Effects of nicotine exposure on renal function of normal and hypercholesterolemic rats.
OBJECTIVE
Renal risks of nicotine exposure associated with hypercholesterolemia are still unknown.


METHODS
Thus, hypercholesterolemic rats (HC) and their control (C) were evaluated by inulin clearance (InCl) measured at baseline and during nicotine infusion (100 microg/kg b.w.). Five groups were studied: (i) C; (ii) DEN (C submitted to a renal denervation); (iii) C + L-arginine (0.25% in drinking water); (iv) HC, and (v) HC + L-arginine (0.25% in drinking water). Furthermore, C and HC had their renal blood flow (RBF) measured and they have also been chronically treated with nicotine (12.5 microg/ml in drinking water) to assess InCl on the 8th day.


RESULTS
Nicotine increased blood pressure in C, DEN and HC and reduced InCl only in C. L-Arginine treatment blunted nicotine effects on blood pressure and increased InCl only in C. Moreover, nicotine did not change RBF in C but elicited in HC, whereas renal vascular resistance was increased in C and unchanged in HC. Indeed, chronic nicotine exposure has also reduced InCl in C.


CONCLUSIONS
Nicotine acted on the adrenergic system and nitric oxide counteracted this action in C, but the same may not be applied to HC. An impairment in renal autoregulation may explain why InCl was unchanged in HC.
Tamaoki
Lie
L
Laboratório de Pesquisa Básica (LIM-12), Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Oshiro-Monreal
Fabíola M
FM
Helou
Claudia M B
CM
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006937:Hypercholesterolemia / Q000503:physiopathology*; D006977:Hypertension, Renal / Q000503:physiopathology*; D007668:Kidney / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D009538:Nicotine / Q000633:toxicity*; D018722:Nicotinic Agonists / Q000633:toxicity*; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012079:Renal Circulation / Q000187:drug effects
D018722:Nicotinic Agonists; D009569:Nitric Oxide; D009538:Nicotine