Release and functional role of neuropeptide Y as a sympathetic modulator in human saphenous vein biopsies

Neuropeptide Y Is Released from Human Mammary and Radial Vascular Biopsies and Is a Functional Modulator of Sympathetic Cotransmission

“…In most cases, the biopsy contained a segment of an intact although clamped secondary mammary artery plus its corresponding vein and associated connective tissue. The biopsy was transported in sterile saline from the surgery rooms to the laboratory for dissection and processing, as detailed by Donoso et al [19]; since the mammary vein was more fragile to the application of exogenous tension, most protocols were conducted with segments of the mammary artery rather than the vein. Great care was exercised to handle all biopsies as expeditiously as possible.…”

“…Great care was exercised to handle all biopsies as expeditiously as possible. However, due to the time of the surgery, on some occasions, tissues could not be studied immediately, in which case biopsies were stored overnight at 4°C, in Krebs-Ringer buffer gassed with 95% O 2 -5% CO 2 , as detailed by Donoso et al [19]. …”

“…Rectangular wave pulses (70 V, 0.5-ms duration) of varying frequencies (2.5–40 Hz) and of increasing duration (1–5 min) were delivered depending on the experimental protocol. The rise in tissue tension evoked by electrical depolarization was recorded with a Grass force displacement transducer connected to a Grass polygraph as described by Donoso et al [19]; responses were normalized against the contraction evoked by a 70 m M KCl standard. In one particular set of experiments, we assessed whether the vasomotor response elicited by transmural electrical depolarization of the nerve terminals surrounding these vessels was sensitive to the blockade of voltage-dependent sodium channels.…”

“…In view of prevailing technical difficulties, few laboratories have approached the direct quantification and analytical identification of the peptide released by transmural electrical nerve terminal depolarization, a criterion that is required to clearly establish the modulator role of NPY in human vascular sympathetic cotransmission. In an effort to further understand the involvement of NPY in human vascular sympathetic reflexes, and to extend our previous studies using human saphenous vein biopsies [14, 19], we now describe and characterize the content and release of hNPY from the perivascular nerve endings surrounding segments of human mammary vessels or radial artery, from patients programmed for elective myocardial revascularization surgery. The present contribution not only extends our previous findings to human thoracic and arm vessels, but also broadens the modulator role of NPY to medium-sized arteries and veins, suggesting that NPY operates in a variety of territories and might be physiologically relevant to human vascular sympathetic reflexes as a whole.…”

Adenosinergic System in the Mesenteric Vessels

“…The two subtypes of purinergic receptors are the P2X and P2Y receptors. The P2X receptors are ATPgated ion channels that cause an influx of Ca 2+ into the smooth muscle cells from the extracellular environment (Donoso et al, 2004). Though there are several P2X receptor isoforms, there is evidence that vascular smooth muscle cells primarily express the P2X1 receptors (Wang et al, 2002).…”