Simulation of hemo- and biochemical toxicities associated with chronic inhalation exposure to 2,2-Dichlorovinyl dimethyl phosphate (DDVP) in Wistar rat

1986 ◽

Vol 44 ◽

pp. 252-253

Author(s):

R. C. Kaufmann ◽

F. K. Khosho ◽

K. S. Amankwah

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Wistar Rats ◽

Polycystic Ovary ◽

Wistar Rat ◽

Polycystic Ovaries ◽

Chemical Diabetes ◽

Scanning Electron

Diabetes decreases the fertility of females, but the mechanisms are not completely understood. In our investigations, we have found that 13% of the female BB Wistar rats that spontaneously developed chemical diabetes had persistent estrous. In this study the ovaries of these rats were examined by scanning electron microscopy(SEM) and compared to normal-cycling controls as well as to rats that had developed polycystic ovaries(PCO) by exposure to constant 1ight.

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Toxic effects of inhaled DMMP on the kidneys of Fischer-344 rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128687 ◽

1987 ◽

Vol 45 ◽

pp. 880-881

Author(s):

D.R. Mattie ◽

C.J. Hixson

Keyword(s):

Left Kidney ◽

Inhalation Exposure ◽

Electron Microscopic Examination ◽

Exposure Period ◽

Male Rats ◽

Continuous Exposure ◽

Fischer 344 Rats ◽

Electron Microscopic ◽

Thin Sections ◽

Fischer 344

Dimethylmethylphosphonate (DMMP) is a simple organophosphate used industrially as a flame retardant and to lower viscosity in polyester and epoxy resins. The military considered the use of DMMP as a nerve gas simulant. Since military use of DMMP involved exposure by inhalation, there was a need for a subchronic inhalation exposure to DMMP to fully investigate its toxic potential.Male Fischer-344 rats were exposed to 25 ppm or 250 ppm DMMP vapor on a continuous basis for 90 days. An equal number of control rats were sham-exposed. Following the 90-day continuous exposure period, 15 male rats were sacrificed from each group. Two rats from each group had the left kidney perfused for electron microscopic examination. The kidneys were perfused from a height of 150 cm water with 1% glutaraldehyde in Sorensen's 0.1M phosphate buffer pH 7.2. An additional kidney was taken from a rat in each group and fixed by immersion in 2.5% glutaraldehyde and 2% paraformaldehyde in 0.1M cacodylate buffer pH 7.4. A portion of the 9 kidneys collected for electron microscopy were processed into Epon 812. Thin sections, stained with uranyl acetate and lead citrate, were examined with a JEOL 100B Transmission Electron Microscope. Microvilli height was measured on photographs of the cells of proximal tubules. This data, along with morphologic features of the cells, allows the proximal convoluted tubules (PCT) to be identified as being S1, S2, or S3 segment PCT.

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Evaluation of hippocampus in rhesus monkeys after chronic (1-year) inhalation exposure to marijuana: I. Electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159539 ◽

1990 ◽

Vol 48 (3) ◽

pp. 398-399

Author(s):

A.M. Andrews ◽

S.W. Wilson ◽

A.C. Scallet ◽

S.F. Ali ◽

J. Bailey ◽

...

Keyword(s):

Synaptic Vesicles ◽

Rhesus Monkeys ◽

Low Dose ◽

Inhalation Exposure ◽

Synaptic Cleft ◽

High Dose ◽

Withdrawal Time ◽

Treatment Groups ◽

Ultrastructural Evidence ◽

Male Rhesus

Exposure of rhesus monkeys (Macaca mulatta) to marijuana via inhalation or to intravenous delta-9-tetrahydrocannabinol (THC), reportedly caused ultrastructural evidence of increased synaptic width. Chronic marijuana smoke in a single rhesus monkey examined after a six month withdrawal time caused ultrastructure changes in the septal, hippocampal and amygdala regions; the synaptic cleft was widened, electron opaque material was found in the cleft and in the pre- and postsynaptic regions, with some clumping of the synaptic vesicles. The objective of our study was to assess neuropathological alterations produced by chronic inhalation of marijuana smoke.Nineteen male rhesus monkeys, 3-5 years of age and weighing 3-8 kg, were divided into four treatment groups: a) sham control, b) placebo smoke (7 days/ week) c) low dose marijuana (2 times/week with 5 days/week sham) and d) high dose marijuana (7 times/week). A smoke exposure consisted of smoke from one cigarette (2.6% THC) burned down to 10 mm butt length. Smoke was administered via smoke generator (ADL II, Arthur D. Little, Inc. Cambridge, MA) and nose-mouth only masks (local production) equipped with one-way valves.

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Ultrastructural and immunocytochemical studies of the rat hypothalamo-neurohypophysial system processed by rapid freezing and freeze-substitution fixation

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100161989 ◽

1990 ◽

Vol 48 (3) ◽

pp. 884-885

Author(s):

Seiji Shioda ◽

Yasumitsu Nakai ◽

Atsushi Ichikawa ◽

Hidehiko Ochiai ◽

Nobuko Naito

Keyword(s):

Osmium Tetroxide ◽

Freeze Substitution ◽

Ultrastructural Localization ◽

Wistar Rat ◽

Neurosecretory Cells ◽

Rapid Freezing ◽

Sodium Metaperiodate ◽

Tissue Sections ◽

Ultrathin Sections ◽

Electron Microscopes

The ultrastructure of neurosecretory cells and glia cells in the supraoptic nucleus (SON) of the hypothalamus and the neurohypophysis (PN) was studied after rapid freezing followed by substituion fixation. Also, the ultrastructural localization of vasopressin (VP) or its carrier protein neurophys in II (NPII) in the SON and PN was demonstrated by using a post-embedding immunoco1loidal gold staining method on the tissue sections processed by rapid freezing and freeze-substitution fixation.Adult male Wistar rat hypothalamus and pituitary gland were quenched by smashing against a copper block surface precooled with liquid helium and freeze-substituted in 3% osmium tetroxide-acetone solutions kept at -80°C for 36-48h. After substituion fixation, the tissue blocks were warmed up to room temperature, washed in acetone and then embedded in an Epon-Araldite mixture. Ultrathin sections mounted on 200 mesh nickel grids were immersed in saturated sodium metaperiodate and then incubated in each of the following solutions: 1 % egg albumin in phosphate buffer, VP or NPII (1/1000-1/5000) antiserum 24h at 4°C, 3) colloidal gold solution (1/20) 1h at 20°C. The sections were washed with distilled waterand dried, then stained with uranylacetate and lead citrate and examined with Hitachi HU-12A and H-800 electron microscopes.

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