2-B-P-066 〇市川 純¹、中川 緑²、井上 隆司² Jun Ichikawa¹, Midori Nakagawa², Ryuji Inoue^{2 1}佐野日本大学短期大学・総合キャリア教育学科・栄養士フィールド、²福岡大・医・生理学 ¹Sano Nihon Univ. Col., ²Dept. Physiol., Fukuoka Univ. Sch. Med. Glomerular podocytes are continuously exposed to neurohumoral factors and blood flow and pressure. We recently found that mechanical stimulation immediately suppressed the receptor-evoked responses of canonical transient receptor potential 6 (TRPC6) channel in podocytes using the intracellular Ca²⁺ imaging and whole-cell patch clamp techniques. This effect coincided with diminished leak of FITC-labelled albumin across the cell-culture insert membrane. In this study, we investigated the effects of cyclic GMP (cGMP) on the albumin leak, the agent reportedly suppressing the heterologously expressed TRPC6 channel activity through protein kinase G-mediated phosphorylation (Takahashi et al., J.Physiol., 586, p4209-4223, 2008). We cultured immortalized mouse podocytes stably expressing wild-type TRPC6 on the cell-culture membrane inserts and induced their differentiation. The podocytes were then simultaneously stimulated by angiotensin II (AgII) and a membrane-expanding agent 2,4,6-trinitrophenol (TNP) for 48 hr, in the presence or absence of 8Br-cGMP, an analogue of cGMP. In 8Br-cGMP-treated cells, the suppression of albumin leakage by AgII and TNP was attenuated. These results imply the complex actions of cGMP on the barrier function which may not be accounted for solely by the inhibition of TRPC6 channel.