Ca release and ryanodine binding in sarcoplasmic reticulum during cardiac myogenesis

Conference · Fri May 01 04:00:00 EDT 1987 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:6023878

Michalak, M

Ca-induced Ca release and pH-induced Ca release activities were identified in sarcoplasmic reticulum (SR) vesicles isolated from mature and fetal sheep hearts. Ca-induced Ca release and pH-induced Ca release were inhibited in fetal and mature SR membranes by micromolar concentration of ruthenium red and ryanodine. Ca release from fetal SR vesicles was, however, inhibited by higher concentration of ruthenium red than that observed in mature membrane. Both fetal and mature SR vesicles bind (/sup 3/H)ryanodine. Fetal SR showed approximately 2.7 times higher binding when compared to mature vesicles. Scatchard analysis of ryanodine binding to SR vesicles revealed that only one, high affinity binding site (K/sub d/ of 6.7 nM) was present in fetal SF vesicles, compared to two binding sites present in the mature SR vesicles. Heavy and light SR vesicles were also isolated from fetal and mature hearts, and their Ca release activities and ryanodine binding were investigated. Mostly heavy SR vesicles isolated from mature hearts exhibited Ca release activities whereas Ca-induced Ca release and pH-induced Ca release were detected in both, light and heavy SR isolated from fetal heart. The authors results indicate that SR Ca release channel is present in the fetal SR, and that it exhibits different affinity to ruthenium red and ryanodine than that observed for mature SR membrane.

• Research Organization: Hospital for Sick Children, Toronto, Ontario
• OSTI ID: 6023878
• Report Number(s): CONF-870644-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 46:6
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AGE DEPENDENCE
ALKALINE EARTH METALS
ANIMALS
BIOCHEMICAL REACTION KINETICS
BODY
CALCIUM
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
DOMESTIC ANIMALS
ELEMENTS
HEART
INSECTICIDES
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
METALS
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PESTICIDES
PROTEINS
REACTION KINETICS
RECEPTORS
RUMINANTS
SARCOPLASMIC RETICULUM
SECRETION
SHEEP
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES