Is Guinea Pig Follicular Fluid Auto-Antigenic? ∗

In reporting some anaphylactic studies with mammalian follicular fluid Lyons and Van de Carr 1 claimed (1) that the follicular fluids of 4 mammals studied (sow, cow, mare and ewe) were closely related immunologically; (2) that guinea pig follicular fluid was auto-antigenic and that fatal anaphylaxis could be produced at a definite time in the oestrous cycle (tenth-sixteenth days) in normal guinea pigs on primary injection of heterologous follicular fluid; (3) that guinea pigs artificially sensitized to heterologous follicular fluid proteins are temporarily desensitized during the early part of the oestrous cycle by the liberation of their own follicular fluid.

While the first of these claims seemed not improbable from what is known about certain non species-specific or relatively species specific antigens, the others seemed so remarkable and, if substantiated, of such biological importance that we were led to try to verify them.

A number of healthy female guinea pigs weighing 300–350 gm. were observed to determine the length of the oestrous cycles. Only those animals having a fairly regular cycle, 15 to 17 days were used. The test injections were made into a large leg vein rather than intracardially, to avoid the danger of a pericardial hemorrhage. The beef and hog follicular fluid used in these experiments was collected as soon as possible after the animals were slaughtered. It was centrifuged and either used immediately or kept frozen until needed, at which time it was thawed slowly at room temperature.