The effect of Ca2+, Cd2+ and Ni2+ on detergent-permeabilized vascular smooth muscle from the shark, Squalus acanthias

• Main Authors: DH Evans, E Chipouras, T Toop, John Donald
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: 1993
• Subjects: Pharmacology and pharmaceutical sciences not elsewhere classified; Animals; Aorta; Cadmium; Calcium; In Vitro Techniques; Nickel; Octoxynol; Sharks; Vascular smooth muscle; Detergent-permeabilized; Triton; spiny dogfish; Squalus acanthias
• Online Access: http://hdl.handle.net/10536/DRO/DU:30094419; https://figshare.com/articles/journal_contribution/The_effect_of_Ca2_Cd2_and_Ni2_on_detergent-permeabilized_vascular_smooth_muscle_from_the_shark_Squalus_acanthias/20868067

We examined the effect of Ca2+, Cd2+, or Ni2+ on vascular smooth muscle intracellular proteins involved in contraction, using rings of detergent-permeabilized aortae from the spiny dogfish, Squalus acanthias. Addition of Ca2+ stimulated contraction of the vascular smooth muscle, and permeabilization by treatment with Triton X-100 increased the sensitivity to Ca2+ nearly 5 log units, demonstrating that this protocol left contractile and regulatory proteins intact. Addition of 1 microM calmodulin did not increase the sensitivity of the rings to Ca2+, suggesting that this preparation is not leaky to this regulatory protein. Neither Cd2+ nor Ni2+ stimulated contraction of permeabilized rings demonstrating that the previously-described contractile action of these heavy metals is not mediated by direct stimulation of intracellular proteins, rather by interaction with sarcolemmal proteins.