Takaho Watanabe

An Orally Active Epoxide Hydrolase Inhibitor Lowers Blood Pressure and Provides Renal Protection in Salt-Sensitive Hypertension

The present study tested the hypothesis that increasing epoxyeicosatrienoic acids by inhibition of soluble epoxide hydrolase (sEH) would lower blood pressure and ameliorate renal damage in salt-sensitive hypertension. Rats were infused with angiotensin and fed a normal-salt diet or an 8% NaCl diet for 14 days. The sEH inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), was given orally to angiotensin-infused animals during the 14-day period. Plasma AUDA metabolite levels were measured, and they averaged 10±2 ng/mL in normal-salt angiotensin hypertension and 19±3 ng/mL in high-salt angiotensin hypertension on day 14 in the animals administered the sEH inhibitor. Mean arterial blood pressure averaged 161±4 mm Hg in normal-salt and 172±5 mm Hg in the high-salt angiotensin hypertension groups on day 14. EH inhibitor treatment significantly lowered blood pressure to 140±5 mm Hg in the normal-salt angiotensin hypertension group and to 151±6 mm Hg in the high-salt angiotensin hypertension group on day 14. The lower arterial blood pressures in the AUDA-treated groups were associated with increased urinary epoxide-to-diol ratios. Urinary microalbumin levels were measured, and ED-1 staining was used to determine renal damage and macrophage infiltration in the groups. Two weeks of AUDA treatment decreased urinary microalbumin excretion in the normal-salt and high-salt angiotensin hypertension groups and macrophage number in the high-salt angiotensin hypertension group. These data demonstrate that sEH inhibition lowers blood pressure and ameliorates renal damage in angiotensin-dependent, salt-sensitive hypertension.

Development of a class-specific immunoassay for the type I pyrethroid insecticides

A general enzyme-linked immunosorbent assay was developed for the type I pyrethroid insecticides, such as permethrin, phenothrin, resmethrin and bioresmethrin. Polyclonal antibodies were generated by immunizing with a permethrin derivative, 2,2-dimethyl-3-(5 � -carboxy-pent-1 � -en-yl)cyclopropanecarboxylic acid-(3-phenoxybenzyl)ester conjugated with thyroglobulin, bovine serum albumin or ovalbumin. Antisera were screened against eight different coating antigens. The antibody–antigen combination with the lowest background, and highest sensitivity for permethrin was further optimized and tested for solvent and detergent tolerance. The I50’s of the optimized immunoassay were 30g/l for permethrin and 20g/l for phenothrin, respectively. No cross-reactivities were measured to the type II pyrethroids, such as esfenvalerate, cyfluthrin, cypermethrin, deltamethrin, fenvalerate and fluvalinate. This assay can be used in monitoring studies to distinguish between types I and II pyrethroids.