Influence of haloperidol on ACTH and beta-endorphin secretion in the rat

The injection of haloperidol, a dopamine receptor blocker, was followed by a large increase of plasma ACTH and beta-endorphin-like immunoreactivity (beta-EI) in the rat. This effect was prevented when the rats were previously treated with corticosteroids. These results suggest that catecholamines inhibit ACTH and beta-endorphin secretion in the rat.     

Studies on the stability of vitamin A in the stomach and small intestine

The instability of vitamin A alcohol relative to vitamin A acetate has been studied in vivo and in vitro.

Vitamin A alcohol is more unstable than vitamin A acetate in human gastric and duodenal juice and in rats' stomachs and intestines and is more marked at lower pH levels and in rats' stomachs.

Alpha tocopherol improved the absorption curve of vitamin A alcohol in man by protecting it in gastric and duodenal juice. This protective effect could not be demonstrated in the rat.

     

Effect of probenecid on free 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and its sulphate in human cerebrospinal fluid

In a mixed group of 46 patients with affective disorder, or with various neurologic disorders, high doses of probenecid (100 mg/kg over 18 hr) produced a significant increase in lumbar cerebrospinal fluid (CSF) levels of 3-methoxy-4-hydroxyphenylethylene glycol (MHPG), the major metabolite of norepinephrine centrally. This increase (averaging 60%) is modest in comparison to probenecid induced increases in homovanillic acid (HVA) or 5-hydroxyindo-leacetic acid (5-HIAA). Analysis for free MHPG and its sulfate showed no significant differences for either compound after nine hours. After 18 hours of treatment significant increases in free MHPG and small but not significant increases of MHPG.SO₄ were found. These results suggest that a probenecid sensitive active transport mechanism for MHPG.SO₄ of the degree demon-strated for HVA and 5-HIAA in humans, and for MHPG.SO₄ in rats, does not occur in human CSF.     

Spondylolysis and spondylolisthesis of the cervical spine

Spondylolysis and spondylolisthesis of the cervical spine are rare entities. The nomenclature and detailed anatomic features of these conditions are discussed. Four new cases are presented and the world literature is reviewed.Picker Scholar, James Picker Foundation     

The medial geniculate body of the tree shrew, Tupaia glis. II. Connections with the neocortex.

In this study the temporal cortex of the tree shrew was subdivided on the basis of cytoarchitectonic criteria, and the connections of each subdivision with the thalamus and midbrain were analyzed with retrograde and anterograde techniques. The results indicate that, with one exception, each subdivision of the medial geniculate body projects to a separate cortical area. The primary auditory cortex receives projections from the ventral nucleus. Surrounding the primary cortex are at least five additional cytoarchitectonically distinct areas which receive projections from the remaining medial geniculate subdivisions. The evidence suggests that there is very little overlap in the projections from each of these geniculate subdivisions. An exception is the projection of the caudal nucleus of the medial division. This subdivision apparently projects to most, if not all, of the cortical target of the medial geniculate body. Although the cortical projections of the caudal nucleus overlap those of the other medial geniculate subdivisions, the laminar distribution of its terminations in cortex is different. The caudal nucleus projects primarily to layer VI whereas the other subdivisions of the medial geniculate body project primarily to layer IV and the adjacent part of layer III. Anterograde techniques were also used to study the projections from the cortex back to the thalamus and to the midbrain. The projections to the thalamus precisely reciprocate the thalamocortical connections. The projections to the midbrain are to the same areas which the preceding study (Oliver and Hall, '78) showed give rise to ascending projections to the medial geniculate body. An exception is the central nucleus of the inferior colliculus which apparently does not receive a projection from the temporal cortex.