Advances in Our Understanding of Oxylipins Derived from Dietary PUFAs

Tobacco smoking continues to be a major risk factor for cardiovascular disease (CVD) and the leading avoidable cause of death worldwide. Tobacco smoking has declined in high-income countries, but the average smoking rate in Japan remains high: 29.4% for men and 7.2% for women in 2017. Of note, the average smoking rate among middle-aged men remains approximately 40%, indicating that a high incidence of smoking-related CVD will continue for a couple of decades in Japan. The adverse effects of tobacco smoking on CVD are more extensive than previously thought. Physicians should be particularly alert to the development and progression of heart failure, atrial fibrillation, and venous thromboembolism, as well as ischemic CVD among tobacco smokers. Increasing use of heat-not-burn tobacco as cigarette alternatives is an emerging issue. Harmful effects do not disappear just by changing the delivery system of tobacco.

Effects of Tobacco Smoking on Cardiovascular Disease

Auscultation of the lung is an important part of the respiratory examination and is helpful in diagnosing various respiratory disorders Auscultation assesses airflow through the trachea-bronchial tree It is important to distinguish normal respiratory sounds from abnormal ones for example crackles, wheezes, and pleural rub in order to make correct diagnosis It is necessary to understand the underlying pathophysiology of various lung sounds generation for better understanding of disease processes Bedside teaching should be strengthened in order to avoid erosion in this age old procedure in the era of technological explosion

Auscultation of the respiratory system

Vascular tone of resistance arteries and arterioles determines peripheral vascular resistance, contributing to the regulation of blood pressure and blood flow to, and within the body's tissues and organs. Ion channels in the plasma membrane and endoplasmic reticulum of vascular smooth muscle cells (SMCs) in these blood vessels importantly contribute to the regulation of intracellular Ca2+ concentration, the primary determinant of SMC contractile activity and vascular tone. Ion channels provide the main source of activator Ca2+ that determines vascular tone, and strongly contribute to setting and regulating membrane potential, which, in turn, regulates the open-state-probability of voltage gated Ca2+ channels (VGCCs), the primary source of Ca2+ in resistance artery and arteriolar SMCs. Ion channel function is also modulated by vasoconstrictors and vasodilators, contributing to all aspects of the regulation of vascular tone. This review will focus on the physiology of VGCCs, voltage-gated K+ (KV) channels, large-conductance Ca2+-activated K+ (BKCa) channels, strong-inward-rectifier K+ (KIR) channels, ATP-sensitive K+ (KATP) channels, ryanodine receptors (RyRs), inositol 1,4,5-trisphosphate receptors (IP3Rs), and a variety of transient receptor potential (TRP) channels that contribute to pressure-induced myogenic tone in resistance arteries and arterioles, the modulation of the function of these ion channels by vasoconstrictors and vasodilators, their role in the functional regulation of tissue blood flow and their dysfunction in diseases such as hypertension, obesity, and diabetes. © 2017 American Physiological Society. Compr Physiol 7:485-581, 2017.

Smooth Muscle Ion Channels and Regulation of Vascular Tone in Resistance Arteries and Arterioles.

Objective To estimate the relative risk forfatal coronary heart disease associated with diabetesin men and women·Design Meta-analysis of prospective cohortstudies·Data sources Studies published between 1966and March 2005, identified through Embase andMedline, using a combined text word and MESHheading search strategy, in addition to studies fromthe Asia Pacific Cohort Studies Collaboration·Review methods Studies were eligible if theyhad reported estimates of the relative risk for fatalcoronary heart disease comparing men and womenwith and without diabetes·Studies were excluded ifthe estimates were not adjusted at least for age·Results 37 studies of type 2 diabetes and fatalcoronary heart disease among a total of 447 064patients were identified·The rate of fatal coronaryheart disease was higher in patients with diabetesthan in those without (5·4v1·6%)·The overallsummary relative risk for fatal coronary heart diseasein patients with diabetes compared with no diabeteswas significantly greater among women than it wasamong men: 3.50, 95% confidence interval 2.70 to4·53v2.06, 1·81 to 2.34·After exclusion of theeight studies that had adjusted only for age, thedifference in risk between the sexes was substantiallyreduced but still highly significant·The pooled ratioof the relative risks ( women: men) from the 29studies with multiple adjusted estimates was 1·46(1·14 to 1·88)·Conclusions The relative risk for fatalcoronary heart disease associated with diabetes is50% higher in women than it is in men·This greaterexcess coronary risk may be explained by more adverse cardiovascular risk profiles among women with diabetes,combined with possible disparities in treatment that favour men·

Excess risk of fatal coronary heart disease associated with diabetes in men and women:meta-analysis of 37 prospective cohort studies

Background and Purpose —The effects of acute smoking on cerebral circulation are controversial. This study was designed (1) to clarify any differences between the effects of cigarette smoking and nicotine infusion and between the effects of single- and multiple-cigarette smoking on cerebral vessels and (2) to probe the mechanism(s) underlying the vascular responses.

Methods —In pentobarbital-anesthetized, mechanically ventilated Sprague-Dawley rats, pial vessel diameters were measured with the use of a cranial window preparation. We studied the effects of (1) 60 puffs per minute of mainstream cigarette smoke from cigarettes having 2 nicotine levels (0.1 and 1 mg per cigarette), (2) administration of nicotine (0.05 mg per body IV), and (3) repeated smoking (four 1 mg nicotine–containing cigarettes at 30-minute intervals) (n=6 each).

Results —Inhalation of smoke from a 0.1 or 1 mg nicotine–containing cigarette for 1 minute caused pial arterioles to constrict at 30 seconds (7.2% and 7.3%, respectively) and then to dilate (peak at 5 to 10 minutes; 4.6% and 17.9%, respectively). Nicotine infusion caused pial vasodilation (35.7%) without an initial vasoconstriction. Repeated smoking suppressed the pial vasodilation but not the initial vasoconstriction. The vasodilation induced by a single cigarette was greatly inhibited by pretreatment with mecamylamine or glibenclamide and attenuated by propranolol or N ω-nitro-l-arginine methyl ester; the initial vasoconstriction was inhibited by seratrodast, a thromboxane A2 receptor antagonist (n=6 in each case).

Conclusions —Single-cigarette smoking had a significant biphasic effect on cerebral arteriolar tone. The vasodilation was attenuated by repeated smoking. The vasodilation is most likely an effect of nicotine, at least in part mediated via sympathetic activation, NO production, and K+ channel activation. The vasoconstriction is partially due to thromboxane A2 induced by cigarette smoke.

Mechanisms Underlying Cerebrovascular Effects of Cigarette Smoking in Rats In Vivo

Background The effects of adrenergic agonists, often used as local anesthetic additives or spinal analgesics, on spinal vessels have not been firmly established. The authors investigated the effects of [Greek small letter alpha]2- and [Greek small letter alpha]1-adrenergic agonists on spinal and cerebral pial vessels in vivo. Methods Pentobarbital-anesthetized dogs (n = 28) were prepared for measurement of spinal pial-vessel diameter in a spinal-window preparation. The authors applied dexmedetomidine, clonidine, phenylephrine, or epinephrine in three different concentrations (0.5, 5.0, and 50 [micro sign]g/ml; [2.1, 1.9, 2.5, and 2.3] x [10-6, 10-5, and 10-4] M, respectively) under the window (one drug in each dog) and measured spinal pial arteriolar and venular diameters in a sequential manner. To enable the comparison of their effects on cerebral vessels, the authors also administered these drugs under a cranial window. Results On topical administration, each drug constricted spinal pial arterioles in a concentration-dependent manner. Phenylephrine and epinephrine induced a significantly larger arteriolar constriction than dexmedetomidine or clonidine at 5 [micro sign]g/ml (8%, 11%, 0%, and 1%, respectively). Spinal pial venules tended to be less constricted than arterioles. In cerebral arterioles, greater constrictions were induced by dexmedetomidine and clonidine than those induced by phenylephrine and epinephrine (14%, 8%, 0%, and 1%, respectively). Cerebral pial venules tended to exhibit larger constrictions than cerebral arterioles (unlike in spinal vessels). Conclusion Dexmedetomidine and clonidine constricted spinal vessels in a concentration-dependent manner, but such vasoconstrictions were smaller than those induced by phenylephrine and epinephrine.

direct Effects of α1- and α2-adrenergic Agonists on Spinal and Cerebral Pial Vessels in Dogs

UNLABELLED We investigated whether the stereoisomers of ropivacaine and bupivacaine exert differential effects on the cerebral microcirculation. Pentobarbital-anesthetized dogs (n = 16) were prepared for measurement of cerebral pial vessel diameters by using a closed cranial window preparation. We administered three different concentrations (10(-7), 10(-5), and 10(-3) M) of each of three drug solutions [R(+), racemic, and S(-) forms of ropivacaine (n = 8) or bupivacaine (n = 8)] under the window in a randomized manner and measured cerebral pial arteriolar diameters. Various physiologic data were obtained before and after topical application of each test solution. All three forms of ropivacaine constricted cerebral pial arterioles, each in a concentration-dependent manner. The rank order for degree of vasoconstriction was S(-) ropivacaine > racemic ropivacaine > R(+) ropivacaine. In contrast, R(+) and racemic bupivacaine dilated, but S(-) bupivacaine constricted, cerebral pial arterioles, each in a concentration-dependent manner. We could find no difference in vascular reactivity to these drugs between large (> or = microm) and small (<100 microm) arterioles. Topical application of these drugs induced no changes in mean blood pressure or heart rate. The observed differences in the microvascular alterations induced by the stereoisomers of ropivacaine and bupivacaine suggest that the vasoactive effects of these drugs on cerebral arterioles could, at least in part, depend on their chirality. IMPLICATIONS The differential effects of the stereoisomers of ropivacaine and bupivacaine on cerebral pial vessels could, at least in part, depend on their chirality.

The differential effects of stereoisomers of ropivacaine and bupivacaine on cerebral pial arterioles in dogs.

Introduction. We previously reported that acute cigarette smoking can cause a dysfunction of endothelium-dependent vasodilation in cerebral vessels, and that blocking the angiotensin II (Ang II) type 1 (AT1) receptor with valsartan prevented this impairment. Our aim was to investigate the effects of a Rho-kinase inhibitor (fasudil) and a Nicotinamide Adenine Dinucleotide PHosphate (NADPH) oxidase inhibitor (apocynin) on smoking-induced endothelial dysfunction in cerebral arterioles.Method. In Sprague—Dawley rats, we used a closed cranial window preparation to measure changes in pial vessel diameters following topical acetylcholine (ACh) before smoking. After one-minute smoking, we again examined the arteriolar responses to ACh. Finally, after intravenous fasudil or apocynin pre-treatment we re-examined the vasodilator responses to topical ACh (before and after cigarette smoking).Results. Under control conditions, cerebral arterioles were dose-dependently dilated by topical ACh (10-6 M and 10-5 M). One hou...

Rho-kinase inhibitor and nicotinamide adenine dinucleotide phosphate oxidase inhibitor prevent impairment of endothelium-dependent cerebral vasodilation by acute cigarette smoking in rats.

We previously reported that acute cigarette smoking can cause a dysfunction of endothelium-dependent vasodilation in cerebral vessels, and that a reduction of oxidative stress by agents such as valsartan, fasudil, or apocynin prevented this impairment. Here, our aim was to investigate the comparative effects of two antiplatelet drugs used for stroke-prevention [a phosphodiesterase-3 inhibitor (cilostazol) and a cyclooxygenase inhibitor (aspirin)] on smoking-induced endothelial dysfunction in cerebral arterioles. In Sprague-Dawley rats, we used a closed cranial window preparation to measure the changes in pial vessel diameters induced by topical application of acetylcholine (ACh) following intraperitoneal injection of 0.5% carboxymethyl cellulose sodium salt (CMC; vehicle control for the antiplatelet drugs). After 1-min smoking (1 mg-nicotine cigarette), the arteriolar responses to ACh were reexamined. Finally, after intraperitoneal cilostazol or aspirin (each in 0.5% CMC) pretreatment, we reexamined the vasodilator responses to topical ACh (before and after cigarette smoking). Under control conditions, cerebral arterioles were dose-relatedly dilated by topical ACh (10(-6) and 10(-5 )M). One hour after 1-min smoking, 10(-5 )M ACh (a) constricted cerebral pial arterioles in the control group and in the aspirin-pretreatment group (responses not significantly different from each other), but (b) dilated cerebral pial arteries in the cilostazol pretreatment groups (responses significantly different from those obtained without cilostazol pretreatment). Thus, cilostazol (but not aspirin) may prevent the smoking-induced impairment of endothelium-dependent vasodilation in cerebral pial arterioles.

Comparative effects of cilostazol and aspirin on the impairment of endothelium-dependent cerebral vasodilation caused by acute cigarette smoking in rats.

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