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Biomedical subjects

A Howe

Publications and source records attributed to A Howe.

At least 37 records · Page 2Linked to original sources
PubMed1976

Structure of cells and nerve endings in abdominal vagal paraganglia of the rat.

The abdominal vagal paraganglia of the rat consist of small groups of cells, interspersed by blood vessels and nerve bundles and lying close to, or within, the vagus nerve or its branches. Each cell group consists of 2-10 Type I cells incompletely invested by 1-3 satellite cells. Type I cells are characterised by the presence of numerous dense-cored vesicles in their cytoplasm and may exhibit 'synaptic'-like contact with each other. Small efferent nerve endings make synaptic contacts with Type I cells. Larger cup-shaped afferent nerve endings also make synaptic contacts of two kinds with Type I cells. Nerve-nerve synapses are often seen within or close to paraganglia. Attention is drawn to the close similarity of fine structure of abdominal vagal paraganglia, carotid body and small intensely fluorescent cells of the superior cervical ganglion in rats. Possible functional implications of this morphological similarity are discussed.

Animals↗
PubMed1975

Nerve endings in rat carotid body.

The carotid body of the rat consists of "glomera" interspersed by blood vessels and nerve bundles. Each "glomus" consists of 2-12 Type I cells, incompletely invested by 1-3 Type II cells. Type I cells are characterised by the presence of numerous dense cored vesicles in their cytoplasm and may exhibit "synaptic" -like contacts with each other. Small efferent nerve endings make synaptic contact with one or more Type I cells. Large cup-shaped afferent nerve endings make multiple synaptic contacts of two kinds with one or more Type I cells. A second kind of efferent nerve ending is occasionally seen in synaptic contact with one of these afferent nerve endings. A model for the mode of operation of the glomus as a chemoreceptor is proposed.

Animals↗
PubMed1975

Abdominal vagal paraganglia: distribution and comparison with carotid body, in the rat.

A study was made of the distribution of abdominal vagal paraganglia in the gastro-oesophageal region of 12 rats. In all rats 4-40 paraganglia were found embedded in, or closely associated with, the vagus nerves and their branches. The paraganglia consisted of groups of rounded, weakly chromaffin-positive cells surrounded by flattened cells and supplied by small nerves and blood vessels. The paraganglia were morphologically identical to simultaneously fixed carotid body tissue and showed similar fluorescence characteristics.

Animals↗
PubMed1969

The effect of hypothalamic lesions on the melanocyte-stimulating hormone content and histology of the pars intermedia of the rat pituitary gland.

1. The effect of bilateral lesions in the anterior hypothalamus on the histology and content of melanocyte-stimulating hormone (MSH) of the pars intermedia has been studied in the adult male rat.2. By 7-15 days striking histological changes, suggestive of hyperactivity, were evident. These changes were accompanied by an elevated MSH content, which was particularly noticeable at 7 days.3. By 7 days there was an increase in the acid phosphatase activity of pars intermedia cells, as demonstrated histochemically.4. It was concluded that a hypothalamic control system exists for the mammalian pars intermedia and may involve both inhibitory and excitatory components.

Acid Phosphatase↗