Loading...
Please wait, while we are loading the content...
Similar Documents
The Ohio State University 1967-09 An Autoradiographic Study of Invertebrate Uptake of DDT-CL 36
| Content Provider | Semantic Scholar |
|---|---|
| Author | Webster, Noah |
| Copyright Year | 2017 |
| Abstract | This research sought to locate autoradiographically DDT-C1 in tissues of leeches, amphipods, and copepods three months after their marsh habitat was treated with the amount of insecticide routinely used for mosquito control. Isotope DDT or its metabolite was found in cytoplasm of nerve cell bodies, gut mucosa, and vascular tissue of leeches. No isotope DDT was detected in the tissue of amphipods and copepods. INTRODUCTION On July 7, 1964, DDT-C1 was applied to a four-acre marsh in western Sandusky Bay, Ohio, to determine the fate of DDT in this natural environment. The plan included the collection of plants and animals at various post-application intervals for quantitative analysis. Because the plan did not include an experimental design for determining exact sites of the labeled compound within any invertebrates, arrangements were made to collect and process some of these organisms, with the objective of locating the isotope. Of several radiochemical techniques available, only autoradiography can be used to locate cellular and subcellular sites of isotope deposition in animal tissue. The purposes of this particular investigation were to determine: (1) whether the isotope was taken up by leeches, amphipods, and copepods, (2) whether the isotope was evenly distributed throughout the bodies of these animals, or relatively concentrated in specific tissues and organs, and (3) the effectiveness of autoradiography in a field study of this type. METHODS AND MATERIALS In preparation for the application of this insecticide to the experimental marsh, technical DDT (0.8 lb.) and chlorine-36-labeled DDT (3.0 millicuries, Emax = 0.71 mev.) in xylene solution were mixed with 400 lbs. of 20-40 mesh "AA" RVM "Attaclay" granules. The granules were applied to the four-acre marsh at the Manuscript received November 17, 1966. THE OHIO JOURNAL OF SCIENCE 67(5): 300, September, 1967. No. 5 INVERTEBRATE UPTAKE OF DDT-CL 301 rate of 100 lbs. per acre (0.2 lb. technical DDT per acre) the amount of insecticide normally used for mosquito control, with a helicopter using an Amchem applicator. The operation took place on a calm morning. A control marsh, located adjacent to the experimental marsh, was not sprayed with DDT-C1 and was isolated by a water-tight dike. Approximately three months post-application, leeches, amphipods, and certain copepods were collected and fixed. Four fixative solutions with properties which seemed suitable for this project were selected. These were: (1) potassium dichromate solution, a strong oxidizing agent, (2) Bouin's solution, containing acetic acid, a very rapid penetrating substance, (3) glutaraldehyde, which has a remarkable reputation for good fixation, and (4) formalin. Relaxation of the leeches and amphipods prior to fixation was accomplished by adding dilute ethyl alcohol, a drop at a time, to the native water in a stender dish containing the animals. The final concentration of alcohol was not determined, but is estimated to have amounted to about 5 per cent or less of the total. Preparation and use of the four fixative solutions used in this experiment are included here. Modified Bouin's fixation Stock Bouin's fixative was prepared according to McManus and Mowry (1960). As soon as the isolated animals relaxed from the effects of the alcohol, Bouin's fixative was added to the stender dish. The volume of fixative used was equal to that of the marsh water which contained the animals to be fixed. The specimens were stored in the fixative until further processing which was preparatory to paraffin embedding. Specimens were stored for from three to twelve months, which, admittedly, is too long. Glutaraldehyde fixation Commercially prepared 25 per cent glutaraldehyde was mixed with an equal volume of Sorenson's buffer (pH 7.4). In the field, this 12.5 per cent mixture was added to an equal volume of habitat water containing specimens. This brought the final concentration to 6.25 per cent. The animals in this solution were fixed for 24 hours before transfer to Sorenson's buffer for storage. Potassium dichromate fixation Five grams of potassium dichromate and 1 gram of calcium chloride (anhydrous) were dissolved in 100 ml of water. In the marsh, this solution was added to an equal volume of water containing the collected specimens. The animals remained in this solution until further histological processing. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://kb.osu.edu/dspace/bitstream/handle/1811/5332/V67N05_300.pdf;jsessionid=8FD08C2AA27AC6BD5E22A3ACE1AE7F7B?sequence=1 |
| Alternate Webpage(s) | https://kb.osu.edu/dspace/bitstream/handle/1811/5332/V67N05_300.pdf;jsessionid=E18199532525A3038325C90A059E670B?sequence=1 |
| Alternate Webpage(s) | https://kb.osu.edu/dspace/bitstream/handle/1811/5332/V67N05_300.pdf;jsessionid=C6BA6D9A56E83EF0D4916F8F96B66508?sequence=1 |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
