All-or-none suppression of glucose sham feeding by an intragastric mixed meal in rats.

Rats were permitted to sham feed a 1 M glucose solution after varying delays (0-40 min) following the intragastric (IG) infusion of a large, nutritionally adequate meal. (a) The metal affected sham feeding in an all-or-none way. After such a meal, sham feeding was either suppressed almost entirely, or it was not suppressed at all as compared with a no-meal control condition. (b) When it occurred, the suppression was short-lived: As little asa 20-min delay after the meal could suffice to change its suppressant effect from «all» to «none»