Biomedical subjects

S L Stoddard

Publications and source records attributed to S L Stoddard.

22 records · Page 2Linked to original sources

PubMed1986

Increases in blood flow from the adrenal gland following medial hypothalamic stimulation in the cat.

Medial hypothalamic sites previously shown to elicit either flight or defense were stimulated in the anesthetized cat. The rate of blood flow from the adrenolumbar (AL) vein ipsilateral to the side of stimulation was measured, as well as the adrenal output of norepinephrine and epinephrine (E). Stimulation at nearly 15% of the hypothalamic sites increased ipsilateral AL venous flow more than 20% over baseline rates. These sites also significantly increased heart rate, mean arterial pressure, and output of E from the ipsilateral adrenal gland. These observations suggest that hypothalamic sites where stimulation increased AL venous flow may overlap with regions that selectively mediate the release of E from the adrenal medulla.

Adrenal Glands↗

PubMed1986

Procedure for staining fixed human brain slices.

UNLABELLED: The described method provides a new technique for differentiating areas of gray and white matter in fixed human brain slices. The technique is a modification of an existing method permitting use of the nonfading copper phthalocyanine dye alcian blue. Stained slices show turquoise gray matter that contrasts sharply with areas of white matter. PROCEDURE: Cut human brains from gross anatomy laboratory cadavers into 4 mm slices and wash in running tap water for 12 hr. Oxidize slices in performic acid for 1.5 hr. Wash in running tap water for 12 hr. Stain slices in shallow dishes in 0.05% aqueous alcian blue. Wash in running tap water for 1 hr. Dry for 2-4 hr and embed in plastic.

Alcian Blue↗

PubMedDate not supplied

Adrenal vein catecholamines and neuropeptides during splanchnic nerve stimulation in cats.

Splanchnic nerve stimulation in bursts at low (5 Hz) and high (50 Hz) frequency (30 V, 1 msec; train duration 1 sec; train rate 0.5/second) was employed in 10 cats under halothane anesthesia, during 10-minute periods, while blood samples were concurrently collected from the adrenal vein and femoral artery for the measurement of norepinephrine (NE), epinephrine (EPI), dopamine (DA), Met-enkephalin (ME), neuropeptide Y (NPY), peptide YY (PYY) and neurotensin (NT). In Group I (n = 5), splanchnic nerve stimulation was initially applied at 5 Hz followed after 20 min by a 50 Hz stimulus, while in Group II (n = 5) the stimulation sequence was reversed. Adrenal vein and femoral artery plasma levels of catecholamines and neuropeptides were not significantly affected by the stimulation sequence, while a significant decrease in blood pressure response was observed in Group II during the 5 Hz stimulation as compared to Group I, indicating desensitization. Splanchnic nerve stimulation at 5 Hz caused a preferential increase in adrenal vein NE (9-fold) versus EPI (7-fold) levels as compared to baseline, while 50 Hz stimulation led to further comparable increases in NE (5-fold) and EPI (6-fold) levels. Significant increases in adrenal vein DA and neuropeptide levels were only observed during 50 Hz stimulation, with DA showing a 5-fold, ME a 2.6-fold and NPY a 3-fold increase as compared to 5 Hz stimulation, and NT a 3.6-fold increase as compared to baseline. Present findings indicate different dynamics in the movement of catecholamines and neuropeptides from the adrenal.

Adrenal Glands↗

PubMedDate not supplied

The adrenal medulla and Parkinson's disease.

This paper reviews the literature describing the condition of the adrenal medulla in Parkinson's disease. Parkinson's disease is a neurodegenerative disorder that is characterized primarily by the loss of dopaminergic neurons in the substantia nigra. Clinical observations have revealed that Parkinson's disease is also frequently accompanied by a variety of autonomic symptoms. The adrenal medulla is a major component of the autonomic nervous system. However, until recently this organ has not been of particular interest in Parkinson's disease. Early studies found histologic abnormalities in adrenal medullary cells, and several groups measured urinary and plasma catecholamines to determine general autonomic status. In the late 1980s adrenal medullary tissue was first transplanted to the caudate nucleus in an attempt to augment the decreased levels of dopamine, and thus treat the symptoms of Parkinson's disease. At this time the status of the adrenal medulla in this disease became clinically important. We measured the total catecholamine content of the parkinsonian adrenal medulla in tissue collected both at autopsy and in conjunction with adrenal-caudate transplants. Adrenal medullary catecholamines and several neuropeptides were severely depressed in parkinsonian glands. Thus, the adrenal medulla appears to be a target of the peripheral manifestations of Parkinson's disease.

Adrenal Medulla↗