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1.
Bombardment of intact anthers of commercial barley (Hordeum vulgare) varieties resulted in 0.5–1.0% of transformed microspores of which 20–40% continued in androgenic development (0.2% of all
bombarded microspores). Using a system based on bombardment of anthers is therefore likely to be more technically efficient
than the use of a microspore isolation, transformation and regeneration system. Bombardment of anthers has a number of technical
and scientific advantages over existing systems for gene transfer and can be considered as a alternative method to existing
methods for genetic transformation in barley. 相似文献
2.
A comparison of barley isolated microspore and anther culture and the influence of cell culture density 总被引:3,自引:0,他引:3
Comparisons were made between the efficiency of barley plant regeneration from anther culture (AC) and isolated microspore
culture (IMC) for the European winter cultivar `Igri' and the spring F1 Australian breeder's hybrid Amagi Nijo×WI2585. In both cases, IMC produced a higher number of green regenerant plantlets
per anther than AC. For `Igri' there was a 100- to 200-fold improvement and for Amagi Nijo×WI2585 there was a five- to ninefold
improvement of IMC over AC. To improve the consistency and reliability of the IMC method, we investigated several parameters,
including maltose concentration, subculture protocol, microspore plating density and colony plating density. Subculturing
during the liquid culture phase produced no significant improvement in the number of microspores developing into colonies.
The optimal concentration of maltose in the liquid induction medium was found to be 90 g l–1. Both microspore plating density and colony plating density were found to influence plant regeneration. Microspores produced
the highest numbers of colonies when plated at densities greater than 5×104 ml–1, and colonies produced optimal numbers of green plantlets when plated at 12.5–25 colonies/cm2.
Received: 23 March 1997 / Revision received: 29 May 1997 / Accepted: 25 June 1997 相似文献
3.
Connie M. Williams Guichang Zhang Marek Michalak D. D. Cass 《Sexual plant reproduction》1997,10(2):83-88
To examine possible calcium (Ca2+)-mediated prefertilization events in male gametes of higher plants, we studied protein phosphorylation and the Ca2+-binding proteins, calmodulin and calreticulin, in sperm cells isolated from maize (Zea mays L.) pollen in the presence and absence of Ca2+. Using immunoblotting, we detected calmodulin and calreticulin and Ca2+-induced variations. Exposure of sperm cells to 1 mM Ca2+ for 1 h increased calmodulin content by 136% compared with the control. Ca2+ had little effect on calreticulin at 1 h, but induced a 34% increase after 3 h. Phosphorylation of proteins was low in 1 h-control
and Ca2+-treated cells. However, a 13-fold increase in phosphorylation of a 18-kDa protein was found at 12 h in the presence of Ca2+. Ca2+-induced changes in calmodulin, calreticulin and protein phosphorylation observed in maize sperm cells may reflect prefertilization
changes in vivo that facilitate sperm cell fusion with egg and central cells.
Received: 26 July 1996 / Revision accepted: 7 February 1997 相似文献
4.
We describe a method for preparing nuclear spreads from cells of live, unfixed zebrafish embryos at the late-gastrula (∼8000
cell) stage of development. The method consists of a sequence of four steps: (1) a slow, gentle lysis, in low to moderate
salt concentration, of cells and then nuclei, to release DNA-containing fibres; (2) spreading of the released fibres by a
transverse fluid flow; (3) electrostatic, and possibly also covalent, attachment of the spread fibers to poly(l-lysine)-coated glass microscope slides; and (4) continued incubation to produce periodic cleavage of the DNA within the fibres,
apparently through activation of endogenous nucleases. The nuclear spreads are imaged with epifluorescence, at a spatial resolution
approaching the Rayleigh limit (∼230 nm for blue light). The epifluorescent signal is provided from Hoechst 33258 bound specifically
to the DNA, from a dye-coupled antibody conjugate bound specifically to histone H1 in the fibres, or from a DNA nick end-labelling
assay. The spontaneous cleavage of DNA-containing fibres in step (4) of the above procedure can be blocked by the chelating
agents EGTA and EDTA, by the caspase-2,3,7 inhibitor N-acetyl-Asp-Glu-Val-Asp-aldehyde, and by the caspase-1,4,5 inhibitors
N-acetyl-Tyr-Val-Ala-Asp-aldehyde and N-acetyl-Tyr-Val-Ala-Asp-chloromethyl ketone. These data suggest that the spontaneous
cleavage of fibres is catalysed by nucleases that become activated through a caspase-mediated mechanism. The involvement of
caspase-dependent nucleases would suggest that an apoptosis pathway is activated in the spreads during their prolonged incubation.
If bona fide apoptosis is induced in living zebrafish embryos by treatment with camptothecin (a topoisomerase I poison), and
then nuclear spreads are prepared, we observe a similar fragmentation of the spread fibres. However, in this case the fragmentation
is more rapid and complete. We hypothesize that, during the early phase of apoptosis, one or more endogenous nucleases are
activated by a caspase-mediated mechanism. The nuclease(s) then specifically recognize and cleave a susceptible, periodically
repeating feature of interphase chromatin.
Received: 19 September 1997; in revised form: 14 November 1997 / Accepted: 15 November 1997 相似文献
5.
Summary In order to identify microspores, suitable for transformation via microinjection of DNA, single microspores of barley (Hordeum vulgare L.) were selected after initial preculture of anthers floating on liquid media and analysed for their development in individual culture in microdroplets of culture medium. Conditions for microculture and plant regeneration from single selected embryogenie microspores were established. The technical feasability of intranuclear microinjection was demonstrated by injecting the fluorescent dye Lucifer Yellow. All essential procedures for a transformation system of barley based on microinjection into microspores have thus been performed successfully. Further efforts to increase efficiencies of culture and microinjection procedures are necessary, however, in order to improve the suitability of this approach towards transformation of barley.Abbreviations MES
2 (N-morpholino) ethanesulfonic acid
- PEG
polyethylene glycol 相似文献
6.
L.V. Nikonova P.A. Nelipovich S.R. Umansky 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1982,699(3):281-289
Possible mechanisms of internucleosomal DNA fragmentation in thymocytes of irradiated rats were studied. It was shown that thymocyte nuclei contain at least two nucleases that cleave DNA between nucleosomes — a Ca2+/Mg2+-dependent nuclease and an acidic one which does not depend on bivalent ions. 2 and 3 h after irradiation at a dose of 10 Gy the initial rate of DNA cleavage by Ca2+/Mg2+-dependent nuclease in isolated nuclei increased three and seven times, respectively, but the kinetics of DNA digestion by acidic nuclease did not change. The experiments with cycloheximide indicated that Ca2+/Mg2+-dependent endonuclease turns over at a high rate. The activity of the cytoplasmic acidic and Mg2+-dependent nucleases was shown to increase (by 40 and 50%, respectively) 3 h after irradiation. The effect is caused by the de novo synthesis of the nucleases. At the same time the activity of nuclear nucleases did not essentially change. The chromatin isolated from rat thymocytes 3 h after irradiation did not differ in its sensitivity to some exogenic nucleases (DNAase I, micrococcal nuclease and nuclease from Serratia marcescens) from the control. Thus, Ca2+/Mg2+-dependent endonuclease seems to be responsible for the postirradiation internucleosomal DNA fragmentation in dying thymocytes. 相似文献
7.
To establish an efficient asparagus microspore culture system, experiments were conducted to investigate the effects of medium
components, period of cold pretreatment for flower buds, and period of anther co-culture on culture response. All factors
affected the frequency of asparagus microspore division and the yields of microspore-derived calli. The best results were
obtained by pretreating genotype G459 flower buds at 4 °C for 7–9 days, co-culturing anthers with shed microspores for 14
days, and including 6% sucrose, 2 mg l–1α-naphthaleneacetic acid and 1 mg l–1 N6-benzylaminopurine in the culture medium. After 4 days of culture, most shed microspores contained starch-like bodies and
died. The 2% of shed microspores lacking these structures divided to produce microcalli. For the best treatments in the different
experiments, about 140 calli per 100 anthers were recovered. Cultured on four different regeneration media, 19.6–21% and 3.9–8.0%
of microspore-derived calli produced shoots and embryos, respectively, and ultimately plantlets, among which 49% were haploid,
34% diploid, 4% triploid and 11% tetraploid.
Received: 3 September 1998 / Revision received: 25 November 1998 / Accepted: 5 December 1998 相似文献
8.
Begoña Echavarri Mercedes Soriano Luis Cistué M. Pilar Vallés Ana M. Castillo 《Plant Cell, Tissue and Organ Culture》2008,93(3):295-301
The effect of ZnSO4 concentration on barley (Hordeum vulgare L.) microspore embryogenesis was investigated using cultivars of different androgenetic response. Concentrations from 0 (control)
to 600 μM in the stress pre-treatment medium alone or in combination with 30 (control) to 600 μM in the embryo induction medium
were assayed in anther culture. Incorporation of Zn2+ in the pre-treatment medium itself did not affect microspore embryogenesis. The optimum concentration in the stress pre-treatment
and induction media was 180 μM for cultivars (cvs.) Igri and Reinette, and 90 μM for cv. Hop. A significant increase of 30
and 300% in cv. Igri and Reinette, respectively, were produced with 180 μM ZnSO4 in both the number of embryos and green plants. In order to confirm the effect of Zn2+ on microspore embryogenesis this micronutrient was incorporated in the induction medium of isolated microspore cultures of
cv. Igri. Concentrations of 90–300 μM ZnSO4 resulted in an increase of 40–53% in the number of embryos and green plants. All these results indicate that the beneficial
effect of Zn2+ is exerted mainly during the culture phase, increasing the number of embryos, leading to an increased number of green plants,
but it had no effect on percentage of regeneration or green plants. 相似文献
9.
The culture of isolated microspores of barley (Hordeum vulgare L. cv. Kymppi, an elite malting barley cultivar) was studied. A careful choice of culture steps resulted in an average regeneration frequency of 300 green plants per starting material spike. Strong seasonal variation in regeneration capacity was observed. The choice of a cold pretreatment method affected the viability of microspores. A cold pretreatment of the collected starting material at +4°C for 4 weeks was needed for the efficient regeneration of green plants from isolated microspore cultures. Glutamine omission from and copper additions to microspore culture were studied. The omission of glutamine did not affect the number of regenerated green plants but did result in an increase in the number of regenerated albino plants. The addition of copper did not improve the regeneration capacity of isolated barley microspores. Transformation by particle bombardment of isolated microspores did not result in the production of transgenic plants. 相似文献
10.
Few biochemical and molecular details are available on microspore growth and development. In this work, a nuclease was partially purified from diffusates of barley (Hordeum vulgare L.) microspores by using concanavalin-A as ligand. The chromatographic preparation contained a 34-kDa protein with nucleolytic activity; the enzyme (called BMN: barley microspore nuclease) was very stable at pH > 8.0 and temperatures below 50 degrees C. Activity was highest at pH 5.6 and increased almost exponentially with temperature until a breakpoint between activity and stability was reached at 70 degrees C. Although BMN was able to cleave RNA, the enzyme showed a remarkable preference for DNA, especially in the single-stranded form. The best homopolymeric substrates were poly(dA) and poly(A), whereas poly(dC), poly(G) and poly(I) were almost completely uncleaved. When incubated with intact nuclei, BMN caused a nucleosomal DNA ladder of approximately 200 bp. On the basis of DNA laddering, substrate specificity, Mg2+ -dependence and best performance at apoplastic pH, BMN can be referred to as a putative apoptotic nuclease involved in pollen development. 相似文献
11.
Metabolism of EDTA and its metal chelates by whole cells and cell-free extracts of strain BNC1 总被引:5,自引:0,他引:5
The influence of metal ions on the metabolism of ethylenediaminetetraacetate (EDTA) by whole cells and cell-free extracts
of strain BNC1 was investigated. Metal-EDTA chelates with thermodynamic stability constants below 1012 were readily mineralized by whole cells with maximum specific turnover rates of 15 (MnEDTA) to 20 (Ca-, Mg-, and BaEDTA)
μmol g protein−1 min−1. With the exception of ZnEDTA, chelates with stability constants greater than 1012 were not oxidized at a significant rate. However, it was shown for Fe(III)EDTA that even strong complexes can be degraded
after pretreatment by addition of calcium and magnesium salts in the pH range 9–11. The range of EDTA chelates converted by
cell-free extracts of strain BNC1 did not depend on their thermodynamic stabilities. The EDTA chelates of Ba2+, Co2+, Mg2+, Mn2+, and Zn2+ were oxidized whereas Ca-, Cd-, Cu-, Fe-, Pb-, and SnEDTA were not. The first catabolic enzyme appears to be an EDTA monooxygenase
since it requires O2, NADH, and FMN for its activity and yields glyoxylate and ethylenediaminetriacetate as products. The latter is further degraded
via N,N′-ethylenediaminediacetate. The maximum specific turnover rate with MgEDTA, the favoured EDTA species, was 50–130 μmol g protein−1 min−1, and the K
m value was 120 μmol/l (K
s for whole cells = 8 μmol/l). Whole cells as well as cell-free extracts of strain BNC1 also converted several structural analogues
of EDTA.
Received: 4 July 1997 / Received revision: 25 September 1997 / Accepted: 29 September 1997 相似文献
12.
Isolated microspores of Brassica napus were cultured on high concentrations of mannitol or polyethylene glycol (PEG 4000), with only a very limited amount of sucrose
(0.08–0.1%) provided as carbohydrate source in the medium. While microspores cultured on high mannitol yielded no embryos
and no embryogenic cell divisions were observed, microspores on high PEG developed into embryos within 2 weeks, and the embryo
yield appeared comparable to that of the sucrose control. When placed under light, PEG embryos quickly changed color from
yellow to dark green, while sucrose embryos first remained yellowish and then slowly changed color to pale green. Three-week-old
PEG embryos were strikingly similar to immature zygotic embryos developed in ovulo, dissected at 14–15 days post-anthesis (DPA), while sucrose embryos differed from the latter in the size and shape, color
and morphology of their cotyledons. These results demonstrate that in microspore embryogenesis of Brassica napus: (1) the level of metabolizable carbohydrate required for microspore embryo induction and formation appears to be substantially
less than commonly used amounts, (2) sucrose as an osmoticum can be replaced with high-molecular-weight PEG. With further
improvement the new method described here might be suitable for other Brassica species and would have a great potential application in breeding programs.
Received: 29 May 1997 / Revision received: 12 August 1997 / Accepted: 2 September 1997 相似文献
13.
Two barley chloroplast nuclease fractions were separated by the affinity chromatography and gel electrophoresis. Both were
about 2 times more active to RNA than to native DNA and about half as active to denaturated DNA as to native DNA. Both fractions
were as active to UV-irradiated (270 J m-2) native DNA as to intact DNA but their action was inhibited by apurinic sites. The enzyme activities were inhibited by high
concentrations of EDTA, NaCl, Mn2+, Ca2+, Zn2+ ions and by N-ethylmaleimide. They do not require Mg2+ ions but are stimulated or at higher concentration inhibited by their presence. Both RNase and DNase were active over a wide
pH range (5.5–9), the optimum for DNase action in the presence of Mg2+ being 6.5, for RNA decomposing activity at pH 8.0. As no mononucleotides were detected in acid soluble form, it seems likely
that DNase acts in the endonucleolytic way. 相似文献
14.
Tracking individual wheat microspores in vitro: identification of embryogenic microspores and body axis formation in the embryo 总被引:11,自引:0,他引:11
The development of isolated, defined wheat microspores undergoing in vitro embryogenesis has been followed by cell tracking.
Isolated wheat (Triticum aestivum L.). microspores were immobilized in Sea Plaque agarose supported by a polypropylene mesh at a low cell density and cultured
in a hormone-free, maltose-containing medium in the presence of ovaries serving as a conditioning factor. Embryogenesis was
followed in microspores isolated from immature anthers of freshly cut tillers or from heat- and starvation-treated, excised
anthers. Three types of microspore were identified on the basis of their cytological features at the start of culture. Type-1
microspores had a big central vacuole and a nucleus close to the microspore wall, usually opposite to the germ pore. This
type was identical to the late microspore stage in anthers developing in vivo. Microspores with a fragmented vacuole and a
peripheral cytoplasmic pocket containing the nucleus were defined as type 2. In type-3 microspores the nucleus was positioned
in a cytoplasmic pocket in the centre of the microspore. Tracking revealed that, irrespective of origin, type-1 microspores
first developed into type 2 and then into type-3 microspores. After a few more days, type-3 microspores absorbed their vacuoles
and differentiated into cytoplasm-rich and starch-accumulating cells, which then divided to form multicellular structures.
Apparently the three types of microspore represent stages in a continuous process and not, as previously assumed, distinct
classes of responding and non-responding microspores. The first cell division of the embryogenic microspores was always symmetric.
Cell tracking also revealed that the original microspore wall opened opposite to a region in the multicellular microspore
which consisted of cells containing starch grains while the remaining cells were starch grain-free. The starch-containing
cells were located close to the germ pore of the microspore. In more advanced embryos the broken microspore wall was detected
at the root pole of the embryo.
Received: 27 December 1999 / Accepted: 11 May 2000 相似文献
15.
Shinrin-yoku (forest-air bathing and walking) effectively decreases blood glucose levels in diabetic patients 总被引:6,自引:0,他引:6
Y. Ohtsuka Noriyuki Yabunaka Shigeru Takayama 《International journal of biometeorology》1998,41(3):125-127
The influence of ”shinrin-yoku” (forest-air bathing and walking) on blood glucose levels in diabetic patients was examined.
Eighty-seven (29 male and 58 female) non-insulin-dependent diabetic patients [61 (SEM 1) years old] participated in the present
study. Shinrin-yoku was performed nine times over a period of 6 years. The patients were divided into two parties. They then
walked in the forest for 3 km or 6 km according to their physical ability and/or the existence of diabetic complications.
The mean blood glucose level after forest walking changed from 179 (SEM 4) mg · 100 ml–1 to 108 (SEM 2) mg · 100 ml–1 (P<0.0001). The level of glycated haemoglobin A1c also decreased from 6.9 (SEM 0.2)% (before the first shinrin-yoku) to 6.5 (SEM 0.1)% (after the last shinrin-yoku; P<0.05). Blood glucose values declined by 74 (SEM 9) mg · 100 ml–1 and 70 (SEM 4) mg · 100 ml–1 after short- and long-distance walking respectively. There was no significant difference between these values. Since the
forest environment causes changes in hormonal secretion and autonomic nervous functions, it is presumed that, in addition
to the increased calorie consumption and improved insulin sensitivity, walking in a forest environment has other beneficial
effects in decreasing blood glucose levels.
Received: 9 July 1997/Accepted: 20 October 1997 相似文献
16.
Isolated wheat microspore culture 总被引:10,自引:0,他引:10
Vicki D. Gustafson P. Stephen Baenziger Martha S. Wright Walter W. Stroup Yang Yen 《Plant Cell, Tissue and Organ Culture》1995,42(2):207-213
The use of doubled haploid plants in a wheat breeding program requires an efficient haploid production system. While the techniques for producing doubled haploids from anther culture are well established, those for isolated microspores are complicated and inefficient. Four methods of isolating microspores from anthers (blending, stirring, macerating, and floating) were compared. Isolated microspores were washed and cultured in liquid medium. The effects of pre-isolation mannitol conditioning, cell density, culture dilution, and sucrose centrifugation on microspore viability were evaluated. Isolation by blending gave the highest initial microspore viability (75%). Mannitol conditioning and purification by sucrose centrifugation had a detrimental effect on initial viability. An initial microspore density of 2 × 105 microspores per ml was necessary for continued microspore viability. One hundred and nine haploid or spontancously doubled haploid plants were regenerated from microspores isolated without mannitol conditioning using the blending method. Based on this research, blender isolation with an initial density of 2 × 105 microspores per ml is recommended for isolated microspore culture.Abbreviations LSmean
least square mean
- MES
2-N-morpholinoethane sulfonic acid
- 2,4-d
2,4-dichlorophenoxyacetic acid
- NAA
-naphtaleneacetic acid 相似文献
17.
A. M. Castillo L. Cistué M. P. Vallés J. M. Sanz I. Romagosa J. L. Molina-Cano 《Plant cell reports》2001,20(2):105-111
The aim of this study was to establish a protocol for an efficient production of agronomical and/or physiological mutants
from model (cvs. Igri and Cobra) and low-androgenic-responding (cv. Volga) cultivars of barley through the application of
a mutagenic agent, sodium azide, to anthers and isolated microspores cultured in vitro. This technology offers the possibilities of screening for recessive mutants in the first generation, selecting for novel
genotypes from very large haploid populations, avoiding chimerism and rapidly fixing selected genotypes as fertile true breeding
lines. The mutagenic treatment, 10–3–10–5
M sodium azide, was applied during the anther induction pre-treatment or immediately after the microspore isolation procedure.
Out of 616 M2 doubled-haploid lines characterised under field conditions, a total of 63 morphological and developmental independent mutant
lines were identified. The percentage of M2 doubled-haploid lines carrying mutations per line analysed was 3.8% when 10–4
M sodium azide was applied to anthers from the low-responding cv. Volga; this increased to 8.6% and 15.6% when 10–5 and 10–4
M sodium azide were applied to freshly isolated microspores from model cultivars.
Received: 18 April 2000 / Revision received: 28 September 2000 / Accepted: 28 September 2000 相似文献
18.
W. Michalek M. Kleine H. Dargatz G. Wenzel A. Jahoor 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1997,95(3):369-374
The hordeins are the major class of storage proteins in barley and are encoded by multigene families. Two YAC-clones specific
for the C-hordein-coding Hor1-locus of barley (Hordeum vulgare L.) were selected. The clones were constructed with DNA from the cultivars ‘Franka’ and ‘Hockey’ and have insert sizes of
330 kb and 350 kb, respectively. Performing partial digestions and hybridizations with vector-specific probes, a restriction
analysis was conducted using restriction enzymes with a 8-bp recognition sequence. Both clones cover the complete region of
the Hor1-locus, but exhibit a different pattern of restriction sites reflecting the polymorphic nature of the locus on the scale of
long-range restriction mapping. The maximal extent of the regions homologous to the Hor1-specific probe, pBSC5, was 105 kb in the ‘Hockey’-derived YAC and 190 kb in the yeast artificial chromosome constructed with
‘Franka’-DNA. Furthermore the high degree of instability observed with the Hor1-specific YAC-clones is discussed in conjunction with the structure of the Hor1-locus.
Received: 19 December 1996 / Accepted: 31 January 1997 相似文献
19.
A method employing isolated microspore culture was established for the androgenic embryogenesis of timothy (Phleum pratense L). Embryos/calli were obtained and green plants regenerated. The induction medium was PG-96 (1.0 mg l−1 2,4-D, 0.1 mg l−1 Kinetin) supplemented with 6% maltose monohydrate. Timothy microspore culture was genotype-dependent, among 12 genotypes,
6 produced embryos/calli and 4 produced green plants. Macerating the spikes with a blender and purifying the microspores at
a mannitol/maltose monohydrate interface gave a relatively high percentage of cell vitality. The optimum microspore developmental
stage was from the very late uninucleate stage to the binucleate stage. Heat shock promoted the initiation of microspore culture.
Over 150 regenerated green plants were obtained; in a random sample of 32 of these 65.6% were doubled haploids (6n=42). Albinism
was a problem in plant regeneration (9.3–22%). This paper is the first to describe timothy androgenic embryogenesis by isolated
microspore culture.
Received: 9 September 1999 / Revision received: 6 December 1999 / Accepted: 13 December 1999 相似文献
20.
K. Katoh M. Ohbo M. Wakui 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1996,166(6):369-374
In order to investigate the cellular mechanisms involved in amylase release in response to stimulation with short-chain fatty
acids, changes in intracellular calcium concentration ([Ca2+]i), membrane current and amylase release were measured in pancreatic acinar cells of sheep. Both octanoate and acetylcholine
raised [Ca2+]i in acinar cells in a concentration-dependent manner. The rise in [Ca2+]i in response to the stimulation with octanoate (10 mmol ⋅ l-1) was reduced in a medium without CaCl2, but was markedly enhanced by reintroduction of CaCl2 into the medium up to 2.56 mmol ⋅ l-1. Perfusion of the cells with a medium containing octanoate (5 mmol ⋅ l-1) or acetylcholine (0.5 μmol ⋅ l-1) immediately raised inward current across the cell membrane at a holding-membrane potential of −30 mV. The inward current
became greater as the holding potential became more negative. The equilibrium potential was 1.8 mV and 3.9 mV for octanoate
and acetylcholine, respectively, being consistent with that for Cl-. Although intracellular application of octanoate through a patch-clamp pipette also raised inward current after several minutes
in some cells (4 out of 12), this possibility was significantly smaller than that for extracellular application. In other
cells, even though the intracellular application of octanoate did not cause an increase in current, it always caused responses
immediately after introduction of the fatty acid into the medium. Stimulation with fatty acid as well as acetylcholine raised
amylase release in a concentration-dependent manner in cells dispersed from tissue segments with crude collagenase and trypsin
inhibitor. Without trypsin inhibitor, crude collagenase significantly and selectively reduced the octanoate (10 mmol ⋅ l-1)-induced amylase release. Dispersion with crude collagenase and trypsin significantly reduced both responses induced by octanoate
and acetylcholine (5.5 μmol ⋅ l-1). We conclude that fatty acids and acetylcholine increase [Ca2+]i, which consequently evokes a rise in transmembrane ion (Cl-) conductance and amylase release, and that trypsin-sensitive protein(s) in the cell membrane are involved in secretory processes
activated by stimulation with fatty acids in ovine pancreatic acinar cells.
Accepted: 14 May 1996 相似文献