OBJECTIVE: Alcoholic neuropathy is characterized by allodynia (a discomfort evoked by normally innocuous stimuli), hyperalgesia (an exaggerated pain in response to painful stimuli) and spontaneous burning pain. The aim of the present study is to investigate the effect of rolipram, a phosphodiesterase 4 inhibitor, against alcohol-induced neuropathy in rats. METHODS: Allodynia was induced by administering 35% v/v ethanol (10 g/kg; oral gavage) to Spraue-Dawley rats for 8 weeks. Rolipram and saline (vehicle) were administered intraperitoneally. Mechanical allodynia was measured by using von Frey filaments. Somatosensory evoked potential (SEP) was proposed as complementary measure to assess the integrity of nerve pathway. RESULTS: The ethanol-induced mechanical allodynia began to manifest from 3 week, and then peaked within 1 week. Beginning from 3 week, latency significantly started to increased in control group. In rolipram treated rats, the shorter latency was sustained until 8 weeks (p<0.05). The mechanical allodynia, which began to manifest on the 3 weeks, intraperitoneal injections of rolipram sustained statistical difference until 8 weeks, the final week of the study (p<0.05). CONCLUSION: This study suggests that rolipram might alleviate mechanical allodynia induced by alcohol in rats, which clearly has clinical implication.
Alcoholic Neuropathy ; Alcoholics ; Animals ; Burns ; Cyclic Nucleotide Phosphodiesterases, Type 4 ; Ethanol ; Evoked Potentials, Somatosensory ; Humans ; Hyperalgesia ; Injections, Intraperitoneal ; Rats ; Rolipram

As it has been reported that the depolarization-induced norepinephrine (NE) release is modulated by activation of presynaptic A-1-adenosine heteroreceptor and various lines of evidence indicate the involvement of adenylate cyclase system in A-1-adenosine post-receptor mechanism in hippocampus, it was attempted to delineate the role of adenylate cyclase system in the A-1-receptor-mediated control of NE release in this study. Slices from rat hippocampus were equilibrated with (3H)-NE and the release of the labelled products was evoked by electrical stimulation (3 Hz, 5 V cm-1, 2 ms, rectangular pulses). The influence of various agents on the evoked tritium-outflow was investigated. N-6-Cyclopentyladenosine (CPA), a specific A-1-adenosine receptor agonist, in concentrations ranging from 0.1 to 10 micrometer decreased the (3H)-NE release in a dose-dependent manner without any change of basal rate of release. 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX, 2 micrometer), a selective A-1-receptor antagonist, inhibited the CPA effect. The responses to N-ethylmaleimide (3 & 10 micrometer), a SH-alkylating agent of G-protein, were characterized by increments of the evoked NE-release and the CPA effects were completely abolished by NEM pretreatment. Forskolin, a specific adenylate cyclase activator, in concentrations ranging from 0.1 to 30 micrometer increased the evoked and basal rate of NE release in a dose-dependent manner and the CPA effects were inhibited by forskolin pretreatment. Rolipram (1 & 10 micrometer), a phosphodiesterase inhibitor, did not affect the evoked NE release, but reduced the CPA effect. And 8-bromo-cAMP (100 & 300 micrometer), a membrane permeable cAMP analogue, inhibited the CPA effect significantly. These results suggest that the A-1-adenosine heteroreceptor plays an important role in NE-release via nucleotide-binding protein G-i in the rat hippocampus and that the adenylate cyclase system might be participated in this process.
8-Bromo Cyclic Adenosine Monophosphate ; Adenylyl Cyclases ; Animals ; Colforsin* ; Electric Stimulation ; Ethylmaleimide ; GTP-Binding Proteins ; Hippocampus* ; Membranes ; Norepinephrine* ; Rats* ; Rolipram

PURPOSE: Pelvic irradiation for the treatment of cancer can affect normal cells, such as the rapidly proliferating spermatogenic cells of the testis, leading to infertility, a common post-irradiation problem. The present study investigated the radioprotective effect of rolipram, a specific phosphodiesterase type-IV inhibitor known to increase the expression and phosphorylation of the cyclic adenosine monophosphate response element-binding protein (CREB), a key factor for spermatogenesis, with the testicular system against pelvic irradiation. MATERIALS AND METHODS: Male C57BL/6 mice were treated with pelvic irradiation (2 Gy) and rolipram, alone or in combination, and were sacrificed at 12 hours and 35 days after irradiation. RESULTS: Rolipram protected germ cells from radiation-induced apoptosis at 12 hours after irradiation and significantly increased testis weight compared with irradiation controls at 35 days. Rolipram also ameliorated radiation-induced testicular morphological changes, such as changes in seminiferous tubular diameter and epithelial height. Additionally, seminiferous tubule repopulation and stem cell survival indices were higher in the rolipram-treated group than in the radiation group. Moreover, rolipram treatment counteracted the radiation-mediated decrease in the sperm count and mobility in the epididymis. CONCLUSIONS: These protective effects of rolipram treatment prior to irradiation may be mediated by the increase in pCREB levels at 12 hours post-irradiation and the attenuated decrease in pCREB levels in the testis at 35 days post-irradiation in the rolipram-treated group. These findings suggest that activation of CREB signaling by rolipram treatment ameliorates the detrimental effects of acute irradiation on testicular dysfunction and the related male reproductive functions in mice.
Adenosine Monophosphate ; Animals ; Apoptosis ; Cyclic AMP Response Element-Binding Protein ; Epididymis ; Germ Cells ; Humans ; Infertility ; Male ; Mice* ; Phosphorylation ; Rolipram* ; Seminiferous Tubules ; Sperm Count ; Spermatogenesis ; Stem Cells ; Testis

OBJECTIVE: Peripheral neuropathy is characterized by hyperalgesia, spontaneous burning pain, and allodynia. The purpose of this study was to investigate the effect of rolipram, a phosphodiesterase-4-specific inhibitor, in a segmental spinal nerve ligation model in rats. METHODS: Both the L5 and L6 spinal nerves of the left side of the rats were ligated. Phosphodiesterase-4 inhibitor (rolipram) and saline (vehicle) were administered intraperitoneally. We measured mechanical allodynia using von Frey filaments and a nerve conduction study. RESULTS: The mechanical allodynia, which began to manifest on the first day, peaked within 2 days. Multiple intraperitoneal injections of rolipram ameliorated the mechanical allodynia. Furthermore, an intraperitoneal administration of rolipram improved the development of pain behavior and nerve conduction velocity. CONCLUSION: This study suggests that the phosphodiesterase-4 inhibitor, rolipram, alleviates mechanical allodynia induced by segmental spinal nerve ligation in rats. This finding may have clinical implications.
Animals ; Burns ; Cyclic Nucleotide Phosphodiesterases, Type 4 ; Hyperalgesia ; Injections, Intraperitoneal ; Ligation ; Neural Conduction ; Peripheral Nerve Injuries ; Peripheral Nervous System Diseases ; Rats ; Rolipram ; Spinal Nerves

OBJECTIVE: To assess the capability of phosphodiesterase type IV inhibitor (rolipram) to suppress IL-12 in human decidua and the subsequent changes of Th-2 cytokine (IL-10) and Th-1 cytokine (TNF-alpha). METHODS: Decidual tissues of 10 first-trimester pregnant women and 10 first-trimester pregnant women diagnosed as missed abortion were collected by dilatation and currettage. The decidual tissues were treated with rolipram for 6 hours. Protein and mRNA expression in the tissues were analysed by western blotting, immunohistochemistry and reverse transcription-polymerase chain reaction. RESULTS: Rolipram, in the concentration above 1 microgram/ml, could decrease the expression of IL-12p35 (control: 46.37+/-7.38, rolipram: 24.34+/-8.46) and IL-12p40 mRNA (control: 31.7+/-5.8, rolipram: 14.9+/-4.6) and protein (control: 52.4+/-8.9, rolipram: 40.9+/-12.1). However, the expression of IL-10 and TNF-alpha mRNA and protein did not changed by rolipram. There was no difference in the cytokine expression pattern between the decidual tissues of normal pregnancy and missed abortion. CONCLUSION: Rolipram, the phosphodiesterase type IV inhibitor, could induce the decrease of IL-12 in human decidua. In human decidual tissue, unlike other human tissues, the decrease of IL-12 by rolipram did not modulate other Th-1/Th-2 cytokines. Inability of IL-12 to modulate other Th-1/Th-2 cytokines might be related with unique cytokine network in human decidua rather than its small extent of decrease.
Abortion, Missed ; Blotting, Western ; Cyclic Nucleotide Phosphodiesterases, Type 4* ; Cytokines* ; Decidua ; Dilatation ; Female ; Humans* ; Immunohistochemistry ; Interleukin-10 ; Interleukin-12 Subunit p35 ; Interleukin-12 Subunit p40 ; Interleukin-12* ; Pregnancy ; Pregnant Women ; RNA, Messenger ; Rolipram ; Tumor Necrosis Factor-alpha

PURPOSE: The objective of this study was to evaluate the relaxant effect of scoparone from Artemisia capillaris on rabbit penile corpus cavernosum smooth muscle (PCCSM) and to elucidate the mechanism of action of scoparone for the treatment of erectile dysfunction (ED). MATERIALS AND METHODS: PCCSM that had been precontracted with phenylephrine was treated with 3 Artemisia herbs (A. princeps, A. capillaris, and A. iwayomogi) and 3 fractions (n-hexane, ethyl acetate, and n-butanol) with different concentrations (0.1, 0.5, 1.0, and 2.0 mg/mL). Four components (esculetin, scopoletin, capillarisin, and scoparone) isolated from A. capillaris were also evaluated. The PCCSM was preincubated with Nω-nitro-L-arginine methyl ester hydrochloride (L-NAME) and 1H-[1,2,4] oxadiazolo [4,3-a]quinoxalin-1-one (ODQ). Cyclic nucleotides in the perfusate were measured by a radioimmunoassay. The interactions of scoparone with udenafil and rolipram were also evaluated. RESULTS: A. capillaris extract relaxed PCCSM in a concentration-dependent manner. Scoparone had the highest relaxant effect on PCCSM among the 4 components (esculetin, scopoletin, capillarisin, and scoparone) isolated from the ethyl acetate fraction. The application of scoparone on PCCSM pretreated with L-NAME and ODQ led to significantly less relaxation. Scoparone also increased the cyclic guanosine monophosphate (cGMP) levels in the perfusate in a concentration-dependent manner. Furthermore, scoparone enhanced udenafil- and rolipram-induced relaxation of the PCCSM. CONCLUSIONS: Scoparone relaxed the PCCSM mainly by activating the nitric oxide-cGMP signaling pathway, and it may be a new promising treatment for ED patients who do not completely respond to udenafil.
Artemisia* ; Coumarins ; Erectile Dysfunction ; Guanosine Monophosphate* ; Guanosine* ; Humans ; Male ; Muscle, Smooth ; NG-Nitroarginine Methyl Ester ; Nitric Oxide ; Nucleotides, Cyclic ; Penile Erection* ; Phenylephrine ; Phosphodiesterase 5 Inhibitors ; Radioimmunoassay ; Relaxation ; Rolipram ; Scopoletin

The aim of this study was to evaluate the relaxant and anti-inflammatory effects of two thalidomide analogs as phosphodiesterase-4 (PDE-4) inhibitors in pregnant rat uterus. Uteri from Wistar female rats were isolated at 19 day of pregnancy. Uterine samples were used in functional studies to evaluate the inhibitory effects of the thalidomide analogs, methyl 3-(4-nitrophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4NO2PDPMe) and methyl 3-(4-aminophthalimido)-3-(3,4-dimethoxyphenyl)-propanoate (4APDPMe), on prostaglandin-F2α (PGF2α)-induced phasic, K⁺-induced tonic, and Ca²⁺-induced contractions. Accumulation of cAMP was quantified in uterine homogenates by ELISA. Anti-inflammatory effect was assessed by using ELISA for determination of the pro-inflammatory cytokines tumor necrosis factor-α (TNFα) and interleukin (IL)-1β, and anti-inflammatory IL-10, from uterine explants stimulated with lipopolysaccharide (LPS). Nifedipine, forskolin and rolipram were used as positive controls where required. Both thalidomide analogs induced a significant inhibition of the uterine contractions induced by the pharmaco- and electro-mechanic stimuli. Nifedipine and forskolin were more potent than the analogs to inhibit the uterine contractility, but these were more potent than rolipram, and 4APDPMe was equieffective to nifedipine. Thalidomide analogs increased uterine cAMP-levels in a concentration-dependent manner. The LPS-induced TNFα and IL-1β uterine secretion was diminished in a concentration-dependent fashion by both analogs, whereas IL-10 secretion was increased significantly. The thalidomide analogs induced utero-relaxant and anti-inflammatory effects, which were associated with the increased cAMP levels as PDE-4 inhibitors in the pregnant rat uterus. Such properties place these thalidomide analogs as potentially safe and effective tocolytic agents in a field that urgently needs improved pharmacological treatments, as in cases of preterm labor.
Animals ; Colforsin ; Cyclic Nucleotide Phosphodiesterases, Type 4 ; Cytokines ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Interleukin-10 ; Interleukins ; Necrosis ; Nifedipine ; Obstetric Labor, Premature ; Phosphodiesterase 4 Inhibitors* ; Pregnancy ; Rats* ; Rolipram ; Thalidomide* ; Tocolytic Agents ; Uterine Contraction ; Uterus*

BACKGROUND/OBJECTIVES: This study evaluated the effects and molecular mechanisms of the Schisandra chinensis fruit extract (SC) and its major compound gomisin A (GA), on the contractility of rabbit penile corpus cavernosum smooth muscle (PCCSM). MATERIALS/METHODS: PCCSM was exposed to SC or GA after appropriate pretreatment with nitric oxide synthase (NOS) blocker, guanylate cyclase blocker, adenylyl cyclase blocker or protein kinase A blocker. Subsequently, we evaluated the cyclic nucleotide in the perfusate by radioimmunoassay, protein expression level of neuronal NOS (nNOS) and endothelial NOS (eNOS) by western blot, and the interaction of SC or GA with udenafil and rolipram. RESULTS: Both SC and GA induce PCCSM relaxations in a concentration-dependent manner. Pretreatment with NOS blocker, guanylate cyclase blocker, adenylyl cyclase blocker or protein kinase A blocker result in significantly decreased relaxation. SC and GA also induce the levels of cyclic nucleotide in the perfusate in a concentration-dependent manner. Perfusion with GA also showed significantly higher levels of eNOS protein. Furthermore, the udenafil and rolipram induced relaxations of PCCSM were enhanced after exposure to SC and GA. Our results indicate that SC and GA induce the relaxation of PCCSM via the nitric oxide (NO)-cGMP and cAMP signaling pathways. CONCLUSIONS: The SC and GA are potential alternative treatments for men who want to consume natural products to ameliorate erectile function, or who do not respond to the commercially available medicines.
Adenylyl Cyclases ; Biological Products ; Blotting, Western ; Cyclic AMP-Dependent Protein Kinases ; Erectile Dysfunction ; Fruit* ; Guanosine Monophosphate* ; Guanosine* ; Guanylate Cyclase ; Humans ; Lignans ; Male ; Muscle, Smooth* ; Neurons ; Nitric Oxide Synthase ; Nitric Oxide* ; Perfusion ; Phosphodiesterase 5 Inhibitors ; Radioimmunoassay ; Relaxation ; Rolipram ; Schisandra*

Phosphodiesterase (PDE) 4 inhibitors have been shown to induce the cAMP-mediated signaling pathway by inhibiting cAMP hydrolysis. This study investigated the effect of a PDE4 inhibitor on the expression of the inducible cAMP early repressor (ICER), which is an endogenous inhibitor of CRE- mediated transcription, in osteoblastic cells. RT-PCR analysis revealed that rolipram, a PDE4 inhibitor, stimulates the ICER mRNA in a dose dependent manner. The induction of ICER mRNA expression by rolipram was suppressed by the inhibitors of protein kinase A (PKA) and p38 MAPK, suggesting the involvement of PKA and p38 MAPK activation in ICER expression by rolipram. It was previously shown that rolipram induced the expression of TNF-related activation-induced cytokine (TRANCE, also known as RANKL, ODF, or OPGL) in osteoblasts. This paper provides evidences that a transcriptional repressor like ICER might modulate TRANCE mRNA expression by rolipram in osteoblasts.
3', 5'-Cyclic-Nucleotide Phosphodiesterase/*antagonists & inhibitors ; Animals ; Animals, Outbred Strains ; Cyclic AMP-Dependent Protein Kinases/metabolism ; DNA-Binding Proteins/genetics/*metabolism ; Gene Expression/drug effects ; Mice ; Osteoblasts/*drug effects/metabolism ; Phosphodiesterase Inhibitors/*pharmacology ; Research Support, Non-U.S. Gov't ; Rolipram/*pharmacology ; Transcription Factors/genetics/*metabolism ; p38 Mitogen-Activated Protein Kinases/metabolism