Adolescent Binge Drinking Produces Tolerance

Early Consumption Can Affect Growth, Brain Function

The 2000 National Household Study on Drug Abuse reports that close to 20 percent of young people between 12 and 17 years of age had consumed alcohol in the preceding month; more than 10 percent reported a "binge" style of drinking, defined as consumption of five or more drinks on one occasion.

In the October 2003 issue of Alcoholism: Clinical & Experimental Research, researchers use adolescent rodents to demonstrate that a binge pattern of alcohol consumption called chronic intermittent ethanol (CIE) exposure can significantly hamper normal growth and alter brain function. "We found that CIE exposure during adolescence produces tolerance, defined as a decrease in the response to a drug due to previous exposure with the drug, in many wide- ranging, biological functions," said Douglas B. Matthews, associate professor of psychology at The University of Memphis and corresponding author for the study. "For example, CIE exposure significantly hampered normal growth as measured by weight gain, and altered liver function as measured by alcohol elimination rates. In addition, CIE exposure appears to alter brain function, as measured by hypnotic and cognitive tolerance. While it is currently unknown if CIE exposure is more serious in adolescence than adulthood, the current research does demonstrate that the tolerance produced by CIE during adolescence can last into adulthood." Researchers used 135 male Sprague- Dawley rats for four experiments. On postnatal day 30 (the rodent equivalent of adolescence), pretreatment consisted of injecting all of the rats with 5.0 g/kg alcohol or saline every 48 hours for 20 days. For experiment I, 24 rats (12 pretreated with alcohol, 12 with saline) were given free access to food and water.

For experiment II, loss of righting reflex (the animal's inability to right itself and return to all fours) was observed in 24 rats (12 pretreated with alcohol, 12 with saline) after each injection. For experiment III, blood alcohol levels were observed and elimination rates calculated for 17 rats (9 pretreated with alcohol, 8 with saline) after the first and fifth pretreatments, then all animals were tested with 5.0 g/kg at completion of pretreatment and elimination rates were recalculated.

For experiment IV, 70 rats (36 pretreated with alcohol, 34 with saline) were trained on a maze task on nontreatment days and, after completing pretreatment and training, were tested after an alcohol challenge (1.0, 1.5 or 2.0 g/kg) or saline. Tests for experiments II, III and IV were repeated in the same animals following 12 alcohol-free days. "The key finding of this set of studies is that CIE exposure during adolescence produces profound tolerance that in some cases can last into adulthood," said Matthews. "These findings suggest adolescence as a unique developmental period where exposure to high alcohol levels can produce changes in biological functions that might have long-lasting implications."

The 2000 National Household Study on Drug Abuse reports that close to 20 percent of young people between 12 and 17 years of age had consumed alcohol in the preceding month; more than 10 percent reported a "binge" style of drinking, defined as consumption of five or more drinks on one occasion.

In the October 2003 issue of Alcoholism: Clinical & Experimental Research, researchers use adolescent rodents to demonstrate that a binge pattern of alcohol consumption called chronic intermittent ethanol (CIE) exposure can significantly hamper normal growth and alter brain function. "We found that CIE exposure during adolescence produces tolerance, defined as a decrease in the response to a drug due to previous exposure with the drug, in many wide- ranging, biological functions," said Douglas B. Matthews, associate professor of psychology at The University of Memphis and corresponding author for the study. "For example, CIE exposure significantly hampered normal growth as measured by weight gain, and altered liver function as measured by alcohol how long does weed stay in your system elimination rates. In addition, CIE exposure appears to alter brain function, as measured by hypnotic and cognitive tolerance. While it is currently unknown if CIE exposure is more serious in adolescence than adulthood, the current research does demonstrate that the tolerance produced by CIE during adolescence can last into adulthood." Researchers used 135 male Sprague- Dawley rats for four experiments. On postnatal day 30 (the rodent equivalent of adolescence), pretreatment consisted of injecting all of the rats with 5.0 g/kg alcohol or saline every 48 hours for 20 days. For experiment I, 24 rats (12 pretreated with alcohol, 12 with saline) were given free access to food and water.

For experiment II, loss of righting reflex (the animal's inability to right itself and return to all fours) was observed in 24 rats (12 pretreated with how long does pot stay in your system alcohol, 12 with saline) after each injection. For experiment III, blood alcohol levels were observed and elimination rates calculated for 17 rats (9 pretreated with alcohol, 8 with saline) after the first and fifth pretreatments, then all animals were tested with 5.0 g/kg at completion of pretreatment and elimination rates were recalculated.

For experiment IV, 70 rats (36 pretreated with alcohol, 34 with saline) were trained on a maze task on nontreatment days and, after completing pretreatment and training, were tested after an alcohol challenge (1.0, 1.5 or 2.0 g/kg) or saline. Tests for experiments II, III and IV were repeated in how long does marijuana stay in your system the same animals following 12 alcohol-free days. "The key finding of this set of studies is that CIE exposure during adolescence produces profound tolerance that in some cases can last into adulthood," said Matthews. "These findings suggest adolescence as a unique developmental period where exposure to high alcohol levels can produce changes in biological functions that might have long-lasting implications."

Part Two: Long-Term Effects Uncertain