scholarly journals Co-culture of embryonic chick heart cells and ciliary ganglia induces parasympathetic responsiveness in embryonic chick heart cells

1993 ◽  
Vol 292 (2) ◽  
pp. 395-399 ◽  
Author(s):  
J V Barnett ◽  
M Taniuchi ◽  
M B Yang ◽  
J B Galper
Keyword(s):  
G Proteins ◽  
Fold Increase ◽  
Heart Cell ◽  
Heart Cells ◽  
Embryonic Chick ◽  
In Ovo ◽  
Chronotropic Response ◽  
Muscarinic Stimulation ◽  
Chick Heart ◽  
Embryonic Chick Heart

We have developed a system for the co-culture of embryonic chick heart cells obtained from embryos at 3.5 days in ovo with ciliary ganglia from chick embryos at 7 days in vivo. After 3 days of co-culture, removal of the ciliary ganglia resulted in complete degeneration of axons within 6-8 h, leaving the post-innervated heart cell culture devoid of neurons. Embryonic chick heart cells at 3.5 days in ovo are unresponsive to muscarinic stimulation. However, following 3 days of co-culture with ciliary ganglia, the heart cells developed a negative chronotropic response to muscarinic stimulation (paired t test, P < 0.02) which persisted for at least 24 h after removal of the ciliary ganglion. The development of muscarinic responsiveness was associated with an increase in the levels of specific alpha-subunits of the guanine nucleotide binding proteins (G-proteins), with a 3-fold increase in the level of alpha 39 (39 kDa subunit) and a 2.5-fold increase in the level of alpha 41. The level of the G-protein subunit alpha s remained unchanged. Culture of embryonic chick heart cells at 3.5 days in ovo with medium conditioned by the growth of embryonic chick heart cells and ciliary ganglia had an effect on the chronotropic response to muscarinic stimulation and on alpha 39 and alpha 41 levels identical to that of co-culture. These data suggest that a soluble factor released during the co-culture of embryonic chick heart cells and ciliary ganglia is capable of inducing muscarinic responsiveness. These studies suggest that innervation of the heart may induce parasympathetic responsiveness by increasing the availability of G-proteins which couple the muscarinic receptor to a physiological response.

Apamin, a highly potent fetal L-type Ca2+ current blocker in single heart cells

1992 ◽  
Vol 262 (2) ◽  
pp. H463-H471 ◽  
Author(s):  
G. Bkaily ◽  
A. Sculptoreanu ◽  
D. Jacques ◽  
D. Economos ◽  
D. Menard
Keyword(s):  
Cell Voltage ◽  
Slow Inward Current ◽  
Heart Cell ◽  
Heart Cells ◽  
Dependent Manner ◽  
Embryonic Chick ◽  
Ventricular Cells ◽  
Chick Heart ◽  
Embryonic Chick Heart

Apamin, a bee venom polypeptide, was reported to block the naturally occurring Ca2+ slow action potentials (APs) in cultured cell reaggregates from old chick hearts [Bkaily, G. et al. Am. J. Physiol. 248 (Heart Circ. Physiol. 17): H961-H965, 1985] as well as the tetrodotoxin (TTX)- and Mn(2+)-insensitive slow Na+ current in young embryonic chick heart cells (Bkaily, G. In Vitro Toxicology. Academic, In press; Bkaily et al. J. Mol. Cell. Cardiol. 23: 25-39, 1991). With the use of the whole cell voltage-clamp technique in single ventricular cells from 10-day-old chick embryos and 17- to 20-wk-old human fetuses, two types of Ca2+ currents (ICa), T and L, were found. These two types of slow inward current in both heart preparations were nearly similar in their voltage, kinetics, and pharmacology. Apamin, a slow Ca2+ action potential blocker in old embryonic chick heart, was found to block the L-type ICa (IL) in a dose-dependent manner without affecting the T-type ICa in both heart cell preparations. The blockade of the IL by apamin was completely reversible upon washout with apamin-free solution. Therefore, when compared with nifedipine or to PN 200-110, apamin seems to be a highly potent L-type Ca2+ channel blocker in heart cells.

Pharmacological analysis of sympathetic function in the embryonic chick heart

1977 ◽  
Vol 232 (3) ◽  
pp. R116-R123
Author(s):  
N. G. Culver ◽  
D. A. Fischman
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Innervation ◽  
Sympathetic Nerves ◽  
Nerve Function ◽  
Embryonic Chick ◽  
Neuronal Function ◽  
In Ovo ◽  
Sympathetic Function ◽  
Chick Heart ◽  
Embryonic Chick Heart

Sympathetic nerve cells enter the embryonic chick heart on the fifth day in ovo, but it is uncertain when these nerves become functional. Using pharmacological probes known to affect the embryonic circulation, sympathetic nerve function was examined at various stages of development. Exogenous norepinephrine elicited cardioacceleration in the hearts of embryos with intact extraembryonic circulation both before (stage 20-24) and after (stage 28-32) sympathetic innervation of the heart, and this acceleration could be inhibited by propranolol and practolol. In contrast, ganglionic stimulation with 1,1-dimethyl-4-phenylpiperazinium iodide (DMPP) elicited cardioacceleration only after stages 27-28 (i.e., after sympathetic innervation), producing a 25-30% increase in heart rate over the predrug levels of 148.7 +/- 1.8 beats/min. DMPP-elicited positive chronotropy was reduced by beta-receptor antagonists, hexamethonium, guanethidine (GuE), and tetrodotoxin. In preparations of the embryonic thorax in which the innervated heart was separated from brain and adrenal influences, DMPP elicited a GuE-sensitive cardioacceleration. It is concluded that during chick embryonic development, no more than a 1-day interval exists between the appearance of sympathetic nerves in the heart and the onset of neuronal function in that organ.

scholarly journals Inactivation kinetics of macroscopic Na+ current in voltage-clamped embryonic chick heart cell.

1993 ◽  
Vol 61 ◽  
pp. 100
Author(s):  
Hideajo Sada ◽  
Kotaro Tanaka ◽  
Hisamitsu Ujihara ◽  
Yasue Yamada ◽  
Takashi Ban
Keyword(s):  
Inactivation Kinetics ◽  
Heart Cell ◽  
Embryonic Chick ◽  
Na Current ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
Kinetics Of

scholarly journals Induction of spreading during fibroblast movement.

1979 ◽  
Vol 81 (3) ◽  
pp. 684-691 ◽  
Author(s):  
W T Chen
Keyword(s):  
Leading Edge ◽  
Fold Increase ◽  
Embryonic Chick ◽  
Trailing Edge ◽  
Area Increase ◽  
Spread Area ◽  
Chick Heart ◽  
Embryonic Chick Heart ◽  
Highly Correlated ◽  
The Relationship

This paper describes the phenomenon of retraction-induced spreading of embryonic chick heart fibroblasts moving in culture. Measurable criteria of cell spreading (increase in area of the spreading lamella, and total spread area of the cell) are found to change predictably with retraction of a portion of the cell margin. Ruffling activity was found to increase. The leading lamella of a spread fibroblast ordinarily advances slowly, with an average area increase of approximately 21 mu2m/min. A 10- to 30-fold increase in spreading occurs within 8 s after onset of retraction at the trailing edge and then decreases slightly so that by 1 min the increase in spreading is five to tenfold. During this period, there is a linear relationship between area increase at the leading edge and area decrease at the trailing edge. During the next 10--15 min, spreading gradually decreases to normal. Although the relationship between area spreading and area retracting of fibroblasts at different phases of movement is not significantly linear, it is highly correlated (Table II). These results suggest that the rate of fibroblast spreading may be inversely related to the degree of spreading of the cell as a whole.

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