The effects of dietary lead on ethanol-reinforced responding.
Sixteen adult male rats were presented with a diet containing no added lead (Group Control) or a diet containing 500 ppm inorganic lead (Group Lead) for 60 days. Subsequently, all animals were trained to lever press on an FR 1 reinforcement schedule for an ethanol reinforcer using a food-induction procedure where 20 g of food were presented to deprived animals 1 hr prior to the training session. Gradually, the daily food allotment was shifted to 15 min post-session and the ethanol concentration maintained at 6% (v/v). On a subsequent dose/response test, serial presentations of 1, 2, 4, 8, 16, and 32% ethanol reinforcement (v/v) were presented to both groups of animals. The results from the initial self-administration test using 6% ethanol as the reward outcome showed that Group Lead lever pressed at a significantly lower rate than Group Control. In addition, on the dose/response test control animals increased responding at a lower concentration, and then as dose levels continued to increase, began to decrease responding earlier than lead-treated animals. Apparently, sensitivity to ethanol effects is decreased by lead toxicity. The importance of these data for understanding other metal/alcohol interactions is discussed.
Nation
J R
JR
Department of Psychology, Texas A & M University, College Station 77843.
Dugger
L M
LM
Dwyer
K K
KK
Bratton
G R
GR
Grover
C A
CA
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003216:Conditioning, Operant / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004435:Eating; D000431:Ethanol / Q000008:administration & dosage*; D007854:Lead / Q000097:blood / Q000633:toxicity*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012054:Reinforcement, Psychology
D007854:Lead; D000431:Ethanol