The binding of 3H-RO 5-4864 to the peripheral-type benzodiazepine receptors (PBZDR) in rat testicular interstitial cells (TIC) was characterized. The binding was saturable, reversible and showed a single high-affinity (K(d) = 5.02 ± 0.86 nM) class of binding sites. The maximal binding capacity (B(max)) in crude mitochondrial fractions (77.6 ± 9.1 pmol/mg protein) represents the highest density of PBZDR in tissues thus far studied. In comparison with the crude mitochondrial fraction the subcellular fractionation of of TIC revealed a 2-fold enrichment of 3H-RO 5-4864 binding sites to the purified mitochondria (B(max) = 140 ± 23 pmol/mg protein). The ability of various drugs to displace 3H-RO 5-4864 from TIC binding sites was examined and the inhibition constants (K(i)) for RO 5-4864, PK 11195, diazepam and flunitrazepam were 3.5, 4.4, 159, and 353 nM, respectively, whereas clonazepam and RO 15-1788 were inefficient in displacing 3H-RO 5-4864 (K(i) > 10 μM). This pharmacological profile is characteristic of PBZDR described in other tissues. In conclusion, rat TIC possess a very high concentration of PBZDR primarily associated with mitochondrial membranes.
Documento: | Artículo |
Título: | Peripheral-type benzodiazepine receptors are highly concentrated in mitochondrial membranes of rat testicular interstitial cells |
Autor: | Calvo, D.J.; Ritta, M.N.; Calandra, R.S.; Medina, J.H. |
Filiación: | Inst. de Biologia/Med. Exp., Obligado 2490, 1428 Buenos Aires, Argentina |
Palabras clave: | Benzodiazepine; Mitochondrial membranes; Peripheral receptor; Testicular interstitial cells; 4' chlorodiazepam; diazepam; flunitrazepam; n sec butyl 1 (2 chlorophenyl) n methyl 3 isoquinolinecarboxamide; radioisotope; receptor; animal cell; article; interstitium; male; mitochondrion; nonhuman; priority journal; rat; testis; topical drug administration |
Año: | 1990 |
Volumen: | 52 |
Número: | 4 |
Página de inicio: | 350 |
Página de fin: | 353 |
DOI: | http://dx.doi.org/10.1159/000125606 |
Título revista: | Neuroendocrinology |
Título revista abreviado: | NEUROENDOCRINOLOGY |
ISSN: | 00283835 |
CODEN: | NUNDA |
CAS: | 4' chlorodiazepam, 14439-61-3; diazepam, 439-14-5; flunitrazepam, 1622-62-4; n sec butyl 1 (2 chlorophenyl) n methyl 3 isoquinolinecarboxamide, 85532-75-8 |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00283835_v52_n4_p350_Calvo |