Cycle and duration of the seminiferous epithelium in puma (Puma concolor).

Puma or sussuarana (Puma concolor) is the second largest feline in the American continent and has an ample latitudinal distribution in very diverse habitats. In relation to its conservation status, the puma is considered an extinction-threatened species. The study of the testis morphology and the spermatogenic process in a species is fundamental for establishing the physiologic patterns that will make possible the selection of the protocols for assisted reproduction.

Prenatal alcohol exposure alters the size, but not the pattern, of the whisker representation in neonatal rat barrel cortex.

Maternal alcohol exposure results in a variety of neurodevelopmental abnormalities that include cognitive and sensorimotor dysfunctions that often persist into adulthood. Many reports of central nervous system disturbances associated within a clinical diagnosis of fetal alcohol syndrome point toward disturbances in central information processing. In this study, we used the rat barrel field cortex as a model system to examine the effects of prenatal alcohol exposure (PAE) on the organization and size of the large whisker representation in layer IV of the posteromedial barrel subfield (PMBSF) in somatosensory cortex.

Assessment of knowledge about malaria among patients reported with fever: a hospital-based study.

Background & Objectives: Knowledge about malaria, attitude and health seeking behaviour of fever patients attending Medicine Out Patient Department at Safdarjang Hospital, New Delhi were studied from June to August 2003.

Methods: Cross-sectional survey comprising 200 fever cases was done with prestructured and pretested questionnaire. Data on sociodemographic profile, history of fever, health seeking behaviour, etc were recorded.

Expression of three carnitine palmitoyltransferase-I isoforms in 10 regions of the rat brain during feeding, fasting, and diabetes.

Inhibition of carnitine palmitoyltransferase-I (CPT-I) activity in the brain has been shown to decrease food intake in rats. We examined the expression of mRNA encoding all three known CPT-I isoforms (alpha, beta, and gamma in 10 different major regions of the rat brain in normal, chow-fed rats, in fasting rats, and in insulin-dependent diabetic rats. Compared with the effects of fasting and diabetes on CPT-I mRNA in the liver and heart, there was either less effect or no effect depending on the particular brain region examined.

Role of the cyclic AMP-dependent protein kinase in homologous resensitization of the beta1-adrenergic receptor.

A fundamental question in biology is how the various motifs in G protein-coupled receptors participate in the divergent functions orchestrated by these molecules. Here we describe a fundamental role for a serine residue at position 312 in the third intracellular loop of the human beta(1)-adrenergic receptor (beta(1)-AR) in endocytic recycling of the agonist-internalized receptor. In receptor recycling experiments that were monitored by confocal microscopy, the agonist-internalized wild-type (WT) beta(1)-AR recycled with a t(0.

Effect of acute stress and gender on isatin in rat tissues and serum.

Isatin is an endogenous indole present in mammalian tissues and fluids. This study was designed to test the effect of both acute stress (AS) and gender on isatin's levels in rat serum, heart and brain, using a HPLC-UV detection method. Basal brain isatin levels were higher in females than in males.

Gestational nicotine exposure attenuates nicotine-stimulated dopamine release in the nucleus accumbens shell of adolescent Lewis rats.

The effects of chronic gestational exposure to nicotine on the nucleus accumbens dopamine response to acute nicotine were determined during adolescence (postnatal day 29-36) in cross-fostered and noncross-fostered Lewis rats. In both males and females, gestational nicotine exposure diminished the adolescent nucleus accumbens dopamine response to 0.07 mg/kg nicotine i.

Norepinephrine release in amygdala of rats during chronic nicotine self-administration: an in vivo microdialysis study.

The essential role of the amygdala in learning and memory, including cue-associated learning, is influenced by local release of norepinephrine (NE). The current study investigated changes in amygdaloid NE secretion in rats learning to self-administer nicotine in an unlimited access model (23 h/day). In vivo microdialysis of NE was performed for 9 h intervals during three phases of nicotine self-administration: acquisition (day 1); early maintenance, when self-administration rates first stabilized (day 8.

Chronic self-administration of nicotine in rats impairs T cell responsiveness.

Chronic exposure of rodents to nicotine via subcutaneously or intracerebroventricularly implanted miniosmotic pumps affects T cell function. However, this method of continuous nicotine administration does not replicate the self-motivated administration of nicotine in human smokers. To determine whether nicotine impairs the immune system under conditions pertinent to human smokers, we investigated the T cell responsiveness of male Lewis rats self-administering (SA) nicotine (0.

Rat strain differences in nicotine self-administration using an unlimited access paradigm.

An effective animal model for elucidating the neurobiological basis of human smoking should simulate important aspects of this behavior. Therefore, a 23 h unlimited access nicotine self-administration model was used to compare inbred Lewis rats, which have a propensity to self-administer drugs of abuse, to inbred Fisher 344 rats and to the outbred Holtzman strain. Using this unlimited access model, 88.

The goitrogen 6-n-propyl-2-thiouracil (PTU) given during testis development increases Sertoli and germ cell numbers per cyst in fish: the tilapia (Oreochromis niloticus) model.

The main objectives of the present study were to investigate the effects of 6-n-propyl-2-thiouracil (PTU) on Sertoli cell proliferation, germ cell number, and testis size in Nile tilapias (Oreochromis niloticus). In this regard, young fish (approximately 1 g BW and approximately 3.5 cm total in length) were treated for a period of 40 d with different concentrations (100 and 150 ppm) of PTU.

Norepinephrine secretion in the hypothalamic paraventricular nucleus of rats during unlimited access to self-administered nicotine: An in vivo microdialysis study.

Norepinephrine (NE) secretion within the hypothalamic paraventricular nucleus (PVN) is pivotal to endocrine and behavioral responses. Activation of NE afferents to PVN also is necessary for the hypothalamo-pituitary-adrenal axis response to passively administered nicotine. The mode of drug delivery is a critical determinant of the dynamics of neurotransmitter secretion, yet the PVN NE response to nicotine self-administration (SA) is unknown.

Expression of delta opioid receptors and transcripts by splenic T cells.

Delta opioid receptors (DORs) and preproenkephalin-A-derived opiate peptides are expressed by mononuclear cells in various lymphoid organs. DOR ligands modulate a variety of immune functions, such as T-cell proliferation, calcium mobilization, and cytokine production. Recently, quiescent T cells were found to express low levels of DOR transcripts, which increased due to the following: cell culture of unstimulated murine splenocytes (depending on cell density); cross-linking the T-cell receptor (TCR) with anti-CD3-epsilon; and a single in vivo exposure to staphylococcal enterotoxin B (SEB).

Expression of delta opioid receptors by splenocytes from SEB-treated mice and effects on phosphorylation of MAP kinase.

Delta opioid receptors (DORs) are known to modulate multiple T-cell responses. However, little is known about the expression of these receptors. These studies evaluated the expression of DOR mRNA and protein after a single in vivo exposure to staphylococcal enterotoxin B (SEB).

Local alpha-bungarotoxin-sensitive nicotinic receptors in the nucleus accumbens modulate nicotine-stimulated dopamine secretion in vivo.

Nicotinic cholinergic receptors in the ventral tegmental area are required for the accumbal dopamine response to systemic nicotine. In contrast, the role of nicotinic receptors located within the nucleus accumbens itself has not been clarified for systemically administered nicotine. In the present study, in vivo microdialysis of accumbal dopamine secretion and receptor antagonist blockade in both the ventral striatal nucleus accumbens and the midbrain ventral tegmental area were used to evaluate this question.

Nicotine up-regulates expression of orexin and its receptors in rat brain.

Orexins are two recently discovered neuropeptides that can stimulate food intake. As the chronic use of tobacco typically leads to a reduction in body weight, it is of interest to determine whether nicotine, the major biologically active tobacco ingredient, has an effect on orexin metabolism in the brain. Using a semiquantitative RT-PCR technique, the levels of messenger RNA (mRNA) for prepro-orexin, orexin A (OX1-R) and orexin B (OX2-R) receptors were 20-50% higher in rats receiving nicotine for 14 days at the level of 2-4 mg/kg day compared with rats receiving saline solvent alone.

Systemic nicotine stimulates dopamine release in nucleus accumbens: re-evaluation of the role of N-methyl-D-aspartate receptors in the ventral tegmental area.

Systemic nicotine stimulates dopamine (DA) release in the nucleus accumbens (NAcc), and N-methyl-D-aspartate (NMDA) receptors in the ventral tegmental area (VTA) appear to be involved. However, it is not known whether the secretion of DA elicited by nicotine depends on the tonic and/or phasic activation of NMDA receptors by glutamate (Glu). To clarify this, in vivo microdialysis was conducted in freely moving, alert rats to measure DA and Glu overflows in the NAcc and Glu in the VTA.

Nicotine administration enhances NPY expression in the rat hypothalamus.

Epidemiological studies have shown an inverse relationship between cigarette smoking and body weight. In rodents, a negative correlation between nicotine and body weight has been reported, but this observation was largely derived from studies where relatively high doses of nicotine ( approximately 12 mg/kg/day) were used. In the current study, we showed that a negative relationship also holds for low doses of nicotine that are comparable to that consumed by average human smokers (<6 mg/kg/day).

Nicotine enhances the biosynthesis and secretion of transthyretin from the choroid plexus in rats: implications for beta-amyloid formation.

Epidemiological studies indicated that cigarette smoking protects against the development of several neurodegenerative disorders, including Alzheimer's disease (AD). However, the molecular mechanism(s) underlying this is poorly understood. To gain insight into these protective effects, we used differential display PCR (DD-PCR) to amplify RNA from various brain regions of rats self-administering (SA) nicotine compared with yoked-saline controls.

Inhibition of nicotine-induced hippocampal norepinephrine release in rats by alpha-conotoxins MII and AuIB microinjected into the locus coeruleus.

Hippocampal norepinephrine (NE) is secreted by neurons projecting from the locus coeruleus (LC) to the hippocampus; LC nicotinic receptors (NAchRs) are involved in the effects of systemic nicotine on this pathway. To clarify the NAchR subtypes, NAchR antagonists, termed alpha-conotoxins, were microinjected into the LC before nicotine; MII and AuIB were used to assess the potential involvement of alpha3beta2 and alpha3beta4 subunit-containing NAchRs, respectively. Nicotine dose-dependently stimulated hippocampal NE release (P < 0.

Local alpha-bungarotoxin-sensitive nicotinic receptors modulate hippocampal norepinephrine release by systemic nicotine.

Previous studies have shown that nicotinic receptors (NAChRs) accessible from the cerebral aqueduct of the brainstem mediate the hippocampal norepinephrine (NE) release induced by i.v. nicotine.