Androgen regulation of adrenocorticotropin and corticosterone secretion in the male rat following novelty and foot shock stressors.

To examine mechanisms responsible for sex differences in hypothalamo-pituitary-adrenal (HPA) axis responsiveness to stress, we studied the role of androgens in the regulation of the adrenocorticotropin (ACTH) and corticosterone (CORT) responses to foot shock and novelty stressors in gonadectomized (GDX) or intact male F344 rats. Foot shock or exposure to a novel open field increased plasma ACTH and CORT, which was significantly greater in GDX vs. intacts.

Localization of androgen receptor within peptidergic neurons of the rat forebrain.

This study tested for the presence of androgen receptor-immunoreactivity in somatostatin, galanin, vasopressin, corticotropin-releasing hormone, and oxytocin neurons in the rat forebrain. The brains of adult male Sprague-Dawley rats were fixed with 4% paraformaldehyde. Androgen receptor was visualized in coronal sections using nickel intensification of diaminobenzidine, and the neuropeptides were identified using a brown diaminobenzidine reaction product.

Decreased postnatal testosterone surge in male rats exposed to ethanol during the last week of gestation.

Prenatal alcohol exposure in the rat is known to interfere with the neurobehavioral sexual differentiation of the male brain. Because normal sexual differentiation of the male brain requires adequate levels of perinatal testosterone, we examined the effect of prenatal ethanol exposure on (1) the postnatal surge of testosterone and (2) the in vitro secretion of testosterone in response to luteinizing hormone (LH) stimulation of testes from fetal alcohol exposed (FAE) animals and controls. Sprague-Dawley dams were administered a fortified liquid diet containing 35% ethanol-derived calories, a pair-fed (PF) isocaloric liquid diet, or given ad libitum access to dry lab chow (CF).

The ontogeny of estrogen receptors in heterochronic hippocampal and neocortical transplants demonstrates an intrinsic developmental program.

We investigated the intrinsic vs. environmental regulation of estrogen receptor (ER) ontogeny in the neocortex, hippocampus and hypothalamus by employing a heterochronic transplantation paradigm. These studies were based on previous reports demonstrating that neural ER develop asynchronously with quantitatively distinct ontogenetic profiles in various brain regions.

Neuroendocrine and neurochemical responses to novelty stress in young and old male F344 rats: effects of d-fenfluramine treatment.

To understand some of the mechanisms underlying the neuroendocrine and neurochemical changes associated with aging, we administered the serotonin [5-hydroxytryptamine (5-HT)] releaser and reuptake inhibitor d-fenfluramine (d-FEN; 0.0, 0.2, or 0.

Induction of c-fos mRNA in the brain and anterior pituitary gland by a novel environment.

To determine the cell groups which are activated by novelty stress, we examined the induction of c-fos mRNA in brain tissues following introduction of male rats to a novel open field. Male Fischer 344 rats were placed in a brightly lit open field and allowed to roam free for 20 min. Control animals were sacrificed upon removal from their home cage.

Hormonal regulation of androgen receptor mRNA in the brain and anterior pituitary gland of the male rat.

To determine possible cellular mechanisms governing androgen action in the brain, we examined the hormonal regulation of androgen receptor (AR) mRNA in neural tissues by Northern blot hybridization and RNase protection analysis. While a single hybridizable species of AR mRNA of approximately 11 kb was found in the anterior pituitary gland (AP) and ventral prostate gland (VP), an additional species of AR mRNA, approximately 2 kb smaller, was revealed in neural tissues. Furthermore, in these neural tissues, hormonal regulation of the two species of mRNA was coordinated; long-term castration increased levels of both forms, while testosterone replacement reduced them.

Estrogenic regulation of proenkephalin mRNA expression in the ventromedial hypothalamus of the adult male rat.

Endogenous opioid peptides and their receptors are regulated by gonadal steroid hormones in the rat hypothalamus. Recent evidence suggests that gonadal steroids are capable of regulating the expression of proenkephalin (PE) mRNA in the ventromedial hypothalamus (VMH) of female, but not male rats. Therefore, we examined the effect of gonadectomy with or without four weeks of hormone treatment on PE mRNA expression in adult male Fisher 344 rats using quantitative in situ hybridization histochemistry.

Serum, CSF, RBC & urinary levels of magnesium & calcium in idiopathic generalised tonic clonic seizures.

Serum, cerebrospinal fluid (CSF) and urinary levels of magnesium and calcium and RBC magnesium levels were studied in 100 patients of idiopathic generalised tonic clonic seizures and 95 healthy controls matched for age and sex. There was a significant reduction in serum, CSF and RBC magnesium levels and a rise in serum and CSF calcium levels in epileptic patients. The 24 h urinary excretion of calcium and magnesium in the epileptics did not differ from controls.

Estrogen-induced alterations in the regulation of mineralocorticoid and glucocorticoid receptor messenger RNA expression in the female rat anterior pituitary gland and brain.

The influence of estrogen (E) on corticosterone (CORT) receptor function in neural tissue was investigated in female Sprague-Dawley rats. This was accomplished by using a sensitive solution-hybridization RNase protection assay to examine the effect of E on the regulation of CORT receptor mRNAs. Animals were bilaterally ovariectomized (OVX), and a Silastic capsule (0.

Characterization of a [3H]glutamate binding site in rat pineal gland: enhanced affinity following superior cervical ganglionectomy.

Glutamate, an excitatory neurotransmitter/neuromodulator involved in cell-to-cell communication within the central nervous system, is now believed to play a role in neuroendocrine function. In this study we describe a single, saturable, stereospecific, and temperature-, time-, and pH-dependent binding site for glutamate in the pineal gland of the rat (Kd = 612 +/- 23 nM, Bmax = 3.17 +/- 0.

Effects of phospholipids on renal function.

The effects of two classes of phospholipids (PL) on renal function have been studied. Bolus injections of 1 ng (10 pmol) of lysophosphatidylcholine (LPC) caused natriuresis and diuresis in rats. Natriuretic activity was eliminated by substituting unsaturated bonds in the 1-acyl group and by removing the choline group on the sn-3 position.

Aluminium phosphide poisoning.

Aluminium phosphide is a solid fumigant pesticide widely used in the Indian subcontinent as a grain preservative. Over the last 5 years there has been a dramatic increase in the number of cases of aluminium phosphide poisoning in India. Ninety-two patients with aluminium phosphide poisoning due to ingestion were studied over a period of 3 years.

Comparison of two weeks versus one week of prenatal ethanol exposure in the rat on gonadal organ weights, sperm count, and onset of puberty.

Sprague-Dawley dams from Harlan Ind. (Indianapolis, IN) were administered a fortified ethanol liquid diet containing 35% ethanol derived calories for two weeks (E-2) beginning on day 7 or one week (E-1) beginning on day 13 of gestation and continuing through parturition. Control dams were pair-fed an isocaloric liquid diet containing no ethanol during these periods or remained on lab chow and water.

Chronic estrogen-induced alterations in adrenocorticotropin and corticosterone secretion, and glucocorticoid receptor-mediated functions in female rats.

The effect of estrogen (E) on the hypothalamic-pituitary-adrenal axis was investigated in female Sprague-Dawley rats. Animals were bilaterally ovariectomized (OVX), and a Silastic capsule (0.5 cm) containing 17 beta-estradiol was sc implanted.

Estrogen receptors are present in neocortical transplants.

Fetal neocortical tissue was grafted into neocortical lesion cavities made in newborn rats. After two weeks survival, in vitro binding of [3H]-estradiol to cytosolic preparations provided evidence of estrogen receptors within the transplants. The observed high levels correspond to previous work demonstrating elevated estrogen receptor levels during the first postnatal week in the rat cerebral cortex.

Tetrodotoxin protects against acute ischemic renal failure in the rat.

Tetrodotoxin has been reported to cause prolonged systemic hypotension without resultant ischemic damage. We tested its ability to protect the kidney during 60 minutes of warm ischemia in uninephrectomized rats. Protection was observed when tetrodotoxin was given intravenously at two microgram.

Effect of lysophosphatidylcholine on renal hemodynamics and excretory function in anesthetized rats.

The effect of myristoyl-lysophosphatidylcholine (myristoyl-LPC) on renal hemodynamics, electrolyte and water excretion was examined over a 90 min period in sodium pentobarbital anesthetized male Sprague Dawley rats. Intravenous infusion of myristoyl-LPC at 13 +/- 3 pmol/min resulted in a small fall in systemic blood pressure, a 13% decrease in renal plasma flow without significantly altering glomerular filtration rate and produced a slightly greater excretion of sodium and water than vehicle controls. These results suggest that short term myristoyl-LPC administration can significantly alter renal function producing a weak natriuresis and diuresis which is not dependent on systemic blood pressure and renal hemodynamic changes.

Erythrocytic glucose-6-phosphate dehydrogenase deficiency in the Bania community of Punjab.

Five hundred members belonging to the Bania community of Punjab were screened for erythrocytic glucose-6-phosphate dehydrogenase (G-6-PD) deficiency. The incidence of enzyme deficiency in males was 2.84 per cent and in females 2.

Selective inhibition of vasoconstrictor responses by platelet-activating factor in rat kidney.

We examined the effect of platelet-activating factor (PAF) on renal vascular reactivity in the pentobarbital sodium-anesthetized male Wistar rat. Intrarenal infusion of C16-PAF at hypotensive (2.5 ng.

Localization of cells containing estrogen receptor-like immunoreactivity in the Brazilian opossum brain.

The Brazilian opossum (Monodelphis domestica) is a small, pouchless marsupial whose young are born in an immature, sexually undifferentiated state. Etgen and Fadem, and Handa and coworkers have biochemically detected and characterized estrogen receptors in the forebrain of the Brazilian opossum. In this study, we have examined the distribution of estrogen receptor-like immunoreactive (ER-LI) cells in the brains of gonadectomized male and female Brazilian opossums using Abbott H222 rat monoclonal estrogen receptor antibody (H222 is a gift of Abbott Labs).

Small cell lung cancer presenting as Cushing's syndrome.

A rare case of small cell carcinoma of the lung who presented with Cushing's syndrome and superior vena cava syndrome is described. The relevant literature is reviewed.

Characterization and distribution of estrogen receptors in the diencephalon of the gray short-tailed opossum.

The Brazilian gray short-tailed opossum is a pouchless marsupial whose young are born sexually undifferentiated making this animal ideal for developmental studies. Previously, Etgen and Fadem (Dev. Brain Res.

Vasorelaxant effect of C16-PAF and C18-PAF on renal blood flow and systemic blood pressure in the anesthetized rat.

The renal vasoactive and systemic hypotensive effects of platelet activating factor (C16:0-PAF and C18:1-PAF) were examined in anesthetized male Wistar rats. Bolus injections of C16-PAF (0.5-25 ng/kg) and C18-PAF (2.