Abstract
Artificial fever is generally regarded as a safe form of therapy even in late pregnancy, 1 but the relatively delicate and rapidly developing blastocyst at about the time of implantation seems to offer the prospect of a low thermal death point with safety to the maternal gonads and tissues. 1 Pincus and Enzmann 2 found that rabbit eggs in vitro could be induced to form polar bodies by 3-min exposures at 45.5°C. These were parthenogenetic activations and the subsequent history of the eggs was not recorded.
A simple method of fever treatment for rabbits was described by Schamberg and Rule, 3 who exposed the animals for 20 min at 45°C (113°F) and brought the body temperature up to 110°F.
To determine whether otherwise harmless periods of induced fever can terminate pregnancy in the rabbit, 20 mature does were mated and each doe was given fever treatment by the method of Schamberg and Rule, 72 to 80 hr after the observed mating or matings. Most of the matings were made to 2 or 3 bucks successively. The 20 matings represent 14 different does, some having been used more than once. The animals were first placed in a bath made from a 50-gallon metal barrel with a false floor of strong wire netting, and water at 100°F was run in until they could just keep their noses above the water line while standing on the netting. During the next 10 min hot water was added to bring the temperature of the Whole bath to 113°F, but the water level was kept constant by side outlet. The rectal temperature was raised to 108-109°F, an encrease of 6-7°F. Twenty min at the fever producing level was followed by a 5-min period during whic cold water was added to bring the bath temperature back to 100°F.
Get full access to this article
View all access options for this article.