Maternal administration of a single dose of retinoic acid (vitamin A acid, 100 mg/kg) on either the 11 th, 11 1/2, 12th, 12 1/2, 13th or 13 1/2 day of gestation produced phocomelia or partial phocomelia in ICR/DUB fetuses. The results depended upon the time of treatment and two gradients of effect were produced: 1) cranio-caudal gradient, since forelimb defects resulted from treatment between days 11 and 13, while similar hindlimb abnormalities were produced by administration of retinoic acid 12 to 24 hours later: 2) proximo-distal gradient, due to the heterogenous sensitivity among individual bones of the limb. In the forelimb, early treatment (11th day) produced humero-ulnar defects and later treatment (12th day) ulnoradial defects. A similar proximo-distal gradient was observed in the hindlimb. The use of teratological studies as a tool to assist morphogenetic investigation is discussed.
Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-14414 |
Date | 01 November 1980 |
Creators | Kwasigroch, Thomas E., Kochhar, D. M. |
Publisher | Digital Commons @ East Tennessee State University |
Source Sets | East Tennessee State University |
Detected Language | English |
Type | text |
Source | ETSU Faculty Works |
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