Showing papers by "David M. Jacobowitz published in 1967"

Histochemical studies of the relationship of chromaffin cells and adrenergic nerve fibers to the cardiac ganglia of several species

Abstract: Atrial cardiac ganglia of rats, cats, guinea pigs and mice were studied for catecholamine-containing structures by a histochemical fluorescence method. Very fine varicose adrenergic fibers were seen in close apposition to some of the cholinergic ganglion cells. The administration of a monoamine oxidase inhibitor followed by 3,4-dihydroxyphenylalanine. resulted in the appearance of catecholamine (CA) fluorescence in some ganglion cells. This suggests that at least some parasympathetic cells are capable of taking up 3,4-dihydroxyphenylalanine and synthesizing and metabolizing CA. Intense CA-fluorescent cells resembling adrenal medullary cells were found in the confines of the atrial ganglia of all species. Positive chromaffin and silver-staining reactions were observed in these cells of the cat atria. The cells are considered to be chromaffin cells and as such can be regarded as an extraneuronal CA pool. One dose of reserpine (5 mg/kg) administered 24 or 4 hr before sacrifice does not appear to affect the CA content of the chromaffin cells. Larger doses of reserpine for a longer period of time lead to a reduction in the intensity of fluorescence of the chromaffin cells. Application of both the CA-fluorescent and acetylcholinesterase histochemical stains to the same section revealed that most chromaffin cellsare innervated by acetylcholinesterase-staining nerve fibers. Some chromaffin cells receive a postganglionic parasympathetic innervation from cholinergic ganglion cells of the heart. It is suggested that the system of adrenergic fibers and chromaffin cells contained around cardiac ganglia functions as a self-controlling or inhibitory influence on ganglionic transmission.

Histochemical and Chemical Studies of the Autonomic Innervation of the Ovary

Abstract: The adrenergic innervation of ovaries of humans, cats and monkeys was studied by a histochemical fluorescence method. Catecholamine-containing nerves were observed in close proximity to blood vessels and within the stromal fibromuscular tissue. The cat ovary contained a dense number of adrenergic nerves. A moderate innervation was seen in the human and fewer nerves in the monkey. Chemical determinations of norepinephrine in the ovaries were consistent with the histochemical observations of the density of catecholamine-containing nerve fibers. Cholinergic nerves were studied by a histochemical method for acetylcholinesterase. Comparatively fewer cholinergic nerves were observed in the ovaries. It is suggested that the adrenergic innervation to the ovary has an influence on ovulation. (Endocrinology 81: 1132, 1967)

The influence of light and dark on the catecholamine content of the retina and choroid.

Abstract: Recent histochemical studies with the use of a fluorescence method to detect catecholaminecontaining neurons have uncovered a system of dopamine-containing amacrine cells as toell as a plexus of norepinephrine-containing nerve terminals in the choroid. This study examined the effect of dark and light adaptation on the catecholamine content of the posterior segment of the eye of the albino guinea pig, rabbit, and rat by quantitative and histochemical means. In the rat and rabbit, there was a significant increase in the dopamine content with light adaptation. In the guinea pig, there was an increase, but this was not statistically significant. A significant increase in the norepinephrine content was observed in the posterior segment of the guinea pig and rabbit ivith light adaptation. The increase in norepinephrine appeared to be a direct effect on the choroidal nerve terminals, since with pigmented guinea pigs the increase was not observed. Likewise, decentralization of the choroid in albino guinea pigs did not alter the changes seen with light adaptation. Histochemical studies demonstrated a consistent increase in the fluorescence of the amacrine cells of the rabbit and guinea pig with light adaptation. It was not possible to show consistent changes in the rat.

A simplified method for the histochemical localization of cardiac catecholamine-containing nerve fibers:

Abstract: An improved, simplified method for the demonstration of the adrenergic innervation to the heart based on perfusion fixation is described. After perfusion with phosphate-buffered paraformaldehyde, s...