Modulation of renal hemodynamics by IGF-1 is absent in spontaneously hypertensive rats.
We recently reported that attenuation of vasoactive agent-induced calcium signal and cell contraction of mesangial cell by insulin-like growth factor 1 (IGF-1), observed in normal mesangial cells, is totally abolished in spontaneously hypertensive rat (SHR) mesangial cells. This phenomenon might be related to the well-known aberrant regulation of SHR glomerular hemodynamics. Since it has been reported that in vivo IGF-1 infusion increases renal plasma flow (RPF) and glomerular filtration rate (GFR), we examined whether the modulation of renal function by IGF-1 is altered in SHR. We performed in vivo renal clearance studies using eight-week-old SHR and control Wistar Kyoto rats (WKY) before and after IGF-1 (5 micrograms/kg) infusion into the left renal artery for 20 minutes. Mean arterial pressure was not affected by IGF-1 in both WKY and SHR. In WKY, IGF-1 increased GFR and RPF, and decreased renal vascular resistance (RVR). However, GFR, RPF, and RVR were not altered by IGF-1 in SHR, while systemic infusion of angiotensin II antagonist, CV-11974, increased GFR and RPF. The present data show that the modulation of renal hemodynamics by IGF-1 is absent in SHR. This might be related the pathophysiology of the development of hypertension.
Inishi
Y
Y
Third Department of Internal Medicine, Ohashi Hospital, Toho University School of Medicine, Japan.
Katoh
T
T
Okuda
T
T
Yamaguchi
T
T
Kurokawa
K
K
D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D001713:Biphenyl Compounds; D001786:Blood Glucose / Q000187:drug effects; D005934:Glucagon / Q000097:blood; D006439:Hemodynamics / Q000187:drug effects*; D006973:Hypertension / Q000503:physiopathology*; D007269:Injections, Intra-Arterial; D007328:Insulin / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000494:pharmacology*; D007668:Kidney / Q000187:drug effects / Q000503:physiopathology*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D013777:Tetrazoles / Q000494:pharmacology
D001562:Benzimidazoles; D001713:Biphenyl Compounds; D001786:Blood Glucose; D007328:Insulin; D013777:Tetrazoles; D007334:Insulin-Like Growth Factor I; D005934:Glucagon; C081643:candesartan