Follicle‐stimulating hormone induces hyperpolarization of immature rat Sertoli cells in monolayer culture.

Abstract

SUMMARY1. The effect of FSH on the membrane potential of Sertoli cells has been investigated by intracellular microelectrode recording from monolayer cultures of cells, isolated from immature rat testes by enzymatic treatment.2. In standard Earle's solution, the membrane potential of unstimulated cells in a 3-day-old monolayer was -21-6 + 0-2 mV (n = 300). The recorded potentials were unchanged on varying the culture period from 3 to 7 days or by removal of chloride or calcium from the media. However, they were decreased in a low-sodium or potassium-rich medium.3. Ovine FSH caused hyperpolarization of-the cell in a dose-dependent manner. Maximal values were obtained with concentrations ranging between 2-9 and 59,ug/ml (-37'0 +02 mV; n = 310). Dibutyryl cyclic AMP (1 mM) produced a similar effect to FSH. Under similar conditions human chorionic gonadotrophin (hCG) had no effect on the membrane potential.4. The FSH-induced hyperpolarization was unchanged by chloride or bicarbonate replacement. It was decreased by low-sodium media (9 mM) (-29-6+ 0-3 mV; n = 110), by removal of calcium (-32-4+0-6 mV; n = 128) and by an increase in the potassium concentration of the bathing medium. A tenfold increase in potassium concentration depolarized the cell by 29-5 mV against 16 mV for unstimulated cells.5. FSH-induced hyperpolarization was decreased by application of ouabain (10-4 M), quinidine (1-4 x 10-4 M) and cobalt (10-3 M) (respectively: -28-7 + 0 3 mV, n = 124; -26-6+003 mV, n = 52 and -24-8+0-3 mV, n = 68) but was unchanged by amiloride (10-4M) and TTX (3 x 10-6M). None of these drugs modified the membrane potential of unstimulated cells.6. All these results suggest that FSH stimulation of Sertoli cells in monolayer culture involves the modification of their membrane permeabilities.

Voltage-Dependent Calcium Current with Properties of T-Type Current in Sertoli Cells from Immature Rat Testis in Primary Cultures1

“…But since we used the whole-cell configuration of the patchclamp technique, and consequently the main messengers of the response to FSH disappeared from the cell cytoplasm, we do not presently exclude the possibility that FSH may control these channels through other messengers. However, because we [9] and others [32] have determined that FSH induces a concentration-dependent increase in the membrane potential, from about -20 mV in control cells to -40 mV in FSH-stimulated cells [9], we also envisage that FSH may control the T-type channel activity by a mechanism of hyperpolarization that should set the membrane potential close to the window current.…”

“…But these channels have never been recorded by the patch-clamp technique. Thus we performed electrophysiological studies in Sertoli cells that exhibit a concentration-dependent responsiveness to FSH by morphological changes [10], by increases in the membrane potential [9], and by increases in diffusional coupling [10]modifications that are not reproduced by hCG, another glycoprotein hormone.…”

“…They showed a rounded and thicker appearance, with fine spinelike projections, and made contact with other isolated cells when cultured for 24 h with 10 ng/ml oFSH. We observed that these cells responded specifically, in a dose-dependent manner, to chronic and acute exposures to FSH by characteristic morphological changes, increases in the membrane potential [9], and increases in intercellular coupling [10]. Finally, a 100% typical response in current was recorded in a population of about 400 cells randomly chosen in 70 different cell cultures.…”

“…Animals, raised at constant temperature (20°C) under a 12L: 12D light cycle, were killed by decapitation, and testes were removed aseptically. After decapsulation, the parenchyma of 6-10 testes was submitted at 37°C to three consecutive enzymatic treatments by collagenase, then pancreatin, and then trypsin, according to a procedure modified from Verhoeven et al [8] and routinely used in our laboratory for electrophysiological studies of immature Sertoli cells [9,10].…”

A New Role for Follicle-Stimulating Hormone in the Regulation of Calcium Flux in Sertoli Cells: Inhibition of Na+/Ca++ Exchange*

“…The presence of a Na + /K + -ATPase in Sertoli cells is well documented (13,14), and treatment with ouabain, a specific inhibitor of this ATPase (14), is known to enhance intracellular Na + levels. When Sertoli cells were preincubated in 135 mM NaCI in the presence of 1 mM ouabain and then exposed to a choline-containing buffer, Na + -dependent 45 Ca ++ uptake was significantly (P < 0.05) higher than that of Sertoli cells preincubated in 135 mM NaCI alone (Fig.…”