Sex-specific effects of an insulin secretagogue in stroke-prone hypertensive rats.

Peuler, Jacob D.; Johnson, Bradford; Phare, Susan M.; Sowers, James R.

doi:10.1161/01.hyp.22.2.214

Cited by 24 publications

(9 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…By blocking the NO pathway, minor contractions were detected, suggesting the local involvement of the prostanoid system (11,36) and muscarinic Ach receptors (37) in addition to the NO pathway. It has been shown that insulin-dependent relaxation of the large vessels (aorta) and gracilis arterioles are predominantly mediated by NO and endothelium-derived hyperpolarizing factor/potassium channels, respectively (38).…”

Section: Figurementioning

confidence: 99%

Arteriolar insulin resistance in a rat model of polycystic ovary syndrome

Sára

Péter

Masszi

et al. 2012

Fertility and Sterility

View full text Add to dashboard Cite

Objective: To investigate the vascular dysfunction caused by insulin resistance in polycystic ovary syndrome (PCOS) and the effectiveness of vitamin D in an animal model. Design: Controlled experimental animal study. Setting: Animal laboratory at a university research institute. Animal(s): Thirty female Wistar rats. Intervention(s): Rats were divided into groups at age 21-28 weeks. Twenty of them were subjected to dihydrotestosterone (DHT) treatment (83 mg/d); ten of them also received parallel vitamin D treatment (120 ng/100 g/wk). Oral glucose tolerance tests with insulin level measurements were performed. Gracilis arterioles were tested for their contractility as well as their nitric oxide (NO)-dependent and insulin-induced dilation using pressure arteriography. Main Outcome Measure(s): Several physiologic parameters, glucose metabolism, and pressure arteriography. Result(s): DHT treatment increased the passive diameter of resistance arterioles, lowered norepinephrine-induced contraction (30.1 AE 4.7% vs. 8.7 AE 3.6%) and reduced acetylcholine-induced (122.0 AE 2.9% vs. 48.0 AE 1.4%) and insulin-induced (at 30 mU/mL: 21.7 AE 5.3 vs. 9.8 AE 5.6%) dilation. Vitamin D treatment restored insulin relaxation and norepinephrine-induced contractility; in contrast, it failed to alter NO-dependent relaxation.

show abstract

Section: Figurementioning

confidence: 99%

Arteriolar insulin resistance in a rat model of polycystic ovary syndrome

Sára

Péter

Masszi

et al. 2012

Fertility and Sterility

View full text Add to dashboard Cite

show abstract

“…6 Cells were maintained in growth medium (Dulbecco's modified Eagle medium supplemented with 9% fetal bovine serum, 0.2% Tylosin, 100 U/tnL penicillin, and 0.1 mg/mL streptomycin) and placed in a 37°C water-jacketed incubator under 5% CO 2 4. Blood clots, fat, and connective tissue were removed.…”

Section: Effects Of Pioglitazone On Calcium Channels In Vascular Smoomentioning

confidence: 99%

Effects of pioglitazone on calcium channels in vascular smooth muscle.

et al. 1994

Self Cite

View full text Add to dashboard Cite

Pioglitazone, an insulin-sensitizing, antidiabetic agent, has blood pressure-lowering effects in insulin-resistant hypertensive rats and attenuates growth factor-induced increases of intracellular Ca 2+ in rat aortic vascular smooth muscle cells. To determine whether modulation of voltagedependent Ca 2+ channels plays a role in this association, we investigated the effects of pioglitazone on voltage-dependent current in cultured rat aortic (a7r5) and freshly dissociated rat tail artery vascular smooth muscle cells. Both cell types were studied with whole-cell patch-clamp techniques. Current through L-type Ca 2+ channels was elicited with a voltage ramp in the presence of Ba 2+ substituted for Ca 2+ . T-type Ca 2+ current was studied using a two-pulse protocol that enabled the isolation of transient current. In a7r5 vascular smooth muscle cells, 2-minute application of pioglitazone (5 and 10 /imol/L) reduced L-type current by 7.9±1.0% (n=8)

show abstract

“…17 Conversely, glyburide, a sulfonylurea antidiabetic agent, increases both plasma insulin concentrations and blood pressure in female (but not in male) stroke-prone SHR. 18 The purpose of the present study was to define the relation between changes in insulin sensitivity and attenuation of hypertension. We have extended our studies in the DS rat to include the 1K1C Sprague-Dawley rat.…”

mentioning

confidence: 99%

Antihypertensive effect of pioglitazone is not invariably associated with increased insulin sensitivity.

1994

View full text Add to dashboard Cite

Hypertension is often associated with insulin resistance, and several chemically diverse agents that increase insulin sensitivity attenuate the development of experimental hypertension. We undertook the present study to determine whether attenuation of hypertension by pioglitazone, a thiazolidinedione derivative that increases insulin sensitivity without increasing insulin secretion, is specifically related to its effect on insulin-mediated glucose uptake. Pioglitazone administered daily by oral gavage (20 mg/kg per day) for 3 weeks attenuated the development of hypertension in both the Dahl salt-sensitive (DS) rat (an insulin-resistant model of hypertension) and the one-kidney, one clip rat (a model of hypertension not associated with insulin resistance). Based on euglycemic I n humans, both epidemiologic and clinical evidence document an association between hypertension and resistance to insulin-stimulated glucose uptake. Although a number of putative mechanisms have been proposed, it is unclear whether insulin resistance, hyperinsulinemia, or both actually cause hypertension. 1To address this question, we and others have recently evaluated the effects of oral hypoglycemic agents on arterial pressure in several rat models of hypertension. Pioglitazone is a thiazolidinedione derivative that increases insulin sensitivity without stimulating endogenous insulin secretion. "10 This agent attenuates the development of hypertension in the DS rat 11 and also prevents increases in blood pressure in the rat caused by feeding high-carbohydrate or high-fat diets.1213 Ciglitazone and CS-045, other thiazolidinedione derivatives, also lower blood pressure in the insulin-resistant, obese Zucker rat. 17 Conversely, glyburide, a sulfonylurea antidiabetic agent, increases both plasma insulin concentrations and blood pressure in female (but not in male) stroke-prone SHR. 18The purpose of the present study was to define the relation between changes in insulin sensitivity and attenuation of hypertension. We have extended our studies in the DS rat to include the 1K1C Sprague-Dawley rat. In each model, we evaluated the effects of pioglitazone and metformin on both arterial pressure and insulin sensitivity, as assessed by the euglycemic insulin clamp technique. Methods Effects of Pioglitazone and Metformin on the Development of Hypertension and on Insulin Sensitivity in the DS RatWe have previously reported that pioglitazone attenuates the development of hypertension in the DS rat." Using an identical protocol in the present study we evaluated the effect of metformin on blood pressure in this animal model.Male DS rats (Brookhaven strain) were purchased from Harlan Sprague Dawley (Indianapolis, Ind) and arrived shortly after weaning. Initially, all animals were fed 0.45% NaCl (diet No. 88311, Teklad) for 1 week and subsequently a 3% NaCl diet (diet No. 89281, Teklad). The rats were housed in individual cages in a temperature-controlled (22°C) and light-controlled (12 hours on, 12 hours off) small-animal facility. All animals ...

show abstract

Sex-specific effects of an insulin secretagogue in stroke-prone hypertensive rats.

Cited by 24 publications

References 38 publications

Arteriolar insulin resistance in a rat model of polycystic ovary syndrome

Arteriolar insulin resistance in a rat model of polycystic ovary syndrome

Effects of pioglitazone on calcium channels in vascular smooth muscle.

Antihypertensive effect of pioglitazone is not invariably associated with increased insulin sensitivity.

Contact Info

Product

Resources

About