Effects of Kampo medicine, keishi-ka shakuyaku-to (TJ-60) on alteration of diacylglycerol metabolism in gastrointestinal smooth muscle of diabetic rats.
Abstract
AIM: To examine the effects of Kampo medicine, keishi-ka-shakuyaku-to (TJ-60) on
the signal transduction in diabetic gastrointestinal dysfunction.
METHODS: Experimental diabetic models were prepared using streptozotocin
(STZ)-treated Wistar rats. Randomly selected STZ rats were treated with insulin
(12 U/kg/d) or TJ-60 (1% of food intake). Diacylglycerol (DG) and DG kinase
activities were quantified in isolated aortic smooth muscle tissue.
RESULTS: One of the key element of the PI-turnover, DG kinase activity in resting
state in gastric smooth muscle was significantly increased compared to the
control value, and carbachol (CCh)-induced response was not detectable, but it
was detected in the control rats. On the other hand resting activity in ileum did
not differ from the control, but the CCh-induced responses were suppressed.
Treatment with TJ-60 indicated resistant effects for the alteration of DG kinase
activities in diabetic intestinal tissues. In order to reveal the mechanism of
the effects, total content of DG was measured, because the DG plays important
role in the PI-turnover and the DG converted from not only PI but also
incorporated glucose under high glucose condition. Patterns of the change in DG
levels were similar to those in DG kinase. These results indicate that the effect
of TJ-60 occurs at the cellular level of DG.
CONCLUSION: Dysfunction of gastrointestinal smooth muscle in diabetes is mediated
by an alternation of DG and DG kinase. TJ-60 influences the alteration and relief
the dysfunction.
Keywords:
the signal transduction in diabetic gastrointestinal dysfunction.
METHODS: Experimental diabetic models were prepared using streptozotocin
(STZ)-treated Wistar rats. Randomly selected STZ rats were treated with insulin
(12 U/kg/d) or TJ-60 (1% of food intake). Diacylglycerol (DG) and DG kinase
activities were quantified in isolated aortic smooth muscle tissue.
RESULTS: One of the key element of the PI-turnover, DG kinase activity in resting
state in gastric smooth muscle was significantly increased compared to the
control value, and carbachol (CCh)-induced response was not detectable, but it
was detected in the control rats. On the other hand resting activity in ileum did
not differ from the control, but the CCh-induced responses were suppressed.
Treatment with TJ-60 indicated resistant effects for the alteration of DG kinase
activities in diabetic intestinal tissues. In order to reveal the mechanism of
the effects, total content of DG was measured, because the DG plays important
role in the PI-turnover and the DG converted from not only PI but also
incorporated glucose under high glucose condition. Patterns of the change in DG
levels were similar to those in DG kinase. These results indicate that the effect
of TJ-60 occurs at the cellular level of DG.
CONCLUSION: Dysfunction of gastrointestinal smooth muscle in diabetes is mediated
by an alternation of DG and DG kinase. TJ-60 influences the alteration and relief
the dysfunction.