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intracellular calcium. Thus, BK-driven current negatively feedbacks on depolarization and opposes SM contraction. Here, we studied the effect of cholesterol enrichment on SM BK currents from rat cerebral arteries. From inside-out patch recordings at [Ca2þ]free=30 microM, we obtained Boltzmann fits to NPo/NPomax-V curves. Surprisingly, one hour-long cholesterol-enrichment using methyl-beta-cyclodextrin prior to patch excision activates BK (Vhalf decreased from À62510 to À8955; p<0.05). Fluorescence imaging using the cholesterol-sensitive dye filipin shows that a significant increase in myocyte cholesterol is achieved within five min. However, myocyte incubation in cholesterol-enriching media for five min prior to patch excision does not activate BK (Vhalf=-5155 mV). In turn, a five min-long enrichment of membrane patches with cholesterol after excision increases Vhalf to À3756 mV (p<0.05). Data point at a time-dependent intracellular mechanism(s) determining between BK activation vs. inhibition by cholesterol. Our earlier work documented increased BK beta1 subunit-associated fluorescence signal in rat cerebral artery myocyte membranes during a high-cholesterol diet. Consistently, surface protein biotinylation followed by Western blotting demonstrates an increase in the myocyte BK beta1 surface fraction from 852 to 2652 % (p<0.01) following 20 min-long cholesterol enrichment. This increase is ablated by brefeldin A, an inhibitor of protein trafficking. We conclude that the switch in cholesterol effect on BK current from inhibition to activation is determined by a trafficking-dependent increase in membrane levels of beta1 subunit. Support: AA-023764 (AB), HL147315 (AD), HL133256 and HL137745 (JJ).

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A man in his 70s presented with right ocular pain, vision loss and temporal headache 4 days after undergoing laser peripheral iridotomy. The patient had lost 10 lbs over the preceding 6 weeks and had a medical history significant for a previously excised melanoma of the left arm. During the course of investigations, the patient was referred to oncology for workup, ultimately leading to a diagnosis of metastatic melanoma. Visceral metastases were identified in the lungs, right anterior fourth rib, left femoral distal diaphysis and medial side of the right globe. The patient decompensated and died shortly after his first radiotherapy treatment.This is the first published report of suprachoroidal haemorrhage secondary to metastasis from suspected cutaneous melanoma. The case highlights the importance of considering malignancy on the differential diagnosis for a suprachoroidal haemorrhage of unknown aetiology and involving oncology early for workup and treatment.