[Change in ghrelin level with the amelioration of glucose and lipid metabolic disorder in OLETF rats].
OBJECTIVE
To explore the exact role of ghrelin in glyco- and lipo-metabolism.


METHODS
We compared the levels of ghrelin mRNA in gastric tissue, ghrelin in gastric tissue and plasma among LETO rats( non diabetes, n=10), OLETF rats( type 2 diabetes, n=10), OLETF/M rats( OLETF rats managed with Metformin at the dose of 100 mg/kg weight, n=10) and OLETF/F rats( OLETF rats managed with Fenofibrate at the dose of 20 mg/kg weight, n=10). The levels of ghrelin mRNA were tested by Northern blotting, and the ghrelin content in gastric tissue and plasma detected by RIA.


RESULTS
At the age of 30 weeks, the ghrelin fasting plasma levels of OLETF rats were lower than those of LETO rats(37.49+/-6.42 vs 58.52+/-5.85, P<0.05). The fasting blood plasma ghrelin levels of OLETF/M groups showed an increased tendency, but the difference of the fasting blood plasma ghrelin levels to those of the untreated OLETF rats were not noticeable(49.65+/-6.76 vs 37.49+/-6.42,P>0.05). However, the fasting blood plasma ghrelin levels of OLETF/F group were more than those that of the untreated OLETF rats (62.02+/-7.35 vs 37.49+/- 6.42,P<0.05). The mRNA and polypeptide levels of ghrelin in stomach tissue had no marked difference in the 4 groups at the age of 17 weeks. At the age of 30 weeks, the difference of mRNA(1.18+/-0.06 vs 1.27+/-0.05,P<0.05) and polypeptide (114.77+/- 31.65 vs 152.87+/-18.24, P<0.05) between OLETF group and LETO group had been observed. Metformin didn't influence the mRNA and polypeptide levels of ghrelin in stomach tissue markedly. Howere, the polypeptide (161.75+/-23.61 vs 114.77+/-31.65, P<0.05) and mRNA(1.36+/-0.09 vs 1.18+/-0.06,P<0.05) levels of ghrelin in stomach tissue of OLETF/F group were markedly higher than those of stomach tissue ghrelin in the untreated OLETF group.


CONCLUSIONS
Our data demonstrate that ghrelin may play a role in protective, compensative and negative-feedback regulation in the disorder of glucose and lipid metabolism.
Wang
Nian-hong
NH
Department of Endocrinology, Peking University First Hospital, Beijing 100034, China.
Guo
Xiao-hui
XH
Wang
Wei
W
D000818:Animals; D015152:Blotting, Northern; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000188:drug therapy / Q000378:metabolism*; D011345:Fenofibrate / Q000627:therapeutic use; D005753:Gastric Mucosa / Q000378:metabolism; D054439:Ghrelin / Q000097:blood* / Q000235:genetics / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D000960:Hypolipidemic Agents / Q000627:therapeutic use*; D008297:Male; D008687:Metformin / Q000627:therapeutic use; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D011897:Random Allocation; D051381:Rats; D020334:Rats, Inbred OLETF; D013270:Stomach / Q000187:drug effects
D054439:Ghrelin; D007004:Hypoglycemic Agents; D000960:Hypolipidemic Agents; D012333:RNA, Messenger; D008687:Metformin; D011345:Fenofibrate