CELLULAR BASIS FOR FOLLICLE-STIMULATING HORMONE-STIMULATED CALCIUM SIGNALING IN SINGLE-RAT SERTOLI CELLS - POSSIBLE DISSOCIATION FROM EFFECTS OF ADENOSINE-3',5'-MONOPHOSPHATE

被引:40
作者
SHARMA, OP
FLORES, JA
LEONG, DA
VELDHUIS, JD
机构
[1] UNIV VIRGINIA, HLTH SCI CTR,DEPT INTERNAL MED, DIV ENDOCRINOL & METAB,BOX 202, CHARLOTTESVILLE, VA 22908 USA
[2] UNIV VIRGINIA, HLTH SCI CTR, NATL SCI FDN CTR BIOL TIMING, CHARLOTTESVILLE, VA 22908 USA
关键词
D O I
10.1210/en.134.4.1915
中图分类号
R5 [内科学];
学科分类号
1002 ; 100201 ;
摘要
To study the cellular basis for FSH-stimulated dose-dependent graded increases in intracellular Ca2+ concentrations in populations of Sertoli cells, we investigated the effects of FSH on free Ca2+ ion concentrations ([Ca2+]i) in individual rat Sertoli cells using the Ca2+-sensitive dye fura-2/AM and digital fluorescent videomicroscopy. Ovine or rat FSH elicited a hormone-specific rise in [Ca2+]i within 20-140 sec, with a peak level 2.7 +/- 0.9-fold greater than the basal value (mean +/- SEM; n = 8) lasting for 4-16 min. The amplitude and kinetics of the FSH-induced [Ca2+]i signal were not dose dependent. Instead, increasing doses of FSH recruited a higher percentage of responding cells. Chelation of extracellular Ca2+ or cotreatment with verapamil or cobalt abolished FSH-induced [Ca2+]i increases. Furthermore, in the presence of extracellular Mn2+, direct evidence for FSH-mediated Ca2+ influx was obtained from the quench of fura-2 fluorescence. Induced Ca2+ increases were mimicked by forskolin or protein kinase-A type I activators [ 8-(6-amino-hexyl)amino-cAMP and N6-benzoyl-cAMP (N6B)]. However, the cAMP analogs, 8-bromo-cAMP, N6,2'-O-dibutyryl cAMP, or protein kinase-A type II activators (8-thiomethyl-cAMP and N6B), induced [Ca2+]i increases even in the absence of extracellular Ca2+, and the time course of the [Ca2+]i rise induced by cAMP analogs was more rapid than that induced by FSH. Similarly, the uninhibited rise in [Ca2+]i induced by FSH in pertussis toxin-pretreated Sertoli celts suggests that PT-sensitive G-proteins are not involved in the action of FSH on [Ca2+]i. In summary, we demonstrate that FSH evokes sustained [Ca2+]i increases in single Sertoli cells in a nongraded fashion and recruits increasing numbers of responding cells in a dose-dependent fashion. We also provide explicit evidence that FSH induces Ca2+ influx. Mimicry of the FSH-induced [Ca2+]i rise by certain cAMP analogs [8-(6-amino-hexyl)amino-cAMP and N6B; protein kinase-A type I activator] or forskolin suggests that Ca2+ may be part of a dual pathway of cAMP-initiated intracellular signaling.
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页码:1915 / 1923
页数:9
相关论文
共 39 条
[1]   MONITORING OF THE ACTIVATION OF RECEPTOR-OPERATED CALCIUM CHANNELS IN HUMAN-PLATELETS [J].
ALONSO, MT ;
SANCHEZ, A ;
GARCIASANCHO, J .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1989, 162 (01) :24-29
[2]  
ANDERSEN TT, 1982, J BIOL CHEM, V257, P1551
[3]  
BEEBE SJ, 1984, J BIOL CHEM, V259, P3539
[4]  
BEEBE SJ, 1988, METHOD ENZYMOL, V159, P531
[5]   DIRECT G-PROTEIN GATING OF ION CHANNELS [J].
BROWN, AM ;
BIRNBAUMER, L .
AMERICAN JOURNAL OF PHYSIOLOGY, 1988, 254 (03) :H401-H410
[6]   REGULATION BY FOLLICLE-STIMULATING-HORMONE AND DIBUTYRYL ADENOSINE-3',5'-MONOPHOSPHATE OF A PHOSPHODIESTERASE ISOENZYME OF THE SERTOLI-CELL [J].
CONTI, M ;
TOSCANO, MV ;
PETRELLI, L ;
GEREMIA, R ;
STEFANINI, M .
ENDOCRINOLOGY, 1982, 110 (04) :1189-1196
[7]   REGULATION OF SERTOLI-CELL CYCLIC ADENOSINE 3'-5' MONOPHOSPHATE PHOSPHODIESTERASE ACTIVITY BY FOLLICLE-STIMULATING-HORMONE AND DIBUTYRYL-CYCLIC-AMP [J].
CONTI, M ;
GEREMIA, R ;
ADAMO, S ;
STEFANINI, M .
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, 1981, 98 (04) :1044-1050
[8]   GUANINE TRIPHOSPHATE-BINDING SITE REGULATION BY FOLLICLE-STIMULATING-HORMONE AND GUANINE DIPHOSPHATE IN MEMBRANES FROM IMMATURE RAT SERTOLI CELLS [J].
FLETCHER, PW ;
REICHERT, LE .
ENDOCRINOLOGY, 1986, 119 (05) :2221-2226
[9]   FOLLICLE-STIMULATING-HORMONE EVOKES AN INCREASE IN INTRACELLULAR FREE CALCIUM-ION CONCENTRATIONS IN SINGLE OVARIAN (GRANULOSA) CELLS [J].
FLORES, JA ;
VELDHUIS, JD ;
LEONG, DA .
ENDOCRINOLOGY, 1990, 127 (06) :3172-3179
[10]   CATIONIC MODULATION OF FOLLICLE-STIMULATING-HORMONE BINDING TO GRANULOSA-CELL RECEPTOR [J].
FORD, KA ;
LABARBERA, AR .
BIOLOGY OF REPRODUCTION, 1987, 36 (03) :643-650