J W Leidy

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The development and sex-related changes in the hypothalamic-pituitary GH axis were examined in lean and obese Zucker male and female rats from 6 to 12 weeks of age. Pituitary GH content was not different in any phenotype/sex group at 6 weeks. GH content increased with age in male rats, but at 10 and 12 weeks content was decreased in obese male rats relative(More)
Measurement of somatostatin (SS) in small microliter volumes of rat plasma obtained from the hypophysial portal circulation would be aided by a sensitive and robust technique not dependent on extraction. We have developed radioimmunoassay (RIA) and chemiluminoimmunoassay (CIA) for SS in unextracted rat plasma from a previously described solid-phase method(More)
Growth hormone secretion is markedly suppressed early in streptozocin induced diabetes mellitus of the rat. Our studies were designed to delineate early changes in hypothalamic regulation by growth hormone-releasing hormone (GHRH) and somatostatin (SS) with the aim of determining the best time period for hypothalamic secretion studies. Although hypothalamic(More)
The purpose of these studies was to evaluate the effect of age-related differences in growth rate on the hypothalamic content of growth hormone-releasing factor (GHRH) and somatostatin (SS) and on the short loop feedback regulation of GHRH and SS. Percent weight gain, GHRH content, and SS content in control adolescent (8 weeks) and adult rats (6 months)(More)
Utilizing a specific RIA for rat (r) GRF, hypothalamus and cerebral cortex from adult rat and long term dissociated fetal rat hypothalamic and cerebral cortical cell cultures were investigated for the presence of rGRF immunoreactivity (IR-GRF). After homogenization in an acidic medium, tissues and cultures were extracted on octadecylsilyl-silica columns,(More)
Brains from 4 normal and 4 colchicine-treated rats were studied for the presence of growth hormone-releasing factor (GRF) using an antibody directed against rat hypothalamic GRF (rGRF). Noncolchicine-treated animals showed intense staining in the external layer of the median eminence. Rats pretreated with intraventricular colchicine for 48 h showed(More)
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