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C B Basbaum

Publications and source records attributed to C B Basbaum.

62 records · Page 4Linked to original sources
PubMed1981

Tracheal submucosal gland serous cells stimulated in vitro with adrenergic and cholinergic agonists. A morphometric study.

A morphometric analysis was made of alterations in serous cell structure induced by adrenergic and cholinergic agonists. Ferret tracheal rings were exposed for 30 min in vitro to one of the following agonists: phenylephrine, terbutaline, or methacholine (all at 10(-5) M). Controls were incubated similarly in medium containing no drugs or medium containing both the agonist and an excess of the appropriate antagonist (phentolamine, propranolol or atropine, all at 10(-4) M). Electron microscopic observation and stereological analysis of the incubated samples revealed that the volume density of serous cell granules in controls (0.30 +/- 0.02, mean +/- SE, n = 4) was significantly reduced by phenylephrine (0.19 +/- 0.03, n = 4) and methacholine (0.17 +/- 0.01, n = 4), but not by terbutaline (0.27 +/- 0.04, n = 4). The presence of antagonists in the medium prevented the observed changes (phenylephrine/phentolamine: 0.29 +/- 0.03, n = 3 and methacholine/atropine: 0.33 +/- 0.06, n = 3). In addition, the volume density of intracellular vacuoles in controls (0.02 +/- 0.05, n = 4) was increased in response to methacholine stimulation (0.12 +/- 0.05, n = 4), but not in response to the other agonists. This effect was blocked by atropine (0.01 +/- 0.00, n = 3). We conclude that serous-cell granules are discharged by both alpha-adrenergic and cholinergic, but not beta-adrenergic stimulation. In addition, cholinergic stimulation evokes the formation of intracellular vacuoles, a possible indication of active ion and water transport.

Animals↗
PubMed1981

Ion contents and other properties of isolated cells from dog tracheal epithelium.

We have developed a preparation of isolated cells from dog tracheal mucosa. The three major cell types of the intact epithelium (ciliated, secretory, and basal) are present in approximately the same proportions as in the intact tissue. These cells show high viability as judged by exclusion of vital dyes, high O2 consumption, and incorporation of amino acids into protein. The intracellular ion contents (in mmol/l cell H2O) are [K]i, 150; [Na]i, 20; and [Cl]i, 50. Ouabain (10(-4) M) causes a rise in [Na]i and a reciprocal loss of intracellular K.

Animals↗
PubMed1980

A morphometric analysis of the autonomic innervation of cat tracheal glands.

Quantitative methods have been used to examine the distribution of adrenergic and cholinergic axon varicosities to serous and mucous cells of cat tracheal glands. Cats were injected with 5-hydroxydopamine (5-OHDA) prior to removal of the trachea in order to fill adrenergic vesicles with intensely osmiophilic material. This facilitated the identification of adrenergic varicosities and provided a means by which they could be easily discriminated from cholinergic varicosities. Of all varicosities identified within 10 micrometer of the glands, 90% were cholinergic and 10% were adrenergic. Most of these varicosities were present in interstitial bundles located between acini. A small number of cholinergic varicosities, however, were located within 20 nm of acinar cells, forming close contact junctions. No differential innervation of serous and mucous cells was observed.

Adrenergic Fibers↗
PubMed1979

Morphological studies of stimulated adrenergic axon varicosities in the mouse vas deferens.

The postganglionic axons of sympathetic neurons innervating the mouse vas deferens were stimulated transmurally in vitro by passing square pulses between two platinum electrodes. The ultrastructural appearance of the adrenergic nerve terminals was compared to samples fixed immediately after 30 min of stimulation and in samples allowed to recover for 2 h before fixation. The contralateral vasa deferentia served as controls, and these were incubated in Krebs solution for the same period as stimulated muscles. For each of four experiments, the mean number of large and small dense-core vesicles per square micrometer was calculated, as were the mean area and perimeter of the axon varicosities in each group. It was found that the number of small vesicles per square micrometer decreased by 60% during the stimulation period, but returned almost to control levels 2 h later. Large vesicles did not change in number during the stimulation or recovery periods. The proportion of vesicles containing cores was also determined for each group and found to decline just after stimulation in the small vesicle population, but to remain constant in the large vesicle population. The core depletion was partly reversed after 2 h. The vesicle recovery process was studied by use of the extracellular tracer horseradish peroxidase (HRP). When HRP was present in the extracellular space during stimulation, large numbers of vesicles contained the marker after recovery from stimulation. Thus, it is proposed that adrenergic axon varicosities recycle vesicle membrane through the plasma membrane in a manner similar to that already described for cholinergic nerve terminals.

Animals↗
PubMed1979

Localization of Na pumps in the tracheal epithelium of the dog.

Binding of [3H]ouabain by the dog's tracheal epithelium shows a nonspecific component depending linearly on ouabain concentration, and a specific saturable component with a Km of 10(-7) M. Control experiments showed that the tracer taken up was not trapped within the extracellular space nor bound to tissue collagen. Inhibition of the saturable uptake by high K, metabolic inhibition, low Na, and low temperature indicated that binding was to Na/K ATPase. One-sided exposures of tissue sheets to tracer showed that the submucosal side took up 10 X as much tracer as the luminal. Autoradiography localized tracer uptake under all conditions to the cells' basolateral membranes.

Animals↗