jpet/2003/055616 revised pparγ agonist provides superior

JPET/2003/055616 REVISED

PPARγ agonist provides superior renal protection vs. angiotensin converting

enzyme inhibition in a rat model of type 2 diabetes with obesity

by

Chris Baylis, Elke-Astrid Atzpodien, Gary Freshour, and Kevin Engels

Department of Physiology

West Virginia University

Morgantown, WV (C.B., G.F., and K.E.)

and

F. Hoffmann-La –Roche AG

Basel, Switzerland (E-A.A.)

Copyright 2003 by the American Society for Pharmacology and Experimental Therapeutics.

JPET Fast Forward. Published on October 14, 2003 as DOI:10.1124/jpet.103.055616This article has not been copyedited and formatted. The final version may differ from this version.JPET Fast Forward. Published on October 14, 2003 as DOI: 10.1124/jpet.103.055616

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Running Head: PPARγ agonists protect the kidney better than ACEI

Address correspondence to: Chris Baylis, Ph.D.,

Professor of Physiology, POB 9229,

West Virginia University Health Sciences Ctr.

1 Medical Center Drive, Morgantown, WV 26506-9229, USA.

Tel: 304 293 1499. fax: 304 293 3973 email: [email protected]

Number of text pages = 14

Number of tables = 1

Number of Figures = 6

Number of References = 37

Number of words in the Abstract = 228

Number of words in the Introduction = 323

Number of words in the Discussion = 933

Abbreviations:

ACEI angiotensin converting enzyme inhibitors

AT1 angiotensin type 1

BP systemic blood pressure

DN diabetic nephropathy (DN)

ESRD end stage renal disease (ESRD)

GFR glomerular filtration rate

PGC glomerular blood pressure

PPAR γ peroxisome proliferator-activated receptor γ

ΠA colloid osmotic pressure of the plasma).

This article has not been copyedited and formatted. The final version may differ from this version.JPET Fast Forward. Published on October 14, 2003 as DOI: 10.1124/jpet.103.055616

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ABSTRACT:

The inbred obese Zucker (ZDF/Gmi, fa/fa) rat develops severe hyperglycemia

and also exhibits severe renal disease. In this study we compared the relative benefits

of long term treatment with angiotensin converting enzyme inhibition (ACEI) to a PPARγ

agonist. Four groups of obese inbred Zucker rats were studied over a 6 month

observation period; untreated animals, rats treated with ACEI alone, rats treated with

PPARγ agonist alone and rats treated with a combination of ACEI and PPARγ agonist.

PPARγ agonist treatment normalized plasma glucose and led to massive increases in

body weight. Both ACEI and PPARγ agonist were effective in reducing the proteinuria

and glomerular and tubular kidney damage. However, the PPARγ agonist exerted

superior renal protection when compared to ACEI, in this model of spontaneously

occurring chronic renal disease (CRD) in the diabetic, obese inbred Zucker rat. Of note,

although ACEI lowered BP, there was no difference in glomerular blood pressure in any

group at the end of the study. The GFR was improved by ACEI with a borderline effect

of PPARγ agonist alone. A mild additive protection on GFR and tubulointerstitial

damage was seen with the combination. Based on the literature it is likely that the

superior protection by PPARγ agonist vs. glomerular and tubular damage as well as

proteinuria extends beyond glycemic and lipidemic control and also reflects direct,

protective intrarenal actions of the PPARγ agonists.


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Diabetic nephropathy (DN) eventually develops in ~ 30% of patients with both

type 1 and type 2 diabetes, and once present will progress in many of these individuals

to end stage renal disease (ESRD). Because of the rapidly increasing prevalence of

type 2 diabetes, this is leading to a massive increase in the incidence of ESRD in the

US and elsewhere (Ritz 1999). Blockade of the angiotensin system is currently the

standard treatment for slowing progression of renal disease in diabetic nephropathy

(DN) (Hollenberg 2002), although this has no inherent beneficial effect on the diabetes.

Where angiotensin converting enzyme inhibitors (ACEI) were first used, these are now

being replaced, or supplemented with angiotensin type 1 (AT1) receptor blockers.

Nevertheless, the incidence of DN in type 2 diabetes continues to increase (Ritz 1999).

In recent years it has also become evident that prolonged tight glycemic control

slows down progression of DN in type 1 diabetics (DCCT 1995) and some (but not all)

studies suggest that good metabolic control is protective to DN in type 2 diabetes (Di

Landro et al 1998). The recent development of the peroxisome proliferator-activated

receptor γ (PPAR γ) agonists has provided a novel means of improved glycemic control.

These drugs (the thiazolidinediones) enhance sensitivity of the peripheral insulin

receptor to glucose in type 2 diabetes, leading to reduced plasma glucose and insulin

levels and reductions in glycosylated Hb. These drugs also exert a beneficial effect on

the lipid profile, are antihypertensive and inhibit collagen type 1 production by the

glomerular mesangial cells ( Rosak 2002; Guan and Breyer 2001).

The present study was conducted to test the relative benefit of long term (6

month) ACEI vs. PPAR γ agonist therapy as well as in combination, in a rat model of

severe type 2 diabetes, the inbred obese Zucker (ZDF/Gmi, fa/fa) rat. When untreated


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these rats develop marked kidney damage compared to their lean littermates (Vora et

al., 1996; Baylis 2001).


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METHODS:

Studies were conducted on 30 inbred obese male Zucker (ZDF/Gmi, fa/fa) rats

purchased from Genetic Models, Inc., Indianapolis, at age 5 weeks. Baseline

measurements of blood glucose and urinary protein excretion (see below) were made at

6 weeks of age and at 8 weeks of age rats were randomized to one of the following 4

groups and followed for 6 months: 1). Controls (n=9), 2). Rats treated with PPAR γ

agonist rosiglitazone (Rosi, oral; 3mg/Kg/d) (n=6), 3). Rats treated with ACE inhibitor

cilazapril (Cil, oral 10mg/kg/d) (n=9), 4). Rats treated with both drugs (n=6). For the two

different drugs, submaximally effective doses were selected based on their specific

pharmacologic effects (reduction of insulin

resistance for PPARγ agonist; antihypertensive effect for ACEI).

One Rosi treated and 2 control rats died during the 6 month observation period and

were not included in any analysis. Body weight and water intakes were measured every

48 hours and the drug concentration adjusted according to water consumption, to give a

constant dose of drug.

All rats were allowed water and were fed Purina 5008 diet ad lib, to maintain a

hyperglycemic state in the obese rats. Eight hour urine collections were made at

monthly intervals and urine frozen for later analysis. Tail vein blood samples were

taken at 2 monthly intervals during the study for analysis of blood glucose and BUN.

After 6 months observation, rats were prepared for terminal acute micropuncture studies

for measurement of glomerular blood pressure and renal hemodynamics. Anesthesia

was induced with ip Inactin; for the grossly obese rats treated with Rosi, an induction

dose of 180mg/kg BW was given followed by frequent iv supplementation (40mg/kg), as


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needed. Controls and Cil alone treated rats received the regular ip induction dose of

120mg/kg with iv supplementation at 20mg/kg, as required. Both jugular veins were

catheterized, one for iv Inactin and one for an infusion of 0.9% NaCl (~0.5% BW) + 3H-

inulin (2 µC/ml) and PAH (0.5g/100ml) was infused at 50µl/kg BW via T piece. Before

starting the NaCl/ inulin/ PAH infusion, an arterial cannula was placed in the right carotid

artery and a 0.2ml blood sample was removed for later estimation of plasma creatinine.

Then the trachea was cannulated, the abdomen opened by a ventral midline incision

and the urinary bladder was catheterized. The perirenal fat was gently cleared from the

left kidney and the kidney was stabilized for micropuncture as described previously

(Deng and Baylis 1995). Paraffin wax blocks were inserted into 5-12 midproximal

tubule segments on the kidney surface, so that stop-flow pressure (Psf) could be

measured proximal to the block.

After an initial bolus and 40 min infusion (~2ml/h) of a solution of 0.9% NaCl

containing 3H-inulin and PAH (PAH concentration in the infusate was varied according

to the group so that plasma PAH was always below 4mg/dl), 2 timed 15 –20 min urine

collections were made with midpoint arterial blood samples (0.2ml). During whole

kidney clearance periods, measurements were made of Psf and free flow proximal

tubule pressure. Then the rat was sacrificed and the kidneys, heart, liver and pancreas

were removed and fixed in 10% buffered formalin for at least 24h for later histologic and

immunohistologic analysis (kidneys only). Measurement of urine creatinine was by

Sigma kits # 555. Blood glucose was measured by Sigma’s glucose Trinder reagent

(Trinder 1969). PAH was analyzed colorimetrically, 3H-inulin activity was determined by


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scintillation counting and plasma protein concentration by refractometer, as described

previously (Deng and Baylis 1995; Smith et al., 1945).

For histology and immunohistochemistry, kidneys were trimmed, processed and

embedded in Paraplast. Kidney sections (2-3 µm thick) were cut and stained with

hematoxylin and eosin (HE) or periodic acid Schiff reagent (PAS). Immunostaining for

expression of CD 68 using the monoclonal antibody Ki-M6 specific for

monocytes/macrophages (BMA T-1005, 1:100 dilution, Biomedicals AG, Switzerland)

(Parwaresch et al., 1986) was performed on kidney sections of 4 animals each per

treatment group. An avidin biotin peroxidase complex technique was applied according

to the manufacturer’s specifications (ready-to-use detection kits and an automated slide

stainer, Ventana Medical System, Strasbourg, France). Renal changes were scored on

a scale of 1+ to 4+ (1+ = minimal, 2+ = slight, 3+ = moderate, 4+ = marked to massive)

as adapted from Zbinden (1976). Tubulointerstitial changes were defined as tubular

degeneration, regeneration and/or atrophy, tubular dilation, hyaline casts, interstitial

inflammatory infiltrates or fibrosis. In addition, for quantification of glomerular sclerosis,

kidney sections (5 µm thick) were cut and stained with PAS as described by us earlier

(Deng and Baylis 1995). Glomerular sclerosis was defined as segmental or global

increases in glomerular matrix, accumulation of hyaline material, and loss of local

capillary organization. All data are given as mean ±SE. Statistical significance was

assumed when p<0.05, using one- and two way ANOVA and Wilcoxon Rank sum test

for quantitative assessment of glomerular injury. All other pathology findings were

expressed as “summary incidence of grading” for each finding.


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RESULTS

As shown in Figure 1 blood glucose was normal in obese rats at 6-8 weeks of

age (time 0) but rose markedly in untreated animals and reached a stable elevated level

by age 14 –16 weeks (month 2). A similar profile was seen in the rats treated with ACEI

whereas blood glucose remained normal in both groups of rats receiving PPARγ

agonist. All PPARγ agonist treated rats were massively obese and body weight

increased profoundly over the 6 month treatment period (Figure 2) in some cases

exceeding 1kg prior to sacrifice. In contrast, the untreated rats and rats given ACEI

alone, showed only moderate weight gain with age. We did not evaluate body

composition but the 24h urinary creatinine excretion gives an index of skeletal muscle

mass. The absolute values were similar in all 4 groups but when factored for body

weight creatinine excretion was significantly higher in untreated or ACEI treated rats

(33.1±3.5 and 29.1±1.6 mg/24h/kgBW) vs. those given PPARγ agonist alone or in

combination (11.8±2.3 and 13.4±2.4; p vs. untreated <0.001 for both), suggesting

greatly increased % of adipose tissue in the PPARγ agonist treated animals.

Unfortunately the high, variable levels of plasma lipids prevented meaningful plasma

creatinine measurements.

The total urine protein excretion rose markedly in the untreated rats, reflecting

development of progressive kidney damage (Figure 3) and was significantly higher

(p<0.05) than all other groups at 6 months of observation. The ACEI was effective in

reducing urinary protein excretion although significant proteinuria (p<0.01 vs. both

PPAR Groups) was still evident after 6 months treatment. In contrast, rats given PPARγ

agonist (either +/- ACEI), developed no proteinuria over the entire treatment period.


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Histologic evaluation of the kidneys revealed pronounced glomerular sclerosis in

untreated rats with some level of injury in 26±1 % of glomeruli. Rats receiving ACEI

alone had less damage (17±1 %; p<0.05 vs. control) but this was still greater than in

either of the PPARγ agonist treated groups (PPARγ agonist alone, 9±1 % damaged

glomeruli; p<0.01 vs. ACEI alone, and PPARγ agonist + ACEI, 10±1 %; p<0.01 vs. ACEI

alone). Figure 4 shows that in addition to a higher % of the total glomeruli being

affected by damage, the grade of injury is also greater in the untreated rats, with

significantly more 3+ and 4+ damage vs. ACEI alone (p<0.05), who in turn have more

2+, 3+ and 4+ injury (p<0.05) than either PPARγ agonist treated group.

In untreated rats, in addition to pronounced glomerular sclerosis, moderate

tubulointerstitial changes were observed. These consisted of tubular atrophy,

degeneration and regeneration, tubular dilation, hyaline casts, and interstitial

mononuclear cell infiltrates and fibrosis. Slight epithelial cell vacuolation was observed

in distal tubules. These vacuolated cells appeared as swollen, clear cells with prominent

cell boundaries and condensed nuclei. (Figure 5, panel A). Treatment with either

PPARγ agonist or ACEI alone or with a combination of both drugs clearly reduced the

development of renal lesions (Figure 5, panels B-D). In addition to the drug-induced

reduction in the incidence and severity of glomerular sclerosis, associated

tubulointerstitial changes were improved in parallel. The tubulointerstitial protection was

greater in rats receiving a combination of PPARγ agonist and ACEI than in animals

given PPARγ alone, and was the least pronounced in animals receiving ACEI alone.

Treatment with PPARγ agonist alone or in combination with ACEI completely inhibited

development of tubular epithelial cell vacuolation. In contrast, treatment with ACEI alone


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had no impact on the incidence and severity of tubular epithelial cell vacuolation. The

incidence of cells expressing CD 68 within the glomeruli using the

monocyte/macrophage marker Ki M6 (Parwaresch et al., 1986) was slight in untreated

rats, minimal in rats given PPARγ agonist alone or ACEI alone, and absent in rats

receiving the combination of ACEI and PPARγ agonist. Hyperplasia of the

juxtaglomerular apparatus (JGA) was minimal in rats given ACEI as reported by others

(Owen and Molon-Noblot 1998) and was marked in rats receiving the combination of

ACEI and PPARγ agonist, with the change extending along afferent arterioles to affect

interlobular arteries. The reason for this greater severity of hyperplasia of the JGA in

the combination group is unknown. Pelvic dilation was present in untreated rats and in

all drug-treated groups to a similar extent.

The data given in Table 1 were derived from the acute study conducted at the

end of the 6 month treatment period. Arterial Hct was lower in both groups of rats

receiving PPARγ agonist than in untreated or ACEI treated rats and since the PPAR γ

agonists are reported to produce fluid retention (Lebovitz 2002), this may account for

the lower Hct although there were no differences in plasma protein concentration or the

colloid osmotic pressure of the plasma (ΠA). Untreated rats had elevated systemic BP

but normal glomerular BP (PGC) while ACEI alone or with PPARγ agonist lowered

systemic BP without altering PGC, which remained normal. The group receiving PPARγ

agonist alone had an elevated BP similar to untreated rats and PGC was also similar to

other groups. The inulin clearance was lowest in untreated rats and GFR significantly

improved in rats given ACEI alone or with PPARγ agonist. There was a borderline

improvement with PPARγ agonist alone (Figure 6).


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DISCUSSION

There was a clear benefit in treatment with either the PPARγ agonist or ACEI in

reducing the structural and functional changes in the kidney in this rat model of obesity

and type 2 diabetes. The main finding of the present study was that PPARγ agonist

gave better protection vs. ACEI on both proteinuria (p<0.005) and glomerular sclerosis

(p<0.02) in association with improved metabolic control. There was an additive

protection against tubulointerstitial damage and macrophage/ monocyte infiltration, a

borderline improvement of GFR and no additional benefit on proteinuria and glomerular

sclerosis when the PPARγ agonist was combined with ACEI vs. PPARγ agonist alone.

The inbred obese Zucker (ZDF/Gmi fa/fa) rat fed the Purina 5008 diet develops severe

diabetes and extensive kidney damage. However, the renal damage does not exhibit all

the characteristics of diabetic nephropathy. In remaining intact glomeruli there is no

evidence of mesangial expansion or thickening of the glomerular basement membrane

and the lesions seen were more indicative of focal segmental glomerular sclerosis

(Baylis 2001). In addition, this inbred strain of Zucker rats has a genetic predisposition

to develop hydronephrosis, seen to an equal extent in both obese and lean rats (Vora et

al., 1996; Baylis 2001). However, most likely the majority of the renal injury in the

obese inbred Zucker rats is due to the metabolic disturbances, since the present study

demonstrates that chronic treatment with PPARγ agonist prevents the proteinuria and

structural damage.

Given the wide range of actions of the PPARγ agonists there are a number of

possible mechanisms for the superior renal protection seen here. The glycemic control

is undoubtedly a factor since hyperglycemia exerts multiple damaging actions on the


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kidney (Phillips et al., 1995; West 2000; Larkins and Dunlop 1992; Brownlee et al.,

1988) and good glycemic control is renoprotective in clinical studies in diabetics (DCCT

1995; Di Landro et al., 1998). The vacuoles seen in the renal distal tubular epithelial

cells of untreated rats were probably the result of abnormal accumulation of glycogen

(resembling Armanni-Ebstein lesion) widely seen in renal tubules of diabetics. PPARγ

agonist treatment completely eradicated these reflecting the normalization of blood

glucose (Wehner 1998). Furthermore, experimentally induced hyperglycemia (with

streptozotocin) in normoglycemic, hyperinsulinemic outbred Zucker rats, causes early

glomerular hypertrophy (Park and Meyer 1995), a key event in progression of CRD

(Daniels and Hostetter 1990). Indeed, glomerular hypertrophy is reported as an early

pathological event in obese Zucker fa/fa and ZDF rats (Coimbra et al., 2000; Hoshi et

al., 2002).

In addition to the hyperglycemia, the untreated obese Zucker rats exhibit severe

hyperlipidemia and dyslipidemia, with LDL cholesterol and triglycerides at 20X that seen

in leans (Baylis 2001). Hyperlipidemia is one likely stimulus underlying progressive

podocyte damage and subsequent glomerular sclerosis in fa/fa rats (Coimbra et al.,

2000). Although not measured in the present study, the lipid lowering actions of the

PPARγ agonist (Rosak 2002; Guan and Breyer 2001) likely contributed to the improved

protection compared to rats treated with ACEI alone. In the outbred Zucker rat that is

not frankly hyperglycemic, chronic treatment with lipid lowering agents affords

considerable protection (Kasiske et al., 1992).

Systemic hypertension is another risk factor for development of kidney disease

and BP was elevated in the untreated inbred obese Zucker rats in the present study. Of


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note, however, the glomerular blood pressure (PGC) was not elevated and although rats

receiving ACEI alone exhibited a significant fall in BP, PGC was not lowered.

Furthermore, the rats receiving PPARγ agonist alone showed no change in either BP or

PGC despite the fact that these animals enjoyed superior renoprotection vs. those given

ACEI alone. These findings suggest that glomerular hypertension was not an important

contributory factor in this model of renal disease.

Several groups have reported that the thiazolidinediones protect the kidney in rat

models of type 1 and type 2 diabetes (Fujii et al., 1997; Buckinham et al., 1998;

McCarthy et al., 2000). In addition to the improved metabolic control it is possible that

PPARγ agonists have more direct beneficial actions on the kidney since constitutively

expressed PPARγ are found in glomeruli, particularly mesangial cells (Guan et al., 2001;

Asano et al., 2000; Nicholas et al., 2001) and PPARγ agonists reduce type I collagen

synthesis in cultured glomerular mesangial cells (Routh et al., 2002; Zheng et al., 2002).

In addition to directly inhibiting glomerular collagen synthesis, PPARγ agonist may also

act indirectly, via its anti-inflammatory action. Glomerular sclerosis positively correlates

with the occurrence of interstitial and glomerular monocytes/ macrophages and

activated mesangial cells (Young et al., 1995; Nikolic-Paterson et al., 1994; Lavaud et

al., 1996). In the present study, the incidence of cells expressing CD 68 within the

glomeruli (determined with the monocyte/macrophage marker Ki-M6), is blunted with

either the ACEI or PPARγ agonist alone, and was absent in rats given PPARγ agonist in

combination with ACEI. Thus both PPARγ agonists and ACEI might act via inhibition of

recruitment or activation of these cells. In fact, PPARγ agonists are protective in the

non-diabetic, 5/6th renal ablation model of glomerulosclerosis (Ma et al., 2001) and exert


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direct anti-inflammatory and antiproliferative actions on the circulation (Ishibashi et al.,

2002), suggesting that the renal protective actions extend beyond improvement of the

metabolic profile.

Overall, long-term administration of the PPARγ agonist was found to be

powerfully protective in the complex model of CRD seen in the inbred obese Zucker rat.

One disadvantage of the PPARγ agonists is that they potently stimulate adipocyte

formation (Rosak 2002; Guan and Breyer 2001) leading to massive obesity. Of note,

however, this obesity is not, in itself, damaging to the kidneys, since rats in the present

study that received PPARγ agonist were massively obese without kidney damage. In

fact the PPARγ agonist treated rats seemed “healthy” despite massive obesity.


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ACKNOWLEDGEMENTS. The excellent technical assistance of Lennie Samsell and

Agnes Klumpp is gratefully acknowledged.


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FOOTNOTES

These studies were supported by funds from F. Hoffmann-La Roche AG, Basel, Switzerland.


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Table 1. Data obtained during micropuncture of inbred obese male Zucker

(ZDF/Gmi, fa/fa) studied at ~ 8months of age after 6 months of no treatment,

angiotensin converting enzyme inhibition (ACEI), peroxisome proliferator-

activated receptor γ agonist (PPARγ) alone or in combination with ACEI.

* denotes a significant difference (p<0.05) vs. untreated rats.

Hct vol/dl CA, g/dl ΠA, mmHg BP, mmHg PGC,

mmHg

Untreated 48±1 5.6±0.2 18±1 144±2 55±4

+ACEI 50±1 5.7±0.3 19±1 120±4* 49±1

+PPARγ 43±1* 6.1±0.3 21±2 130±5 53±3

+PPARγ/ACEI 41±1* 6.2±0.1* 21±1 100±8* 52±4


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Table 2. Incidence of animals with renal tubulointerstitial change in each of the 4 groups

at each level of severity of change. 0 denotes no change; 1+ denotes minimal change;

2+ denotes slight change; 3+ denotes moderate change; 4+ denotes marked to massive

change.

Incidence and severity

Number of

rats

examined

0

1+

2+

3+

4+

Untreated

7 0 0 3 4 0

PPARγ agonist

5 0 3 2 0 0

ACEI

9 0 0 8 1 0

PPARγ agonist +

ACEI

6 0 6 0 0 0


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FIGURE LEGENDS

Figure 1.

The plasma glucose (mg/dl) at 6-8 weeks of age (prior to initiation of treatment) and

over the 6 month observation period in untreated (open circles), ACEI treated (closed

circles), PPARγ agonist treated (open triangles) and PPARγ agonist + ACEI treated

(closed triangles) rats.

Figure 2.

The body weight (g) at 6-8 weeks of age (prior to initiation of treatment) and over the 6

month observation period in untreated (open circles), ACEI treated (closed circles),

PPARγ agonist treated (open triangles) and PPARγ agonist + ACEI treated (closed

triangles) rats.

Figure 3

The total urinary protein excretion (mg/24h) at 6-8 weeks of age (prior to initiation of

treatment) and over the 6 month observation period in untreated (open circles), ACEI

treated (closed circles), PPARγ agonist treated (open triangles) and PPARγ agonist +

ACEI treated (closed triangles) rats.

Figure 4.

The % of damaged glomeruli in each of the 4 groups at each level of severity of

damage. 1+ denotes less that 25% of the glomerulus damaged; 2+ denotes 26-50%

damage, 3+ denotes 51-75% damage, 4+ denotes 76-100% damage.

Figure 5.

Renal cortex of obese ZDF fa/fa rats, Hematoxylin and Eosin staining, Bar=200µm. A:

untreated rat showing tubular atrophy, tubular dilation, hyaline casts, interstitial fibrosis


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and inflammatory infiltrates, and glomerular sclerosis. B: PPARγ agonist treated rat,

normal morphology. C: ACEI treated rat, focal tubular degeneration and regeneration,

tubular dilation with hyaline casts, glomerular sclerosis, and hyperplasia of

juxtaglomerular apparatus. D: combination treatment of PPARγ agonist and ACEI:

normal morphology except for hyperplasia of juxtaglomerular apparatus.

Figure 6.

The glomerular filtration rate, factored for kidney weight, measured from the inulin

clearance (CIN, ml/min/gKW) after the 6 month observation period in each group.

* denotes p<0.05 vs. untreated Zucker rats.


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Time of Treatment (months)

0 2 4 6

Plasmaglucosemg/dL

0

100

200

300

400

500

600

700

Untreated

ACEI

PPARγagonist +ACEI

PPARγagonist

This article has not been copyedited and form

atted. The final version m

ay differ from this version.

JPET

Fast Forward. Published on O

ctober 14, 2003 as DO

I: 10.1124/jpet.103.055616 at ASPET Journals on January 5, 2019 jpet.aspetjournals.org Downloaded from



0 1 2 3 4 5 6

Bodyweight

(g)

200

400

600

800

1000

1200




JPET






0 1 2 3 4 5 6

Urin

e pr

otei

n ex

cret

ion

(mg/

24h)

0

100

200

300

400




JPET





Untreated

0

2

4

6

8

10

12

ACEI

0

2

4

6

8

10

12

PPARγagonist

0

2

4

6

8

10

12

PPARγagonist+ACEI

Level of sclerosis

1+ 2+ 3+ 4+

Affe

cted

glo

mer

uli (

%)

0

2

4

6

8

10

12




JPET





A B

C D

Figure 5




JPET





Treatment

CIN

(m

l/min

/gkw

)

0.0

0.5

1.0

1.5

* *p<0.12

Untreated ACEI PPARγagonist

PPARγagonist+ACEI




JPET






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jpet/2003/055616 revised pparγ agonist provides superior

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