and acid protease together with increased counts of tubular cells in the urine but did not increase ALP, gamma-GTP and LAP excretions. It is concluded that tubular cell counts, LDH isoenzymes and battery of these enzymes in urine are useful markers for detecting the severity and the site of renal damage in addition that urinary protein is a useful marker for detecting glomerular damage.

Effects of drugs on pituitary fine structure in laboratory animals

Although an increasing number of chemicals are reported to affect endocrine glands, only a few studies are dealing with their toxic effect on pituitary. The drugs can induce lesions acting directly on endocrine cells or indirectly by interfering with the regulation of their endocrine activities. Some drugs stimulate pituitary cell proliferation leading to hyperplasia and tumor formation; other chemicals have an inhibitory effect on adenohypophysial cells; and only one drug, hexadimethrine bromide, has been found to induce pituitary necrosis. Although complex toxicologic studies have been carried out on many chemicals, the mechanism of action of most drugs is not completely elucidated and further studies are necessary to establish structure function correlations.