Single and mixture per- and polyfluoroalkyl substances accumulate in developing Northern leopard frog brains and produce complex neurotransmission alterations.

Per- and polyfluoroalkyl substances (PFAS) are present in water and >99% of human serum. They are found in brains of wildlife; however, little is known about effects on the developing brain. To determine the effects of PFAS on brain and cardiac innervation, we conducted an outdoor mesocosm experiment with Northern leopard frog larvae (Rana pipiens) exposed to control, 10 ppb perfluorooctane sulfonate (PFOS), or a PFAS mixture totaling 10 ppb that mimicked aqueous film forming foam-impacted surface water (4 ppb PFOS, 3 ppb perfluorohexane sulfonate, 1.25 ppb perfluorooctanoate, 1.25 ppb perfluorohexanoate, and 0.5 ppb perfluoro-n-pentanoate). Water was spiked with PFAS and 25 larvae (Gosner stage (GS) 25) added to each mesocosm (n = 4 mesocosms per treatment). After 30 days, we harvested eight brains per mesocosm and remaining larvae developed to GS 46 (i.e. metamorphosis) before brains and hearts were collected. Weight, length, GS, and time to metamorphosis were recorded. Brain concentrations of all five PFAS were quantified using LC/MS/MS. Dopamine and metabolites, serotonin and its metabolite, norepinephrine, γ-aminobutyric acid, and glutamate were quantified using High Performance Liquid Chromatography with electrochemical detection while acetylcholine and acetylcholinesterase activity were quantified with the Invitrogen Amplex Red Acetylcholine Assay. PFOS accumulated in the brain time- and dose-dependently. After 30 days, the mixture decreased serotonin while both PFAS treatments decreased glutamate. Interestingly, acetylcholine increased in PFAS treatments at GS 46. This research shows that developmental environmentally relevant exposure to PFAS changes neurotransmitters, especially acetylcholine.

Dopamine changes in a rat model of intracerebral hemorrhage.

Recent case reports suggest that dopamine (DA) replacement may reduce behavioral deficits resulting from hemorrhages along the nigrostriatal tract. In the rat model of intracerebral hemorrhage (ICH), behavioral deficits are first evident on day 1, with return to near control levels by day 28. The current study was conducted to determine if striatal dopamine alterations are correlated with behavioral deficits. Gamma-aminobutyric acid (GABA) levels were measured to determine selectivity. Striatal DA, DA metabolites, and GABA were determined at days 1, 3, 7, and 28 after ICH by high-pressure liquid chromatography with electrochemical detection. ICH resulted in significant increases above control in DA contralateral to the lesion (177 to 361% above control, days 1 to 28). There were also significant, but much less marked changes in GABA. In the ipsilateral striatum, significant DA increases also occurred (approximately 200%, at day 3 and approximately 275% day 28), while GABA alterations were not significant. These results indicate that the striatal DA system is selectively altered after ICH. Further studies will be needed to determine if regional dopamine alterations occur relative to the location of the hematoma.

Interaction of LY171883 and other peroxisome proliferators with fatty-acid-binding protein isolated from rat liver.

Fatty-acid-binding protein (FABP) is a 14 kDa protein found in hepatic cytosol which binds and transports fatty acids and other hydrophobic ligands throughout the cell. The purpose of this investigation was to determine whether LY171883, a leukotriene D4 antagonist, and other peroxisome proliferators bind to FABP and displace an endogenous fatty acid. [3H]Oleic acid was used to monitor the elution of FABP during chromatographic purification. [14C]LY171883 had a similar elution profile when substituted in the purification, indicating a common interaction with FABP. LY171883 and its structural analogue, LY189585, as well as the hypolipidaemic peroxisome proliferators clofibric acid, ciprofibrate, bezafibrate and WY14,643, displaced [3H]oleic acid binding to FABP. Analogues of LY171883 that do not induce peroxisome proliferation only weakly displaced oleate binding. [3H]Ly171883 bound directly to FABP with a Kd of 10.8 microM, compared with a Kd of 0.96 microM for [3H]oleate. LY171883 binding was inhibited by LY189585, clofibric acid, ciprofibrate and bezafibrate. These findings demonstrate that peroxisome proliferators, presumably due to their structural similarity to fatty acids, are able to bind to FABP and displace an endogenous ligand from its binding site. Interaction of peroxisome proliferators with FABP may be involved in perturbations of fatty acid metabolism caused by these agents as well as in the development of the pleiotropic response of peroxisome proliferation.

The effects of fructose on adenosine triphosphate depletion following mitochondrial dysfunction and lethal cell injury in isolated rat hepatocytes.

Mitochondrial injury in aerobic mammalian cells is associated with a rapid depletion of adenosine triphosphate (ATP) which occurs prior to the onset of lethal cell injury. In this report, the relationships between ATP depletion and lethal cell injury were examined in rat hepatocytes using oligomycin as a model mitochondrial toxicant and fructose as an alternative carbohydrate source for glycolysis. Oligomycin was more potent in causing lethal cell injury in hepatocytes isolated from fasted animals than cells from fed animals. The onset of cell injury (leakage of lactate dehydrogenase) in cells from fed animals correlated with the depletion of stored glycogen and ATP. The degree and time course profile of oligomycin-induced ATP depletion could be duplicated with 50 mM fructose alone in hepatocytes from fasted animals; however, fructose did not cause lethal cell injury. Oligomycin caused marked accumulation of adenosine monophosphate (AMP) and inorganic phosphate (Pi) and a conservation of adenine nucleotides. In contrast, fructose (50 mM) caused a decrease in Pi, no persistent change in AMP, and a depletion of the adenine nucleotide pool. Fructose, at concentrations greater than 1.0 mM, protected hepatocytes from oligomycin-induced toxicity. Blockade of mitochondrial ATP synthesis with oligomycin resulted in massive ATP depletion. In the presence of oligomycin, 5.0 mM fructose maintained cellular ATP content similar to that of control cells, whereas 50 mM fructose did not, demonstrating the biphasic effect of increasing fructose concentrations on cellular ATP content. Fructose-induced protection of hepatocytes from oligomycin toxicity was due to glycolytic fructose metabolism as hepatocytes incubated with iodoacetate (30 microM), fructose, and oligomycin had reduced viability and ATP content. In conclusion, interruption of mitochondrial ATP synthesis leads to marked ATP depletion and lethal cell injury. Cell injury is clearly not due to ATP depletion alone since increased glycolytic ATP production from either glycogen or fructose can maintain cell integrity in the absence of mitochondrial ATP synthesis and at low cellular ATP levels.

Lung water and vascular permeability-surface area in premature newborn lambs with hyaline membrane disease.

Extravascular lung water and vascular permeability-surface area products were measured with a multiple indicator dilution method in 6 premature lambs with hyaline membrane disease 1-5 hours following delivery by cesarean section. The indicators used were 51Cr-labelled erythrocytes, 125I-albumin, 3H-water, and 14C-urea. Results were compared with previously obtained data in newborn lambs without hyaline membrane disease also delivered by cesarean section. Extravascular lung water was significantly higher in lambs with hyaline membrane disease [23.2 +/- 1.0 (SEM) vs. 10.7 +/- 1.4 ml/kg body wt]. Vascular permeability-surface area products for 14C-urea were significantly lower in lambs with hyaline membrane disease (0.30 +/- 0.10 vs 0.78 +/- 0.11 ml/s per kg). It is concluded that extravascular lung water is high in lambs with hyaline membrane disease. Permeability-surface area products for 14C-urea is low in lambs with hyaline membrane disease, which probably indicates a decrease in detectable surface area for exchange due to derecruitment or hypoperfusion of pulmonary exchange vessels in edematous and hypoxic areas of the lungs.

Hormonal control of femoral gland secretion in the lizard, Amphibolurus ornatus.

Castration of the male lizard Amphibolurus ornatus results in atrophy of the femoral glands. The amount of secretion collected from glands decreased from (mean +/- SE) 136.6 +/- 13.0 micrograms/g body wt prior to castration to 102.7 +/- 14.6 micrograms/g body wt 28 days after castration (P less than 0.001). Over the same period the secretion from a group of intact males increased. Biosynthesis of steroids by testicular tissue from A. ornatus was studied in vitro using [4-14C]progesterone as substrate. A single androgen, probably testosterone, was isolated. Daily injections for 28 days of 1 microgram/g body wt of testosterone propionate (TP) and 5 alpha-dihydrotestosterone (DHT) stimulated femoral gland secretion in castrated males (TP, 201.8 +/- 21.5 micrograms/g body wt; DHT, 142.8 +/- 16.0 micrograms/g body wt). The glands of animals receiving injection medium only remained atrophic. Identical regimes of TP and DHT also stimulated femoral gland secretion in intact females from which no exudate could initially be collected. These data are consistent with the hypothesis that lizard femoral glands are androgen-dependent secondary sex characters.

Isolation and preliminary toxicological evaluation of arsenobetaine - the water-soluble arsenical constituent from the hepatopancreas of the western rock lobster.

The water soluble arsenic compound present in the hepatopancreas of the western rock lobster (Panulirus cygnus George) has been isolated as the reineckate salt and has been identified as arsenobetaine. Intraperitoneal injection of arsenobetaine into mice at 500 mg kg-1 did not result in mortality, and no symptoms of poisoning were observed. Mice treated with arsenobetaine at 360 mg kg-1 rapidly eliminated the compound in their excreta and no evidence was obtained for metabolic alteration. When tested in the Ames' Salmonella typhimurium system for chemical mutagens, both in the presence and absence of liver microsomal oxidase fraction, arsenobetaine gave consistently negative results.

Uptake of Tc-99m-PIPIDA in pulmonary metastases from a hepatoma.

Metastatic pulmonary nodules from a well-differentiated hepatoma were well demonstrated by a Tc-99m-labeled hepatobiliary imaging agent. Uptake of this type of radionuclide by metastases from a primary hepatic malignancy has not previously been reported. Such radiopharmaceuticals may prove useful in the future as imaging agents for primary hepatobiliary tumors.

Subcutaneous fat necrosis in pancreatitis.

A case of subcutaneous fat necrosis as the initial manifestation of an attack of acute pancreatitis is presented. The accompanying features of respiratory distress syndrome, leukemoid reaction, shock, pleural effusions, and arthritis due to necrosis of periarticular fat are described. Autopsy findings are pancreatic pseudocyst, serofibrinous peritonitis, pleuritis, and pericarditis and fat necrosis not only in the subcutaneous fat but also in the pericardial, pleural, mediastinal, mesenteric, retroperitoneal, and pericalyceal fat.

Metastatic abdominal implants of endometrial carcinoma demonstrated on 99mtc-methylene diphosphonate bone scan.

Metastatic serosal and omental implants from a primary papillary endometrial carcinoma were well demonstrated by radionuclide uptake on a bone scan utilizing 99mTc-methylene diphosphonate. Imaging of an endometrial malignancy by a 99mTc-labeled phosphate compound has not previously been reported. While the exact mechanism of accumulation in such soft-tissue neoplastic foci is not known, several possibilities have been suggested. In this particular case, the mechanism appears related in some way to the presence of dystrophic calcifications within the metastatic deposits.