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Biomedical subjects

S A Joseph

Publications and source records attributed to S A Joseph.

At least 73 records · Page 4Linked to original sources
PubMed1981

Immunocytochemical localization of luteinizing hormone-releasing hormone (LHRH) in Vibratome-sectioned brain.

Immunocytochemical localization of neuropeptides such as luteinizing hormone-releasing hormone (LHRH) is generally performed on Bouin's fixed tissue sections, following tissue dehydration in alcohols and embedment in paraffin. When the final reaction product accurately reflects content and distribution of the neuropeptide has not been examined carefully. Our data indicate a decrease in radioimmunoassayable LHRH content of brain fixed in Bouin's solution and a further significant reduction following dehydration with alcohol. In order to circumvent this loss of hormone, sections of fixed brain were cut on a Vibratome at 30 micron and collected in phosphate-saline buffer. These Vibratome sections revealed a significantly greater amount of overall immunoreactivity and fiber distribution as compared to paraffin-embedded sectioned tissue. These results suggest that certain neuropeptides, soluble in alcohol, can be extracted during dehydration processes necessary for paraffin embedment.

Animals↗
PubMed1980

Distribution of somatostatin in the rat brain: telencephalon and diencephalon.

The distribution of somatostatin (SRIF) was examined using the unlabeled antibody enzyme method of immunocytochemistry on thick 30-50 microns Vibratome sections. The greatest population of SRIF-neurons was observed along the ventricular wall in the preoptic area and anterior hypothalamus. Dense accumulations of fibers were observed in the suprachiasmatic, ventromedial and arcuate nuclei, the internal and external zone of the median eminence, the organum vasculosum of the lamina terminalis and the subfornical organ. Extrahypothalamic sites of SRIF-containing neurons and fibers were also observed throughout the telencephalon. The widespread distribution of SRIF is consistent with radioimmunoassay data and suggests a diverse physiological role for somatostatin.

Animals↗
PubMed1980

Immunoreactive adrenocorticotropin in rat brain: a neuroanatomical study using antiserum generated against synthetic ACTH.

In this study an antiserum generated against synthetic ACTH1--39 is used to provide a neuroanatomical map of ACTH-immunoreactivity in rat brain. Groups of ACTH-immunoreactive cell bodies were located in the basal hypothalamus, extending from the retrochiasmatic region to the mammillary nuclei. The fiber distribution indicates a broad innervation of structures in the hypothalamus, which include the medial preoptic region; bed nucleus of the anterior commissure and stria terminalis; perifornical region; periventricular stratum; and paraventricular, dorsomedial, arcuate, and mammillary nuclei. Fibers from the hypothalamus reach the amygdaloid nuclei directly in two separate bundles. A large dorsal ACTH-immunoreactive bundle emerges from the anterior hypothalamic region, distributes to the periventricular thalamic nuclei, and continues more posteriorly to the midbrain periaquaductal gray. It is speculated that the cell bodies in the ventral tuberal region of the hypothalamus are responsible for the vast innervation of fibers to the forebrain, diencephalon, and brainstem.

Adrenocorticotropic Hormone↗
PubMed1978

Specificity of the immunocytochemical luteinizing hormone-releasing hormone receptor reaction.

Affinity-purified anti-LHRH, affinity-purified LHRH-anti-LHRH complex, as well as antisera depleted of anti-LHRH by solid phase immunoabsorption were used to test the specificity of the immunocytochemical approach for detection of receptor-bound LHRH. The solid phase immunoabsorbent was prepared by attaching LHRH to Sepharose via an RNase spacer. Purified anti-LHRH was eluted from the immunoabsorbent by acidification. Unabsorbed antisera as well as purified antibody conferred moderate immunocytochemical staining to the secretion granules of rat pituitary gonadotrophs. Staining intensity became greatly increased upon treatment of the electron microscopic sections with LHRH before immunocytochemical staining. All gonadotroph staining was abolished when absorbed antisera were used. The specificity of the immunoabsorbent was tested on mixtures of anti-LHRH and anti-ACTH17-39. On absorption of such mixtures with insolubilized LHRH, all gonadotroph staining disappeared, but the optical density indices of ACTH staining remained unaffected. It is concluded that gonadotroph secretion granules contain, in addition to an LHRH receptor reacting with LHRH in vitro, stable complexes of endogenous LHRH with receptor.

Adrenocorticotropic Hormone↗