Effects of Ca sup 2+ antagonists on sup 45 Ca sup 2+ uptake by rat whole brain P1 and P2 fractions

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Research Communications in Chemical Pathology and Pharmacology; (USA)

OSTI ID:5412544

Honda, H; Shibuya, T; Salafsky, B ^[1]

---

1. Univ. of Illinois, Rockford (USA)

Voltage-dependent {sup 45}Ca{sup 2+} uptake into rat whole brain P1 (nonsynaptosomal) and P2 (synaptosomal) fractions was measured after 60-s KCl-stimulated depolarization to investigate possible inhibitory effects of Ca{sup 2+} antagonists, nitrendipine, diltiazem, verapamil and ifenprodil tartrate. All drugs (10(-5)M) had little influence on {sup 45}Ca{sup 2+} uptake by whole brain P1 fraction in both nondepolarizing and depolarizing mediums. Diltiazem (10(-5)M) had no influence on {sup 45}Ca{sup 2+} uptake by whole brain P2 fraction under both conditions. However, nitrendipine (10(-5)M) verapamil (10(-5)M) and ifenprodil tartrate inhibited depolarization-dependent {sup 45}Ca{sup 2+} uptake by whole brain P2 fraction, while nondepolarization-dependent {sup 45}Ca{sup 2+} uptake was not affected by these drugs. The inhibitory sequence of depolarization-dependent {sup 45}Ca{sup 2+} uptake by P2 fraction was: ifenprodil tartrate greater than nitrendipine greater than verapamil. These results suggest that ifenprodil tartrate, nitrendipine and verapamil specifically inhibit depolarization-dependent synaptosomal {sup 45}Ca{sup 2+} uptake, but that diltiazem has little influence on it.

• OSTI ID: 5412544
• Journal Information: Research Communications in Chemical Pathology and Pharmacology; (USA), Journal Name: Research Communications in Chemical Pathology and Pharmacology; (USA) Vol. 64:3; ISSN 0034-5164; ISSN RCOCB
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CALCIUM 45
CALCIUM COMPOUNDS
CALCIUM ISOTOPES
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
DAYS LIVING RADIOISOTOPES
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MEMBRANES
NERVOUS SYSTEM
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PORINS
PROTEINS
RADIOISOTOPES
RATS
REACTION KINETICS
RODENTS
TRACER TECHNIQUES
VERTEBRATES