[Effects of losartan on the levels of angiotensin II and its type-1 receptor in diabetic rat kidney].
OBJECTIVE
To investigate the effect of losartan, an angiotensin II type-1 receptor (AT1R) antagonist, on the levels of angiotensin II (Ang II) and AT1R in diabetic rat kidney.


METHODS
Male Wistar rats were divided into 3 groups, group A (n=11) served as the control group, group B (n=11) included the diabetic rats (induced by intraperitoneal injection of streptozotocin) without any therapy, and group C (n=9) diabetic rats treated with losartan. After 18 weeks of treatment, the kidneys were taken from all the rats to measure the expression of AT1R mRNA by RT-PCR and detect the Ang II level. Blood was also drawn from the heart to measure Ang II level, and 24-hour urine was collected to measure albumin level (urine albumin excretion, UAE) with rat albumin enzyme immunoassay kit.


RESULTS
The blood and renal Ang II levels showed no significant difference between the 3 groups. The expression of renal AT1R mRNA in group B (0.62-/+0.17) was significantly lower than that in group A (1.13-/+0.82, P<0.01) and group C (1.13-/+0.62,P<0.01). UAE in group B (2.18-/+1.98 mg) was significantly higher than that in group A (0.41-/+0.47 mg/d, P<0.01) and C (0.65 -/+0.89 mg/d, P<0.01).


CONCLUSIONS
Losartan can increase the expression of AT1R mRNA in diabetic rat kidneys without altering the blood and renal Ang II levels.
Wu
Wen
W
Department of Endocrinology, Institute of Geriatrics, People's Hospital of Guangdong Province, Guangzhou 510080, China.
Ding
He-lin
HL
Chen
Li-hong
LH
Fu
Zu-zhi
ZZ
D000804:Angiotensin II / Q000097:blood / Q000378:metabolism*; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000188:drug therapy* / Q000235:genetics; D007118:Immunoassay / Q000379:methods; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019808:Losartan / Q000627:therapeutic use*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D047228:Angiotensin II Type 1 Receptor Blockers; D012333:RNA, Messenger; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II; D019808:Losartan