Neurosteroid Analogues. 4. The Effect of Methyl Substitution at the C-5 and C-10 Positions of Neurosteroids on Electrophysiological Activity at GABAA Receptors
摘要:
A series of analogues of the neuroactive steroids 3 alpha-hydroxy-5 alpha-pregnan-20-one and 3 alpha-hydroxy-5 beta-pregnan-20-one were studied to elucidate the mode of binding of 5 alpha- and 5 beta-reduced steroids to steroid binding sites on GABA(A) receptors. Analogues which were either 3 alpha-hydroxy-20-ketosteroids or 3 alpha-hydroxysteroid-17 beta-carbonitriles and which contained various methyl group substitution patterns at C-5 and C-10 were prepared. Evaluations utilized whole-cell patch clamp electrophysiological methods carried out on cultured rat hippocampal neurons, and the results obtained with the rigid 17 beta-carbonitrile analogs were analyzed using molecular modeling methods. The molecular modeling results provide a rationale for the observation that the configuration of the hydroxyl group at C-3 is a greater determinant of anesthetic potency than the configuration of the A,B ring fusion at C-5. The electrophysiological results identify steric restrictions for the space that can be occupied in 5 alpha- and 5 beta-reduced steriod modulators of GABA(A) receptors in the regions of space proximate to the steroid C-5, C-10, and possibly C-4 positions. This information is useful for the development of nonsteroidal analogues that can modulate GABA(A) receptors via interactions at steroid binding sites.
Neurosteroid Analogues. 4. The Effect of Methyl Substitution at the C-5 and C-10 Positions of Neurosteroids on Electrophysiological Activity at GABAA Receptors
摘要:
A series of analogues of the neuroactive steroids 3 alpha-hydroxy-5 alpha-pregnan-20-one and 3 alpha-hydroxy-5 beta-pregnan-20-one were studied to elucidate the mode of binding of 5 alpha- and 5 beta-reduced steroids to steroid binding sites on GABA(A) receptors. Analogues which were either 3 alpha-hydroxy-20-ketosteroids or 3 alpha-hydroxysteroid-17 beta-carbonitriles and which contained various methyl group substitution patterns at C-5 and C-10 were prepared. Evaluations utilized whole-cell patch clamp electrophysiological methods carried out on cultured rat hippocampal neurons, and the results obtained with the rigid 17 beta-carbonitrile analogs were analyzed using molecular modeling methods. The molecular modeling results provide a rationale for the observation that the configuration of the hydroxyl group at C-3 is a greater determinant of anesthetic potency than the configuration of the A,B ring fusion at C-5. The electrophysiological results identify steric restrictions for the space that can be occupied in 5 alpha- and 5 beta-reduced steriod modulators of GABA(A) receptors in the regions of space proximate to the steroid C-5, C-10, and possibly C-4 positions. This information is useful for the development of nonsteroidal analogues that can modulate GABA(A) receptors via interactions at steroid binding sites.
Neurosteroid Analogues. 4. The Effect of Methyl Substitution at the C-5 and C-10 Positions of Neurosteroids on Electrophysiological Activity at GABA<sub>A</sub> Receptors
作者:Mingcheng Han、Charles F. Zorumski、Douglas F. Covey
DOI:10.1021/jm960304p
日期:1996.1.1
A series of analogues of the neuroactive steroids 3 alpha-hydroxy-5 alpha-pregnan-20-one and 3 alpha-hydroxy-5 beta-pregnan-20-one were studied to elucidate the mode of binding of 5 alpha- and 5 beta-reduced steroids to steroid binding sites on GABA(A) receptors. Analogues which were either 3 alpha-hydroxy-20-ketosteroids or 3 alpha-hydroxysteroid-17 beta-carbonitriles and which contained various methyl group substitution patterns at C-5 and C-10 were prepared. Evaluations utilized whole-cell patch clamp electrophysiological methods carried out on cultured rat hippocampal neurons, and the results obtained with the rigid 17 beta-carbonitrile analogs were analyzed using molecular modeling methods. The molecular modeling results provide a rationale for the observation that the configuration of the hydroxyl group at C-3 is a greater determinant of anesthetic potency than the configuration of the A,B ring fusion at C-5. The electrophysiological results identify steric restrictions for the space that can be occupied in 5 alpha- and 5 beta-reduced steriod modulators of GABA(A) receptors in the regions of space proximate to the steroid C-5, C-10, and possibly C-4 positions. This information is useful for the development of nonsteroidal analogues that can modulate GABA(A) receptors via interactions at steroid binding sites.