The effects of nonselective nitric-oxide synthase (NOS) inhibitors [N--nitro-L-arginine methyl ester (L-NAME) and N--nitro-L-arginine (L-NNA)] and specific neuronal NOS (nNOSon adrenergic nerve-mediated vasoconstriction were studied in rat perfused mesenteric vascular beds without endothelium. Perfusion of L-NAME, L-NNA, or L-VNIO markedly augmented vasoconstrictor responses to periarterial nerve stimulation (PNS; 2-8 Hz) without affecting vasoconstriction induced by exogenously injected norepinephrine (NE). Addition of L-arginine, a precursor for the synthesis of nitric oxide (NO), reversed the augmentation of the PNS response by L-NAME. The PNS (8 Hz)-evoked NE release in the perfusate was increased by L-NAME perfusion. In preparations treated with capsaicin [a depleter of calcitonin gene-related peptide (CGRP)-containing nerves], L-NAME did not augment vasoconstrictor responses to PNS or NE injection. Combined perfusion of CGRP(8-37) (a CGRP receptor antagonist) and L-NAME induced additive augmentation of the vasoconstrictor response to PNS but did not affect the response to NE injection. In preparations with active tone produced by methoxamine and in the presence of guanethidine, L-NAME perfusion did not affect the vasodilator response induced by PNS. Immunostaining of the mesenteric artery showed the presence of nNOS-like immunopositive nerve fibers, which were absent in arteries pretreated with capsaicin. These findings suggest that NO, which is released from perivascular capsaicin-sensitive nerves, presynaptically inhibits neurogenic NE release to modulate adrenergic neurotransmission.

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From 2002 to 2018, the number of patients with prostate cancer significantly increased from 679,023 to 1276,106 worldwide. Total prostatectomy (including robot-assisted prostatectomy), radiation therapy, and pharmacological treatment are commonly used to treat prostate cancer. The Chief of the Pharmaceutical Safety Division, that is, the Federation of Pharmaceutical Manufacturers’ Associations of Japan (FPMAJ), recently called for the revision of package inserts for ethical drugs. However, the pathogenesis of interstitial lung disease (ILD), a serious drug-induced adverse effect, remains unclear. Moreover, there have been no large-scale evaluations of potential complications associated with currently used antiandrogens, which are commonly employed to treat prostate cancer. Hence, ILD, as an adverse event, remains poorly understood. Therefore, we conducted a survey of reports in the Japanese Adverse Drug Event Report (JADER) database to investigate the potential association between the reporting of ILD and antiandrogen drug use in clinical practice. The occurrence of ILD was investigated by evaluating the relationship between antiandrogen drug use and ILD. Adverse event signals were detected with reporting odds ratios (RORs), using data from the JADER and FDA Adverse Event Reporting System (FAERS) databases, for the analysis of post-marketing adverse event reports. The JADER was used to examine the time profile of adverse event occurrence for each drug, whereas the FAERS was used to screen cases of unknown adverse events and analyze their trends of occurrence. The analysis of data from both databases revealed the 95% confidence interval lower limits of ROR for bicalutamide and flutamide to be > 1, and adverse event signals were detected following the use of either drug. While caution should be exercised for drugs that are new to the market, we conclude that drugs with similar therapeutic effects that have been in use for a long period should also be re-examined for potential adverse events.

An endogenous cannabinoid anandamide (N-arachidonoylethanolamide) has been shown to cause vasodilatation in vitro and a brief vasoconstriction followed by prolonged depressor response in vivo. This study investigated the vascular effects of anandamide and underlying mechanisms in rat mesenteric vascular beds. In preparations with an intact endothelium and active tone, anandamide at low concentrations (0.1 - 1 nM) caused a concentration-dependent decrease in perfusion pressure due to vasodilatation, but at high concentrations (10 nM - 1 µM) elicited an initial and sharp increase in perfusion pressure due to vasoconstriction followed by long-lasting vasodilatation in a concentration-dependent manner. Treatment with SR141716A [cannabinoid-1 (CB(1))-receptor antagonist] blunted both the vasoconstrictor and vasodilator responses. Also, removal of the endothelium and indomethacin (cyclooxygenase inhibitor), but not adrenergic denervation with 6-hydoxydopamine (adrenergic neurotoxin), markedly inhibited the vasoconstrictor response to anandamide, while these treatments did not affect vasodilatation. The vasodilatation, but not vasoconstriction, in response to anandamide was markedly attenuated by capsazepine [selective antagonist for transient receptor potential vanilloid-1 (TRPV1)], pretreatment with capsaicin [calcitonin gene-related peptide (CGRP)ergic-nerve depletor], or cold-storage denervation. These results suggest that in rat mesenteric vascular beds, anandamide causes CB(1)-receptor- and prostanoid-mediated endothelium-dependent vasoconstriction and perivascular capsaicin-sensitive CGRPergic nerve-mediated vasodilatation.

Abstract. Mechanisms underlying bradykinin-induced vasoconstriction were investigated in rat perfused mesenteric vascular beds with active tone. In preparations with intact endothelium, bolus injections of bradykinin (1 to 1,000 pmol) dose-dependently produced three-phase vascular effects, which consisted of a first-phase vasodilation followed by a second-phase vasoconstriction and a subsequent third-phase vasodilation; these effects were abolished by FR172357 (bradykinin B 2 -receptor antagonist), but not by des-Arg 9 -[Leu 8 ]-bradykinin (bradykinin B 1 -receptor antagonist). In preparations with intact endothelium, indomethacin (cyclooxygenase inhibitor), seratrodast (thromboxane A 2 (TXA 2 )-receptor antagonist), ONO-3708 (TXA 2 / prostaglandin H 2 (PGH 2 )-receptor antagonist) or ozagrel (TXA 2 synthesis inhibitor) markedly inhibited the bradykinin-induced vasoconstriction. In preparations without endothelium, the bradykinin-induced vasoconstriction was abolished by indomethacin and ONO-3708, while seratrodast and ozagrel had no effect. These results suggest that the endothelium-dependent vasoconstriction of bradykinin is mainly mediated by TXA 2 and that prostanoids other than TXA 2 , probably PGH 2 , in mesenteric vascular smooth muscle are responsible for bradykinin-induced endothelium-independent vasoconstriction.