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The activities of jejunal carbohydrate-metabolizing enzymes show adaptive drugs, and sex hormones. To learn whether insulin, tolbutamide, and glucagon had effects on these enzymes, we performed serial peroral jejunal biopsies in normal young men and in obese patients, before and after treatment with these agents. Jejunal mucosa was assayed for glycolytic enzyme activities, pyruvate kinase (PK), hexokinase (HK), and fructose-1,6-diphosphate aldolase (FDPA), and the nonglycolytic enzyme activity, fructose diphosphatase (FDPase). Insulin significantly increased the activity of jejunal PK (+48% change from control) and HK (+6%), decreased the activity of FDPase (-36%),and had no effect on FDPA. Glucagon had opposite effects; the activity of PK was decreased (-33%) and FDPase was increased (+50%). Tolbutamide significantly increased the activities of PK (+47%), HK (+14%), and FDPA (+7%), and decreased the activities of FDPase (-36%). The results of tolbutamide on glycolytic enzyme activities were independent of endogenous insulin. The data support the concept that jejunal carbohydrate-metabolizing enzymes in man respond to hormones and drugs similar to responses observed in rat liver. This is important because it now gives us a means of studying the actions of these hormones directly in human tissue.
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
October 1978,
Gastroenterology,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
May 2001,
Biological & pharmaceutical bulletin,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
March 1983,
Biochemical pharmacology,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
January 2022,
Dose-response : a publication of International Hormesis Society,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
January 1998,
Metabolism: clinical and experimental,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
February 1982,
The Journal of clinical endocrinology and metabolism,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
April 1974,
The Cornell veterinarian,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
January 1966,
Enzymologia biologica et clinica,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
July 1971,
Hormone and metabolic research = Hormon- und Stoffwechselforschung = Hormones et metabolisme,
E G Lufkin, and
O D Taunton, and
F B Stifel, and
N S Rosensweig, and
L Hagler, and
R S Teplick, and
R H Herman
August 1965,
Naika hokan. Japanese archives of internal medicine,
