Sensory nerves and transient receptor potential vanilloid 1 channels in CO2 regulation of cerebrovascular tone

Cocaine Constriction of Rat Basilar Artery in situ: Roles of Nitric Oxide and Endothelin-1

“…As we previously demonstrated [18], sensory nerves were denervated in adult rats injected with capsaicin as pups since capsaicin dilatation was greatly reduced in basilar artery in situ in these adult rats. We also reported that the basal diameter of the basilar artery was not altered in adults that were injected with capsaicin as pups [18]. …”

“…However, 10 µmol/l cocaine still caused 10.2 and 10.3% constriction (n = 2) in these vessels. In these same two vessels, we previously reported [18] that capsaicin superfusion caused a plateau dilator response of ∼10%.…”

“…Since superfusion with capsaicin desensitized transient receptor potential vanilloid 1 channels of the basilar artery in situ [18], we also tested whether cocaine constriction was decreased in basilar artery following 10 µmol/l capsaicin superfusion for 30-60 min in vessels from adult rats injected with capsaicin as pups. However, 10 µmol/l cocaine still caused 10.2 and 10.3% constriction (n = 2) in these vessels.…”

Cerebral microvasculature resistance to acute endothelin-1-induced functional down-regulation in rat

“…As described (Yoon et al, 2014), flow velocity was measured with a Vasamedics BPM2 laser-Doppler fitted with a 0.8 mm diameter probe in an in situ window preparation of the rat ventral midbrain. The probe was positioned in the cranial window with the probe located just over but not touching a region of the midbrain surface lateral to the basilar artery and essentially visually devoid of vessels.…”