Elevation of intracavernous pressure and NO-cGMP activity by a new herbal formula in penile tissues of spontaneous hypertensive male rats

Rubus occidentalis and Ellagic Acid Affect the Contractility of Penile Corpus Cavernosum Smooth Muscle through the Nitric Oxide-Cyclic Guanosine Monophosphate and Cyclic Adenosine 3',5'-Monophosphate Signaling Pathway

The present study was designed to evaluate the relaxation effect of Rubus occidentalis (RO) and ellagic acid (EA) on rabbit penile corpus cavernosum smooth muscle (PCCSM). Rabbit PCCSM was treated with ROE or EA after preincubation with nitric oxide synthase (NOS), guanylate cyclase (GC), adenylyl cyclase (AC) or protein kinase A (PKA) blocker. Cyclic nucleotides in the perfusate were analyzed using radioimmunoassay (RIA). Subsequently, perfused PCCSMs were subjected to analysis to evaluate the expression level of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS). The interaction of ROE or EA with phosphodiesterase (PDE) 5 and PDE4 inhibitors, such as udenafil (UDE) and rolipram (ROL), were also evaluated. Both ROE and EA relaxed the PCCSM in a concentration-dependent manner. Coincubation of ROE or EA with NOS, GC, AC, or PKA blocker significantly decreased the ROE- and EA-induced relaxation. Pretreatment of ROE and EA significantly upregulated the cyclic guanosine monophosphate (cGMP), cyclic adenosine 3′,5′-monophosphate (cAMP), and eNOS levels in the perfused PCCSM. Furthermore, the treatment of ROE and EA markedly increased the UDE- and ROL-induced relaxation of the PCCSM. In conclusion, ROE and EA induced PCCSM relaxation by activating the nitric oxide (NO)-cGMp and cAMp signaling pathways and may have a synergistic action to improve erectile function.

Ameliorative Effects of Loganin on Arthritis in Chondrocytes and Destabilization of the Medial Meniscus-Induced Animal Model

Arthritis is a common inflammatory disease that causes pain, stiffness, and joint swelling. Here, we investigated the ameliorative effects of loganin on arthritis in vitro and in vivo. A single bioactive compound was fractionated and isolated from Cornus officinalis (CO) extract to screen for anti-arthritic effects. A single component, loganin, was identified as a candidate. The CO extract and loganin inhibited the expression of factors associated with cartilage degradation, such as cyclooxygenase-2 (COX-2), matrix metalloproteinase 3 (MMP-3), and matrix metalloproteinase 13 (MMP-13), in interukin-1 beta (IL-1β)-induced chondrocyte inflammation. In addition, prostaglandin and collagenase levels were reduced following treatment of IL-1β-induced chondrocytes with loganin. In the destabilization of the medial meniscus (DMM)-induced mouse model, loganin administration attenuated cartilage degeneration by inhibiting COX-2, MMP-3, and MMP-13. Transverse micro-CT images revealed that loganin reduced DMM-induced osteophyte formation. These results indicate that loganin has protective effects in DMM-induced mice.

A randomized, controlled study of treatment with ojayeonjonghwan for patients with late onset hypogonadism

Objectives: We investigate the effects of Ojayeonjonghwan (KH-204) in men with late-onset hypogonadism (LOH) symptoms.Material and methods: Initial PSA, testosterone, lipid profile and questionnaires about LOH-related symptoms were checked. After 8 weeks of the treatment (control or KH-204), questionnaires and serological tests were repeated to evaluate the efficacy of the agent. The changes of variables in each group and the difference between two groups were compared.Results: A total of 78 men were enrolled, and randomly assigned to the control group (n = 39) or KH-204 group (n = 39). Baseline characteristics of both group are comparable. AMS total score of control and KH-204 group were both improved at 8 weeks (p = .010, <.001), and there was a statistically significant difference between the two groups (favorable in KH-204 group, p = .006). At 8 weeks, total IIEF score of control and KH-204 group were both improved, and there was no statistically significant difference in the degree of improvement between the two groups (p = .303). There was no statistically significant difference of laboratory findings, in intra-group changes and inter-group comparisons.Conclusions: KH-204 was found to be effective in all LOH symptoms without changing of laboratory results. KH-204 may be safely used for treatment of male with LOH-related symptoms.

The genus Cuscuta (Convolvolaceac): An updated review on indigenous uses, phytochemistry, and pharmacology

Cuscuta, commonly known as dodder, is a genus of family convolvolaceace. Approximately 170 species of Cuscuta are extensively distributed in temperate and subtropical areas of the world. Species of this genus are widely used as essential constituents in functional foods and traditional medicinal systems. Various parts of many members of Cuscuta have been found efficacious against a variety of diseases. Phytochemical investigations have confirmed presence of biologically active moieties such as flavonoids, alkaloids, lignans, saponines, phenolics, tannins, and fatty acids. Pharmacological studies and traditional uses of these plants have proved that they are effective antibacterial, antioxidant, antiostioporotic, hepatoprotective, anti-inflammatory, antitumor, antipyretic, antihypertensive, analgesic, anti hair fall, and antisteriogenic agents.

Neuronal nitric oxide synthase activity mediates Lycium barbarum polysaccharides-enhanced sexual performance without stimulating noncontact erection in rats

RATIONALE

Lycium barbarum polysaccharide (LBP) is known to promote reproductive functions. However, its role in noncontact erection (NCE) of penis initiated by brain regions including medial preoptic area (MPOA) and paraventricular nucleus (PVN) regions responsible for sexual behavior has not been investigated.

OBJECTIVES

Therefore, this study initially investigated the effects of LBP on male sexual function, and subsequently, the mechanistic insight was investigated through assessing the expression of neuronal nitric oxide synthase (nNOS) in the MPOA and PVN.

METHODS

The adult male rats were treated with 100 mg/kg of LBP or vehicle by oral gavage. Before and after 14 days of treatment, copulatory behavior and noncontact erection (NCE) were recorded. After the last behavioral test, the brain was isolated to measure nNOS expression in the MPOA and PVN.

RESULTS

Data showed that LBP treatment significantly increased both the frequencies of intromission as well as ejaculation, compared to the control group. Whereas, a reduced post-ejaculatory interval was observed compared to same group on day 0. Furthermore, the treatment led to an increased intromission ratio, inter-intromission interval, and the number of MPOA nNOS-immunoreactive cells (nNOS-ir). Additionally, a significantly positive correlation between ejaculation frequency and MPOA nNOS-ir cells was recorded. Of note, LBP treatment had no effects on NCE and PVN nNOS-ir expression.

CONCLUSION

These findings suggest that LBP enhances sexual behavior through increased nNOS expression in the MPOA in male rats.

Effects of a combination of herbal extracts (modified Ojayeonjonghwan (Wuzi Yanzong wan)) on partial urethral obstruction-induced detrusor overactivity in rats: impact on the nitric oxide pathway and oxidative stress

Background

We investigated the effects of a berry mixture formula (modified Ojayeonjonghwan (Wuzi Yanzong Wan, MO formula) on detrusor overactivity (DO).

Methods

The MO formula consisted of 5 seeds obtained from 5 types of berry plants. Twenty-four Sprague-Dawley rats were randomly assigned to four groups: sham-operated (control), partial urethral obstruction-induced DO (DO group), 0.03 mg/kg solifenacin-treated DO (solifenacin group) and 200 mg/kg MO formula -treated DO (berry mixture). The control and overactive groups were administered distilled water for 4 weeks, and the solifenacin and MO formula groups were treated with the respective medication for 4 weeks. After treatment, cystometrography was performed. At the endo of cystometrography, their bladder tissues were used for identifying the muscarinic receptors, endothelial nitric oxide synthase(eNOS), RhoA, Rock-I & II, 8-hydroxy-2′ –deoxyguanosine(8-OHdG), superoxide dismutase(SOD), interleukin-6 &-8(IL-6, IL-8), and tumor necrosis factor-alpha(TNF-a). The tissues were stained and the muscle-to-collagen ratio was identified.

Results

The presence of the muscarinic receptors were not significantly different between the solifenacin and MO formula groups. However, significant differences were found between the solifenacin and MO formula groups in terms of eNOS, RhoA, Rock-I and -II levels. The muscle-to-collagen ratio was statistically lower in the DO and solifenacin groups; however, no significant difference was observed between the control and MO formula groups. Under oxidative stress, SOD showed a similar result as 8-OHgG. The MO formula group exhibited anti-inflammatory effects, showing that no significant difference was found between the control and MO formula groups regarding values of IL-6, IL-8, and TNF-a. However, the DO and solifenacin groups showed increased IL-6, IL-8, and TNF-a levels. Cystometrography showed that the OAB and solifenacin groups having a significantly lower value than the control and MO formula groups. The mean contraction interval was shorter in the DO, MO formula, and solifenacin groups and the highest in the control group.

Conclusions

The MO formula exhibited a similar pharmacologic effect to that of solifenacin, with anti-inflammatory and antioxidant effects. Enhancement of the MO formula by the nitric oxide pathway affected DO including BPH-related DO. The MO formula may be one of the alternative choices of anticholinergics, a treatment for DO.

Ethnopharmacology of Cuscuta epithymum: A comprehensive review on ethnobotany, phytochemistry, pharmacology and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta epithymum (L.) L. (C. epithymum; Convolvulaceae) is a parasitic plant that has long been used locally and traditionally in Asia, Europe and other regions.

AIM OF THE REVIEW

The study intends to reflect the significance of the C. epithymum in traditional medicine. This review aims to grant insight into the species' botany, pharmacological activities and phytochemistry with distinctive emphasis on its ethnomedicinal and traditional applications in all over the world. The review endeavors to rule out any inconsistency between the species' traditional application and its pharmacological activity, and presenting any coherence existing.

MATERIALS AND METHODS

The books on ethnomedicine and the main medieval Persian medicine textbooks including Makhzan Al- Advieh, The canon of medicine, Zakhireh kharazmshahi and etc were explored for C. epithymum. Additionally, information on the ethnobotany, phytochemistry, morphology, taxonomy, modern medicinal uses, and pharmacological activities were collected in electronic databases including Google Scholar, Science Direct, Scopus, and PubMed using the keywords "Cuscuta epithymum," "traditional medicine," "ethnomedicine," "phytochemistry," "pharmacology" and "activity." Then, the available articles from 1975 to 2017 were employed for this study.

RESULTS

C. epithymum is a rootless plant, widely distributed and available in every continent except Antarctica. It was used traditionally in formularies or by rural people and as geriatric drug, detergent, purgative, disorders in the melancholic humor, joint, kidney, urinary tract, gastrointestinal system, nervous system, etc. In modern medicine, the extract of C. epithymum showed anti-microbial, cytotoxic, anticonvulsant, anti-urease, immune stimulatory, hepatoprotective effect, and antioxidant activity. The main phytochemical constituents are alkaloids; saponins; tannins; triterpenoids; steroids; carbohydrates; aromatic compounds; flavonoids and the hydroxycinnamic acid derivatives.

CONCLUSION

The modern pharmacological studies have validated the traditional and ethnobotanical uses of C. epithymum. However, many aspects of this herb have not been studied yet. In addition, information about the phytochemistry and toxicological profile is insufficient. Owing to the extensive traditional uses of C. epithymum. Hence further studies on pharmacological activities, phytochemistry, and toxicity and adverse effects seem to be necessary to appraise the medicinal values of C. epithymum.

Effect of Korean Herbal Formula (Modified Ojayeonjonghwan) on Androgen Receptor Expression in an Aging Rat Model of Late Onset Hypogonadism

Purpose

Testosterone replacement therapy is an effective treatment for late-onset hypogonadism (LOH) despite a few contraindications and side-effects. The aim of this study was to determine whether modified Ojayeonjonghwan (KH-204, Korean herbal formula) improved LOH. KH-204 is a strong antioxidant herbal formula. We evaluated the effect of Korean herbal prescription on androgen receptor (AR) expression in an aged rat model of LOH.

Materials and Methods

Eighteen-month-old rats were used as aged LOH rat models. Eighteen Sprague-Dawley rats were randomly divided into three equal groups of six animals each and treated with one of the following: 1) normal control group (oral administration with distilled water, n=6), 2) KH-204 200 group (oral administration with 200 mg/kg of KH-204, n=6), and 3) KH-204 400 group (oral administration with 400 mg/kg of KH-204, n=6). After four weeks of treatment (once daily, distilled water or KH-204), serum testosterone levels, changes in testicular and epididymal weight, Western blotting analysis of AR expression and measurement of oxidative stress were examined.

Results

Treatment with the herbal formulation KH-204 200 mg/kg and 400 mg/kg (1) increased the weights of testis and epididymis; (2) increased the level of serum testosterone; (3) increased the level of superoxide dismutase and reduced the level of 8-hydroxy-20-deoxyguanosine; and (4) upregulated AR expression in testicular tissue.

Conclusions

KH-204 might be an effective alternative for LOH. It improves antioxidant mechanisms and increases testicular AR expression without side-effects.

Cuscuta arvensis Beyr "Dodder": In Vivo Hepatoprotective Effects Against Acetaminophen-Induced Hepatotoxicity in Rats

Cuscuta arvensis Beyr. is a parasitic plant, and commonly known as "dodder" in Europe, in the United States, and "tu si zi shu" in China. It is one of the preferred spices used in sweet and savory dishes. Also, it is used as a folk medicine for the treatment particularly of liver problems, knee pains, and physiological hepatitis, which occur notably in newborns and their mothers in the southeastern part of Turkey. The purpose of this study was to investigate the hepatoprotective effects and antioxidant activities of aqueous and methanolic extracts of C. arvensis Beyr. on acetaminophen (APAP)-induced acute hepatotoxicity in rats. The results were supported by subsequent histopathological studies. The hepatoprotective activity of both the aqueous and methanolic extracts at an oral dose of 125 and 250 mg/kg was investigated by observing the reduction levels or the activity of alkaline phosphatase, alkaline transaminase, aspartate aminotransferase, blood urine nitrogen, and total bilirubin content. In vivo antioxidant activity was determined by analyzing the serum superoxide dismutase, malondialdehyde, glutathione, and catalase levels. Chromatographic methods were used to isolate biologically active compounds from the extract, and spectroscopic methods were used for structure elucidation. Both the methanolic and aqueous extracts exerted noticable hepatoprotective and antioxidant effects supporting the folkloric usage of dodder. One of the bioactive compounds was kaempferol-3-O-rhamnoside, isolated and identified from the methanolic extract.

Antioxidant and Antifibrotic Effect of a Herbal Formulation In Vitro and in the Experimental Andropause via Nrf2/HO-1 Signaling Pathway

The Korean herbal formulation Ojayeonjonghwan is used for improving late-onset hypogonadism (LOH) symptoms such as erectile dysfunction (ED). A previous research suggested that a modified Ojayeonjonghwan (KH-204) could be used as an alternative to the treatment for ED. The pharmacological effects were examined in different conditions, including in vitro and in vivo. We measured the survival rate of TM3 Leydig cells under the oxidative stress condition. The s.c. injection of leuprorelin was used to induce androgen deprivation. We measured serum testosterone levels, oxidative stress, and apoptosis. The results of the treatment by KH-204 (1) preserved TM3 cells from oxidative stress by improving the expression of nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1); (2) lowered the expression of transforming growth factor-beta (TGF-β) 1/SMAD; (3) increased the average of serum testosterone in androgen-deprived male rats; (4) kept the activation of spermatogenesis; (5) upgraded the contents of 8-hydroxy-20-deoxyguanosine (8-OHdG) and degraded the contents of superoxide dismutase (SOD); and (6) reduced apoptosis. We studied that KH-204 improved testicular dysfunction in LOH. It is likely, at least in part, to degrade oxidative stress through the Nrf2/HO-1 pathway. These findings may offer credible evidences for the use of new alternative therapies to treat LOH.

The herbal formula KH-204 is protective against erectile dysfunction by minimizing oxidative stress and improving lipid profiles in a rat model of erectile dysfunction induced by hypercholesterolaemia

Background

Hypercholesterolaemia (HC) is a major risk factor for ischemic heart disease and is also known to be a risk factor for erectile dysfunction (ED). ED caused by HC is thought to be related to HC-induced oxidative stress damage in the vascular endothelium and erectile tissue. KH-204 is an herbal formula with a strong antioxidant effect. We evaluated the effects of KH-204 on erectile function in a rat model of HC-induced ED.

Methods

Male Sprague-Dawley rats (6 weeks old) were divided into normal control, high-fat and cholesterol diet (HFC), and HFC with KH-204 treatment (HFC + KH) groups (n = 12 each). Normal control group rats were fed normal chow diet. HFC and HFC + KH group rats were fed high-fat and cholesterol diets and treated with or without daily oral doses of KH-204 for 12 weeks. Subsequently, intracavernous pressure (ICP) and mean arterial pressure (MAP) were measured, and lipid profiles, expression of endothelial (eNOS) and neuronal (nNOS) nitric oxide synthase, oxidative stress (8-hydroxy-2-deoxyguanosine), and ratio of smooth muscle cells and collagen fibres were evaluated in the serum and corpora tissue.

Results

Compared to the HFC group, the HFC + KH group showed statistically significant increases in peak ICP and ICP/MAP ratio, expression of eNOS and nNOS, and ratio of smooth muscle cells and collagen fibres (p < 0.05). The HFC + KH group also showed statistically significant decreases in oxidative stress (p < 0.05). Further the lipid profiles of this group were ameliorated compared to those of the HFC group (p < 0.05).

Conclusions

The current study shows that the antioxidant and hypolipidemic effects of KH-204 are effective in ameliorating ED by restoring endothelial dysfunction and suggests that KH-204 may be a potential therapeutic agent for ED by correcting the fundamental cause of ED.

Current Status and Clinical Studies of Oriental Herbs in Sexual Medicine in Korea

Erectile dysfunction (ED) is one of the most common diseases among aging men. Although previous studies have shown that type 5 phosphodiesterase inhibitors (PDE5-Is) are very effective for the treatment of ED, many researchers are currently attempting to identify therapeutic agents from natural sources with comparable or better effects than PDE5-Is. Herbal medicine is thought to be advantageous because it is natural; moreover, it not only treats isolated symptoms, but also maintains general well-being. Furthermore, since newly created chemical compound libraries have limited structural diversity with regard to pharmaceutical agents, more attention has recently been paid to the ability of oriental herbs to enhance physical health, including sexual function. Herein, we review the current status of Korean preclinical or clinical studies of the application of oriental herbs to sexual medicine.

Cuscuta chinensis Lam.: A systematic review on ethnopharmacology, phytochemistry and pharmacology of an important traditional herbal medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Cuscuta chinensis Lam. has found its use as a traditional medicine in China, Korea, Pakistan, Vietnam, India and Thailand. It is commonly used as an anti-aging agent, anti-inflammatory agent, pain reliever and aphrodisiac. To provide an overview of the ethnopharmacology, phytochemistry, pharmacokinetics, pharmacology and clinical applications of Cuscuta chinensis, as well as being an evidence base for further research works of the plant.

MATERIALS AND METHODS

The present review covers the literature available from 1985 to 2014. The information was collected from journals, books, theses and electronic search (Google Scholar, PubMed, ScienceDirect, ESBCO, Springerlink and CNKI). Literature abstracts and full-text articles were analyzed and included in the review.

RESULTS

Many phytochemicals have been isolated, identified and published to date, including: at least 18 flavonoids; 13 phenolic acids; 2 steroids; 1 hydroquinone; 10 volatile oils; 22 lignans; 9 polysaccharides; 2 resin glycosides; 16 fatty acids. These phytochemicals and plant extracts exhibit a range of pharmacological activities that include hepatoprotective, renoprotective, antiosteoporotic, antioxidant, anti-aging, antimutagenic, antidepressant, improve sexual function, abortifacient effects, etc.

CONCLUSION

This present review offers primary information for further studies of Cuscuta chinensis. The in vitro studies and in vivo models have provided a bioscientific explanation for its various ethnopharmacological uses and pharmacological activities (most notably antioxidant effects) especially in the prevention of hepatic disease and renal failure. It is necessary and important to do more pharmacokinetic and toxicological research works on human subjects in order to inform the possible active compounds in the body and validate its safety in clinical uses.

Effects of KH-204 on the expression of heat shock protein 70 and germ cell apoptosis in infertility rat models

Background

Idiopathic infertility is a significant number of causes of male infertility. Empirical treatments are used for idiopathic male infertility, and antioxidant supplementation is a kind of management of oxidative stress related infertility. We investigated the antioxidant effects of the modified Ojayeonjonghwan (KH-204) in a rat model of cryptorchidism.

Method

Male rats were divided into four groups (n = 8 in each): a normal control group, a cryptorchidism-induced control group and two cryptorchidism-induced groups treated p.o. with either 200 or 400 mg/kg, KH-204 for 4 weeks. The testes and epididymides from rats in all groups were removed, weighed and subjected to histological examination and semen analysis after surgery. Oxidative stress was assessed by measuring 8-hydroxy-20-deoxyguanosine (8-OHdG), superoxide dismutase (SOD) and heat shock protein (HSP) levels. Apoptosis was determined using a terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling assay.

Results

Treatment with the multi-herbal medicine KH-204 (1) increased the mean weight of the cryptorchid testes; (2) restored sperm counts, motility and germinal cell layer thickness; (3) decreased levels of 8-OHdG and increased levels of SOD; and (4) decreased HSP70 levels and apoptosis.

Conclusions

KH-204 reduces the oxidative stress in an experimental rat model of cryptorchidism, and it may alleviate HSP expression and germ cell apoptosis.

What is the role of unripe Rubus coreanus extract on penile erection?

The effect of unripe Rubus coreanus extract on rabbit penile corpus cavernosum (PCC) was evaluated. Penises were obtained from healthy male New Zealand white rabbits (2.5-3.0 kg). The pre-contracted penis with phenylephrine (Phe, 10 μM) was treated with various concentrations of an extract of unripe R. coreanus (0.5, 1, 2, 3 and 4 mg/mL). The change in penile tension was recorded, cyclic nucleotides in the perfusate and the PCC were measured by radioimmunoassay, and the expression of neuronal nitric oxide synthase (nNOS) and endothelial nitric oxide synthase (eNOS) in the perfused PCC were measured by western blotting. The interaction between unripe R. coreanus and sildenafil was also evaluated. The PCC relaxation induced by the extracts of R. coreanus was in a concentration-dependent manner and enhanced sildenafil-induced PCC relaxation. The perfusion of penile cavernous tissue with the unripe R. coreanus extract increased cGMP and cAMP in the tissue and in the perfusate and the expression of eNOS and nNOS in the tissue. The unripe R. coreanus extract exerts a relaxing effect on penile cavernous tissue in part by activating the NO-cGMP system and it may improve erectile dysfunction (ED), which does not completely respond to sildenafil citrate.

Phytotherapy: emerging therapeutic option in urologic disease

Phytotherapy belongs to the area of complementary and alternative medicine (CAM) and the definition of phytotherapy is the use of plants or plant extracts for medicinal uses. Interest in phytotherapy is growing in both Asian and western countries for its use in the prevention and management of disease, improvement of general health and anti-aging. And also, there are several studies about the efficacy of phytotherapy in urologic diseases like benign prostatic hyperplasia (BPH), erectile dysfunction (ED), late-onset hypogonadism (LOH) and infertility in males. Phytotherapy for BPH including saw palmetto, pygeum, and nettles, is under vigorous research for the therapeutic effect. No solid evidence showing better effective treatment modality for ED than placebo has been found yet for phytotherapy. Recently, a potent NO donor, L-arginine is under research with promising results. Phytotherapy is used by a number of patients with urological disease, and urologists need to have accurate knowledge about phytotherapy as well as keep a cautious approach. The possible effects and side effects should be defined and related to urologic patients by urologists.

Control of systemic and pulmonary blood pressure by nitric oxide formed through neuronal nitric oxide synthase

Nitric oxide formed by neuronal nitric oxide synthase (nNOS) in the brain, autonomic inhibitory (nitrergic) nerves, and heart plays important roles in the control of blood pressure. Activation of nitrergic nerves innervating the systemic vasculature elicits vasodilatation, decreases peripheral resistance, and lowers blood pressure. Impairment of nitrergic nerve function, as well as endothelial dysfunction, results in systemic and pulmonary hypertension and decreased regional blood flow. Blockade of nNOS activity in the brain, particularly the medulla and hypothalamus, causes systemic hypertension. Under hypertensive states, such as those in spontaneously hypertensive and Dahl salt-sensitive rats, the expression of the nNOS gene in the brain is increased; this appears to counteract the activated sympathetic function in the vasomotor center. The present article summarizes information concerning the modulation of systemic and pulmonary hypertension through nNOS-derived nitric oxide produced in the brain and periphery.