Comparative study on altered hepatic metabolism of CYP3A substrates in rats with glycerol‐induced acute renal failure

Abstract

To examine the mechanism accounting for the diverse alteration of hepatic metabolism of CYP3A substrates observed with renal function being severely impaired, the hepatic drug metabolizing activity was evaluated using liver microsomes prepared from rats with glycerol-induced acute renal failure (ARF). Midazolam, nifedipine and rifabutin were employed as representative CYP3A substrates. When the Michaelis-Menten parameters, K(m) and V(max) , were examined in the incubation study, the K(m) values of midazolam and nifedipine in ARF rats were shown to decrease by 50.9% and 29.9% compared with the normal value, respectively. The V(max) values of midazolam and nifedipine in ARF rats also decreased by 49.3% and 28.0%, respectively, showing that their decreased K(m) values accompanied the decreased V(max) values. The parameters of nifedipine seemed to alter to a lesser extent than those of midazolam. As for rifabutin metabolism, the decrease in the K(m) value was observed in ARF rats, but it did not accompany the decrease in the V(max) value. Then, the hepatic expressions of the CYP3A subfamily were examined with western blotting using anti-CYP3A1 and anti-CYP3A2 antibodies. It was revealed that the hepatic expression of CYP3A2 decreased, while that of CYP3A1 was unaffected. Additionally, a band signal deduced to originate from CYP3A9 was clearly detected in ARF, but not in normal rats. Considering each substrate having different specificities for CYP3A subfamily member proteins, individual alterations of hepatic CYP3A subfamily expression seem to underlie the diverse alterations of hepatic metabolism of CYP3A substrates in ARF rats.

Significant increase in plasma 4β-hydroxycholesterol concentration in patients after kidney transplantation

“…However, several studies in rats (1)(2)(3)(4)(5)(6) and in patients (7)(8)(9) have shown that renal failure also decreases the metabolic clearance of drugs, particularly those metabolized by cytochrome P450 (CYP). The underlying causes of altered CYP functional expression observed in kidney disease remain unclear, but several studies indicate that uremic toxins4 ␤ -Hydroxycholesterol after kidney transplantation 2569 500 l of water and 2 ml of n-hexane were added, and extraction was performed by vortexing for 1 min.…”

Association of Plasma Concentration of 4β-Hydroxycholesterol with CYP3A5 Polymorphism and Plasma Concentration of Indoxyl Sulfate in Stable Kidney Transplant Recipients

“…A multitude of environmental, genetic, and physiologic factors are known to influence CYP3A4 expression and activity (Klein and Zanger, 2013). Several studies in rats (Rege et al, 2003;Kusaba et al, 2012;Velenosi et al, 2012) and in patients (Dowling et al, 2003;Kirwan et al, 2009Kirwan et al, , 2012 have shown that renal failure decreases CYP3A expression and function. We have previously reported a significant increase in plasma concentration of 4b-hydroxycholesterol as an endogenous marker of CYP3A activity in patients with end-stage renal disease after kidney transplantation (Suzuki et al, 2013).…”

Interspecies comparison of hepatic metabolism of six newly synthesized retinoid X receptor agonistic compounds possessing a 6-[N-ethyl-N-(alkoxyisopropylphenyl)amino]nicotinic acid skeleton in rat and human liver microsomes

“…Hepatic metabolism of the compounds was evaluated in the incubation experiments with the rat and human liver microsomes in the same manner as previously reported 10,11 . In brief, the incubation mixture was prepared with phosphate buffer containing 250-500 mg of the microsomal protein.…”

“…The pooled liver microsomes were prepared with the ultracentrifugation method previously reported 10,11 . Male Wistar rats were obtained from Japan SLC Inc. (Hamamatsu, Japan).…”