Cardiac and renal endothelin-1 binding sites in streptozotocin-induced diabetic rats.
The aim of this work was to study cardiac and renal endothelin binding sites during the progression of diabetes. Male Crl:CD (BR) rats were made diabetic by injection of streptozotocin (STZ, 45 mg kg-1 i.v.). Only rats with a glycaemia of 500 mg per 100 ml or higher, were used. The hearts were taken at 2, 4 or 6 weeks and kidneys at 2 and 6 weeks, after diabetes induction, for binding studies. In the heart, the number of Et-1 binding sites was significantly increased 2 weeks after STZ-induction of diabetes (449 +/- 13 vs. 345 +/- 18 fmol (mg protein) -1, in controls; p < 0.05) without modification of KD value (104 +/- 5 vs 101 +/- 7 pM). Comparable results were obtained 4 and 6 weeks after STZ-induction. In the kidney both the parameters were unchanged at all the times tested.


CONCLUSIONS
a specific increase in cardiac Et-1 binding sites, without change in affinity of the peptide, was found 2, 4 and 6 weeks after diabetes induction; while renal Et-1 binding sites were not modified.
Vesci
L
L
Department of Pharmacology, Sigma-Tau S.p.A., Pomezia, Italy.
Mattera
G G
GG
Tobia
P
P
Corsico
N
N
Calvani
M
M
D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism* / Q000473:pathology; D019332:Endothelin-1 / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D006352:Heart Ventricles; D007668:Kidney / Q000378:metabolism*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D013311:Streptozocin; D013997:Time Factors
D019332:Endothelin-1; D013311:Streptozocin