Multiple forms of glucose-adenosine triphosphate phosphotransferase in rat mammary gland.

Abstract

Measurements have been made of the total hexokinase activity and of the relative amounts of types I and II hexokinase in rat mammary gland and at different stages of the lactation cycle. The total hexokinase activity increased during lactation, that of type II increasing to a greater extent than that of type I; the type II/type I activity ratio rose from a pregnancy value of about 1 to a mid-lactation value of 3, returning to 1 on involution. The changes in type II hexokinase activity during the lactation cycle parallel the changes in the insulin sensitivity of mammary-gland tissue. A study of the effect of alloxan-diabetes on mammary-gland hexokinase during the mid-lactation period revealed that, although the total glucose-phosphorylating capacity of the mammary gland was almost unchanged, the relative contributions of type I and type II hexokinases altered, decreasing the type II/type I activity ratio to about 1.

• Authors: E Walters, P McLean
• Journal: The Biochemical journal (Biochem J) Vol. 104 Issue 3 Pg. 778-83 (Sep 1967) ISSN: 0264-6021 [Print] England
• PMID: 6049924 (Publication Type: Journal Article)

Chemical References

• Hexokinase
• Glucokinase

Topics

• Animals
• Diabetes Mellitus, Experimental (complications)
• Electrophoresis
• Female
• Glucokinase (metabolism)
• Hexokinase (metabolism)
• Lactation
• Mammary Glands, Animal (enzymology)
• Oxidative Phosphorylation
• Pregnancy
• Pregnancy, Animal
• Rats
• Spectrophotometry