Swelling‐activated cation channels mediate depolarization of rat cerebrovascular smooth muscle by hyposmolarity and intravascular pressure

摘要: 1. Increases in intravascular pressure depolarize vascular smooth muscle cells. Based on the attenuating effects of Cl- channel antagonists, it has been suggested that swelling-activated channels may be integral to this response. Consequently, study tested for presence a conductance both intact rat cerebral arteries and isolated 2. A 50 mosmol l-1 hyposmotic challenge (300 250 l-1) constricted arteries. This constriction contained all salient features pressure-induced response including cell depolarization rise intracellular Ca2+ was blocked by voltage-operated antagonists. The hyposmotically induced attenuated DIDS microM) tamoxifen (1 microM), consistent with conductance. 3. current identified sensitive antagonists IAA-94 (100 microM). However, contrary expectations, reversal potential shifted Na+ equilibrium not potential, indicating carried cations anions. cation Gd3+, antagonist. 4. Gd3+ also swelling- cells 5. These findings suggest arise from activation is inhibited DIDS, tamoxifen, gadolinium.